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Huang Y, Lin Q, Zhou Y, Zhu J, Ma Y, Wu K, Ning Z, Zhang Z, Liu N, Li M, Liu Y, Tu T, Liu Q. Amino acid profile alteration in age-related atrial fibrillation. J Transl Med 2024; 22:259. [PMID: 38461346 PMCID: PMC10925006 DOI: 10.1186/s12967-024-05028-7] [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: 10/08/2023] [Accepted: 02/24/2024] [Indexed: 03/11/2024] Open
Abstract
BACKGROUND Amino acids (AAs) are one of the primary metabolic substrates for cardiac work. The correlation between AAs and both atrial fibrillation (AF) and aging has been documented. However, the relationship between AAs and age-related AF remains unclear. METHODS Initially, the plasma AA levels of persistent AF patients and control subjects were assessed, and the correlations between AA levels, age, and other clinical indicators were explored. Subsequently, the age-related AF mouse model was constructed and the untargeted myocardial metabolomics was conducted to detect the level of AAs and related metabolites. Additionally, the gut microbiota composition associated with age-related AF was detected by a 16S rDNA amplicon sequencing analysis on mouse fecal samples. RESULTS Higher circulation levels of lysine (Student's t-test, P = 0.001), tyrosine (P = 0.002), glutamic acid (P = 0.008), methionine (P = 0.008), and isoleucine (P = 0.014), while a lower level of glycine (P = 0.003) were observed in persistent AF patients. The feature AAs identified by machine learning algorithms were glutamic acid and methionine. The association between AAs and age differs between AF and control subjects. Distinct patterns of AA metabolic profiles were observed in the myocardial metabolites of aged AF mice. Aged AF mice had lower levels of Betaine, L-histidine, L-alanine, L-arginine, L-Pyroglutamic acid, and L-Citrulline compared with adult AF mice. Aged AF mice also presented a different gut microbiota pattern, and its functional prediction analysis showed AA metabolism alteration. CONCLUSION This study provided a comprehensive network of AA disturbances in age-related AF from multiple dimensions, including plasma, myocardium, and gut microbiota. Disturbances of AAs may serve as AF biomarkers, and restoring their homeostasis may have potential benefits for the management of age-related AF.
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Affiliation(s)
- Yunying Huang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Qiuzhen Lin
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Yong Zhou
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Jiayi Zhu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Yingxu Ma
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Keke Wu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Zuodong Ning
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Zixi Zhang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Na Liu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Mohan Li
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
- Department of Geriatrics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, 100730, People's Republic of China
| | - Yaozhong Liu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China
- Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan, Ann Arbor, MI, USA
| | - Tao Tu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China.
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China.
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China.
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China.
| | - Qiming Liu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 410011, Hunan, People's Republic of China.
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China.
- Cardiovascular Disease Research Center of Hunan Province, Changsha, 410011, Hunan, People's Republic of China.
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, 410011, Hunan, People's Republic of China.
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Balan AI, Halațiu VB, Scridon A. Oxidative Stress, Inflammation, and Mitochondrial Dysfunction: A Link between Obesity and Atrial Fibrillation. Antioxidants (Basel) 2024; 13:117. [PMID: 38247541 PMCID: PMC10812976 DOI: 10.3390/antiox13010117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024] Open
Abstract
The adipose tissue has long been thought to represent a passive source of triglycerides and fatty acids. However, extensive data have demonstrated that the adipose tissue is also a major endocrine organ that directly or indirectly affects the physiological functions of almost all cell types. Obesity is recognized as a risk factor for multiple systemic conditions, including metabolic syndrome, type 2 diabetes mellitus, sleep apnea, cardiovascular disorders, and many others. Obesity-related changes in the adipose tissue induce functional and structural changes in cardiac myocytes, promoting a wide range of cardiovascular disorders, including atrial fibrillation (AF). Due to the wealth of epidemiologic data linking AF to obesity, the mechanisms underlying AF occurrence in obese patients are an area of rich ongoing investigation. However, progress has been somewhat slowed by the complex phenotypes of both obesity and AF. The triad inflammation, oxidative stress, and mitochondrial dysfunction are critical for AF pathogenesis in the setting of obesity via multiple structural and functional proarrhythmic changes at the level of the atria. The aim of this paper is to provide a comprehensive view of the close relationship between obesity-induced oxidative stress, inflammation, and mitochondrial dysfunction and the pathogenesis of AF. The clinical implications of these mechanistic insights are also discussed.
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Affiliation(s)
- Alkora Ioana Balan
- Center for Advanced Medical and Pharmaceutical Research, University of Medicine, Pharmacy, Science and Technology “George Emil Palade” of Târgu Mureș, 540142 Târgu Mureș, Romania;
| | - Vasile Bogdan Halațiu
- Physiology Department, University of Medicine, Pharmacy, Science and Technology “George Emil Palade” of Târgu Mureș, 540142 Târgu Mureș, Romania;
| | - Alina Scridon
- Center for Advanced Medical and Pharmaceutical Research, University of Medicine, Pharmacy, Science and Technology “George Emil Palade” of Târgu Mureș, 540142 Târgu Mureș, Romania;
- Physiology Department, University of Medicine, Pharmacy, Science and Technology “George Emil Palade” of Târgu Mureș, 540142 Târgu Mureș, Romania;
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Ramos-Mondragón R, Lozhkin A, Vendrov AE, Runge MS, Isom LL, Madamanchi NR. NADPH Oxidases and Oxidative Stress in the Pathogenesis of Atrial Fibrillation. Antioxidants (Basel) 2023; 12:1833. [PMID: 37891912 PMCID: PMC10604902 DOI: 10.3390/antiox12101833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/26/2023] [Accepted: 09/29/2023] [Indexed: 10/29/2023] Open
Abstract
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and its prevalence increases with age. The irregular and rapid contraction of the atria can lead to ineffective blood pumping, local blood stasis, blood clots, ischemic stroke, and heart failure. NADPH oxidases (NOX) and mitochondria are the main sources of reactive oxygen species in the heart, and dysregulated activation of NOX and mitochondrial dysfunction are associated with AF pathogenesis. NOX- and mitochondria-derived oxidative stress contribute to the onset of paroxysmal AF by inducing electrophysiological changes in atrial myocytes and structural remodeling in the atria. Because high atrial activity causes cardiac myocytes to expend extremely high energy to maintain excitation-contraction coupling during persistent AF, mitochondria, the primary energy source, undergo metabolic stress, affecting their morphology, Ca2+ handling, and ATP generation. In this review, we discuss the role of oxidative stress in activating AF-triggered activities, regulating intracellular Ca2+ handling, and functional and anatomical reentry mechanisms, all of which are associated with AF initiation, perpetuation, and progression. Changes in the extracellular matrix, inflammation, ion channel expression and function, myofibril structure, and mitochondrial function occur during the early transitional stages of AF, opening a window of opportunity to target NOX and mitochondria-derived oxidative stress using isoform-specific NOX inhibitors and mitochondrial ROS scavengers, as well as drugs that improve mitochondrial dynamics and metabolism to treat persistent AF and its transition to permanent AF.
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Affiliation(s)
- Roberto Ramos-Mondragón
- Department of Pharmacology, University of Michigan, 1150 West Medical Center Drive, 2301 Medical Science Research Building III, Ann Arbor, MI 48109, USA; (R.R.-M.); (L.L.I.)
| | - Andrey Lozhkin
- Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan, Ann Arbor, MI 48019, USA; (A.L.); (A.E.V.); (M.S.R.)
| | - Aleksandr E. Vendrov
- Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan, Ann Arbor, MI 48019, USA; (A.L.); (A.E.V.); (M.S.R.)
| | - Marschall S. Runge
- Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan, Ann Arbor, MI 48019, USA; (A.L.); (A.E.V.); (M.S.R.)
| | - Lori L. Isom
- Department of Pharmacology, University of Michigan, 1150 West Medical Center Drive, 2301 Medical Science Research Building III, Ann Arbor, MI 48109, USA; (R.R.-M.); (L.L.I.)
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nageswara R. Madamanchi
- Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan, Ann Arbor, MI 48019, USA; (A.L.); (A.E.V.); (M.S.R.)
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Jiménez-Sábado V, Casabella-Ramón S, Llach A, Gich I, Casellas S, Ciruela F, Chen SRW, Guerra JM, Ginel A, Benítez R, Cinca J, Tarifa C, Hove-Madsen L. Beta-blocker treatment of patients with atrial fibrillation attenuates spontaneous calcium release-induced electrical activity. Biomed Pharmacother 2023; 158:114169. [PMID: 36592495 DOI: 10.1016/j.biopha.2022.114169] [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: 10/06/2022] [Revised: 12/21/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023] Open
Abstract
AIMS Atrial fibrillation (AF) has been associated with excessive spontaneous calcium release, linked to cyclic AMP (cAMP)-dependent phosphorylation of calcium regulatory proteins. Because β-blockers are expected to attenuate cAMP-dependent signaling, we aimed to examine whether the treatment of patients with β-blockers affected the incidence of spontaneous calcium release events or transient inward currents (ITI). METHODS The impact of treatment with commonly used β-blockers was analyzed in human atrial myocytes from 371 patients using patch-clamp technique, confocal calcium imaging or immunofluorescent labeling. Data were analyzed using multivariate regression analysis taking into account potentially confounding effects of relevant clinical factors RESULTS: The L-type calcium current (ICa) density was diminished significantly in patients with chronic but not paroxysmal AF and the treatment of patients with β-blockers did not affect ICa density in any group. By contrast, the ITI frequency was elevated in patients with either paroxysmal or chronic AF that did not receive treatment, and β-blocker treatment reduced the frequency to levels observed in patients without AF. Confocal calcium imaging showed that β-blocker treatment also reduced the calcium spark frequency in patients with AF to levels observed in those without AF. Furthermore, phosphorylation of the ryanodine receptor (RyR2) at Ser-2808 and phospholamban at Ser-16 was significantly lower in patients with AF that received β-blockers. CONCLUSION Together, our findings demonstrate that β-blocker treatment may be of therapeutic utility to prevent spontaneous calcium release-induced atrial electrical activity; especially in patients with a history of paroxysmal AF displaying preserved ICa density.
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Affiliation(s)
- Verónica Jiménez-Sábado
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Sergi Casabella-Ramón
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain; Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Anna Llach
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ignasi Gich
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Sandra Casellas
- Servicio de Cirugía Cardíaca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Francisco Ciruela
- Pharmacology Unit, Dept. Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Spain; Neuropharmacology and Pain Group, Neuroscience Program, Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, L'Hospitalet de Llobregat, Spain
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, Canada
| | - José M Guerra
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Servicio de Cardiología and Univ. Autònoma de Barcelona, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Antonino Ginel
- Servicio de Cirugía Cardíaca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Raúl Benítez
- Dept. d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Univ. Politècnica de Catalunya, Barcelona, Spain
| | - Juan Cinca
- Servicio de Cardiología and Univ. Autònoma de Barcelona, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Carmen Tarifa
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain
| | - Leif Hove-Madsen
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain.
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Miao W, Shi J, Huang J, Lin Y, Cui C, Zhu Y, Zheng B, Li M, Jiang Q, Chen M. Azoramide ameliorated tachypacing-induced injury of atrial myocytes differentiated from human induced pluripotent stem cell by regulating endoplasmic reticulum stress. Stem Cell Res 2022; 60:102686. [DOI: 10.1016/j.scr.2022.102686] [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: 07/04/2021] [Revised: 01/16/2022] [Accepted: 01/19/2022] [Indexed: 11/24/2022] Open
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Reinhardt F, Beneke K, Pavlidou NG, Conradi L, Reichenspurner H, Hove-Madsen L, Molina CE. Abnormal Calcium Handling in Atrial Fibrillation Is Linked to Changes in Cyclic AMP Dependent Signaling. Cells 2021; 10:cells10113042. [PMID: 34831263 PMCID: PMC8616167 DOI: 10.3390/cells10113042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 01/03/2023] Open
Abstract
Both, the decreased L-type Ca2+ current (ICa,L) density and increased spontaneous Ca2+ release from the sarcoplasmic reticulum (SR), have been associated with atrial fibrillation (AF). In this study, we tested the hypothesis that remodeling of 3′,5′-cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) signaling is linked to these compartment-specific changes (up- or down-regulation) in Ca2+-handling. Perforated patch-clamp experiments were performed in atrial myocytes from 53 patients with AF and 104 patients in sinus rhythm (Ctl). A significantly higher frequency of transient inward currents (ITI) activated by spontaneous Ca2+ release was confirmed in myocytes from AF patients. Next, inhibition of PKA by H-89 promoted a stronger effect on the ITI frequency in these myocytes compared to myocytes from Ctl patients (7.6-fold vs. 2.5-fold reduction), while the β-agonist isoproterenol (ISO) caused a greater increase in Ctl patients (5.5-fold vs. 2.1-fold). ICa,L density was larger in myocytes from Ctl patients at baseline (p < 0.05). However, the effect of ISO on ICa,L density was only slightly stronger in AF than in Ctl myocytes (3.6-fold vs. 2.7-fold). Interestingly, a significant reduction of ICa,L and Ca2+ sparks was observed upon Ca2+/Calmodulin-dependent protein kinase II inhibition by KN-93, but this inhibition had no effect on ITI. Fluorescence resonance energy transfer (FRET) experiments showed that although AF promoted cytosolic desensitization to β-adrenergic stimulation, ISO increased cAMP to similar levels in both groups of patients in the L-type Ca2+ channel and ryanodine receptor compartments. Basal cAMP signaling also showed compartment-specific regulation by phosphodiesterases in atrial myocytes from 44 Ctl and 43 AF patients. Our results suggest that AF is associated with opposite changes in compartmentalized PKA/cAMP-dependent regulation of ICa,L (down-regulation) and ITI (up-regulation).
