1
|
Liu J, Mai T, Ren H, Chang Y, Li C, Lv G, Zheng D, Liao X, Yu Y, Zhang F, Zhao S, Liu X, Liu S, Zhao H, Luo B, Liu C, Huang E. Arrhythmia onsets triggered by acute myocardial ischemia are not mediated by lysophosphoglycerides accumulation in ventricular myocardium. Sci Rep 2024; 14:9589. [PMID: 38670979 PMCID: PMC11053080 DOI: 10.1038/s41598-024-57047-5] [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: 12/28/2023] [Accepted: 03/13/2024] [Indexed: 04/28/2024] Open
Abstract
Lysophosphoglycerides (LPLs) have been reported to accumulate in myocardium and serve as a cause of arrhythmias in acute myocardial ischemia. However, in this study we found that LPLs level in the ventricular myocardium was decreased by the onset of acute myocardial ischemia in vivo in rats. Decreasing of LPLs level in left ventricular myocardium, but not right, was observed within 26 min of left myocardial ischemia, regardless of whether arrhythmias were triggered. Lower LPLs level in the ventricular myocardium was also observed in aconitine-simulated ventricular fibrillation (P < 0.0001) and ouabain-simulated III° atrioventricular block (P < 0.0001). Shot-lasting electric shock, e.g., ≤ 40 s, decreased LPLs level, while long-lasting, e.g., 5 min, increased it (fold change = 2.27, P = 0.0008). LPLs accumulation was observed in long-lasting myocardial ischemia, e.g., 4 h (fold change = 1.20, P = 0.0012), when caspase3 activity was elevated (P = 0.0012), indicating increased cell death, but not coincided with higher frequent arrhythmias. In postmortem human ventricular myocardium, differences of LPLs level in left ventricular myocardium was not observed among coronary artery disease- and other heart diseases-caused sudden death and non-heart disease caused death. LPLs level manifested a remarkable increasing from postmortem 12 h on in rats, thus abolishing the potential for serving as biomarkers of sudden cardiac death. Token together, in this study we found that LPLs in ventricular myocardium were initially decreased by the onset of ischemia, LPLs accumulation do not confer arrhythmogenesis during acute myocardial ischemia. It is necessary to reassess the roles of LPLs in myocardial infarction.
Collapse
Affiliation(s)
- Jiawei Liu
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Tingting Mai
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Han Ren
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Yafei Chang
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Chao Li
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
- Department of Clinical Medicine, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Guoli Lv
- Guangzhou Forensic Science Institute, Guangzhou, 510030, China
- Key Laboratory of Forensic Pathology, Ministry of Public Security, Guangzhou, 510050, China
| | - Da Zheng
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Xinbiao Liao
- Key Laboratory of Forensic Pathology, Ministry of Public Security, Guangzhou, 510050, China
| | - Yangeng Yu
- Key Laboratory of Forensic Pathology, Ministry of Public Security, Guangzhou, 510050, China
| | - Fu Zhang
- Key Laboratory of Forensic Pathology, Ministry of Public Security, Guangzhou, 510050, China
| | - Shuquan Zhao
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Xiaoshan Liu
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Shuiping Liu
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Hu Zhao
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Bin Luo
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
| | - Chao Liu
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
- Key Laboratory of Forensic Pathology, Ministry of Public Security, Guangzhou, 510050, China.
- National Anti-Drug Laboratory Guangdong Regional Center, Guangzhou, 510230, China.
| | - Erwen Huang
- Faculty of Forensic Medicine, Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China.
| |
Collapse
|
2
|
Ferrero JM, Gonzalez-Ascaso A, Matas JFR. The mechanisms of potassium loss in acute myocardial ischemia: New insights from computational simulations. Front Physiol 2023; 14:1074160. [PMID: 36923288 PMCID: PMC10009276 DOI: 10.3389/fphys.2023.1074160] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/13/2023] [Indexed: 03/03/2023] Open
Abstract
Acute myocardial ischemia induces hyperkalemia (accumulation of extracellular potassium), a major perpetrator of lethal reentrant ventricular arrhythmias. Despite considerable experimental efforts to explain this pathology in the last decades, the intimate mechanisms behind hyperkalemia remain partially unknown. In order to investigate these mechanisms, we developed a novel computational model of acute myocardial ischemia which couples a) an electrophysiologically detailed human cardiomyocyte model that incorporates modifications to account for ischemia-induced changes in transmembrane currents, with b) a model of cardiac tissue and extracellular K + transport. The resulting model is able to reproduce and explain the triphasic time course of extracellular K + concentration within the ischemic zone, with values of [ K + ] o close to 14 mmol/L in the central ischemic zone after 30 min. In addition, the formation of a [ K + ] o border zone of approximately 1.2 cm 15 min after the onset of ischemia is predicted by the model. Our results indicate that the primary rising phase of [ K + ] o is mainly due to the imbalance between K + efflux, that increases slightly, and K + influx, that follows a reduction of the NaK pump activity by more than 50%. The onset of the plateau phase is caused by the appearance of electrical alternans (a novel mechanism identified by the model), which cause an abrupt reduction in the K + efflux. After the plateau, the secondary rising phase of [ K + ] o is caused by a subsequent imbalance between the K + influx, which continues to decrease slowly, and the K + efflux, which remains almost constant. Further, the study shows that the modulation of these mechanisms by the electrotonic coupling is the main responsible for the formation of the ischemic border zone in tissue, with K + transport playing only a minor role. Finally, the results of the model indicate that the injury current established between the healthy and the altered tissue is not sufficient to depolarize non-ischemic cells within the healthy tissue.
