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Struckman HL, Moise N, King DR, Soltisz A, Buxton A, Dunlap I, Chen Z, Radwański PB, Weinberg SH, Veeraraghavan R. Unraveling Impacts of Chamber-Specific Differences in Intercalated Disc Ultrastructure and Molecular Organization on Cardiac Conduction. JACC Clin Electrophysiol 2023; 9:2425-2443. [PMID: 37498248 PMCID: PMC11102000 DOI: 10.1016/j.jacep.2023.05.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 07/28/2023]
Abstract
BACKGROUND Propagation of action potentials through the heart coordinates the heartbeat. Thus, intercalated discs, specialized cell-cell contact sites that provide electrical and mechanical coupling between cardiomyocytes, are an important target for study. Impaired propagation leads to arrhythmias in many pathologies, where intercalated disc remodeling is a common finding, hence the importance and urgency of understanding propagation dependence on intercalated disc structure. Conventional modeling approaches cannot predict changes in propagation elicited by perturbations that alter intercalated disc ultrastructure or molecular organization, because of lack of quantitative structural data at subcellular through nano scales. OBJECTIVES This study sought to quantify intercalated disc structure at these spatial scales in the healthy adult mouse heart and relate them to chamber-specific properties of propagation as a precursor to understanding the effects of pathological intercalated disc remodeling. METHODS Using super-resolution light microscopy, electron microscopy, and computational image analysis, we provide here the first ever systematic, multiscale quantification of intercalated disc ultrastructure and molecular organization. RESULTS By incorporating these data into a rule-based model of cardiac tissue with realistic intercalated disc structure, and comparing model predictions of electrical propagation with experimental measures of conduction velocity, we reveal that atrial intercalated discs can support faster conduction than their ventricular counterparts, which is normally masked by interchamber differences in myocyte geometry. Further, we identify key ultrastructural and molecular organization features underpinning the ability of atrial intercalated discs to support faster conduction. CONCLUSIONS These data provide the first stepping stone to elucidating chamber-specific effects of pathological intercalated disc remodeling, as occurs in many arrhythmic diseases.
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Affiliation(s)
- Heather L Struckman
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA; The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Nicolae Moise
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - D Ryan King
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Andrew Soltisz
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA; The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Andrew Buxton
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Izabella Dunlap
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Zhenhui Chen
- Krannert Cardiovascular Research Center, Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Przemysław B Radwański
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA; Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Seth H Weinberg
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA; The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA; The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
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2
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García-Mendívil L, Pérez-Zabalza M, Oliver-Gelabert A, Vallejo-Gil JM, Fañanás-Mastral J, Vázquez-Sancho M, Bellido-Morales JA, Vaca-Núñez AS, Ballester-Cuenca C, Diez E, Ordovás L, Pueyo E. Interindividual Age-Independent Differences in Human CX43 Impact Ventricular Arrhythmic Risk. Research (Wash D C) 2023; 6:0254. [PMID: 38023417 PMCID: PMC10650968 DOI: 10.34133/research.0254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023]
Abstract
Connexin 43 (CX43) is one of the major components of gap junctions, the structures responsible for the intercellular communication and transmission of the electrical impulse in the left ventricle. There is limited information on the histological changes of CX43 with age and their effect on electrophysiology, especially in humans. Here, we analyzed left ventricular biopsies from living donors starting at midlife to characterize age-related CX43 remodeling. We assessed its quantity, degree of lateralization, and spatial heterogeneity together with fibrotic deposition. We observed no significant age-related remodeling of CX43. Only spatial heterogeneity increased slightly with age, and this increase was better explained by biological age than by chronological age. Importantly, we found that CX43 features varied considerably among individuals in our population with no relevant relationship to age or fibrosis content, in contrast to animal species. We used our experimental results to feed computational models of human ventricular electrophysiology and to assess the effects of interindividual differences in specific features of CX43 and fibrosis on conduction velocity, action potential duration, and arrhythmogenicity. We found that larger amounts of fibrosis were associated with the highest arrhythmic risk, with this risk being increased when fibrosis deposition was combined with a reduction in CX43 amount and/or with an increase in CX43 spatial heterogeneity. These mechanisms underlying high arrhythmic risk in some individuals were not associated with age in our study population. In conclusion, our data rule out CX43 remodeling as an age-related arrhythmic substrate in the population beyond midlife, but highlight its potential as a proarrhythmic factor at the individual level, especially when combined with increased fibrosis.
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Affiliation(s)
- Laura García-Mendívil
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - María Pérez-Zabalza
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Centro Universitario de la Defensa (CUD), Zaragoza 50090, Spain
| | - Antoni Oliver-Gelabert
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - José María Vallejo-Gil
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Javier Fañanás-Mastral
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Manuel Vázquez-Sancho
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | | | | | - Carlos Ballester-Cuenca
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Emiliano Diez
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU), CONICET, Mendoza 5500, Argentina
| | - Laura Ordovás
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Fundación Agencia Aragonesa para la Investigación y el Desarrollo (ARAID), Zaragoza 50018, Spain
| | - Esther Pueyo
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza 50018, Spain
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3
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Mfarej MG, Hyland CA, Sanchez AC, Falk MM, Iovine MK, Skibbens RV. Cohesin: an emerging master regulator at the heart of cardiac development. Mol Biol Cell 2023; 34:rs2. [PMID: 36947206 PMCID: PMC10162415 DOI: 10.1091/mbc.e22-12-0557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 03/23/2023] Open
Abstract
Cohesins are ATPase complexes that play central roles in cellular processes such as chromosome division, DNA repair, and gene expression. Cohesinopathies arise from mutations in cohesin proteins or cohesin complex regulators and encompass a family of related developmental disorders that present with a range of severe birth defects, affect many different physiological systems, and often lead to embryonic fatality. Treatments for cohesinopathies are limited, in large part due to the lack of understanding of cohesin biology. Thus, characterizing the signaling networks that lie upstream and downstream of cohesin-dependent pathways remains clinically relevant. Here, we highlight alterations in cohesins and cohesin regulators that result in cohesinopathies, with a focus on cardiac defects. In addition, we suggest a novel and more unifying view regarding the mechanisms through which cohesinopathy-based heart defects may arise.