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Affiliation(s)
- Franziska Reinhardt
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
| | - Kira Beneke
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Nefeli Grammatica Pavlidou
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Lenard Conradi
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona, IIBB-CSIC and IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain;
| | - Cristina E. Molina
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
- Correspondence: ; Tel.: +49-407-4105-7095
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Yoon S, Eom GH, Kang G. Nitrosative Stress and Human Disease: Therapeutic Potential of Denitrosylation. Int J Mol Sci 2021; 22:ijms22189794. [PMID: 34575960 PMCID: PMC8464666 DOI: 10.3390/ijms22189794] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 01/22/2023] Open
Abstract
Proteins dynamically contribute towards maintaining cellular homeostasis. Posttranslational modification regulates the function of target proteins through their immediate activation, sudden inhibition, or permanent degradation. Among numerous protein modifications, protein nitrosation and its functional relevance have emerged. Nitrosation generally initiates nitric oxide (NO) production in association with NO synthase. NO is conjugated to free thiol in the cysteine side chain (S-nitrosylation) and is propagated via the transnitrosylation mechanism. S-nitrosylation is a signaling pathway frequently involved in physiologic regulation. NO forms peroxynitrite in excessive oxidation conditions and induces tyrosine nitration, which is quite stable and is considered irreversible. Two main reducing systems are attributed to denitrosylation: glutathione and thioredoxin (TRX). Glutathione captures NO from S-nitrosylated protein and forms S-nitrosoglutathione (GSNO). The intracellular reducing system catalyzes GSNO into GSH again. TRX can remove NO-like glutathione and break down the disulfide bridge. Although NO is usually beneficial in the basal context, cumulative stress from chronic inflammation or oxidative insult produces a large amount of NO, which induces atypical protein nitrosation. Herein, we (1) provide a brief introduction to the nitrosation and denitrosylation processes, (2) discuss nitrosation-associated human diseases, and (3) discuss a possible denitrosylation strategy and its therapeutic applications.
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Affiliation(s)
- Somy Yoon
- Department of Pharmacology, Chonnam National University Medical School, Hwasun 58128, Korea;
| | - Gwang Hyeon Eom
- Department of Pharmacology, Chonnam National University Medical School, Hwasun 58128, Korea;
- Correspondence: (G.-H.E.); (G.K.); Tel.: +82-61-379-2837 (G.-H.E.); +82-62-220-5262 (G.K.)
| | - Gaeun Kang
- Division of Clinical Pharmacology, Chonnam National University Hospital, Gwangju 61469, Korea
- Correspondence: (G.-H.E.); (G.K.); Tel.: +82-61-379-2837 (G.-H.E.); +82-62-220-5262 (G.K.)
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Sari M, Yazar H, Kocayigit I, Karagoz A, Ayturk M, Fidan S, Arslantas U, Cakmak EO, Alici G, Ozkan B. Alteration of serum biomarkers in patients with hypertrophic cardiomyopathy with and without atrial fibrillation. Biomark Med 2021; 15:1131-1142. [PMID: 34402630 DOI: 10.2217/bmm-2021-0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: We sought to determine the relationship between presence of atrial fibrillation (AF) and serum biomarkers, including native thiol (antioxidant), disulphide/native thiol ratio, Hs-CRP and high-sensitivity Troponin-I (Hs-TnI) in hypertrophic cardiomyopathy (HCM). Materials & methods: We enrolled consecutive 121 HCM outpatients without AF and 40 HCM outpatients with AF. A 12-lead electrocardiogram, transthoracic echocardiography and 24/48-h ambulatory rhythm monitoring were performed for all patients. Fasting venous blood samples were taken from all study patients to measure serum thiol-disulphide homeostasis, Hs-CRP and Hs-TnI. Results: Serum-native thiol was lower and disulphide/native thiol ratio was more oxidized in HCM patients with AF (p < 0.001). Also, HCM patients with AF had higher Hs-TnI and Hs-CRP than no-AF HCM patients. Disulphide/native thiol ratio, serum-native thiol, age, NYHA functional class≥III, and advanced diastolic dysfunction were independently associated with the presence of AF in HCM. Conclusion: In addition to clinical and echocardiographic findings, oxidative stress is also associated with AF in HCM patients.
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Affiliation(s)
- Munevver Sari
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Hayrullah Yazar
- Department of Biochemistry, Faculty of Medicine, Sakarya University, Sakarya, Turkey
| | - Ibrahim Kocayigit
- Department of Cardiology, Sakarya University Education & Research Hospital, Sakarya, Turkey
| | - Ali Karagoz
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Mehmet Ayturk
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Serdar Fidan
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Ugur Arslantas
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Ender O Cakmak
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Gokhan Alici
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
| | - Birol Ozkan
- Department of Cardiology, University of Health Sciences Turkey, Kartal Kosuyolu High Specialization Health Application and Research Center, Istanbul, Turkey
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9
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Jiang Y, Damiris K, Suero-Abreu G, Xu B, Ahlawat S. Reflux esophagitis is associated with higher risks of acute stroke and transient ischemic attacks in patients hospitalized with atrial fibrillation: A nationwide inpatient sample analysis. Medicine (Baltimore) 2021; 100:e26502. [PMID: 34160467 PMCID: PMC8238265 DOI: 10.1097/md.0000000000026502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/01/2021] [Indexed: 01/04/2023] Open
Abstract
Reflux esophagitis (RE) is a subset of gastroesophageal reflux disease (GERD) with endoscopic evidence of esophageal inflammation, which has been linked to an increased incidence of atrial fibrillation (AF). However, data on the effect of RE on patient outcomes is limited. We sought to examine the potential association of RE with outcomes of patients with AF in a nationwide study.The National Inpatient Sample (NIS) database was queried to identify hospitalized adult patients with AF and RE between 2010 and 2014. Primary outcomes included inpatient mortality, length of stay (LOS), and total hospital charges. AF related complications such as acute stroke, transient ischemic attack (TIA) and acute heart failure were assessed as secondary outcomes. Propensity score matching and multivariate regression analysis were used.Six lakh sixty seven thousands five hundred twenty patients were admitted for primary diagnosis of AF out of which 5396 had a secondary diagnosis of RE. In the AF with RE cohort, the average age was 73.6 years, 41.5% were male, and 79.9% were Caucasian. There was a greater prevalence of concomitant dyslipidemia, chronic liver disease and chronic pulmonary disease (P < .01) when compared to the AF without RE cohort. Patients with AF and RE also had higher incidence of acute strokes and TIAs (P < .05), longer LOS (P < .001), and higher hospital charges (P < .05) with no difference in acute heart failure (P = .08), hospital mortality (P = .12), or CHA2DS2-VASc score (P = .67).In hospitalized patients with AF, RE was associated with a higher rate of acute stroke and TIAs, longer LOS, and greater hospital charges.
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Affiliation(s)
- Yi Jiang
- Department of Medicine, Rutgers New Jersey Medical School, Newark
| | | | | | - Binghong Xu
- Center for Asian Health, Saint Barnabas Medical Center, Livingston
| | - Sushil Ahlawat
- Division of Gastroenterology and Hepatology, Rutgers New Jersey Medical School, Newark, NJ
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10
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Herraiz-Martínez A, Tarifa C, Jiménez-Sábado V, Llach A, Godoy-Marín H, Colino H, Nolla-Colomer C, Casabella S, Izquierdo-Castro P, Benítez I, Benítez R, Roselló-Díez E, Rodríguez-Font E, Viñolas X, Ciruela F, Cinca J, Hove-Madsen L. Influence of sex on intracellular calcium homeostasis in patients with atrial fibrillation. Cardiovasc Res 2021; 118:1033-1045. [PMID: 33788918 PMCID: PMC8930070 DOI: 10.1093/cvr/cvab127] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 03/30/2021] [Indexed: 11/22/2022] Open
Abstract
Aims Atrial fibrillation (AF) has been associated with intracellular calcium disturbances in human atrial myocytes, but little is known about the potential influence of sex and we here aimed to address this issue. Methods and results Alterations in calcium regulatory mechanisms were assessed in human atrial myocytes from patients without AF or with long-standing persistent or permanent AF. Patch-clamp measurements revealed that L-type calcium current (ICa) density was significantly smaller in males with than without AF (−1.15 ± 0.37 vs. −2.06 ± 0.29 pA/pF) but not in females with AF (−1.88 ± 0.40 vs. −2.21 ± 0.0.30 pA/pF). In contrast, transient inward currents (ITi) were more frequent in females with than without AF (1.92 ± 0.36 vs. 1.10 ± 0.19 events/min) but not in males with AF. Moreover, confocal calcium imaging showed that females with AF had more calcium spark sites than those without AF (9.8 ± 1.8 vs. 2.2 ± 1.9 sites/µm2) and sparks were wider (3.0 ± 0.3 vs. 2.2 ± 0.3 µm) and lasted longer (79 ± 6 vs. 55 ± 8 ms), favouring their fusion into calcium waves that triggers ITIs and afterdepolarizations. This was linked to higher ryanodine receptor phosphorylation at s2808 in women with AF, and inhibition of adenosine A2A or beta-adrenergic receptors that modulate s2808 phosphorylation was able to reduce the higher incidence of ITI in women with AF. Conclusion Perturbations of the calcium homoeostasis in AF is sex-dependent, concurring with increased spontaneous SR calcium release-induced electrical activity in women but not in men, and with diminished ICa density in men only.