Collapse
Affiliation(s)
- Jose M Ferrero
- Centro de Investigacion e Innovacion en Bioingenieria, Universitat Politecnica de Valencia, Valencia, Spain
| | - Ana Gonzalez-Ascaso
- Centro de Investigacion e Innovacion en Bioingenieria, Universitat Politecnica de Valencia, Valencia, Spain.,Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
| | - Jose F Rodriguez Matas
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Milan, Italy
| |
Collapse
|
3
|
Analysis of vulnerability to reentry in acute myocardial ischemia using a realistic human heart model. Comput Biol Med 2021; 141:105038. [PMID: 34836624 DOI: 10.1016/j.compbiomed.2021.105038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022]
Abstract
Electrophysiological alterations of the myocardium caused by acute ischemia constitute a pro-arrhythmic substrate for the generation of potentially lethal arrhythmias. Experimental evidence has shown that the main components of acute ischemia that induce these electrophysiological alterations are hyperkalemia, hypoxia (or anoxia in complete artery occlusion), and acidosis. However, the influence of each ischemic component on the likelihood of reentry is not completely established. Moreover, the role of the His-Purkinje system (HPS) in the initiation and maintenance of arrhythmias is not completely understood. In the present work, we investigate how the three components of ischemia affect the vulnerable window (VW) for reentry using computational simulations. In addition, we analyze the role of the HPS on arrhythmogenesis. A 3D biventricular/torso human model that includes a realistic geometry of the central and border ischemic zones with one of the most electrophysiologically detailed model of ischemia to date, as well as a realistic cardiac conduction system, were used to assess the VW for reentry. Four scenarios of ischemic severity corresponding to different minutes after coronary artery occlusion were simulated. Our results suggest that ischemic severity plays an important role in the generation of reentries. Indeed, this is the first 3D simulation study to show that ventricular arrhythmias could be generated under moderate ischemic conditions, but not in mild and severe ischemia. Moreover, our results show that anoxia is the ischemic component with the most significant effect on the width of the VW. Thus, a change in the level of anoxia from moderate to severe leads to a greater increment in the VW (40 ms), in comparison with the increment of 20 ms and 35 ms produced by the individual change in the level of hyperkalemia and acidosis, respectively. Finally, the HPS was a necessary element for the generation of approximately 17% of reentries obtained. The retrograde conduction from the myocardium to HPS in the ischemic region, conduction blocks in discrete sections of the HPS, and the degree of ischemia affecting Purkinje cells, are suggested as mechanisms that favor the generation of ventricular arrhythmias.
Collapse
|
4
|
Late sodium current associated cardiac electrophysiological and mechanical dysfunction. Pflugers Arch 2017; 470:461-469. [DOI: 10.1007/s00424-017-2079-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/27/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022]
|
5
|
Bubb KJ, Birgisdottir AB, Tang O, Hansen T, Figtree GA. Redox modification of caveolar proteins in the cardiovascular system- role in cellular signalling and disease. Free Radic Biol Med 2017; 109:61-74. [PMID: 28188926 DOI: 10.1016/j.freeradbiomed.2017.02.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/18/2017] [Accepted: 02/05/2017] [Indexed: 02/07/2023]
Abstract
Rapid and coordinated release of a variety of reactive oxygen species (ROS) such as superoxide (O2.-), hydrogen peroxide (H2O2) and peroxynitrite, in specific microdomains, play a crucial role in cell signalling in the cardiovascular system. These reactions are mediated by reversible and functional modifications of a wide variety of key proteins. Dysregulation of this oxidative signalling occurs in almost all forms of cardiovascular disease (CVD), including at the very early phases. Despite the heavily publicized failure of "antioxidants" to improve CVD progression, pharmacotherapies such as those targeting the renin-angiotensin system, or statins, exert at least part of their large clinical benefit via modulating cellular redox signalling. Over 250 proteins, including receptors, ion channels and pumps, and signalling proteins are found in the caveolae. An increasing proportion of these are being recognized as redox regulated-proteins, that reside in the immediate vicinity of the two major cellular sources of ROS, nicotinamide adenine dinucleotide phosphate oxidase (Nox) and uncoupled endothelial nitric oxide synthase (eNOS). This review focuses on what is known about redox signalling within the caveolae, as well as endogenous protective mechanisms utilized by the cell, and new approaches to targeting dysregulated redox signalling in the caveolae as a therapeutic strategy in CVD.