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Affiliation(s)
- Michael G. Mfarej
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | - Caitlin A. Hyland
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | - Annie C. Sanchez
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | - Matthias M. Falk
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | - M. Kathryn Iovine
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
| | - Robert V. Skibbens
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015
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Struckman HL, Moise N, King DR, Soltisz A, Buxton A, Dunlap I, Chen Z, Radwański PB, Weinberg SH, Veeraraghavan R. Unraveling Chamber-specific Differences in Intercalated Disc Ultrastructure and Molecular Organization and Their Impact on Cardiac Conduction. bioRxiv 2023:2023.02.13.528369. [PMID: 36824727 PMCID: PMC9949041 DOI: 10.1101/2023.02.13.528369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
During each heartbeat, the propagation of action potentials through the heart coordinates the contraction of billions of individual cardiomyocytes and is thus, a critical life process. Unsurprisingly, intercalated discs, which are cell-cell contact sites specialized to provide electrical and mechanical coupling between adjacent cardiomyocytes, have been the focus of much investigation. Slowed or disrupted propagation leads to potentially life-threatening arrhythmias in a wide range of pathologies, where intercalated disc remodeling is a common finding. Hence, the importance and urgency of understanding intercalated disc structure and its influence on action potential propagation. Surprisingly, however, conventional modeling approaches cannot predict changes in propagation elicited by perturbations that alter intercalated disc ultrastructure or molecular organization, owing to lack of quantitative structural data at subcellular through nano scales. In order to address this critical gap in knowledge, we sought to quantify intercalated disc structure at these finer spatial scales in the healthy adult mouse heart and relate them to function in a chamber-specific manner as a precursor to understanding the impacts of pathological intercalated disc remodeling. Using super-resolution light microscopy, electron microscopy, and computational image analysis, we provide here the first ever systematic, multiscale quantification of intercalated disc ultrastructure and molecular organization. By incorporating these data into a rule-based model of cardiac tissue with realistic intercalated disc structure, and comparing model predictions of electrical propagation with experimental measures of conduction velocity, we reveal that atrial intercalated discs can support faster conduction than their ventricular counterparts, which is normally masked by inter-chamber differences in myocyte geometry. Further, we identify key ultrastructural and molecular organization features underpinning the ability of atrial intercalated discs to support faster conduction. These data provide the first stepping stone to elucidating chamber-specific impacts of pathological intercalated disc remodeling, as occurs in many arrhythmic diseases.
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5
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Mead TJ. ADAMTS6: Emerging roles in cardiovascular, musculoskeletal and cancer biology. Front Mol Biosci 2022; 9:1023511. [DOI: 10.3389/fmolb.2022.1023511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/05/2022] [Indexed: 11/13/2022] Open
Abstract
ADAMTS family members control mammalian development and disease, primarily through their function as proteases, by regulation of extracellular matrix composition. Until recently, ADAMTS6 was known as one of the orphan proteinases of the nineteen-member family with a relatively unknown expression pattern and function. Emerging focus on this enzyme has started to uncover these unknowns and revealed a vast importance and requirement of ADAMTS6 in cardiovascular and musculoskeletal development. In addition, ADAMTS6 has been linked to numerous disease settings including several types of cancer. This review summarizes the necessity of ADAMTS6 during development, its role in disease and requirement for essential prospective studies to fully realize its biological implications and potential for therapeutic intervention.
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6
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Zhao M, Han M, Liang L, Song Q, Li X, Du Y, Hu D, Cheng Y, Wang QK, Ke T. Mog1 deficiency promotes cardiac contractile dysfunction and isoproterenol-induced arrhythmias associated with cardiac fibrosis and Cx43 remodeling. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166429. [PMID: 35533905 DOI: 10.1016/j.bbadis.2022.166429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/21/2022] [Accepted: 05/02/2022] [Indexed: 10/18/2022]
Abstract
Our earlier studies identified MOG1 as a Nav1.5-binding protein that promotes Nav1.5 intracellular trafficking to plasma membranes. Genetic studies have identified MOG1 variants responsible for cardiac arrhythmias. However, the physiological functions of MOG1 in vivo remain incompletely characterized. In this study, we generated Mog1 knockout (Mog1-/-) mice. Mog1-/- mice did not develop spontaneous arrhythmias at the baseline, but exhibited a prolongation of QRS duration. Mog1-/- mice treated with isoproterenol (ISO), but not with flecainide, exhibited an increased risk of arrhythmias and even sudden death. Mog1-/- mice had normal cardiac morphology, however, LV systolic dysfunction was identified and associated with an increase in ventricular fibrosis. Whole-cell patch-clamping and Western blotting analysis clearly demonstrated the normal cardiac expression and function of Nav1.5 in Mog1-/- mice. Further RNA-seq and iTRAQ analysis identified critical pathways and genes, including extracellular matrix (Mmp2), gap junction (Gja1), and mitochondrial components that were dysregulated in Mog1-/- mice. RT-qPCR, Western blotting, and immunofluorescence assays revealed reduced cardiac expression of Gja1 in Mog1-/- mice. Dye transfer assays confirmed impairment of gap-junction function; Cx43 gap-junction enhancer ZP123 decreased arrhythmia inducibility in ISO-treated Mog1-/- mice. Transmission electron microscopy analysis revealed abnormal sarcomere ultrastructure and altered mitochondrial morphology in Mog1-/- mice. Mitochondrial dynamics was found to be disturbed, and associated with a trend toward increased mitochondrial fusion in Mog1-/- mice. Meanwhile, the level of ATP supply was increased in the hearts of Mog1-/- mice. These results indicate that MOG1 plays an important role in cardiac electrophysiology and cardiac contractile function.
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Affiliation(s)
- Miao Zhao
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China
| | - Meng Han
- Hubei Provincial Key Laboratory of Occurrence and Intervention of Kidney Diseases, Medical College, Hubei Polytechnic University, Huangshi, Hubei Province, PR China
| | - Lina Liang
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China
| | - Qixue Song
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055 Shenzhen, PR China
| | - Xia Li
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China
| | - Yimei Du
- Research Center of Ion Channelopathy, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, PR China
| | - Dongping Hu
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China
| | - Yu Cheng
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China
| | - Qing K Wang
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China.
| | - Tie Ke
- Center for Human Genome Research, The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, PR China.