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Affiliation(s)
| | - Carmen Tarifa
- Biomedical Research Institute Barcelona Centre IIBB-CSIC.,IIB Sant Pau
| | | | | | - Hector Godoy-Marín
- Dept. Pathology and Experimental Therapeutics, IDIBELL, Univ. Barcelona, L'Hospitalet de Llobregat, Spain.,Neuroscience Institute, Univ. Barcelona, Spain
| | - Hildegard Colino
- Biomedical Research Institute Barcelona Centre IIBB-CSIC.,IIB Sant Pau
| | | | - Sergi Casabella
- Biomedical Research Institute Barcelona Centre IIBB-CSIC.,IIB Sant Pau
| | | | - Iván Benítez
- Biostatistic Unit, Biomedical Research Institute, IRBLleida, Spain
| | - Raul Benítez
- Dept. Automatic Control, Univ. Politècnica de Catalunya, Barcelona
| | - Elena Roselló-Díez
- Dept. Cardiac Surgery, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Univ. Autònoma de Barcelona, Spain
| | | | - Xavier Viñolas
- Dept. Cardiology, Hospital de la Santa Creu i Sant Pau, Barcelona
| | - Francisco Ciruela
- Dept. Pathology and Experimental Therapeutics, IDIBELL, Univ. Barcelona, L'Hospitalet de Llobregat, Spain.,Neuroscience Institute, Univ. Barcelona, Spain
| | - Juan Cinca
- Dept. Cardiology, Hospital de la Santa Creu i Sant Pau, Barcelona.,CIBERCV.,Univ. Autònoma de Barcelona, Spain
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona Centre IIBB-CSIC.,IIB Sant Pau.,CIBERCV
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11
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Mighiu AS, Recalde A, Ziberna K, Carnicer R, Tomek J, Bub G, Brewer AC, Verheule S, Shah AM, Simon JN, Casadei B. Inducibility, but not stability, of atrial fibrillation is increased by NOX2 overexpression in mice. Cardiovasc Res 2021; 117:2354-2364. [PMID: 33483749 PMCID: PMC8479801 DOI: 10.1093/cvr/cvab019] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/01/2020] [Accepted: 01/13/2021] [Indexed: 01/17/2023] Open
Abstract
Aims Gp91-containing NADPH oxidases (NOX2) are a significant source of myocardial superoxide production. An increase in NOX2 activity accompanies atrial fibrillation (AF) induction and electrical remodelling in animal models and predicts incident AF in humans; however, a direct causal role for NOX2 in AF has not been demonstrated. Accordingly, we investigated whether myocardial NOX2 overexpression in mice (NOX2-Tg) is sufficient to generate a favourable substrate for AF and further assessed the effects of atorvastatin, an inhibitor of NOX2, on atrial superoxide production and AF susceptibility. Methods and results NOX2-Tg mice showed a 2- to 2.5-fold higher atrial protein content of NOX2 compared with wild-type (WT) controls, which was associated with a significant (twofold) increase in NADPH-stimulated superoxide production (2-hydroxyethidium by HPLC) in left and right atrial tissue homogenates (P = 0.004 and P = 0.019, respectively). AF susceptibility assessed in vivo by transoesophageal atrial burst stimulation was modestly increased in NOX2-Tg compared with WT (probability of AF induction: 88% vs. 69%, respectively; P = 0.037), in the absence of significant alterations in AF duration, surface ECG parameters, and LV mass or function. Mechanistic studies did not support a role for NOX2 in promoting electrical or structural remodelling, as high-resolution optical mapping of atrial tissues showed no differences in action potential duration and conduction velocity between genotypes. In addition, we did not observe any genotype difference in markers of fibrosis and inflammation, including atrial collagen content and Col1a1, Il-1β, Il-6, and Mcp-1 mRNA. Similarly, NOX2 overexpression did not have consistent effects on RyR2 Ca2+ leak nor did it affect PKA or CaMKII-mediated RyR2 phosphorylation. Finally, treatment with atorvastatin significantly inhibited atrial superoxide production in NOX2-Tg but had no effect on AF induction in either genotype. Conclusion Together, these data indicate that while atrial NOX2 overexpression may contribute to atrial arrhythmogenesis, NOX2-derived superoxide production does not affect the electrical and structural properties of the atrial myocardium.
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Affiliation(s)
| | - Alice Recalde
- Division of Cardiovascular Medicine, University of Oxford, UK
| | - Klemen Ziberna
- Division of Cardiovascular Medicine, University of Oxford, UK
| | | | - Jakub Tomek
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK
| | - Alison C Brewer
- King's College London British Heart Foundation Centre of Excellence, School of Cardiovascular Medicine & Sciences, London, UK
| | - Sander Verheule
- Department of Physiology, Maastricht University, Maastricht, Netherlands
| | - Ajay M Shah
- King's College London British Heart Foundation Centre of Excellence, School of Cardiovascular Medicine & Sciences, London, UK
| | - Jillian N Simon
- Division of Cardiovascular Medicine, University of Oxford, UK
| | - Barbara Casadei
- Division of Cardiovascular Medicine, University of Oxford, UK
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12
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Atrial fibrillation rhythm is associated with marked changes in metabolic and myofibrillar protein expression in left atrial appendage. Pflugers Arch 2021; 473:461-475. [PMID: 33454842 DOI: 10.1007/s00424-021-02514-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/26/2020] [Accepted: 01/04/2021] [Indexed: 12/15/2022]
Abstract
Atrial fibrillation (AF) is strongly associated with risk of stroke and heart failure. AF promotes atrial remodeling that increases risk of stroke due to left atrial thrombogenesis, and increases energy demand to support high rate electrical activity and muscle contraction. While many transcriptomic studies have assessed AF-related changes in mRNA abundance, fewer studies have assessed proteomic changes. We performed a proteomic analysis on left atrial appendage (LAA) tissues from 12 patients with a history of AF undergoing elective surgery; atrial rhythm was documented at time of surgery. Proteomic analysis was performed using liquid chromatography with mass spectrometry (LC/MS-MS). Data-dependent analysis identified 3090 unique proteins, with 408 differentially expressed between sinus rhythm and AF. Ingenuity Pathway Analysis of differentially expressed proteins identified mitochondrial dysfunction, oxidative phosphorylation, and sirtuin signaling among the most affected pathways. Increased abundance of electron transport chain (ETC) proteins in AF was accompanied by decreased expression of ETC complex assembly factors, tricarboxylic acid cycle proteins, and other key metabolic modulators. Discordant changes were also evident in the contractile unit with both up and downregulation of key components. Similar pathways were affected in a comparison of patients with a history of persistent vs. paroxysmal AF, presenting for surgery in sinus rhythm. Together, these data suggest that while the LAA attempts to meet the energetic demands of AF, an uncoordinated response may reduce ATP availability, contribute to tissue contractile and electrophysiologic heterogeneity, and promote a progression of AF from paroxysmal episodes to development of a substrate amenable to persistent arrhythmia.
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13
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Yoo S, Pfenniger A, Hoffman J, Zhang W, Ng J, Burrell A, Johnson DA, Gussak G, Waugh T, Bull S, Benefield B, Knight BP, Passman R, Wasserstrom JA, Aistrup GL, Arora R. Attenuation of Oxidative Injury With Targeted Expression of NADPH Oxidase 2 Short Hairpin RNA Prevents Onset and Maintenance of Electrical Remodeling in the Canine Atrium: A Novel Gene Therapy Approach to Atrial Fibrillation. Circulation 2020; 142:1261-1278. [PMID: 32686471 PMCID: PMC9277750 DOI: 10.1161/circulationaha.119.044127] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common heart rhythm disorder in adults and a major cause of stroke. Unfortunately, current treatments of AF are suboptimal because they are not targeted to the molecular mechanisms underlying AF. Using a highly novel gene therapy approach in a canine, rapid atrial pacing model of AF, we demonstrate that NADPH oxidase 2 (NOX2) generated oxidative injury causes upregulation of a constitutively active form of acetylcholine-dependent K+ current (IKACh), called IKH; this is an important mechanism underlying not only the genesis, but also the perpetuation of electric remodeling in the intact, fibrillating atrium. METHODS To understand the mechanism by which oxidative injury promotes the genesis and maintenance of AF, we performed targeted injection of NOX2 short hairpin RNA (followed by electroporation to facilitate gene delivery) in atria of healthy dogs followed by rapid atrial pacing. We used in vivo high-density electric mapping, isolation of atrial myocytes, whole-cell patch clamping, in vitro tachypacing of atrial myocytes, lucigenin chemiluminescence assay, immunoblotting, real-time polymerase chain reaction, immunohistochemistry, and Masson trichrome staining. RESULTS First, we demonstrate that generation of oxidative injury in atrial myocytes is a frequency-dependent process, with rapid pacing in canine atrial myocytes inducing oxidative injury through the induction of NOX2 and the generation of mitochondrial reactive oxygen species. We show that oxidative injury likely contributes to electric remodeling in AF by upregulating IKACh by a mechanism involving frequency-dependent activation of PKCε (protein kinase C epsilon). The time to onset of nonsustained AF increased by >5-fold in NOX2 short hairpin RNA-treated dogs. Furthermore, animals treated with NOX2 short hairpin RNA did not develop sustained AF for up to 12 weeks. The electrophysiological mechanism underlying AF prevention was prolongation of atrial effective refractory periods, at least in part attributable to the attenuation of IKACh. Attenuated membrane translocation of PKCε appeared to be a likely molecular mechanism underlying this beneficial electrophysiological remodeling. CONCLUSIONS NOX2 oxidative injury (1) underlies the onset, and the maintenance of electric remodeling in AF, as well, and (2) can be successfully prevented with a novel, gene-based approach. Future optimization of this approach may lead to a novel, mechanism-guided therapy for AF.
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Affiliation(s)
- Shin Yoo
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Anna Pfenniger
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Jacob Hoffman
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Wenwei Zhang
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Jason Ng
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Amy Burrell
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - David A. Johnson
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Georg Gussak
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Trent Waugh
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Suzanne Bull
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Brandon Benefield
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Bradley P. Knight
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Rod Passman
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - J. Andrew Wasserstrom
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | | | - Rishi Arora
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
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14
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Regulation of cardiovascular calcium channel activity by post-translational modifications or interacting proteins. Pflugers Arch 2020; 472:653-667. [PMID: 32435990 DOI: 10.1007/s00424-020-02398-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023]
Abstract
Voltage-gated calcium channels are the major pathway for Ca2+ influx to initiate the contraction of smooth and cardiac muscles. Alterations of calcium channel function have been implicated in multiple cardiovascular diseases, such as hypertension, atrial fibrillation, and long QT syndrome. Post-translational modifications do expand cardiovascular calcium channel structure and function to affect processes such as channel trafficking or polyubiquitination by two E3 ubiquitin ligases, Ret finger protein 2 (Rfp2) or murine double minute 2 protein (Mdm2). Additionally, biophysical property such as Ca2+-dependent inactivation (CDI) could be altered through binding of calmodulin, or channel activity could be modulated via S-nitrosylation by nitric oxide and phosphorylation by protein kinases or by interacting protein partners, such as galectin-1 and Rem. Understanding how cardiovascular calcium channel function is post-translationally remodeled under distinctive disease conditions will provide better information about calcium channel-related disease mechanisms and improve the development of more selective therapeutic agents for cardiovascular diseases.
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15
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Molecular mechanisms by which iNOS uncoupling can induce cardiovascular dysfunction during sepsis: Role of posttranslational modifications (PTMs). Life Sci 2020; 255:117821. [PMID: 32445759 DOI: 10.1016/j.lfs.2020.117821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 01/01/2023]
Abstract
Human sepsis is the result of a multifaceted pathological process causing marked dysregulation of cardiovascular responses. A more sophisticated understanding of the pathogenesis of sepsis is certainly prerequisite. Evidence from studies provide further insight into the role of inducible nitric oxide synthase (iNOS) isoform. Results on inhibition of iNOS in sepsis models remain inconclusive. Concern has been devoted to improving our knowledge and understanding of the role of iNOS. The aim of this review is to define the role of iNOS in redox homeostasis disturbance, the detailed mechanisms linking iNOS and posttranslational modifications (PTMs) to cardiovascular dysfunctions, and their future implications in sepsis settings. Many questions related to the iNOS and PTMs still remain open, and much more work is needed on this.
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16
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Khan MS, Yamashita K, Sharma V, Ranjan R, Dosdall DJ. RNAs and Gene Expression Predicting Postoperative Atrial Fibrillation in Cardiac Surgery Patients Undergoing Coronary Artery Bypass Grafting. J Clin Med 2020; 9:jcm9041139. [PMID: 32316120 PMCID: PMC7231013 DOI: 10.3390/jcm9041139] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023] Open
Abstract
Postoperative atrial fibrillation (POAF) is linked with increased morbidity, mortality rate and financial liability. About 20–50% of patients experience POAF after coronary artery bypass graft (CABG) surgery. Numerous review articles and meta-analyses have investigated links between patient clinical risk factors, demographic conditions, and pre-, peri- and post-operative biomarkers to forecast POAF incidence in CABG patients. This narrative review, for the first time, summarize the role of micro-RNAs, circular-RNAs and other gene expressions that have shown experimental evidence to accurately predict the POAF incidence in cardiac surgery patients after CABG. We envisage that identifying specific genomic markers for predicting POAF might be a significant step for the prevention and effective management of this type of post-operative complication and may provide critical perspective into arrhythmogenic substrate responsible for POAF.
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Affiliation(s)
- Muhammad Shuja Khan
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT 84112, USA; (M.S.K.); (K.Y.); (R.R.)
| | - Kennosuke Yamashita
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT 84112, USA; (M.S.K.); (K.Y.); (R.R.)
- Division of Cardiovascular Medicine, The University of Utah-Health, Salt Lake City, UT 84132, USA
| | - Vikas Sharma
- Division of Cardiothoracic Surgery, The University of Utah-Health, Salt Lake City, UT 84132, USA;
| | - Ravi Ranjan
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT 84112, USA; (M.S.K.); (K.Y.); (R.R.)