Collapse
Affiliation(s)
- Kristen J Bubb
- Kolling Institute of Medical Research, University of Sydney and Cardiology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - Asa Birna Birgisdottir
- Kolling Institute of Medical Research, University of Sydney and Cardiology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia; Department of Cardiothoracic and Vascular Surgery, Heart and Lung Clinic, University Hospital of North Norway, Tromsø, Norway
| | - Owen Tang
- Kolling Institute of Medical Research, University of Sydney and Cardiology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - Thomas Hansen
- Kolling Institute of Medical Research, University of Sydney and Cardiology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - Gemma A Figtree
- Kolling Institute of Medical Research, University of Sydney and Cardiology Department, Royal North Shore Hospital, St Leonards, NSW 2065, Australia.
| |
Collapse
|
6
|
Gasparova I, Kubatka P, Opatrilova R, Caprnda M, Filipova S, Rodrigo L, Malan L, Mozos I, Rabajdova M, Nosal V, Kobyliak N, Valentova V, Petrovic D, Adamek M, Kruzliak P. Perspectives and challenges of antioxidant therapy for atrial fibrillation. Naunyn Schmiedebergs Arch Pharmacol 2016; 390:1-14. [PMID: 27900409 DOI: 10.1007/s00210-016-1320-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 11/18/2016] [Indexed: 12/26/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia associated with significant morbidity and mortality. The mechanisms underlying the pathogenesis of AF are poorly understood, although electrophysiological remodeling has been described as an important initiating step. There is growing evidence that oxidative stress is involved in the pathogenesis of AF. Many known triggers of oxidative stress, such as age, diabetes, smoking, and inflammation, are linked with an increased risk of arrhythmia. Numerous preclinical studies and clinical trials reported the importance of antioxidant therapy in the prevention of AF, using vitamins C and E, polyunsaturated fatty acids, statins, or nitric oxide donors. The aim of our work is to give a current overview and analysis of opportunities, challenges, and benefits of antioxidant therapy in AF.
Collapse
Affiliation(s)
- Iveta Gasparova
- Institute of Biology, Genetics and Medical Genetics, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovak Republic, Slovakia
| | - Peter Kubatka
- Department of Medical Biology, Jessenius Faculty of Medicine, Comenius University in Bratislava, Martin, Slovak Republic, Slovakia
| | - Radka Opatrilova
- Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Martin Caprnda
- 2nd Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Slavomira Filipova
- Department of Cardiology, National Institute of Cardiovascular Diseases, Bratislava, Slovakia
| | - Luis Rodrigo
- Faculty of Medicine, University of Oviedo, Central University of Asturias (HUCA), Oviedo, Spain
| | - Leone Malan
- Hypertension in Africa Research Team (HART), North-West University, Potchefstroom Campus, Potchefstroom, South Africa
| | - Ioana Mozos
- Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
| | - Miroslava Rabajdova
- Department of Medical and Clinical Biochemistry, Faculty of Medicine, Pavol Jozef Safarik University, Kosice, Slovakia
| | - Vladimir Nosal
- Clinic of Neurology, Jessenius Faculty of Medicine, Comenius University and University Hospital in Martin, Martin, Slovak Republic
| | - Nazarii Kobyliak
- Department of Endocrinology, Bogomolets National Medical University, Kyiv, Ukraine
| | - Vanda Valentova
- Department of Medical Biology, Jessenius Faculty of Medicine, Comenius University in Bratislava, Martin, Slovak Republic, Slovakia
| | - Daniel Petrovic
- Institute of Histology and Embryology, Faculty of Medicine, University of Ljublana, Ljublana, Slovenia
| | - Mariusz Adamek
- Department of Thoracic Surgery, Medical University of Silesia, Zabrze, Poland
| | - Peter Kruzliak
- Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic. .,2nd Department of Surgery, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
| |
Collapse
|
7
|
Yang KC, Kyle JW, Makielski JC, Dudley SC. Mechanisms of sudden cardiac death: oxidants and metabolism. Circ Res 2015; 116:1937-55. [PMID: 26044249 PMCID: PMC4458707 DOI: 10.1161/circresaha.116.304691] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/09/2015] [Indexed: 02/07/2023]
Abstract
Ventricular arrhythmia is the leading cause of sudden cardiac death (SCD). Deranged cardiac metabolism and abnormal redox state during cardiac diseases foment arrhythmogenic substrates through direct or indirect modulation of cardiac ion channel/transporter function. This review presents current evidence on the mechanisms linking metabolic derangement and excessive oxidative stress to ion channel/transporter dysfunction that predisposes to ventricular arrhythmias and SCD. Because conventional antiarrhythmic agents aiming at ion channels have proven challenging to use, targeting arrhythmogenic metabolic changes and redox imbalance may provide novel therapeutics to treat or prevent life-threatening arrhythmias and SCD.