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7
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O' Brien S, Holmes AP, Johnson DM, Kabir SN, O' Shea C, O' Reilly M, Avezzu A, Reyat JS, Hall AW, Apicella C, Ellinor PT, Niederer S, Tucker NR, Fabritz L, Kirchhof P, Pavlovic D. Increased atrial effectiveness of flecainide conferred by altered biophysical properties of sodium channels. J Mol Cell Cardiol 2022; 166:23-35. [PMID: 35114252 DOI: 10.1016/j.yjmcc.2022.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
Atrial fibrillation (AF) affects over 1% of the population and is a leading cause of stroke and heart failure in the elderly. A feared side effect of sodium channel blocker therapy, ventricular pro-arrhythmia, appears to be relatively rare in patients with AF. The biophysical reasons for this relative safety of sodium blockers are not known. Our data demonstrates intrinsic differences between atrial and ventricular cardiac voltage-gated sodium currents (INa), leading to reduced maximum upstroke velocity of action potential and slower conduction, in left atria compared to ventricle. Reduced atrial INa is only detected at physiological membrane potentials and is driven by alterations in sodium channel biophysical properties and not by NaV1.5 protein expression. Flecainide displayed greater inhibition of atrial INa, greater reduction of maximum upstroke velocity of action potential, and slowed conduction in atrial cells and tissue. Our work highlights differences in biophysical properties of sodium channels in left atria and ventricles and their response to flecainide. These differences can explain the relative safety of sodium channel blocker therapy in patients with atrial fibrillation.
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Affiliation(s)
- Sian O' Brien
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Daniel M Johnson
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Christopher O' Shea
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Molly O' Reilly
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Adelisa Avezzu
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Jasmeet S Reyat
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Amelia W Hall
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Clara Apicella
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven Niederer
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Nathan R Tucker
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Larissa Fabritz
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; University Center of Cardiovascular Science, University Heart and Vascular Center UKE, Hamburg, Germany; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Paulus Kirchhof
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Davor Pavlovic
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK.
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8
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Wang L, Wada Y, Ballan N, Schmeckpeper J, Huang J, Rau CD, Wang Y, Gepstein L, Knollmann BC. Triiodothyronine and dexamethasone alter potassium channel expression and promote electrophysiological maturation of human-induced pluripotent stem cell-derived cardiomyocytes. J Mol Cell Cardiol 2021; 161:130-138. [PMID: 34400182 PMCID: PMC9809541 DOI: 10.1016/j.yjmcc.2021.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a promising tool for disease modeling and drug development. However, hiPSC-CMs remain functionally immature, which hinders their utility as a model of human cardiomyocytes. OBJECTIVE To improve the electrophysiological maturation of hiPSC-CMs. METHODS AND RESULTS On day 16 of cardiac differentiation, hiPSC-CMs were treated with 100 nmol/L triiodothyronine (T3) and 1 μmol/L Dexamethasone (Dex) or vehicle for 14 days. On day 30, vehicle- and T3 + Dex-treated hiPSC-CMs were dissociated and replated either as cell sheets or single cells. Optical mapping and patch-clamp technique were used to examine the electrophysiological properties of vehicle- and T3 + Dex-treated hiPSC-CMs. Compared to vehicle, T3 + Dex-treated hiPSC-CMs had a slower spontaneous beating rate, more hyperpolarized resting membrane potential, faster maximal upstroke velocity, and shorter action potential duration. Changes in spontaneous activity and action potential were mediated by decreased hyperpolarization-activated current (If) and increased inward rectifier potassium currents (IK1), sodium currents (INa), and the rapidly and slowly activating delayed rectifier potassium currents (IKr and IKs, respectively). Furthermore, T3 + Dex-treated hiPSC-CM cell sheets (hiPSC-CCSs) exhibited a faster conduction velocity and shorter action potential duration than the vehicle. Inhibition of IK1 by 100 μM BaCl2 significantly slowed conduction velocity and prolonged action potential duration in T3 + Dex-treated hiPSC-CCSs but had no effect in the vehicle group, demonstrating the importance of IK1 for conduction velocity and action potential duration. CONCLUSION T3 + Dex treatment is an effective approach to rapidly enhance electrophysiological maturation of hiPSC-CMs.
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Affiliation(s)
- Lili Wang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA,Correspondence to: Lili Wang, Ph.D., Division of Clinical Pharmacology, Vanderbilt University Medical Center, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232-0575 Or Bjorn C. Knollmann, MD, Ph.D., Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART), Vanderbilt, University Medical Center, Medical Research Building IV, Rm. 1265, 2215B Garland Ave, Nashville, TN 37232-0575,
| | - Yuko Wada
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Nimer Ballan
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, POB 9649, Haifa 3109601, Israel
| | - Jeffrey Schmeckpeper
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Jijun Huang
- Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Christoph Daniel Rau
- Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Yibin Wang
- Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Lior Gepstein
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, POB 9649, Haifa 3109601, Israel,Cardiology Department, Rambam Health Care Campus, Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, 2 Efron St. POB 9649, Haifa, 3109601, Israel
| | - Bjorn C. Knollmann
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA,Correspondence to: Lili Wang, Ph.D., Division of Clinical Pharmacology, Vanderbilt University Medical Center, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232-0575 Or Bjorn C. Knollmann, MD, Ph.D., Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART), Vanderbilt, University Medical Center, Medical Research Building IV, Rm. 1265, 2215B Garland Ave, Nashville, TN 37232-0575,
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9
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Poelzing S, Weinberg SH, Keener JP. Initiation and entrainment of multicellular automaticity via diffusion limited extracellular domains. Biophys J 2021; 120:5279-5294. [PMID: 34757078 DOI: 10.1016/j.bpj.2021.10.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 09/12/2021] [Accepted: 10/26/2021] [Indexed: 01/07/2023] Open
Abstract
Electrically excitable cells often spontaneously and synchronously depolarize in vitro and in vivo preparations. It remains unclear how cells entrain and autorhythmically activate above the intrinsic mean activation frequency of isolated cells with or without pacemaking mechanisms. Recent studies suggest that cyclic ion accumulation and depletion in diffusion-limited extracellular volumes modulate electrophysiology by ephaptic mechanisms (nongap junction or synaptic coupling). This report explores how potassium accumulation and depletion in a restricted extracellular domain induces spontaneous action potentials in two different computational models of excitable cells without gap junctional coupling: Hodgkin-Huxley and Luo-Rudy. Importantly, neither model will spontaneously activate on its own without external stimuli. Simulations demonstrate that cells sharing a diffusion-limited extracellular compartment can become autorhythmic and entrained despite intercellular electrical heterogeneity. Autorhythmic frequency is modulated by the cleft volume and potassium fluxes through the cleft. Additionally, inexcitable cells can suppress or induce autorhythmic activity in an excitable cell via a shared cleft. Diffusion-limited shared clefts can also entrain repolarization. Critically, this model predicts a mechanism by which diffusion-limited shared clefts can initiate, entrain, and modulate multicellular automaticity in the absence of gap junctions.