- Division of Cardiovascular Medicine, The University of Utah-Health, Salt Lake City, UT 84132, USA
- Department of Biomedical Engineering, The University of Utah, Salt Lake City, UT 84112, USA
| | - Derek James Dosdall
- Nora Eccles Harrison Cardiovascular Research and Training Institute, The University of Utah, Salt Lake City, UT 84112, USA; (M.S.K.); (K.Y.); (R.R.)
- Division of Cardiovascular Medicine, The University of Utah-Health, Salt Lake City, UT 84132, USA
- Division of Cardiothoracic Surgery, The University of Utah-Health, Salt Lake City, UT 84132, USA;
- Department of Biomedical Engineering, The University of Utah, Salt Lake City, UT 84112, USA
- Correspondence: ; Tel.: +1-801-587-2036
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17
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Antonopoulos AS, Goliopoulou A, Oikonomou E, Tsalamandris S, Papamikroulis GA, Lazaros G, Tsiamis E, Latsios G, Brili S, Papaioannou S, Gennimata V, Tousoulis D. Redox State in Atrial Fibrillation Pathogenesis and Relevant Therapeutic Approaches. Curr Med Chem 2019; 26:765-779. [PMID: 28721830 DOI: 10.2174/0929867324666170718130408] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/04/2016] [Accepted: 12/04/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Myocardial redox state is a critical determinant of atrial biology, regulating cardiomyocyte apoptosis, ion channel function, and cardiac hypertrophy/fibrosis and function. Nevertheless, it remains unclear whether the targeting of atrial redox state is a rational therapeutic strategy for atrial fibrillation prevention. OBJECTIVE To review the role of atrial redox state and anti-oxidant therapies in atrial fibrillation. METHOD Published literature in Medline was searched for experimental and clinical evidence linking myocardial redox state with atrial fibrillation pathogenesis as well as studies looking into the role of redoxtargeting therapies in the prevention of atrial fibrillation. RESULTS Data from animal models have shown that altered myocardial nitroso-redox balance and NADPH oxidases activity are causally involved in the pathogenesis of atrial fibrillation. Similarly experimental animal data supports that increased reactive oxygen / nitrogen species formation in the atrial tissue is associated with altered electrophysiological properties of atrial myocytes and electrical remodeling, favoring atrial fibrillation development. In humans, randomized clinical studies using redox-related therapeutic approaches (e.g. statins or antioxidant agents) have not documented any benefits in the prevention of atrial fibrillation development (mainly post-operative atrial fibrillation risk). CONCLUSION Despite strong experimental and translational data supporting the role of atrial redox state in atrial fibrillation pathogenesis, such mechanistic evidence has not been translated to clinical benefits in atrial fibrillation risk in randomized clinical studies using redox-related therapies.
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Affiliation(s)
| | | | | | | | | | - George Lazaros
- 1st Cardiology Department, Athens Medical School, Athens, Greece
| | | | - George Latsios
- 1st Cardiology Department, Athens Medical School, Athens, Greece
| | - Stella Brili
- 1st Cardiology Department, Athens Medical School, Athens, Greece
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18
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Ni H, Zhang H, Grandi E, Narayan SM, Giles WR. Transient outward K + current can strongly modulate action potential duration and initiate alternans in the human atrium. Am J Physiol Heart Circ Physiol 2018; 316:H527-H542. [PMID: 30576220 DOI: 10.1152/ajpheart.00251.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Efforts to identify the mechanisms for the initiation and maintenance of human atrial fibrillation (AF) often focus on changes in specific elements of the atrial "substrate," i.e., its electrophysiological properties and/or structural components. We used experimentally validated mathematical models of the human atrial myocyte action potential (AP), both at baseline in sinus rhythm (SR) and in the setting of chronic AF, to identify significant contributions of the Ca2+-independent transient outward K+ current ( Ito) to electrophysiological instability and arrhythmia initiation. First, we explored whether changes in the recovery or restitution of the AP duration (APD) and/or its dynamic stability (alternans) can be modulated by Ito. Recent reports have identified disease-dependent spatial differences in expression levels of the specific K+ channel α-subunits that underlie Ito in the left atrium. Therefore, we studied the functional consequences of this by deletion of 50% of native Ito (Kv4.3) and its replacement with Kv1.4. Interestingly, significant changes in the short-term stability of the human atrial AP waveform were revealed. Specifically, this K+ channel isoform switch produced discontinuities in the initial slope of the APD restitution curve and appearance of APD alternans. This pattern of in silico results resembles some of the changes observed in high-resolution clinical electrophysiological recordings. Important insights into mechanisms for these changes emerged from known biophysical properties (reactivation kinetics) of Kv1.4 versus those of Kv4.3. These results suggest new approaches for pharmacological management of AF, based on molecular properties of specific K+ isoforms and their changed expression during progressive disease. NEW & NOTEWORTHY Clinical studies identify oscillations (alternans) in action potential (AP) duration as a predictor for atrial fibrillation (AF). The abbreviated AP in AF also involves changes in K+ currents and early repolarization of the AP. Our simulations illustrate how substitution of Kv1.4 for the native current, Kv4.3, alters the AP waveform and enhances alternans. Knowledge of this "isoform switch" and related dynamics in the AF substrate may guide new approaches for detection and management of AF.
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Affiliation(s)
- Haibo Ni
- Biological Physics Group, School of Physics and Astronomy, University of Manchester , Manchester , United Kingdom.,Department of Pharmacology, University of California , Davis, California
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, University of Manchester , Manchester , United Kingdom
| | - Eleonora Grandi
- Department of Pharmacology, University of California , Davis, California
| | - Sanjiv M Narayan
- Division of Cardiology, Cardiovascular Institute, Stanford University , Stanford, California
| | - Wayne R Giles
- Faculties of Kinesiology and Medicine, University of Calgary , Calgary, Alberta , Canada
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19
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Yoo S, Aistrup G, Shiferaw Y, Ng J, Mohler PJ, Hund TJ, Waugh T, Browne S, Gussak G, Gilani M, Knight BP, Passman R, Goldberger JJ, Wasserstrom JA, Arora R. Oxidative stress creates a unique, CaMKII-mediated substrate for atrial fibrillation in heart failure. JCI Insight 2018; 3:120728. [PMID: 30385719 DOI: 10.1172/jci.insight.120728] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 09/27/2018] [Indexed: 12/31/2022] Open
Abstract
The precise mechanisms by which oxidative stress (OS) causes atrial fibrillation (AF) are not known. Since AF frequently originates in the posterior left atrium (PLA), we hypothesized that OS, via calmodulin-dependent protein kinase II (CaMKII) signaling, creates a fertile substrate in the PLA for triggered activity and reentry. In a canine heart failure (HF) model, OS generation and oxidized-CaMKII-induced (Ox-CaMKII-induced) RyR2 and Nav1.5 signaling were increased preferentially in the PLA (compared with left atrial appendage). Triggered Ca2+ waves (TCWs) in HF PLA myocytes were particularly sensitive to acute ROS inhibition. Computational modeling confirmed a direct relationship between OS/CaMKII signaling and TCW generation. CaMKII phosphorylated Nav1.5 (CaMKII-p-Nav1.5 [S571]) was located preferentially at the intercalated disc (ID), being nearly absent at the lateral membrane. Furthermore, a decrease in ankyrin-G (AnkG) in HF led to patchy dropout of CaMKII-p-Nav1.5 at the ID, causing its distribution to become spatially heterogeneous; this corresponded to preferential slowing and inhomogeneity of conduction noted in the HF PLA. Computational modeling illustrated how conduction slowing (e.g., due to increase in CaMKII-p-Nav1.5) interacts with fibrosis to cause reentry in the PLA. We conclude that OS via CaMKII leads to substrate for triggered activity and reentry in HF PLA by mechanisms independent of but complementary to fibrosis.
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Affiliation(s)
- Shin Yoo
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Gary Aistrup
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Yohannes Shiferaw
- Department of Physics, California State University, Northridge, California, USA
| | - Jason Ng
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Peter J Mohler
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Thomas J Hund
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Trent Waugh
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Suzanne Browne
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Georg Gussak
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mehul Gilani
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Bradley P Knight
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rod Passman
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Jeffrey J Goldberger
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - J Andrew Wasserstrom
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rishi Arora
- Feinberg Cardiovascular Research and Renal Institute, Northwestern University-Feinberg School of Medicine, Chicago, Illinois, USA
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20
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Lubbers ER, Price MV, Mohler PJ. Arrhythmogenic Substrates for Atrial Fibrillation in Obesity. Front Physiol 2018; 9:1482. [PMID: 30405438 PMCID: PMC6204377 DOI: 10.3389/fphys.2018.01482] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 10/01/2018] [Indexed: 12/19/2022] Open
Abstract
Global obesity rates have nearly tripled since 1975. This obesity rate increase is mirrored by increases in atrial fibrillation (AF) that now impacts nearly 10% of Americans over the age of 65. Numerous epidemiologic studies have linked incidence of AF and obesity and other obesity-related diseases, including hypertension and diabetes. Due to the wealth of epidemiologic data linking AF with obesity-related disease, mechanisms of AF pathogenesis in the context of obesity are an area of ongoing investigation. However, progress has been somewhat slowed by the complex phenotype of obesity; separating the effects of obesity from those of related sequelae is problematic. While the initiation of pathogenic pathways leading to AF varies with disease (including increased glycosylation in diabetes, increased renin angiotensin aldosterone system activation in hypertension, atrial ischemia in coronary artery disease, and sleep apnea) the pathogenesis of AF is united by shared mediators of altered conduction in the atria. We suggest focusing on these downstream mediators of AF in obesity is likely to yield more broadly applicable data. In the context of obesity, AF is driven by the interrelated processes of inflammation, atrial remodeling, and oxidative stress. Obesity is characterized by a constant low-grade inflammation that leads to increased expression of pro-inflammatory cytokines. These cytokines contribute to changes in cardiomyocyte excitability. Atrial structural remodeling, including fibrosis, enlargement, and fatty infiltration is a prominent feature of AF and contributes to the altered conduction. Finally, obesity impacts oxidative stress. Within the cardiomyocyte, oxidative stress is increased through both increased production of reactive oxygen species and by downregulation of scavenging enzymes. This increased oxidative stress modulates of cardiomyocyte excitability, increasing susceptibility to AF. Although the initiating insults vary, inflammation, atrial remodeling, and oxidative stress are conserved mechanisms in the pathophysiology of AF in the obese patients. In this review, we highlight mechanisms that have been shown to be relevant in the pathogenesis of AF across obesity-related disease.
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Affiliation(s)
- Ellen R. Lubbers
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- Medical Scientist Training Program, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Morgan V. Price
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Peter J. Mohler
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
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21
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Korantzopoulos P, Letsas K, Fragakis N, Tse G, Liu T. Oxidative stress and atrial fibrillation: an update. Free Radic Res 2018; 52:1199-1209. [PMID: 30003814 DOI: 10.1080/10715762.2018.1500696] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Atrial remodelling involves electrophysiological and structural abnormalities that promote the development and perpetuation of atrial fibrillation. Experimental and clinical data indicate that oxidative stress is implicated in the pathophysiology of atrial remodelling. The mechanistic links between atrial remodelling and oxidative stress are complex with several underlying diseases and conditions may affect these pathways. Therefore, the development of antioxidant interventions in this setting remains difficult. Besides classical antioxidant compounds, several agents with pleiotropic effects, including anti-inflammatory and antioxidant, have been tested in experimental and clinical settings with variable results. Strategies applying conventional antioxidants in specific situations such as postoperative atrial fibrillation show beneficial effects, especially the two-step regimen of antioxidants combination. Of note, there are limited data on the development of strategies that target specific sources of reactive oxygen species implicated in atrial remodelling. Lifestyle, diet, and risk factors modification is a complementary promising approach. This updated review provides a concise and critical overview of all available data regarding oxidative stress and its modulation in atrial fibrillation. Future directions on this exciting field are also discussed.