Collapse
Affiliation(s)
- Kai-Chien Yang
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - John W Kyle
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.)
| | - Jonathan C Makielski
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
| | - Samuel C Dudley
- From the Department of Pharmacology (K.-C.Y.) and Division of Cardiology, Department of Internal Medicine (K.-C.Y.), National Taiwan University Hospital, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison (J.W.K., J.C.M.); and Lifespan Cardiovascular Institute, the Providence VA Medical Center, and Brown University, RI (S.C.D.).
| |
Collapse
|
8
|
Trenor B, Gomis-Tena J, Cardona K, Romero L, Rajamani S, Belardinelli L, Giles WR, Saiz J. In silico assessment of drug safety in human heart applied to late sodium current blockers. Channels (Austin) 2015; 7:249-62. [PMID: 23696033 DOI: 10.4161/chan.24905] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Drug-induced action potential (AP) prolongation leading to Torsade de Pointes is a major concern for the development of anti-arrhythmic drugs. Nevertheless the development of improved anti-arrhythmic agents, some of which may block different channels, remains an important opportunity. Partial block of the late sodium current (I(NaL)) has emerged as a novel anti-arrhythmic mechanism. It can be effective in the settings of free radical challenge or hypoxia. In addition, this approach can attenuate pro-arrhythmic effects of blocking the rapid delayed rectifying K(+) current (I(Kr)). The main goal of our computational work was to develop an in-silico tool for preclinical anti-arrhythmic drug safety assessment, by illustrating the impact of I(Kr)/I(NaL) ratio of steady-state block of drug candidates on "torsadogenic" biomarkers. The O'Hara et al. AP model for human ventricular myocytes was used. Biomarkers for arrhythmic risk, i.e., AP duration, triangulation, reverse rate-dependence, transmural dispersion of repolarization and electrocardiogram QT intervals, were calculated using single myocyte and one-dimensional strand simulations. Predetermined amounts of block of I(NaL) and I(Kr) were evaluated. "Safety plots" were developed to illustrate the value of the specific biomarker for selected combinations of IC(50)s for I(Kr) and I(NaL) of potential drugs. The reference biomarkers at baseline changed depending on the "drug" specificity for these two ion channel targets. Ranolazine and GS967 (a novel potent inhibitor of I(NaL)) yielded a biomarker data set that is considered safe by standard regulatory criteria. This novel in-silico approach is useful for evaluating pro-arrhythmic potential of drugs and drug candidates in the human ventricle.
Collapse
|
9
|
Cardiac late Na+ current: Proarrhythmic effects, roles in long QT syndromes, and pathological relationship to CaMKII and oxidative stress. Heart Rhythm 2015; 12:440-8. [DOI: 10.1016/j.hrthm.2014.11.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Indexed: 12/16/2022]
|
10
|
Lipid metabolites and their differential pro-arrhythmic profiles: of importance in the development of a new anti-arrhythmic pharmacology. Mol Cell Biochem 2014; 393:191-7. [DOI: 10.1007/s11010-014-2060-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 04/11/2014] [Indexed: 01/12/2023]
|
11
|
Abstract
Late I Na is an integral part of the sodium current, which persists long after the fast-inactivating component. The magnitude of the late I Na is relatively small in all species and in all types of cardiomyocytes as compared with the amplitude of the fast sodium current, but it contributes significantly to the shape and duration of the action potential. This late component had been shown to increase in several acquired or congenital conditions, including hypoxia, oxidative stress, and heart failure, or due to mutations in SCN5A, which encodes the α-subunit of the sodium channel, as well as in channel-interacting proteins, including multiple β subunits and anchoring proteins. Patients with enhanced late I Na exhibit the type-3 long QT syndrome (LQT3) characterized by high propensity for the life-threatening ventricular arrhythmias, such as Torsade de Pointes (TdP), as well as for atrial fibrillation. There are several distinct mechanisms of arrhythmogenesis due to abnormal late I Na, including abnormal automaticity, early and delayed after depolarization-induced triggered activity, and dramatic increase of ventricular dispersion of repolarization. Many local anesthetic and antiarrhythmic agents have a higher potency to block late I Na as compared with fast I Na. Several novel compounds, including ranolazine, GS-458967, and F15845, appear to be the most selective inhibitors of cardiac late I Na reported to date. Selective inhibition of late I Na is expected to be an effective strategy for correcting these acquired and congenital channelopathies.