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Affiliation(s)
- Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Heart and Reparative Medicine, and the Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Roanoke, Virginia.
| | - Seth H Weinberg
- Department of Biomedical Engineering, Davis Heart and Lung Research Institute, and the Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - James P Keener
- Department of Mathematics, University of Utah, Salt Lake City, Utah
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10
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Chen YL, Chen YC, Chang YT, Wang HT, Liu WH, Chong SZ, Lin PT, Hsu PY, Su MC, Lin MC. GJA1 Expression and Left Atrial Remodeling in the Incidence of Atrial Fibrillation in Patients with Obstructive Sleep Apnea Syndrome. Biomedicines 2021; 9:1463. [PMID: 34680580 DOI: 10.3390/biomedicines9101463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/06/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022] Open
Abstract
Obstructive sleep apnea syndrome (OSAS) is an important risk factor for atrial fibrillation (AF). GJA1 gene encoding connexin43, a major protein in cardiac gap junctions, plays a crucial role in the synchronized contraction of the heart and in cardiac arrhythmia. However, little is known regarding the role of GJA1 expression in the incidence of AF in patients with OSAS. All prospectively enrolled OSAS patients underwent polysomnography, electrocardiography, a 24-h Holter test, and echocardiography. Moderate-to-severe OSAS was defined as an apnea-hypopnea index (AHI) ≥ 15. Exosomes were purified from the plasma of all OSAS patients and incubated in HL-1 cells to investigate the effect of exosomes from patients with and without AF on GJA1 expression. A total of 129 patients were recruited for this study; 26 were excluded due to an AHI < 15. Of the 103 enrolled patients, 21 had AF, and 82 did not. Multivariate analysis showed diabetes mellitus, lower sleep efficiency, lower left ventricular ejection fraction, and larger left atrial (LA) size were independent predictors of AF occurrence in OSAS patients. The area under the receiver operating characteristic curve for LA with a size ≥38.5 mm for predicting AF occurrence in OSAS patients was 0.795 (95% confidence interval [0.666, 0.925]); p < 0.001). GJA1 expression in HL-1 cells incubated with exosomes from OSAS patients with AF was lower than that with exosomes from patients without AF after controlling for age and sex and was negatively correlated with the AHI and oxygen desaturation index (ODI), especially during the non-rapid eye movement period (NREM) of OSAS patients with AF (all p < 0.05). LA size was an independent predictor of AF occurrence in OSAS patients. The AHI and ODI in the NREM period of OSAS patients with AF were negatively correlated with GJA1 expression in HL-1 cells, which offers a hint that GJA1 may play a crucial role in the development of AF in patients with OSAS.
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11
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Ai X, Yan J, Pogwizd SM. Serine-threonine protein phosphatase regulation of Cx43 dephosphorylation in arrhythmogenic disorders. Cell Signal 2021; 86:110070. [PMID: 34217833 PMCID: PMC8963383 DOI: 10.1016/j.cellsig.2021.110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
Regulation of cell-to-cell communication in the heart by the gap junction protein Connexin43 (Cx43) involves modulation of Cx43 phosphorylation state by protein kinases, and dephosphorylation by protein phosphatases. Dephosphorylation of Cx43 has been associated with impaired intercellular coupling and enhanced arrhythmogenesis in various pathologic states. While there has been extensive study of the protein kinases acting on Cx43, there has been limited studies of the protein phosphatases that may underlie Cx43 dephosphorylation. The focus of this review is to introduce serine-threonine protein phosphatase regulation of Cx43 phosphorylation state and cell-to-cell communication, and its impact on arrhythmogenesis in the setting of chronic heart failure and myocardial ischemia, as well as on atrial fibrillation. We also discuss the therapeutic potential of modulating protein phosphatases to treat arrhythmias in these clinical settings.
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Affiliation(s)
- Xun Ai
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Jiajie Yan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Steven M Pogwizd
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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12
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Rodríguez-Sinovas A, Sánchez JA, Valls-Lacalle L, Consegal M, Ferreira-González I. Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:4413. [PMID: 33922534 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
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13
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Li C, Zhang H, Xie Y, Liu S, Zhao R, Huang J, Huang J, Wei Y. Effects of CMYA1 overexpression on cardiac structure and function in mice. Acta Biochim Biophys Sin (Shanghai) 2021; 53:593-600. [PMID: 33792654 PMCID: PMC8047858 DOI: 10.1093/abbs/gmab029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Indexed: 12/11/2022] Open
Abstract
CMYA1 (cardiomyopathy-associated protein 1, also termed Xin) localizes to the intercalated disks (ICDs) of the myocardium and functions to maintain ICD structural integrity and support signal transduction among cardiomyocytes. Our previous study showed that CMYA1 overexpression impairs the function of gap junction intercellular communication processes. Successful model generation was verified based on PCR, western blot analysis, immunohistochemistry, and immunofluorescence analysis. Myocardial CMYA1 expression was confirmed at both the mRNA and the protein levels in the CMYA1-OE transgenic mice. Masson's trichrome staining and electron microscopy revealed myocardial fibrosis and uneven bead width or the interruption of ICDs in the hearts of the CMYA1-OE transgenic mice. Furthermore, the Cx43 protein level was reduced in the CMYA1-OE mice, and co-immunoprecipitation assays of heart tissue protein extracts revealed a physical interaction between CMYA1 and Cx43. Electrocardiogram analysis enabled the detection of an obvious ventricular bigeminy for the CMYA1-OE mice. In summary, analysis of our mouse model indicates that elevated CMYA1 levels may induce myocardial fibrosis, impair ICDs, and downregulate the expression of Cx43. The observed ventricular bigeminy in the CMYA1-OE mice may be mediated by the reduced Cx43 protein level.