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Affiliation(s)
| | - Konstantinos Letsas
- b Second Department of Cardiology, Laboratory of Cardiac Electrophysiology , "Evangelismos" General Hospital of Athens , Athens , Greece
| | - Nikolaos Fragakis
- c Third Department of Cardiology , Hippokration Hospital, Medical School, Aristotle University of Thessaloniki , Thessaloniki , Athens , Greece
| | - Gary Tse
- d Department of Medicine and Therapeutics , Chinese University of Hong Kong , Hong Kong , P. R. China.,e Li Ka Shing Institute of Health Sciences, Faculty of Medicine , Chinese University of Hong Kong , Hong Kong , China
| | - Tong Liu
- f Department of Cardiology , Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University , Tianjin , P. R. China
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22
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Regulation of protein function by S-nitrosation and S-glutathionylation: processes and targets in cardiovascular pathophysiology. Biol Chem 2017; 398:1267-1293. [DOI: 10.1515/hsz-2017-0150] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/07/2017] [Indexed: 02/07/2023]
Abstract
AbstractDecades of chemical, biochemical and pathophysiological research have established the relevance of post-translational protein modifications induced by processes related to oxidative stress, with critical reflections on cellular signal transduction pathways. A great deal of the so-called ‘redox regulation’ of cell function is in fact mediated through reactions promoted by reactive oxygen and nitrogen species on more or less specific aminoacid residues in proteins, at various levels within the cell machinery. Modifications involving cysteine residues have received most attention, due to the critical roles they play in determining the structure/function correlates in proteins. The peculiar reactivity of these residues results in two major classes of modifications, with incorporation of NO moieties (S-nitrosation, leading to formation of proteinS-nitrosothiols) or binding of low molecular weight thiols (S-thionylation, i.e. in particularS-glutathionylation,S-cysteinylglycinylation andS-cysteinylation). A wide array of proteins have been thus analyzed in detail as far as their susceptibility to either modification or both, and the resulting functional changes have been described in a number of experimental settings. The present review aims to provide an update of available knowledge in the field, with a special focus on the respective (sometimes competing and antagonistic) roles played by proteinS-nitrosations andS-thionylations in biochemical and cellular processes specifically pertaining to pathogenesis of cardiovascular diseases.
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Valli H, Ahmad S, Chadda KR, Al-Hadithi ABAK, Grace AA, Jeevaratnam K, Huang CLH. Age-dependent atrial arrhythmic phenotype secondary to mitochondrial dysfunction in Pgc-1β deficient murine hearts. Mech Ageing Dev 2017; 167:30-45. [PMID: 28919427 PMCID: PMC5652526 DOI: 10.1016/j.mad.2017.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/24/2017] [Accepted: 09/13/2017] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Ageing and several age-related chronic conditions including obesity, insulin resistance and hypertension are associated with mitochondrial dysfunction and represent independent risk factors for atrial fibrillation (AF). MATERIALS AND METHODS Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts modeling age-dependent chronic mitochondrial dysfunction during regular pacing and programmed electrical stimulation (PES). RESULTS AND DISCUSSION The Pgc-1β-/- genotype was associated with a pro-arrhythmic phenotype progressing with age. Young and aged Pgc-1β-/- hearts showed compromised maximum action potential (AP) depolarization rates, (dV/dt)max, prolonged AP latencies reflecting slowed action potential (AP) conduction, similar effective refractory periods and baseline action potential durations (APD90) but shortened APD90 in APs in response to extrasystolic stimuli at short stimulation intervals. Electrical properties of APs triggering arrhythmia were similar in WT and Pgc-1β-/- hearts. Pgc-1β-/- hearts showed accelerated age-dependent fibrotic change relative to WT, with young Pgc-1β-/- hearts displaying similar fibrotic change as aged WT, and aged Pgc-1β-/- hearts the greatest fibrotic change. Mitochondrial deficits thus result in an arrhythmic substrate, through slowed AP conduction and altered repolarisation characteristics, arising from alterations in electrophysiological properties and accelerated structural change.
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Affiliation(s)
- Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Karan R Chadda
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom; Faculty of Health and Medical Sciences, University of Surrey, GU2 7AL, Guildford, Surrey, United Kingdom
| | - Ali B A K Al-Hadithi
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Kamalan Jeevaratnam
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom; Faculty of Health and Medical Sciences, University of Surrey, GU2 7AL, Guildford, Surrey, United Kingdom; PU-RCSI School of Medicine, Perdana University, 43400, Serdang, Selangor Darul Ehsan, Malaysia
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, United Kingdom; Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom.
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24
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Samman Tahhan A, Sandesara PB, Hayek SS, Alkhoder A, Chivukula K, Hammadah M, Mohamed-Kelli H, O'Neal WT, Topel M, Ghasemzadeh N, Ko YA, Aida H, Gafeer M, Sperling L, Vaccarino V, Liang Y, Jones DP, Quyyumi AA. Association between oxidative stress and atrial fibrillation. Heart Rhythm 2017; 14:1849-1855. [PMID: 28757307 DOI: 10.1016/j.hrthm.2017.07.028] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND Oxidative stress (OS) may be a key mechanism underlying the development of atrial fibrillation (AF) in experimental studies, but data in humans remain limited. OBJECTIVE Systemic OS can be estimated by measurements of circulating levels of the aminothiols including glutathione, cysteine, and their oxidized products. We tested the hypothesis that the redox potentials of glutathione (EhGSH) and cysteine will be associated with prevalent and incident AF. METHODS Plasma levels of aminothiols were measured in 1439 patients undergoing coronary angiography, of whom 148 (10.3%) had a diagnosis of AF. After a median follow-up of 6.3 years, 104 of 917 patients (11.5%) developed incident AF. Multivariate logistic regression and Cox regression models were used to determine whether OS markers were independent predictors of prevalent and incident AF after adjustment for traditional risk factors, heart failure, coronary artery disease, and high-sensitivity C-reactive protein level. RESULTS For each 10% increase in EhGSH, the odds of prevalent AF was 30% higher (odds ratio [OR] 1.3; 95% confidence interval [CI] 1.1-1.7; P = .02) and 90% higher (OR 1.9; 95% CI 1.3-2.7; P = .004) when the median was used as a cutoff. The EhGSH level above the median was more predictive of chronic AF (OR 4.0; 95% CI 1.3-12.9; P = .01) than of paroxysmal AF (OR 1.7; 95% CI 1.1-2.7; P = .03). Each 10% increase in EhGSH level was associated with a 40% increase in the risk of incident AF (hazard ratio 1.4; 95% CI 1.1-1.7; P = .01). CONCLUSION Increased OS measured by the redox potentials of glutathione is associated with prevalent and incident AF. Therapies that modulate OS need to be investigated to treat and prevent AF.
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Affiliation(s)
- Ayman Samman Tahhan
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Pratik B Sandesara
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Salim S Hayek
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Ayman Alkhoder
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Kaavya Chivukula
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Muhammad Hammadah
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Heval Mohamed-Kelli
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Wesley T O'Neal
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Matthew Topel
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Nima Ghasemzadeh
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Yi-An Ko
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Hiroshi Aida
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Mazen Gafeer
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Laurence Sperling
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia
| | - Viola Vaccarino
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Yongliang Liang
- Division of Pulmonary, Allergy and Critical Care Medicine, Clinical Biomarkers Laboratory, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Dean P Jones
- Division of Pulmonary, Allergy and Critical Care Medicine, Clinical Biomarkers Laboratory, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Arshed A Quyyumi
- Division of Cardiology, Emory University School of Medicine, Emory Clinical Cardiovascular Research Institute, Atlanta, Georgia.
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Bond RC, Bryant SM, Watson JJ, Hancox JC, Orchard CH, James AF. Reduced density and altered regulation of rat atrial L-type Ca 2+ current in heart failure. Am J Physiol Heart Circ Physiol 2017; 312:H384-H391. [PMID: 27923791 PMCID: PMC5402008 DOI: 10.1152/ajpheart.00528.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 11/21/2016] [Accepted: 11/23/2016] [Indexed: 11/22/2022]
Abstract
Constitutive regulation by PKA has recently been shown to contribute to L-type Ca2+ current (ICaL) at the ventricular t-tubule in heart failure. Conversely, reduction in constitutive regulation by PKA has been proposed to underlie the downregulation of atrial ICaL in heart failure. The hypothesis that downregulation of atrial ICaL in heart failure involves reduced channel phosphorylation was examined. Anesthetized adult male Wistar rats underwent surgical coronary artery ligation (CAL, N=10) or equivalent sham-operation (Sham, N=12). Left atrial myocytes were isolated ~18 wk postsurgery and whole cell currents recorded (holding potential=-80 mV). ICaL activated by depolarizing pulses to voltages from -40 to +50 mV were normalized to cell capacitance and current density-voltage relations plotted. CAL cell capacitances were ~1.67-fold greater than Sham (P ≤ 0.0001). Maximal ICaL conductance (Gmax ) was downregulated more than 2-fold in CAL vs. Sham myocytes (P < 0.0001). Norepinephrine (1 μmol/l) increased Gmax >50% more effectively in CAL than in Sham so that differences in ICaL density were abolished. Differences between CAL and Sham Gmax were not abolished by calyculin A (100 nmol/l), suggesting that increased protein dephosphorylation did not account for ICaL downregulation. Treatment with either H-89 (10 μmol/l) or AIP (5 μmol/l) had no effect on basal currents in Sham or CAL myocytes, indicating that, in contrast to ventricular myocytes, neither PKA nor CaMKII regulated basal ICaL Expression of the L-type α1C-subunit, protein phosphatases 1 and 2A, and inhibitor-1 proteins was unchanged. In conclusion, reduction in PKA-dependent regulation did not contribute to downregulation of atrial ICaL in heart failure.NEW & NOTEWORTHY Whole cell recording of L-type Ca2+ currents in atrial myocytes from rat hearts subjected to coronary artery ligation compared with those from sham-operated controls reveals marked reduction in current density in heart failure without change in channel subunit expression and associated with altered phosphorylation independent of protein kinase A.
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Affiliation(s)
- Richard C Bond
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Simon M Bryant
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Judy J Watson
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Jules C Hancox
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Clive H Orchard
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Andrew F James
- Cardiovascular Research Laboratories, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
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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.
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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.
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Abstract
Atrial fibrillation (AF) is an extremely prevalent arrhythmia that presents a wide range of therapeutic challenges. AF usually begins in a self-terminating paroxysmal form (pAF). With time, the AF pattern often evolves to become persistent (nonterminating within 7 days). Important differences exist between pAF and persistent AF in terms of clinical features, in particular the responsiveness to antiarrhythmic drugs and ablation therapy. AF mechanisms have been extensively reviewed, but few or no Reviews focus specifically on the pathophysiology of pAF. Accordingly, in this Review, we examine the available data on the electrophysiological basis for pAF occurrence and maintenance, as well as the molecular mechanisms forming the underlying substrate. We first consider the mechanistic insights that have been obtained from clinical studies in the electrophysiology laboratory, noninvasive observations, and genetic studies. We then discuss the information about underlying molecular mechanisms that has been obtained from experimental studies on animal models and patient samples. Finally, we discuss the data available from animal models with spontaneous AF presentation, their relationship to clinical findings, and their relevance to understanding the mechanisms underlying pAF. Our analysis then turns to potential factors governing cases of progression from pAF to persistent AF and the clinical implications of the basic mechanisms we review. We conclude by identifying and discussing questions that we consider particularly important to address through future research in this area.
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28
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Kertai MD, Qi W, Li YJ, Lombard FW, Liu Y, Smith MP, Stafford-Smith M, Newman MF, Milano CA, Mathew JP, Podgoreanu MV. Gene signatures of postoperative atrial fibrillation in atrial tissue after coronary artery bypass grafting surgery in patients receiving β-blockers. J Mol Cell Cardiol 2016; 92:109-15. [PMID: 26860460 PMCID: PMC4967350 DOI: 10.1016/j.yjmcc.2016.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/30/2016] [Accepted: 02/05/2016] [Indexed: 02/04/2023]
Abstract
Atrial tissue gene expression profiling may help to determine how differentially expressed genes in the human atrium before cardiopulmonary bypass (CPB) are related to subsequent biologic pathway activation patterns, and whether specific expression profiles are associated with an increased risk for postoperative atrial fibrillation (AF) or altered response to β-blocker (BB) therapy after coronary artery bypass grafting (CABG) surgery. Right atrial appendage (RAA) samples were collected from 45 patients who were receiving perioperative BB treatment, and underwent CABG surgery. The isolated RNA samples were used for microarray gene expression analysis, to identify probes that were expressed differently in patients with and without postoperative AF. Gene expression analysis was performed to identify probes that were expressed differently in patients with and without postoperative AF. Gene set enrichment analysis (GSEA) was performed to determine how sets of genes might be systematically altered in patients with postoperative AF. Of the 45 patients studied, genomic DNA from 42 patients was used for target sequencing of 66 candidate genes potentially associated with AF, and 2,144 single-nucleotide polymorphisms (SNPs) were identified. We then performed expression quantitative trait loci (eQTL) analysis to determine the correlation between SNPs identified in the genotyped patients, and RAA expression. Probes that met a false discovery rate<0.25 were selected for eQTL analysis. Of the 17,678 gene expression probes analyzed, 2 probes met our prespecified significance threshold of false discovery rate<0.25. The most significant probe corresponded to vesicular overexpressed in cancer - prosurvival protein 1 gene (VOPP1; 1.83 fold change; P=3.47×10(-7)), and was up-regulated in patients with postoperative AF, whereas the second most significant probe, which corresponded to the LOC389286 gene (0.49 fold change; P=1.54×10(-5)), was down-regulated in patients with postoperative AF. GSEA highlighted the role of VOPP1 in pathways with biologic relevance to myocardial homeostasis, and oxidative stress and redox modulation. Candidate gene eQTL showed a trans-acting association between variants of G protein-coupled receptor kinase 5 gene, previously linked to altered BB response, and high expression of VOPP1. In patients undergoing CABG surgery, RAA gene expression profiling, and pathway and eQTL analysis suggested that VOPP1 plays a novel etiological role in postoperative AF despite perioperative BB therapy.