Collapse
|
12
|
Coppini R, Ferrantini C, Mazzoni L, Sartiani L, Olivotto I, Poggesi C, Cerbai E, Mugelli A. Regulation of intracellular Na(+) in health and disease: pathophysiological mechanisms and implications for treatment. Glob Cardiol Sci Pract 2013; 2013:222-42. [PMID: 24689024 PMCID: PMC3963757 DOI: 10.5339/gcsp.2013.30] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/01/2013] [Indexed: 12/19/2022] Open
Abstract
Transmembrane sodium (Na+) fluxes and intracellular sodium homeostasis are central players in the physiology of the cardiac myocyte, since they are crucial for both cell excitability and for the regulation of the intracellular calcium concentration. Furthermore, Na+ fluxes across the membrane of mitochondria affect the concentration of protons and calcium in the matrix, regulating mitochondrial function. In this review we first analyze the main molecular determinants of sodium fluxes across the sarcolemma and the mitochondrial membrane and describe their role in the physiology of the healthy myocyte. In particular we focus on the interplay between intracellular Ca2+ and Na+. A large part of the review is dedicated to discuss the changes of Na+ fluxes and intracellular Na+ concentration([Na+]i) occurring in cardiac disease; we specifically focus on heart failure and hypertrophic cardiomyopathy, where increased intracellular [Na+]i is an established determinant of myocardial dysfunction. We review experimental evidence attributing the increase of [Na+]i to either decreased Na+ efflux (e.g. via the Na+/K+ pump) or increased Na+ influx into the myocyte (e.g. via Na+ channels). In particular, we focus on the role of the “late sodium current” (INaL), a sustained component of the fast Na+ current of cardiac myocytes, which is abnormally enhanced in cardiac diseases and contributes to both electrical and contractile dysfunction. We analyze the pathophysiological role of INaL enhancement in heart failure and hypertrophic cardiomyopathy and the consequences of its pharmacological modulation, highlighting the clinical implications. The central role of Na+ fluxes and intracellular Na+ physiology and pathophysiology of cardiac myocytes has been highlighted by a large number of recent works. The possibility of modulating Na+ inward fluxes and [Na+]i with specific INaL inhibitors, such as ranolazine, has made Na+a novel suitable target for cardiac therapy, potentially capable of addressing arrhythmogenesis and diastolic dysfunction in severe conditions such as heart failure and hypertrophic cardiomyopathy.
Collapse
Affiliation(s)
- Raffaele Coppini
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Cecilia Ferrantini
- Department of Clinical and Experimental Medicine, division of Physiology, University of Florence, Italy
| | - Luca Mazzoni
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Laura Sartiani
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Iacopo Olivotto
- Referral Center for Cardiomyopathies, Careggi University Hospital, Florence, Italy
| | - Corrado Poggesi
- Department of Clinical and Experimental Medicine, division of Physiology, University of Florence, Italy
| | - Elisabetta Cerbai
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Alessandro Mugelli
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| |
Collapse
|
13
|
Li Y, Liu D, Liu Y, Li E, Wang H, Liu K, Qi J. Protein nitration promotes inducible nitric oxide synthase transcription mediated by NF-κB in high glucose-stimulated human lens epithelial cells. Mol Cell Endocrinol 2013; 370:78-86. [PMID: 23454417 DOI: 10.1016/j.mce.2013.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 02/01/2013] [Accepted: 02/19/2013] [Indexed: 12/15/2022]
Abstract
Although an important event in hyperglycaemia-induced oxidative stress is the nuclear factor-kappa b (NF-κB)-activated inducible nitric oxide synthase (iNOS) expression, the underlying mechanism is not fully characterized. Peroxynitrite, formed from NO and superoxide, can induce multiple proteins nitration, even including NF-κB and iNOS, to alter their functions. In this study, we found high glucose caused conspicuous nitration of nuclear NF-κB p65 and its co-activator p300 in human lens epithelial cells. The nitration of NF-κB and p300 promoted their co-localization and binding to ensure the activation of the iNOS gene transcription. Moreover, nearly all predicted NF-κB binding sites in the human iNOS gene promoter were responsive to high glucose stimulation, might for a synergistic role. While, only the NF-κB binding site -5212 showed significant alterations by high glucose and peroxynitrite stimulations, indicating it a more important role in the protein nitration promoted iNOS gene transcription. Our results demonstrated that protein nitration can promote the NF-κB-activated iNOS gene transcription in human lens epithelial cells by high glucose stimulation.