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Affiliation(s)
- Chunyan Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
- Department of Clinical Laboratory, Beijing Jishuitan Hospital, Beijing 100032, China
| | - Hongliang Zhang
- Department of Cardiology, The First Affiliated Hospital of Jiamusi University, Jiamusi 154002, China
| | - Yuanyuan Xie
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Shenghua Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Ranxu Zhao
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Jian Huang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Jie Huang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Yingjie Wei
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
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14
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Chen YL, Chuang JH, Wang HT, Chen HC, Liu WH, Yang MY. Altered Expression of Circadian Clock Genes in Patients with Atrial Fibrillation Is Associated with Atrial High-Rate Episodes and Left Atrial Remodeling. Diagnostics (Basel) 2021; 11:diagnostics11010090. [PMID: 33430447 PMCID: PMC7828089 DOI: 10.3390/diagnostics11010090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 11/16/2022] Open
Abstract
A prominent circadian variation is present in atrial fibrillation (AF) attacks that may be related to the expression of circadian clock genes. Little is known about the expression of circadian clock genes in AF. We prospectively enrolled 73 patients who had received pacemaker implantation, in order to define the burden of atrial high-rate episodes (AHREs) accurately. AF was diagnosed clinically in 43 (59%) patients (15 with persistent AF and 28 with paroxysmal AF). The expression levels of circadian clock genes of peripheral blood leukocytes were checked. There were more males and patients with a larger left atrial (LA) size and lower expression levels of BMAL1, CRY2, NR1D1, NR1D2, PER2, RORA, RORC, and TIM genes in persistent AF group than in other groups. There was a significant correlation between higher AHRE burden and larger LA size and between higher AHRE burden and decreased expression of circadian clock genes in patients with AF. LA volume and the expression of CRY1, NR1D1, and RORA are significantly associated with AHRE burden. However, the underlying mechanism needs to be elucidated in further studies.
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Affiliation(s)
- Yung-Lung Chen
- Section of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; (Y.-L.C.); (H.-C.C.); (W.-H.L.)
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Jiin-Haur Chuang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Division of Pediatric Surgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
| | - Hui-Ting Wang
- Emergency Department, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan;
| | - Huang-Chung Chen
- Section of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; (Y.-L.C.); (H.-C.C.); (W.-H.L.)
| | - Wen-Hao Liu
- Section of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; (Y.-L.C.); (H.-C.C.); (W.-H.L.)
| | - Ming-Yu Yang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
- Correspondence: ; Tel.: +886-7-731-7123 (ext. 8865)
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15
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Macquart C, Jüttner R, Morales Rodriguez B, Le Dour C, Lefebvre F, Chatzifrangkeskou M, Schmitt A, Gotthardt M, Bonne G, Muchir A. Microtubule cytoskeleton regulates Connexin 43 localization and cardiac conduction in cardiomyopathy caused by mutation in A-type lamins gene. Hum Mol Genet 2020; 28:4043-4052. [PMID: 29893868 DOI: 10.1093/hmg/ddy227] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 01/08/2023] Open
Abstract
Mutations in the lamin A/C gene (LMNA) cause an autosomal dominant inherited form of dilated cardiomyopathy associated with cardiac conduction disease (hereafter referred to as LMNA cardiomyopathy). Compared with other forms of dilated cardiomyopathy, mutations in LMNA are responsible for a more aggressive clinical course owing to a high rate of malignant ventricular arrhythmias. Gap junctions are intercellular channels that allow direct communication between neighboring cells, which are involved in electrical impulse propagation and coordinated contraction of the heart. For gap junctions to properly control electrical synchronization in the heart, connexin-based hemichannels must be correctly targeted to intercalated discs, Cx43 being the major connexin in the working myocytes. We here showed an altered distribution of Cx43 in a mouse model of LMNA cardiomyopathy. However, little is known on the molecular mechanisms of Cx43 remodeling in pathological context. We now show that microtubule cytoskeleton alteration and decreased acetylation of α-tubulin lead to remodeling of Cx43 in LMNA cardiomyopathy, which alters the correct communication between cardiomyocytes, ultimately leading to electrical conduction disturbances. Preventing or reversing this process could offer a strategy to repair damaged heart. Stabilization of microtubule cytoskeleton using Paclitaxel improved intraventricular conduction defects. These results indicate that microtubule cytoskeleton contributes to the pathogenesis of LMNA cardiomyopathy and that drugs stabilizing the microtubule may be beneficial for patients.