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Affiliation(s)
- Miklos D Kertai
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA.
| | - Wenjing Qi
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA
| | - Yi-Ju Li
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA; Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Frederick W Lombard
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912
| | - Michael P Smith
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
| | - Mark Stafford-Smith
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
| | - Mark F Newman
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
| | - Carmelo A Milano
- Department of Surgery, Division of Cardiothoracic Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Joseph P Mathew
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
| | - Mihai V Podgoreanu
- Department of Anesthesiology, Duke Perioperative Genomics Program, Duke University Medical Center, Durham, NC 27710, USA
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29
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Simon JN, Ziberna K, Casadei B. Compromised redox homeostasis, altered nitroso-redox balance, and therapeutic possibilities in atrial fibrillation. Cardiovasc Res 2016; 109:510-8. [PMID: 26786158 PMCID: PMC4777914 DOI: 10.1093/cvr/cvw012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/15/2016] [Indexed: 12/31/2022] Open
Abstract
Although the initiation, development, and maintenance of atrial fibrillation (AF) have been linked to alterations in myocyte redox state, the field lacks a complete understanding of the impact these changes may have on cellular signalling, atrial electrophysiology, and disease progression. Recent studies demonstrate spatiotemporal changes in reactive oxygen species production shortly after the induction of AF in animal models with an uncoupling of nitric oxide synthase activity ensuing in the presence of long-standing persistent AF, ultimately leading to a major shift in nitroso–redox balance. However, it remains unclear which radical or non-radical species are primarily involved in the underlying mechanisms of AF or which proteins are targeted for redox modification. In most instances, only free radical oxygen species have been assessed; yet evidence from the redox signalling field suggests that non-radical species are more likely to regulate cellular processes. A wider appreciation for the distinction of these species and how both species may be involved in the development and maintenance of AF could impact treatment strategies. In this review, we summarize how redox second-messenger systems are regulated and discuss the recent evidence for alterations in redox regulation in the atrial myocardium in the presence of AF, while identifying some critical missing links. We also examine studies looking at antioxidants for the prevention and treatment of AF and propose alternative redox targets that may serve as superior therapeutic options for the treatment of AF.
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Affiliation(s)
- Jillian N Simon
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Klemen Ziberna
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Barbara Casadei
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
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30
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Frolov RV, Weckström M. Harnessing the Flow of Excitation: TRP, Voltage-Gated Na(+), and Voltage-Gated Ca(2+) Channels in Contemporary Medicine. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 103:25-95. [PMID: 26920687 DOI: 10.1016/bs.apcsb.2015.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cellular signaling in both excitable and nonexcitable cells involves several classes of ion channels. Some of them are of minor importance, with very specialized roles in physiology, but here we concentrate on three major channel classes: TRP (transient receptor potential channels), voltage-gated sodium channels (Nav), and voltage-gated calcium channels (Cav). Here, we first propose a conceptual framework binding together all three classes of ion channels, a "flow-of-excitation model" that takes into account the inputs mediated by TRP and other similar channels, the outputs invariably provided by Cav channels, and the regenerative transmission of signals in the neural networks, for which Nav channels are responsible. We use this framework to examine the function, structure, and pharmacology of these channel classes both at cellular and also at whole-body physiological level. Building on that basis we go through the pathologies arising from the direct or indirect malfunction of the channels, utilizing ion channel defects, the channelopathies. The pharmacological interventions affecting these channels are numerous. Part of those are well-established treatments, like treatment of hypertension or some forms of epilepsy, but many other are deeply problematic due to poor drug specificity, ion channel diversity, and widespread expression of the channels in tissues other than those actually targeted.
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Affiliation(s)
- Roman V Frolov
- Division of Biophysics, Department of Physics, University of Oulu, Oulun Yliopisto, Finland.
| | - Matti Weckström
- Division of Biophysics, Department of Physics, University of Oulu, Oulun Yliopisto, Finland
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31
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Herraiz-Martínez A, Álvarez-García J, Llach A, Molina CE, Fernandes J, Ferrero-Gregori A, Rodríguez C, Vallmitjana A, Benítez R, Padró JM, Martínez-González J, Cinca J, Hove-Madsen L. Ageing is associated with deterioration of calcium homeostasis in isolated human right atrial myocytes. Cardiovasc Res 2015; 106:76-86. [PMID: 25712961 PMCID: PMC4362404 DOI: 10.1093/cvr/cvv046] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Aims Ageing-related cardiac disorders such as heart failure and atrial fibrillation often present with intracellular calcium homeostasis dysfunction. However, knowledge of the intrinsic effects of ageing on cellular calcium handling in the human heart is sparse. Therefore, this study aimed to analyse how ageing affects key mechanisms that regulate intracellular calcium in human atrial myocytes. Methods and results Whole membrane currents and intracellular calcium transients were measured in isolated human right atrial myocytes from 80 patients with normal left atrial dimensions and no history of atrial fibrillation. Patients were categorized as young (<55 years, n = 21), middle aged (55–74 years, n = 42), and old (≥75 years, n = 17). Protein levels were determined by western blot. Ageing was associated with the following electrophysiological changes: (i) a 3.2-fold decrease in the calcium transient (P < 0.01); (ii) reduction of the L-type calcium current (ICa) amplitude (2.4 ± 0.3 pA/pF vs. 1.4 ± 0.2 pA/pF, P < 0.01); (iii) lower levels of L-type calcium channel alpha-subunit (P < 0.05); (iv) lower rates of both fast (14.5 ± 0.9 ms vs. 20.9 ± 1.9, P < 0.01) and slow (73 ± 3 vs. 120 ± 12 ms, P < 0.001) ICa inactivation; and (v) a decrease in the sarcoplasmic reticulum calcium content (10.1 ± 0.8 vs. 6.4 ± 0.6 amol/pF, P < 0.005) associated with a significant decrease in both SERCA2 (P < 0.05) and calsequestrin-2 (P < 0.05) protein levels. In contrast, ageing did not affect spontaneous sarcoplasmic reticulum calcium release. Conclusion Ageing is associated with depression of SR calcium content, L-type calcium current, and calcium transient amplitude that may favour a progressive decline in right atrial contractile function with age.
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Affiliation(s)
- Adela Herraiz-Martínez
- Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain
| | - Jesus Álvarez-García
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Anna Llach
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Cristina E Molina
- Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain
| | - Jacqueline Fernandes
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Andreu Ferrero-Gregori
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Cristina Rodríguez
- Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain
| | - Alexander Vallmitjana
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Raúl Benítez
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Josep M Padró
- Department of Cardiac Surgery, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain
| | - José Martínez-González
- Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain
| | - Juan Cinca
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Leif Hove-Madsen
- Cardiovascular Research Centre CSIC-ICCC and IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, St Antoni Mª Claret 167, Barcelona 08025, Spain
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Deshmukh A, Barnard J, Sun H, Newton D, Castel L, Pettersson G, Johnston D, Roselli E, Gillinov AM, McCurry K, Moravec C, Smith JD, Van Wagoner DR, Chung MK. Left atrial transcriptional changes associated with atrial fibrillation susceptibility and persistence. Circ Arrhythm Electrophysiol 2014; 8:32-41. [PMID: 25523945 DOI: 10.1161/circep.114.001632] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Prior transcriptional studies of atrial fibrillation (AF) have been limited to specific transcripts, animal models, chronic AF, right atria, or small samples. We sought to characterize the left atrial transcriptome in human AF to distinguish changes related to AF susceptibility and persistence. METHODS AND RESULTS Left atrial appendages from 239 patients stratified by coronary artery disease, valve disease, and AF history (no history of AF, AF history in sinus rhythm at surgery, and AF history in AF at surgery) were selected for genome-wide mRNA microarray profiling. Transcripts were examined for differential expression with AF phenotype group. Enrichment in differentially expressed genes was examined in 3 gene set collections: a transcription factor collection, defined by shared conserved cis-regulatory motifs, a miRNA collection, defined by shared 3' untranslated region motifs, and a molecular function collection, defined by shared Gene Ontology molecular function. AF susceptibility was associated with decreased expression of the targets of CREB/ATF family, heat-shock factor 1, ATF6, SRF, and E2F1 transcription factors. Persistent AF activity was associated with decreased expression in genes and gene sets related to ion channel function consistent with reported functional changes. CONCLUSIONS AF susceptibility was associated with decreased expression of targets of several transcription factors related to inflammation, oxidation, and cellular stress responses. In contrast, changes in ion channel expression were associated with AF activity but were limited in AF susceptibility. Our results suggest that significant transcriptional remodeling marks susceptibility to AF, whereas remodeling of ion channel expression occurs later in the progression or as a consequence of AF.
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Affiliation(s)
- Amrish Deshmukh
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - John Barnard
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Han Sun
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - David Newton
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Laurie Castel
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Gosta Pettersson
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Douglas Johnston
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Eric Roselli
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - A Marc Gillinov
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Kenneth McCurry
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Christine Moravec
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Jonathan D Smith
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - David R Van Wagoner
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.)
| | - Mina K Chung
- From the Department of Medicine, University of Chicago, IL (A.D.); Department of Quantitative Health Sciences (J.B; H.S.), Department of Molecular Cardiology (L.C., D.R.V.W., M.K.C.), and Department of Cellular and Molecular Medicine, Cleveland Clinic (J.D.S.), Lerner Research Institute, OH; Department of Cardiovascular Medicine (D.N., C.M., J.D.S., M.K.C.) and Department of Cardiovascular Medicine and Thoracic and Cardiovascular Surgery (G.P., D.J., E.R., A.M.G., K.M.), Heart and Vascular Institute, Cleveland, OH; and Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (C.M., J.D.S., D.R.V.W., M.K.C.).
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Wolke C, Bukowska A, Goette A, Lendeckel U. Redox control of cardiac remodeling in atrial fibrillation. Biochim Biophys Acta Gen Subj 2014; 1850:1555-65. [PMID: 25513966 DOI: 10.1016/j.bbagen.2014.12.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/04/2014] [Accepted: 12/09/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a potential cause of thromboembolic events. AF induces significant changes in the electrophysiological properties of atrial myocytes and causes alterations in the structure, metabolism, and function of the atrial tissue. The molecular basis for the development of structural atrial remodeling of fibrillating human atria is still not fully understood. However, increased production of reactive oxygen or nitrogen species (ROS/RNS) and the activation of specific redox-sensitive signaling pathways observed both in patients with and animal models of AF are supposed to contribute to development, progression and self-perpetuation of AF. SCOPE OF REVIEW The present review summarizes the sources and targets of ROS/RNS in the setting of AF and focuses on key redox-sensitive signaling pathways that are implicated in the pathogenesis of AF and function either to aggravate or protect from disease. MAJOR CONCLUSIONS NADPH oxidases and various mitochondrial monooxygenases are major sources of ROS during AF. Besides direct oxidative modification of e.g. ion channels and ion handling proteins that are crucially involved in action potential generation and duration, AF leads to the reversible activation of redox-sensitive signaling pathways mediated by activation of redox-regulated proteins including Nrf2, NF-κB, and CaMKII. Both processes are recognized to contribute to the formation of a substrate for AF and, thus, to increase AF inducibility and duration. GENERAL SIGNIFICANCE AF is a prevalent disease and due to the current demographic developments its socio-economic relevance will further increase. Improving our understanding of the role that ROS and redox-related (patho)-mechanisms play in the development and progression of AF may allow the development of a targeted therapy for AF that surpasses the efficacy of previous general anti-oxidative strategies. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation.