Collapse
Affiliation(s)
- Yanning Li
- Department of Molecular Biology, Hebei Key Lab of Laboratory Animal, Hebei Medical University, Shijiazhuang, China
| | | | | | | | | | | | | |
Collapse
|
14
|
Sovari AA, Dudley SC. Reactive oxygen species-targeted therapeutic interventions for atrial fibrillation. Front Physiol 2012; 3:311. [PMID: 22934062 PMCID: PMC3429082 DOI: 10.3389/fphys.2012.00311] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 07/15/2012] [Indexed: 01/14/2023] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia that requires medical attention, and its incidence is increasing. Current ion channel blockade therapies and catheter ablation have significant limitations in treatment of AF, mainly because they do not address the underlying pathophysiology of the disease. Oxidative stress has been implicated as a major underlying pathology that promotes AF; however, conventional antioxidants have not shown impressive therapeutic effects. A more careful design of antioxidant therapies and better selection of patients likely are required to treat effectively AF with antioxidant agents. Current evidence suggest inhibition of prominent cardiac sources of reactive oxygen species (ROS) such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and targeting subcellular compartments with the highest levels of ROS may prove to be effective therapies for AF. Increased serum markers of oxidative stress may be an important guide in selecting the AF patients who will most likely respond to antioxidant therapy.
Collapse
Affiliation(s)
- Ali A Sovari
- Section of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago Chicago, IL, USA
| | | |
Collapse
|
15
|
Moreno JD, Clancy CE. Pathophysiology of the cardiac late Na current and its potential as a drug target. J Mol Cell Cardiol 2011; 52:608-19. [PMID: 22198344 DOI: 10.1016/j.yjmcc.2011.12.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 11/30/2011] [Accepted: 12/07/2011] [Indexed: 12/19/2022]
Abstract
A pathological increase in the late component of the cardiac Na(+) current, I(NaL), has been linked to disease manifestation in inherited and acquired cardiac diseases including the long QT variant 3 (LQT3) syndrome and heart failure. Disruption in I(NaL) leads to action potential prolongation, disruption of normal cellular repolarization, development of arrhythmia triggers, and propensity to ventricular arrhythmia. Attempts to treat arrhythmogenic sequelae from inherited and acquired syndromes pharmacologically with common Na(+) channel blockers (e.g. flecainide, lidocaine, and amiodarone) have been largely unsuccessful. This is due to drug toxicity and the failure of most current drugs to discriminate between the peak current component, chiefly responsible for single cell excitability and propagation in coupled tissue, and the late component (I(NaL)) of the Na(+) current. Although small in magnitude as compared to the peak Na(+) current (~1-3%), I(NaL) alters action potential properties and increases Na(+) loading in cardiac cells. With the increasing recognition that multiple cardiac pathological conditions share phenotypic manifestations of I(NaL) upregulation, there has been renewed interest in specific pharmacological inhibition of I(Na). The novel antianginal agent ranolazine, which shows a marked selectivity for late versus peak Na(+) current, may represent a novel drug archetype for targeted reduction of I(NaL). This article aims to review common pathophysiological mechanisms leading to enhanced I(NaL) in LQT3 and heart failure as prototypical disease conditions. Also reviewed are promising therapeutic strategies tailored to alter the molecular mechanisms underlying I(Na) mediated arrhythmia triggers.