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Affiliation(s)
- Coline Macquart
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Rene Jüttner
- Max-Delbrück-Center for Molecular Medicine, DE-13092 Berlin, Germany
| | - Blanca Morales Rodriguez
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Caroline Le Dour
- Department of Medicine.,Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Florence Lefebvre
- Signaling and Cardiovascular Pathophysiology, UMRS 1180, Université Paris-Sud, INSERM, Chatenay-Malabry 92216, France
| | - Maria Chatzifrangkeskou
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Alain Schmitt
- Institut Cochin, INSERM U1016-CNRS UMR 8104, Université Paris Descartes-Sorbonne Paris Cité, Paris F-75014, France
| | - Michael Gotthardt
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany.,Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, 13092 Berlin, Germany
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Antoine Muchir
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
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16
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Rahmutula D, Zhang H, Wilson EE, Olgin JE. Absence of natriuretic peptide clearance receptor attenuates TGF-β1-induced selective atrial fibrosis and atrial fibrillation. Cardiovasc Res 2020; 115:357-372. [PMID: 30239604 DOI: 10.1093/cvr/cvy224] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 09/14/2018] [Indexed: 01/04/2023] Open
Abstract
Aims TGF-β1 plays an important role in atrial fibrosis and atrial fibrillation (AF); previous studies have shown that the atria are more susceptible to TGF-β1 mediated fibrosis than the ventricles. Natriuretic peptides (NPs) play an important role in cardiac remodelling and fibrosis, but the role of natriuretic peptide clearance (NPR-C) receptor is largely unknown. We investigated the role of NPR-C in modulating TGF-β1 signalling in the atria. Methods and results MHC-TGF-β1 transgenic (TGF-β1-Tx) mice, which develop isolated atrial fibrosis and AF, were cross-bred with NPR-C knock-out mice (NPR-C-KO). Transverse aortic constriction (TAC) was performed in wild type (Wt) and NPR-C knockout mice to study. Atrial fibrosis and AF inducibility in a pathophysiologic model. Electrophysiology, molecular, and histologic studies were performed in adult mice. siRNA was used to interrogate the interaction between TGF-β1 and NP signalling pathways in isolated atrial and ventricular fibroblasts/myofibroblasts. NPR-C expression level was 17 ± 5.8-fold higher in the atria compared with the ventricle in Wt mice (P = 0.009). Cross-bred mice demonstrated markedly decreased pSmad2 and collagen expression, atrial fibrosis, and AF compared with TGF-β1-Tx mice with intact NPR-C. There was a marked reduction in atrial fibrosis gene expression and AF inducibility in the NPR-C-KO-TAC mice compared with Wt-TAC. In isolated fibroblasts, knockdown of NPR-C resulted in a marked reduction of pSmad2 (56 ± 4% and 24 ± 14% reduction in atrial and ventricular fibroblasts, respectively) and collagen (76 ± 15% and 35 ± 23% reduction in atrial and ventricular fibroblasts/myofibroblasts, respectively) in response to TGF-β1 stimulation. This effect was reversed by simultaneously knocking down NPR-A but not with simultaneous knock down of PKG-1. Conclusion The differential response to TGF-β1 stimulated fibrosis between the atria and ventricle are in part mediated by the abundance of NPR-C receptors in the atria.
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Affiliation(s)
- Dolkun Rahmutula
- Division of Cardiology, Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Avenue, M1182, Box 0124, San Francisco, CA, USA
| | - Hao Zhang
- Division of Cardiology, Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Avenue, M1182, Box 0124, San Francisco, CA, USA
| | - Emily E Wilson
- Division of Cardiology, Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Avenue, M1182, Box 0124, San Francisco, CA, USA
| | - Jeffrey E Olgin
- Division of Cardiology, Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Avenue, M1182, Box 0124, San Francisco, CA, USA
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17
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Edling C, Fazmin I, Saadeh K, Chadda K, Ahmad S, Valli H, Huang CH, Jeevaratnam K. Molecular basis of arrhythmic substrate in ageing murine peroxisome proliferator-activated receptor γ co-activator deficient hearts modelling mitochondrial dysfunction. Biosci Rep 2019; 39:BSR20190403. [PMID: 31778152 PMCID: PMC6911157 DOI: 10.1042/bsr20190403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 11/19/2019] [Accepted: 11/26/2019] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION Ageing and chronic metabolic disorders are associated with mitochondrial dysfunction and cardiac pro-arrhythmic phenotypes which were recently attributed to slowed atrial and ventricular action potential (AP) conduction in peroxisome proliferator-activated receptor γ co-activator deficient (Pgc-1β-/-) mice. METHODS We compared expression levels of voltage-gated Na+ channel (NaV1.5) and gap junction channels, Connexins 40 and 43 (Cx40 and Cx43) in the hearts of young and old, and wild-type (WT) and Pgc-1β-/- mice. This employed Western blotting (WB) for NaV1.5, Cx40 and Cx43 in atrial/ventricular tissue lysates, and immunofluorescence (IF) from Cx43 was explored in tissue sections. Results were analysed using two-way analysis of variance (ANOVA) for independent/interacting effects of age and genotype. RESULTS In atria, increased age and Pgc-1β-/- genotype each independently decreased both Cx40 and Cx43 expression without interacting effects. In IF experiments, both age and Pgc-1β deletion independently reduced Cx43 expression. In ventricles, age and genotype exerted interacting effects in WB studies of NaV1.5 expression. Young Pgc-1β-/- then showed greater NaV1.5 expression than young WT ventricles. However, neither age nor Pgc-1β deletion affected Cx43 expression, independently or through interacting effects in both WB and IF studies. CONCLUSION Similar pro-arrhythmic atrial/ventricular phenotypes arise in aged/Pgc-1β-/- from differing contributions of altered protein expression and functional effects that may arise from multiple acute mechanisms.
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Affiliation(s)
- Charlotte E. Edling
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, United Kingdom
| | - Ibrahim T. Fazmin
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, United Kingdom
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom
| | - Khalil Saadeh
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, United Kingdom
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom
| | - Karan R. Chadda
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, United Kingdom
- 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
| | - Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom
| | - Christopher L.-H. Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom
- Department of Biochemistry, Hopkins Building, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, United Kingdom
- Department of Biochemistry, Hopkins Building, University of Cambridge, Cambridge CB2 1QW, United Kingdom
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18
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Wang M, Smith K, Yu Q, Miller C, Singh K, Sen CK. Mitochondrial connexin 43 in sex-dependent myocardial responses and estrogen-mediated cardiac protection following acute ischemia/reperfusion injury. Basic Res Cardiol 2019; 115:1. [PMID: 31741053 DOI: 10.1007/s00395-019-0759-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/05/2019] [Indexed: 01/23/2023]
Abstract
Preserving mitochondrial activity is crucial in rescuing cardiac function following acute myocardial ischemia/reperfusion (I/R). The sex difference in myocardial functional recovery has been observed after I/R. Given the key role of mitochondrial connexin43 (Cx43) in cardiac protection initiated by ischemic preconditioning, we aimed to determine the implication of mitochondrial Cx43 in sex-related myocardial responses and to examine the effect of estrogen (17β-estradiol, E2) on Cx43, particularly mitochondrial Cx43-involved cardiac protection following I/R. Mouse primary cardiomyocytes and isolated mouse hearts (from males, females, ovariectomized females, and doxycycline-inducible Tnnt2-controlled Cx43 knockout without or with acute post-ischemic E2 treatment) were subjected to simulated I/R in culture or Langendorff I/R (25-min warm ischemia/40-min reperfusion), respectively. Mitochondrial membrane potential and mitochondrial superoxide production were measured in cardiomyocytes. Myocardial function and infarct size were determined. Cx43 and its isoform, Gja1-20k, were assessed in mitochondria. Immunoelectron microscopy and co-immunoprecipitation were also used to examine mitochondrial Cx43 and its interaction with estrogen receptor-α by E2 in mitochondria, respectively. There were sex disparities in stress-induced cardiomyocyte mitochondrial function. E2 partially restored mitochondrial activity in cardiomyocytes following acute injury. Post-ischemia infusion of E2 improved functional recovery and reduced infarct size with increased Cx43 content and phosphorylation in mitochondria. Ablation of cardiac Cx43 aggravated mitochondrial damage and abolished E2-mediated cardiac protection during I/R. Female mice were more resistant to myocardial I/R than age-matched males with greater protective role of mitochondrial Cx43 in female hearts. Post-ischemic E2 usage augmented mitochondrial Cx43 content and phosphorylation, increased mitochondrial Gja1-20k, and showed cardiac protection.