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Affiliation(s)
- Carmen Wolke
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, D-17487 Greifswald, Germany
| | - Alicja Bukowska
- EUTRAF Working Group: Molecular Electrophysiology, University Hospital Magdeburg, D-39120 Magdeburg, Germany
| | - Andreas Goette
- EUTRAF Working Group: Molecular Electrophysiology, University Hospital Magdeburg, D-39120 Magdeburg, Germany; Department of Cardiology and Intensive Care Medicine, St. Vincenz-Hospital, D-33098 Paderborn, Germany
| | - Uwe Lendeckel
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, D-17487 Greifswald, Germany.
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Heijman J, Voigt N, Nattel S, Dobrev D. Cellular and molecular electrophysiology of atrial fibrillation initiation, maintenance, and progression. Circ Res 2014; 114:1483-99. [PMID: 24763466 DOI: 10.1161/circresaha.114.302226] [Citation(s) in RCA: 472] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common clinically relevant arrhythmia and is associated with increased morbidity and mortality. The incidence of AF is expected to continue to rise with the aging of the population. AF is generally considered to be a progressive condition, occurring first in a paroxysmal form, then in persistent, and then long-standing persistent (chronic or permanent) forms. However, not all patients go through every phase, and the time spent in each can vary widely. Research over the past decades has identified a multitude of pathophysiological processes contributing to the initiation, maintenance, and progression of AF. However, many aspects of AF pathophysiology remain incompletely understood. In this review, we discuss the cellular and molecular electrophysiology of AF initiation, maintenance, and progression, predominantly based on recent data obtained in human tissue and animal models. The central role of Ca(2+)-handling abnormalities in both focal ectopic activity and AF substrate progression is discussed, along with the underlying molecular basis. We also deal with the ionic determinants that govern AF initiation and maintenance, as well as the structural remodeling that stabilizes AF-maintaining re-entrant mechanisms and finally makes the arrhythmia refractory to therapy. In addition, we highlight important gaps in our current understanding, particularly with respect to the translation of these concepts to the clinical setting. Ultimately, a comprehensive understanding of AF pathophysiology is expected to foster the development of improved pharmacological and nonpharmacological therapeutic approaches and to greatly improve clinical management.
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Affiliation(s)
- Jordi Heijman
- From the Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany (J.H., N.V., D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (S.N.); and Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (S.N.)
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Simon JN, Duglan D, Casadei B, Carnicer R. Nitric oxide synthase regulation of cardiac excitation-contraction coupling in health and disease. J Mol Cell Cardiol 2014; 73:80-91. [PMID: 24631761 DOI: 10.1016/j.yjmcc.2014.03.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 02/07/2023]
Abstract
Significant advances in our understanding of the ability of nitric oxide synthases (NOS) to modulate cardiac function have provided key insights into the role NOS play in the regulation of excitation-contraction (EC) coupling in health and disease. Through both cGMP-dependent and cGMP-independent (e.g. S-nitrosylation) mechanisms, NOS have the ability to alter intracellular Ca(2+) handling and the myofilament response to Ca(2+), thereby impacting the systolic and diastolic performance of the myocardium. Findings from experiments using nitric oxide (NO) donors and NOS inhibition or gene deletion clearly implicate dysfunctional NOS as a critical contributor to many cardiovascular disease states. However, studies to date have only partially addressed NOS isoform-specific effects and, more importantly, how subcellular localization of NOS influences ion channels involved in myocardial EC coupling and excitability. In this review, we focus on the contribution of each NOS isoform to cardiac dysfunction and on the role of uncoupled NOS activity in common cardiac disease states, including heart failure, diabetic cardiomyopathy, ischemia/reperfusion injury and atrial fibrillation. We also review evidence that clearly indicates the importance of NO in cardioprotection. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".
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Affiliation(s)
- Jillian N Simon
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Drew Duglan
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Barbara Casadei
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Ricardo Carnicer
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK.
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Rozmaritsa N, Christ T, Van Wagoner DR, Haase H, Stasch JP, Matschke K, Ravens U. Attenuated response of L-type calcium current to nitric oxide in atrial fibrillation. Cardiovasc Res 2013; 101:533-42. [PMID: 24336332 DOI: 10.1093/cvr/cvt334] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
AIM Nitric oxide (NO) synthesized by cardiomyocytes plays an important role in the regulation of cardiac function. Here, we studied the impact of NO signalling on calcium influx in human right atrial myocytes and its relation to atrial fibrillation (AF). METHODS AND RESULTS Right atrial appendages (RAAs) were obtained from patients in sinus rhythm (SR) and AF. The biotin-switch technique was used to evaluate endogenous S-nitrosylation of the α1C subunit of L-type calcium channels. Comparing SR to AF, S-nitrosylation of Ca(2+) channels was similar. Direct effects of the NO donor S-nitroso-N-acetyl-penicillamine (SNAP) on L-type calcium current (ICa,L) were studied in cardiomyocytes with standard voltage-clamp techniques. In SR, ICa,L increased with SNAP (100 µM) by 48%, n/N = 117/56, P < 0.001. The SNAP effect on ICa,L involved activation of soluble guanylate cyclase and protein kinase A. Specific inhibition of phosphodiesterase (PDE)3 with cilostamide (1 µM) enhanced ICa,L to a similar extent as SNAP. However, when cAMP was elevated by PDE3 inhibition or β-adrenoceptor stimulation, SNAP reduced ICa,L, pointing to cGMP-cAMP cross-regulation. In AF, the stimulatory effect of SNAP on ICa,L was attenuated, while its inhibitory effect on isoprenaline- or cilostamide-stimulated current was preserved. cGMP elevation with SNAP was comparable between the SR and AF group. Moreover, the expression of PDE3 and soluble guanylate cyclase was not reduced in AF. CONCLUSION NO exerts dual effects on ICa,L in SR with an increase of basal and inhibition of cAMP-stimulated current, and in AF NO inhibits only stimulated ICa,L. We conclude that in AF, cGMP regulation of PDE2 is preserved, but regulation of PDE3 is lost.
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Affiliation(s)
- Nadiia Rozmaritsa
- Department of Pharmacology and Toxicology, Dresden University of Technology, Dresden, Germany
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Castillo RL, Arias C, Farías JG. Omega 3 chronic supplementation attenuates myocardial ischaemia-reperfusion injury through reinforcement of antioxidant defense system in rats. Cell Biochem Funct 2013; 32:274-81. [DOI: 10.1002/cbf.3012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/24/2013] [Accepted: 10/02/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Rodrigo L. Castillo
- Pathophysiology Program, Biomedical Sciences Institute, Faculty of Medicine; Universidad de Chile; Santiago Chile
| | - Consuelo Arias
- Departamento de Ingeniería Química, Facultad de Ingeniería y Ciencias; Universidad de la Frontera; Temuco Chile
| | - Jorge G. Farías
- Departamento de Ingeniería Química, Facultad de Ingeniería y Ciencias; Universidad de la Frontera; Temuco Chile
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Purohit A, Rokita AG, Guan X, Chen B, Koval OM, Voigt N, Neef S, Sowa T, Gao Z, Luczak ED, Stefansdottir H, Behunin AC, Li N, El-Accaoui RN, Yang B, Swaminathan PD, Weiss RM, Wehrens XHT, Song LS, Dobrev D, Maier LS, Anderson ME. Oxidized Ca(2+)/calmodulin-dependent protein kinase II triggers atrial fibrillation. Circulation 2013; 128:1748-57. [PMID: 24030498 DOI: 10.1161/circulationaha.113.003313] [Citation(s) in RCA: 233] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is a growing public health problem without adequate therapies. Angiotensin II and reactive oxygen species are validated risk factors for AF in patients, but the molecular pathways connecting reactive oxygen species and AF are unknown. The Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) has recently emerged as a reactive oxygen species-activated proarrhythmic signal, so we hypothesized that oxidized CaMKIIδ could contribute to AF. METHODS AND RESULTS We found that oxidized CaMKII was increased in atria from AF patients compared with patients in sinus rhythm and from mice infused with angiotensin II compared with mice infused with saline. Angiotensin II-treated mice had increased susceptibility to AF compared with saline-treated wild-type mice, establishing angiotensin II as a risk factor for AF in mice. Knock-in mice lacking critical oxidation sites in CaMKIIδ (MM-VV) and mice with myocardium-restricted transgenic overexpression of methionine sulfoxide reductase A, an enzyme that reduces oxidized CaMKII, were resistant to AF induction after angiotensin II infusion. CONCLUSIONS Our studies suggest that CaMKII is a molecular signal that couples increased reactive oxygen species with AF and that therapeutic strategies to decrease oxidized CaMKII may prevent or reduce AF.
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Affiliation(s)
- Anil Purohit
- Department of Internal Medicine, Division of Cardiovascular Medicine and Cardiovascular Research Center, Carver College of Medicine (A.P., A.G.R., X.G., B.C., O.M.K., Z.G., E.D.L., H.S., A.C.B., R.N.E.-A., P.D.S., R.M.W., L.-S.S., M.E.A.), Department of Obstetrics and Gynecology (B.Y.), and Department of Molecular Physiology and Biophysics (M.E.A.), University of Iowa, Iowa City; Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany, and Division of Experimental Cardiology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany (N.V., D.D.); Cardiology and Pneumology, German Heart Center, University Hospital Goettingen, Goettingen, Germany (S.N., T.S., L.S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (N.L., X.H.T.W.)
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Redpath CJ, Bou Khalil M, Drozdzal G, Radisic M, McBride HM. Mitochondrial hyperfusion during oxidative stress is coupled to a dysregulation in calcium handling within a C2C12 cell model. PLoS One 2013; 8:e69165. [PMID: 23861961 PMCID: PMC3704522 DOI: 10.1371/journal.pone.0069165] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 06/11/2013] [Indexed: 01/04/2023] Open
Abstract
Atrial Fibrillation is the most common sustained cardiac arrhythmia worldwide harming millions of people every year. Atrial Fibrillation (AF) abruptly induces rapid conduction between atrial myocytes which is associated with oxidative stress and abnormal calcium handling. Unfortunately this new equilibrium promotes perpetuation of the arrhythmia. Recently, in addition to being the major source of oxidative stress within cells, mitochondria have been observed to fuse, forming mitochondrial networks and attach to intracellular calcium stores in response to cellular stress. We sought to identify a potential role for rapid stimulation, oxidative stress and mitochondrial hyperfusion in acute changes to myocyte calcium handling. In addition we hoped to link altered calcium handling to increased sarcoplasmic reticulum (SR)-mitochondrial contacts, the so-called mitochondrial associated membrane (MAM). We selected the C2C12 murine myotube model as it has previously been successfully used to investigate mitochondrial dynamics and has a myofibrillar system similar to atrial myocytes. We observed that rapid stimulation of C2C12 cells resulted in mitochondrial hyperfusion and increased mitochondrial colocalisation with calcium stores. Inhibition of mitochondrial fission by transfection of mutant DRP1K38E resulted in similar effects on mitochondrial fusion, SR colocalisation and altered calcium handling. Interestingly the effects of 'forced fusion' were reversed by co-incubation with the reducing agent N-Acetyl cysteine (NAC). Subsequently we demonstrated that oxidative stress resulted in similar reversible increases in mitochondrial fusion, SR-colocalisation and altered calcium handling. Finally, we believe we have identified that myocyte calcium handling is reliant on baseline levels of reactive oxygen species as co-incubation with NAC both reversed and retarded myocyte response to caffeine induced calcium release and re-uptake. Based on these results we conclude that the coordinate regulation of mitochondrial fusion and MAM contacts may form a point source for stress-induced arrhythmogenesis. We believe that the MAM merits further investigation as a therapeutic target in AF-induced remodelling.
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Affiliation(s)
- Calum J Redpath
- Cellular Electrophysiology Laboratory, University of Ottawa Heart Institute, University of Ottawa, Ottawa, ON, Canada.