Collapse
Affiliation(s)
- Jonathan D Moreno
- Tri-Institutional MD-PhD Program, Weill Cornell Medical College/The Rockefeller University/Sloan-Kettering Cancer Institute, New York, NY 10021, USA
| | | |
Collapse
|
16
|
Gurung IS, Medina-Gomez G, Kis A, Baker M, Velagapudi V, Neogi SG, Campbell M, Rodriguez-Cuenca S, Lelliott C, McFarlane I, Oresic M, Grace AA, Vidal-Puig A, Huang CLH. Deletion of the metabolic transcriptional coactivator PGC1β induces cardiac arrhythmia. Cardiovasc Res 2011; 92:29-38. [PMID: 21632884 PMCID: PMC3172981 DOI: 10.1093/cvr/cvr155] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/17/2011] [Accepted: 05/26/2011] [Indexed: 01/23/2023] Open
Abstract
AIMS Peroxisome proliferator-activated receptor-γ coactivators PGC1α and PGC1β modulate mitochondrial biogenesis and energy homeostasis. The function of these transcriptional coactivators is impaired in obesity, insulin resistance, and type 2 diabetes. We searched for transcriptomic, lipidomic, and electrophysiological alterations in PGC1β(-/-) hearts potentially associated with increased arrhythmic risk in metabolic diseases. METHODS AND RESULTS Microarray analysis in mouse PGC1β(-/-) hearts confirmed down-regulation of genes related to oxidative phosphorylation and the electron transport chain and up-regulation of hypertrophy- and hypoxia-related genes. Lipidomic analysis showed increased levels of the pro-arrhythmic and pro-inflammatory lipid, lysophosphatidylcholine. PGC1β(-/-) mouse electrocardiograms showed irregular heartbeats and an increased incidence of polymorphic ventricular tachycardia following isoprenaline infusion. Langendorff-perfused PGC1β(-/-) hearts showed action potential alternans, early after-depolarizations, and ventricular tachycardia. PGC1β(-/-) ventricular myocytes showed oscillatory resting potentials, action potentials with early and delayed after-depolarizations, and burst firing during sustained current injection. They showed abnormal diastolic Ca(2+) transients, whose amplitude and frequency were increased by isoprenaline, and Ca(2+) currents with negatively shifted inactivation characteristics, with increased window currents despite unaltered levels of CACNA1C RNA transcripts. Inwardly and outward rectifying K(+) currents were all increased. Quantitiative RT-PCR demonstrated increased SCN5A, KCNA5, RYR2, and Ca(2+)-calmodulin dependent protein kinase II expression. CONCLUSION PGC1β(-/-) hearts showed a lysophospholipid-induced cardiac lipotoxicity and impaired bioenergetics accompanied by an ion channel remodelling and altered Ca(2+) homeostasis, converging to produce a ventricular arrhythmic phenotype particularly during adrenergic stress. This could contribute to the increased cardiac mortality associated with both metabolic and cardiac disease attributable to lysophospholipid accumulation.
Collapse
Affiliation(s)
- Iman S. Gurung
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Gema Medina-Gomez
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Adrienn Kis
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Michael Baker
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Vidya Velagapudi
- VTT Technical Research Centre of Finland, Tietotie 2, PO Box 1000, Espo,Finland
| | - Sudeshna Guha Neogi
- Genomics CoreLab, NIHR-Cambridge Biomedical Research Centre, University of Cambridge, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
| | - Mark Campbell
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Sergio Rodriguez-Cuenca
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Christopher Lelliott
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Ian McFarlane
- Genomics CoreLab, NIHR-Cambridge Biomedical Research Centre, University of Cambridge, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
| | - Matej Oresic
- VTT Technical Research Centre of Finland, Tietotie 2, PO Box 1000, Espo,Finland
| | - Andrew A. Grace
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, University of Cambridge, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Christopher L.-H. Huang
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| |
Collapse
|
17
|
Gandhi C, Upaganalawar A, Balaraman R. Protection against in vivo focal myocardial ischemia/reperfusion injury-induced arrhythmias and apoptosis by hesperidin. Free Radic Res 2009; 43:817-27. [PMID: 19579067 DOI: 10.1080/10715760903071656] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Among the heart diseases, ischemia and reperfusion (I/R) induced arrhythmias contribute to episodes of sudden death. Cardiac arrhythmias during ischemia reperfusion are believed to be related to oxidative stress. Therefore, the aim of this study was to examine whether treatment with hesperidin alleviates arrhythmias and infarct size in experimentally-induced myocardial I/R injury using an in vivo rat model. In this study haemodynamics parameters, markers of inflammation, biomarkers of oxidative stress and tissue nitrite level and infarct size of the heart were estimated in various groups. I/R showed a significant decrease in tissue nitrite and antioxidant level and significant increase in arrhythmias, inflammation and myocardial cell apoptosis. Treatment with hesperidin showed a significant increase in tissue nitrite, antioxidant level and reduction in inflammation, arrhythmias and apoptosis. In conclusion, the protecting effect of hesperidin in I/R induced arrhythmias is due to reduction in inflammation and oxidative stress.