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Affiliation(s)
- Meijing Wang
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.
| | - Kwynlyn Smith
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Qing Yu
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Caroline Miller
- Electron Microscopy Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kanhaiya Singh
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chandan K Sen
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
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19
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Alvarez CK, Cronin E, Baker WL, Kluger J. Heart failure as a substrate and trigger for ventricular tachycardia. J Interv Card Electrophysiol 2019; 56:229-247. [PMID: 31598875 DOI: 10.1007/s10840-019-00623-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 09/06/2019] [Indexed: 02/06/2023]
Abstract
Heart failure (HF) is a major cause of morbidity and mortality with more than 5.1 million individuals affected in the USA. Ventricular tachyarrhythmias (VAs) including ventricular tachycardia and ventricular fibrillation are common in patients with heart failure. The pathophysiology of these mechanisms as well as the contribution of heart failure to the genesis of these arrhythmias is complex and multifaceted. Myocardial hypertrophy and stretch with increased preload and afterload lead to shortening of the action potential at early repolarization and lengthening of the action potential at final repolarization which can result in re-entrant ventricular tachycardia. Myocardial fibrosis and scar can create the substrate for re-entrant ventricular tachycardia. Altered calcium handling in the failing heart can lead to the development of proarrhythmic early and delayed after depolarizations. Various medications used in the treatment of HF such as loop diuretics and angiotensin converting enzyme inhibitors have not demonstrated a reduction in sudden cardiac death (SCD); however, beta-blockers (BB) are effective in reducing mortality and SCD. Amongst patients who have HF with reduced ejection fraction, the angiotensin receptor-neprilysin inhibitor (sacubitril/valsartan) has been shown to reduce cardiovascular mortality, specifically by reducing SCD, as well as death due to worsening HF. Implantable cardioverter-defibrillator (ICD) implantation in HF patients reduces the risk of SCD; however, subsequent mortality is increased in those who receive ICD shocks. Prophylactic ICD implantation reduces death from arrhythmia but does not reduce overall mortality during the acute post-myocardial infarction (MI) period (less than 40 days), for those with reduced ejection fraction and impaired autonomic dysfunction. Furthermore, although death from arrhythmias is reduced, this is offset by an increase in the mortality from non-arrhythmic causes. This article provides a review of the aforementioned mechanisms of arrhythmogenesis in heart failure; the role and impact of HF therapy such as cardiac resynchronization therapy (CRT), including the role, if any, of CRT-P and CRT-D in preventing VAs; the utility of both non-invasive parameters as well as multiple implant-based parameters for telemonitoring in HF; and the effect of left ventricular assist device implantation on VAs.
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Affiliation(s)
- Chikezie K Alvarez
- Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY, 10467, USA.
| | - Edmond Cronin
- University of Connecticut School of Medicine, Farmington, CT, USA
| | - William L Baker
- University of Connecticut School of Pharmacy, Storrs, CT, USA
| | - Jeffrey Kluger
- Hartford Healthcare Heart and Vascular Institute, Hartford Hospital, Hartford, CT, USA
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20
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Chadda KR, Fazmin IT, Ahmad S, Valli H, Edling CE, Huang CLH, Jeevaratnam K. Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients. Sleep 2019; 41:5054592. [PMID: 30016501 DOI: 10.1093/sleep/zsy136] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 07/13/2018] [Indexed: 01/01/2023] Open
Abstract
Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.
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Affiliation(s)
- Karan R Chadda
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Ibrahim T Fazmin
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Charlotte E Edling
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom.,Department of Biochemistry, Hopkins Building, University of Cambridge, Cambridge, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
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21
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Jæger KH, Edwards AG, McCulloch A, Tveito A. Properties of cardiac conduction in a cell-based computational model. PLoS Comput Biol 2019; 15:e1007042. [PMID: 31150383 PMCID: PMC6561587 DOI: 10.1371/journal.pcbi.1007042] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 06/12/2019] [Accepted: 04/23/2019] [Indexed: 11/18/2022] Open
Abstract
The conduction of electrical signals through cardiac tissue is essential for maintaining the function of the heart, and conduction abnormalities are known to potentially lead to life-threatening arrhythmias. The properties of cardiac conduction have therefore been the topic of intense study for decades, but a number of questions related to the mechanisms of conduction still remain unresolved. In this paper, we demonstrate how the so-called EMI model may be used to study some of these open questions. In the EMI model, the extracellular space, the cell membrane, the intracellular space and the cell connections are all represented as separate parts of the computational domain, and the model therefore allows for study of local properties that are hard to represent in the classical homogenized bidomain or monodomain models commonly used to study cardiac conduction. We conclude that a non-uniform sodium channel distribution increases the conduction velocity and decreases the time delays over gap junctions of reduced coupling in the EMI model simulations. We also present a theoretical optimal cell length with respect to conduction velocity and consider the possibility of ephaptic coupling (i.e. cell-to-cell coupling through the extracellular potential) acting as an alternative or supporting mechanism to gap junction coupling. We conclude that for a non-uniform distribution of sodium channels and a sufficiently small intercellular distance, ephaptic coupling can influence the dynamics of the sodium channels and potentially provide cell-to-cell coupling when the gap junction connection is absent. The electrochemical wave traversing the heart during every beat is essential for cardiac pumping function and supply of blood to the body. Understanding the stability of this wave is crucial to understanding how lethal arrhythmias are generated. Despite this importance, our knowledge of the physical determinants of wave propagation are still evolving. One particular challenge has been the lack of accurate mathematical models of conduction at the cellular level. Because cardiac muscle is an electrical syncytium, in which direct charge transfer between cells drives wave propagation, classical bidomain and monodomain tissue models employ a homogenized approximation of this process. This approximation is not valid at the length scale of single cells, and prevents any analysis of how cellular structures impact cardiac conduction. Instead, so-called microdomain models must be used for these questions. Here we utilize a recently developed modelling framework that is well suited to represent small collections of cells. By applying this framework, we show that concentration of sodium channels at the longitudinal borders of myocytes accelerates cardiac conduction. We also demonstrate that when juxtaposed cells are sufficiently close, this non-uniform distribution induces large ephaptic currents, which contribute to intercellular coupling.