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Methods for detection and characterization of protein S-nitrosylation. Methods 2013; 62:138-50. [PMID: 23628946 DOI: 10.1016/j.ymeth.2013.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 04/15/2013] [Accepted: 04/18/2013] [Indexed: 11/24/2022] Open
Abstract
Reversible protein S-nitrosylation, defined as the covalent addition of a nitroso moiety to the reactive thiol group on a cysteine residue, has received increasing recognition as a critical post-translational modification that exerts ubiquitous influence in a wide range of cellular pathways and physiological processes. Due to the lability of the S-NO bond, which is a dynamic modification, and the low abundance of endogenously S-nitrosylated proteins in vivo, unambiguous identification of S-nitrosylated proteins and S-nitrosylation sites remains methodologically challenging. In this review, we summarize recent advancements and the use of state-of-art approaches for the enrichment, systematic identification and quantitation of S-nitrosylation protein targets and their modification sites at the S-nitrosoproteome scale. These advancements have facilitated the global identification of >3000 S-nitrosylated proteins that are associated with wide range of human diseases. These strategies hold promise to site-specifically unravel potential molecular targets and to change S-nitrosylation-based pathophysiology, which may further the understanding of the potential role of S-nitrosylation in diseases.
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Ozaydin M, Icli A, Yucel H, Akcay S, Peker O, Erdogan D, Varol E, Dogan A, Okutan H. Metoprolol vs. carvedilol or carvedilol plus N-acetyl cysteine on post-operative atrial fibrillation: a randomized, double-blind, placebo-controlled study. Eur Heart J 2013; 34:597-604. [DOI: 10.1093/eurheartj/ehs423] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Abstract
Reactive oxygen species (ROS) have been associated with various human diseases, and considerable attention has been paid to investigate their physiological effects. Various ROS are synthesized in the mitochondria and accumulate in the cytoplasm if the cellular antioxidant defense mechanism fails. The critical balance of this ROS synthesis and antioxidant defense systems is termed the redox system of the cell. Various cardiovascular diseases have also been affected by redox to different degrees. ROS have been indicated as both detrimental and protective, via different cellular pathways, for cardiac myocyte functions, electrophysiology, and pharmacology. Mostly, the ROS functions depend on the type and amount of ROS synthesized. While the literature clearly indicates ROS effects on cardiac contractility, their effects on cardiac excitability are relatively under appreciated. Cardiac excitability depends on the functions of various cardiac sarcolemal or mitochondrial ion channels carrying various depolarizing or repolarizing currents that also maintain cellular ionic homeostasis. ROS alter the functions of these ion channels to various degrees to determine excitability by affecting the cellular resting potential and the morphology of the cardiac action potential. Thus, redox balance regulates cardiac excitability, and under pathological regulation, may alter action potential propagation to cause arrhythmia. Understanding how redox affects cellular excitability may lead to potential prophylaxis or treatment for various arrhythmias. This review will focus on the studies of redox and cardiac excitation.
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Affiliation(s)
- Nitin T Aggarwal
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI 53792, USA
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Atrial remodeling: New pathophysiological mechanism of atrial fibrillation. Med Hypotheses 2013; 80:53-6. [DOI: 10.1016/j.mehy.2012.10.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 10/18/2012] [Indexed: 11/17/2022]
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Nakatani Y, Nishida K, Sakabe M, Kataoka N, Sakamoto T, Yamaguchi Y, Iwamoto J, Mizumaki K, Fujiki A, Inoue H. Tranilast prevents atrial remodeling and development of atrial fibrillation in a canine model of atrial tachycardia and left ventricular dysfunction. J Am Coll Cardiol 2012; 61:582-8. [PMID: 23273396 DOI: 10.1016/j.jacc.2012.11.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/26/2012] [Accepted: 11/05/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This study sought to assess the effects of tranilast on atrial remodeling in a canine atrial fibrillation (AF) model. BACKGROUND Tranilast inhibits transforming growth factor (TGF)-β1 and prevents fibrosis in many pathophysiological settings. However, the effects of tranilast on atrial remodeling remain unclear. METHODS Beagles were subjected to atrial tachypacing (400 beats/min) for 4 weeks while treated with placebo (control dogs, n = 8) or tranilast (tranilast dogs, n = 10). Sham dogs (n = 6) did not receive atrial tachypacing. Atrioventricular conduction was preserved. Ventricular dysfunction developed in the control and tranilast dogs due to rapid ventricular responses. RESULTS Atrial fibrillation duration (211 ± 57 s) increased, and AF cycle length and atrial effective refractory period shortened in controls, but these changes were suppressed in tranilast dogs (AF duration, 18 ± 10 s, p < 0.01 vs. control). The L-type calcium channel α1c (Cav1.2) micro ribonucleic acid expression decreased in control dogs (sham 1.38 ± 0.24 vs. control 0.65 ± 0.12, p < 0.01), but not in tranilast dogs (0.97 ± 0.14, p = not significant vs. sham). Prominent atrial fibrosis (fibrous tissue area, sham 0.8 ± 0.1 vs. control 9.3 ± 1.3%, p < 0.01) and increased expression of tissue inhibitor of metalloproteinase protein 1 were observed in control dogs but not in tranilast dogs (fibrous tissue area, 1.4 ± 0.2%, p < 0.01 vs. control). The TGF-β1 (sham 1.00 ± 0.07 vs. control 3.06 ± 0.87, p < 0.05) and Rac1 proteins were overexpressed in control dogs, but their overexpression was inhibited in tranilast dogs (TGF-β1, 1.28 ± 0.20, p < 0.05 vs. control). CONCLUSIONS Tranilast prevented atrial remodeling and suppressed AF development in a canine model. Its inhibition of TGF-β1 and Rac1 overexpression may contribute to its antiremodeling effects.
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Affiliation(s)
- Yosuke Nakatani
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
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Liu T, Korantzopoulos P, Li G. Antioxidant therapies for the management of atrial fibrillation. Cardiovasc Diagn Ther 2012; 2:298-307. [PMID: 24282730 PMCID: PMC3839156 DOI: 10.3978/j.issn.2223-3652.2012.10.07] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Accepted: 10/31/2012] [Indexed: 12/20/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice, representing a major public health problem. Recent evidence suggests oxidative stress may play an important role in the pathogenesis and perpetuation of AF. In the past few years, experimental data and clinical evidence have tested the concept of antioxidant therapies to prevent AF. Besides statins, ACE-inhibitors (ACEIs) and/or angiotensin-receptor blockers (ARBs), and omega-3 polyunsaturated fatty acids, several other interventions with antioxidant properties, such as Vitamin C and E, thiazolidinediones, N-acetylcysteine, probucol, nitric oxide donors or precursors, NADPH oxidase inhibitors, Xanthine oxidase inhibitors have emerged as novel strategies for the management of AF. We aim to review recent evidence regarding antioxidant therapies in the prevention and treatment of atrial fibrillation.
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Affiliation(s)
- Tong Liu
- Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People’s Republic of China
| | | | - Guangping Li
- Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People’s Republic of China
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46
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Bers DM, Grandi E. Human atrial fibrillation: insights from computational electrophysiological models. Trends Cardiovasc Med 2012; 21:145-50. [PMID: 22732550 DOI: 10.1016/j.tcm.2012.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 04/09/2012] [Accepted: 04/10/2012] [Indexed: 11/16/2022]
Abstract
Computational electrophysiology has proven useful to investigate the mechanisms of cardiac arrhythmias at various spatial scales, from isolated myocytes to the whole heart. This article reviews how mathematical modeling has aided our understanding of human atrial myocyte electrophysiology to study the contribution of structural and electrical remodeling to human atrial fibrillation. Potential new avenues of investigation and model development are suggested.
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Affiliation(s)
- Donald M Bers
- Department of Pharmacology, University of California at Davis, Davis, CA 95616-8636, USA.
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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.
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Affiliation(s)
- Ali A Sovari
- Section of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago Chicago, IL, USA
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Aoki Y, Hatakeyama N, Yamamoto S, Kinoshita H, Matsuda N, Hattori Y, Yamazaki M. Role of ion channels in sepsis-induced atrial tachyarrhythmias in guinea pigs. Br J Pharmacol 2012; 166:390-400. [PMID: 22050008 DOI: 10.1111/j.1476-5381.2011.01769.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Supraventricular tachyarrhythmias, including atrial fibrillation, are occasionally observed in patients suffering from sepsis. Modulation of cardiac ion channel function and expression by sepsis may have a role in the genesis of tachyarrhythmias. EXPERIMENTAL APPROACH Sepsis was induced by LPS (i.p.; 300 µg·kg(-1) ) in guinea pigs. Membrane potentials and ionic currents were measured in atrial myocytes isolated from guinea pigs 10 h after LPS, using whole cell patch-clamp methods. KEY RESULTS In atrial cells from LPS-treated animals, action potential duration (APD) was significantly shortened. It was associated with a reduced L-type Ca(2+) current and an increased delayed rectifier K(+) current. These electrophysiological changes were eliminated when N(G) -nitro-l-arginine methyl ester (l-NAME) or S-ethylisothiourea was given together with LPS. In atrial tissues from LPS-treated animals, Ca(2+) channel subunits (Ca(v) 1.2 and Ca(v) 1.3) decreased and delayed rectifier K(+) channel subunits (K(v) 11.1 and K(v) 7.1) increased. However, L-NAME treatment did not substantially reverse such changes in atrial expression in LPS-treated animals, with the exception that K(v) 11.1 subunits returned to control levels. After LPS injection, inducible NOS in atrial tissues was up-regulated, and atrial NO production clearly increased. CONCLUSIONS AND IMPLICATIONS In atrial myocytes from guinea pigs with sepsis, APD was significantly shortened. This may reflect nitration of the ion channels which would alter channel functions, rather than changes in atrial expression of the channels. Shortening of APD could serve as one of the mechanisms underlying atrial tachyarrhythmia in sepsis.
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Affiliation(s)
- Yuta Aoki
- Department of Anesthesiology, University of Toyama, Toyama, Japan.
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Ramos-Mondragón R, Galindo CA, García-Castañeda M, Sánchez-Vargas JL, Vega AV, Gómez-Viquez NL, Avila G. Chronic potentiation of cardiac L-type Ca(2+) channels by pirfenidone. Cardiovasc Res 2012; 96:244-54. [PMID: 22847236 DOI: 10.1093/cvr/cvs248] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIMS On the basis of its ability to inhibit fibrosis, pirfenidone has drawn the attention as an intriguing candidate for treating cardiac disease. However, its precise electrophysiological effects have yet to be elucidated. Here, we have investigated its potential to modulate ion channels. METHODS AND RESULTS Adult rat cardiac myocytes were investigated using whole-cell patch-clamp, western-blot and qRT-PCR techniques. Pirfenidone increased the density of L-type Ca(2+) current (I(CaL,) 50-100%), without significantly altering Na(+), K(+), or T-type Ca(2+) currents. The effect was dose-dependent, with an EC(50) of 2.8 µM. Its onset was slow, with a lag period larger than 1 h and time to maximum of 24-48 h. Concomitant changes were observed in the voltage-dependent activation of I(CaL) (-5 mV shift in both V(1/2) and k). In contrast, the following properties of I(CaL) remained normal: steady-state inactivation, Ca(V)1.2 levels (mRNA and protein), and intramembrane charge movement. Indeed, the conductance-to-charge ratio, or G(max)/Q(max), was increased by 80%. The effect on I(CaL) was mimicked by an inhibitor of nitric oxide (NO) synthase (NOS), and attenuated by both cyclic adenosine monophosphate (cAMP) and cAMP-dependent protein kinase (PKA) inhibitors. Conversely, cytokines, reactive oxygen species, and Ca(2+) were all ruled out as possible intermediaries. Additional experiments suggest that pirfenidone increases action potential duration by ∼50%. CONCLUSION Pirfenidone augments I(CaL), not through higher expression of L-type channels, but through promoting their Ca(2+)-conducting activity. A possible inhibition of NOS expression is likely involved, with subsequent reduced NO production and stimulated cAMP/PKA signalling. These findings may be relevant to the cardioprotective effect of pirfenidone.
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Grandi E, Workman AJ, Pandit SV. Altered Excitation-Contraction Coupling in Human Chronic Atrial Fibrillation. J Atr Fibrillation 2012; 4:495. [PMID: 28496736 DOI: 10.4022/jafib.495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 02/10/2012] [Accepted: 03/19/2012] [Indexed: 12/19/2022]
Abstract
This review focuses on the (mal)adaptive processes in atrial excitation-contraction coupling occurring in patients with chronic atrial fibrillation. Cellular remodeling includes shortening of the atrial action potential duration and effective refractory period, depressed intracellular Ca2+ transient, and reduced myocyte contractility. Here we summarize the current knowledge of the ionic bases underlying these changes. Understanding the molecular mechanisms of excitation-contraction-coupling remodeling in the fibrillating human atria is important to identify new potential targets for AF therapy.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California at Davis, Davis, CA, USA
| | - Antony J Workman
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK
| | - Sandeep V Pandit
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, USA
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