Collapse
Affiliation(s)
- Chintan Gandhi
- Pharmacy Department, Faculty of Technology and Engineering, M. S. University of Baroda, Kalabhavan, Gujarat, India.
| | | | | |
Collapse
|
18
|
Wu Y, Song Y, Belardinelli L, Shryock JC. The Late Na+ Current (INa) Inhibitor Ranolazine Attenuates Effects of Palmitoyl-L-Carnitine to Increase Late INa and Cause Ventricular Diastolic Dysfunction. J Pharmacol Exp Ther 2009; 330:550-7. [DOI: 10.1124/jpet.109.151936] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
19
|
Kraichely RE, Strege PR, Sarr MG, Kendrick ML, Farrugia G. Lysophosphatidyl choline modulates mechanosensitive L-type Ca2+ current in circular smooth muscle cells from human jejunum. Am J Physiol Gastrointest Liver Physiol 2009; 296:G833-9. [PMID: 19179622 PMCID: PMC2670668 DOI: 10.1152/ajpgi.90610.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The L-type Ca2+ channel expressed in gastrointestinal smooth muscle is mechanosensitive. Direct membrane stretch and shear stress result in increased Ca2+ entry into the cell. The mechanism for mechanosensitivity is not known, and mechanosensitivity is not dependent on an intact cytoskeleton. The aim of this study was to determine whether L-type Ca2+ channel mechanosensitivity is dependent on tension in the lipid bilayer in human jejunal circular layer myocytes. Whole cell currents were recorded in the amphotericin-perforated-patch configuration, and lysophosphatidyl choline (LPC), lysophosphatidic acid (LPA), and choline were used to alter differentially the tension in the lipid bilayer. Shear stress (perfusion at 10 ml/min) was used to mechanostimulate L-type Ca2+ channels. The increase in L-type Ca2+ current induced by shear stress was greater in the presence of LPC (large head-to-tail proportions), but not LPA or choline, than in the control perfusion. The increased peak Ca2+ current also did not return to baseline levels as in control conditions. Furthermore, steady-state inactivation kinetics were altered in the presence of LPC, leading to a change in window current. These findings suggest that changes in tension in the plasmalemmal membrane can be transmitted to the mechanosensitive L-type Ca2+ channel, leading to altered activity and Ca2+ entry in the human jejunal circular layer myocyte.
Collapse
Affiliation(s)
- Robert E. Kraichely
- Enteric Neuroscience Program, Miles and Shirley Fiterman Center for Digestive Diseases, and Gastroenterologic and General Surgery, Mayo Clinic, Rochester, Minnesota
| | - Peter R. Strege
- Enteric Neuroscience Program, Miles and Shirley Fiterman Center for Digestive Diseases, and Gastroenterologic and General Surgery, Mayo Clinic, Rochester, Minnesota
| | - Michael G. Sarr
- Enteric Neuroscience Program, Miles and Shirley Fiterman Center for Digestive Diseases, and Gastroenterologic and General Surgery, Mayo Clinic, Rochester, Minnesota
| | - Michael L. Kendrick
- Enteric Neuroscience Program, Miles and Shirley Fiterman Center for Digestive Diseases, and Gastroenterologic and General Surgery, Mayo Clinic, Rochester, Minnesota
| | - Gianrico Farrugia
- Enteric Neuroscience Program, Miles and Shirley Fiterman Center for Digestive Diseases, and Gastroenterologic and General Surgery, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
20
|
Oxidative stress and inflammation in atrial fibrillation: role in pathogenesis and potential as a therapeutic target. J Cardiovasc Pharmacol 2009; 52:306-13. [PMID: 18791466 DOI: 10.1097/fjc.0b013e31817f9398] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Atrial fibrillation (AF) is one of the most prevalent and vexing cardiovascular conditions. Available treatments for AF based on ion channel blockade are only poorly effective. The fundamental mechanisms that underlie AF are still not clearly understood, and likely vary depending on the etiology of AF. In older individuals with senile AF, likely mechanisms include abnormal calcium cycling, oxidant stress, and deleterious inflammatory responses. Clinical and experimental evidence is provided to support the role of oxidant and inflammatory mechanisms in AF. On the basis of these studies, the prospects of manipulating oxidant and inflammatory pathways as targets for therapeutic intervention are discussed.
Collapse
|
21
|
Pathophysiology and pharmacology of the cardiac “late sodium current”. Pharmacol Ther 2008; 119:326-39. [DOI: 10.1016/j.pharmthera.2008.06.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Accepted: 06/04/2008] [Indexed: 12/19/2022]
|
22
|
Van Wagoner DR. Better never than late? New insights into a mechanism linking metabolic stress to altered cardiac repolarization. J Mol Cell Cardiol 2008; 44:238-40. [PMID: 18201718 DOI: 10.1016/j.yjmcc.2007.12.004] [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: 12/05/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
|