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Affiliation(s)
| | | | - Andrew McCulloch
- Department of Bioengineering, University of California, San Diego, California, United States of America
| | - Aslak Tveito
- Simula Research Laboratory, Oslo, Norway
- * E-mail:
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22
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Saravanan S, Sareen N, Abu-El-Rub E, Ashour H, Sequiera GL, Ammar HI, Gopinath V, Shamaa AA, Sayed SSE, Moudgil M, Vadivelu J, Dhingra S. Graphene Oxide-Gold Nanosheets Containing Chitosan Scaffold Improves Ventricular Contractility and Function After Implantation into Infarcted Heart. Sci Rep 2018; 8:15069. [PMID: 30305684 DOI: 10.1038/s41598-018-33144-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/14/2018] [Indexed: 12/26/2022] Open
Abstract
Abnormal conduction and improper electrical impulse propagation are common in heart after myocardial infarction (MI). The scar tissue is non-conductive therefore the electrical communication between adjacent cardiomyocytes is disrupted. In the current study, we synthesized and characterized a conductive biodegradable scaffold by incorporating graphene oxide gold nanosheets (GO-Au) into a clinically approved natural polymer chitosan (CS). Inclusion of GO-Au nanosheets in CS scaffold displayed two fold increase in electrical conductivity. The scaffold exhibited excellent porous architecture with desired swelling and controlled degradation properties. It also supported cell attachment and growth with no signs of discrete cytotoxicity. In a rat model of MI, in vivo as well as in isolated heart, the scaffold after 5 weeks of implantation showed a significant improvement in QRS interval which was associated with enhanced conduction velocity and contractility in the infarct zone by increasing connexin 43 levels. These results corroborate that implantation of novel conductive polymeric scaffold in the infarcted heart improved the cardiac contractility and restored ventricular function. Therefore, our approach may be useful in planning future strategies to construct clinically relevant conductive polymer patches for cardiac patients with conduction defects.
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23
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Prins BP, Mead TJ, Brody JA, Sveinbjornsson G, Ntalla I, Bihlmeyer NA, van den Berg M, Bork-Jensen J, Cappellani S, Van Duijvenboden S, Klena NT, Gabriel GC, Liu X, Gulec C, Grarup N, Haessler J, Hall LM, Iorio A, Isaacs A, Li-Gao R, Lin H, Liu CT, Lyytikäinen LP, Marten J, Mei H, Müller-Nurasyid M, Orini M, Padmanabhan S, Radmanesh F, Ramirez J, Robino A, Schwartz M, van Setten J, Smith AV, Verweij N, Warren HR, Weiss S, Alonso A, Arnar DO, Bots ML, de Boer RA, Dominiczak AF, Eijgelsheim M, Ellinor PT, Guo X, Felix SB, Harris TB, Hayward C, Heckbert SR, Huang PL, Jukema JW, Kähönen M, Kors JA, Lambiase PD, Launer LJ, Li M, Linneberg A, Nelson CP, Pedersen O, Perez M, Peters A, Polasek O, Psaty BM, Raitakari OT, Rice KM, Rotter JI, Sinner MF, Soliman EZ, Spector TD, Strauch K, Thorsteinsdottir U, Tinker A, Trompet S, Uitterlinden A, Vaartjes I, van der Meer P, Völker U, Völzke H, Waldenberger M, Wilson JG, Xie Z, Asselbergs FW, Dörr M, van Duijn CM, Gasparini P, Gudbjartsson DF, Gudnason V, Hansen T, Kääb S, Kanters JK, Kooperberg C, Lehtimäki T, Lin HJ, Lubitz SA, Mook-Kanamori DO, Conti FJ, Newton-Cheh CH, Rosand J, Rudan I, Samani NJ, Sinagra G, Smith BH, Holm H, Stricker BH, Ulivi S, Sotoodehnia N, Apte SS, van der Harst P, Stefansson K, Munroe PB, Arking DE, Lo CW, Jamshidi Y. Exome-chip meta-analysis identifies novel loci associated with cardiac conduction, including ADAMTS6. Genome Biol 2018; 19:87. [PMID: 30012220 PMCID: PMC6048820 DOI: 10.1186/s13059-018-1457-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/23/2018] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Genome-wide association studies conducted on QRS duration, an electrocardiographic measurement associated with heart failure and sudden cardiac death, have led to novel biological insights into cardiac function. However, the variants identified fall predominantly in non-coding regions and their underlying mechanisms remain unclear. RESULTS Here, we identify putative functional coding variation associated with changes in the QRS interval duration by combining Illumina HumanExome BeadChip genotype data from 77,898 participants of European ancestry and 7695 of African descent in our discovery cohort, followed by replication in 111,874 individuals of European ancestry from the UK Biobank and deCODE cohorts. We identify ten novel loci, seven within coding regions, including ADAMTS6, significantly associated with QRS duration in gene-based analyses. ADAMTS6 encodes a secreted metalloprotease of currently unknown function. In vitro validation analysis shows that the QRS-associated variants lead to impaired ADAMTS6 secretion and loss-of function analysis in mice demonstrates a previously unappreciated role for ADAMTS6 in connexin 43 gap junction expression, which is essential for myocardial conduction. CONCLUSIONS Our approach identifies novel coding and non-coding variants underlying ventricular depolarization and provides a possible mechanism for the ADAMTS6-associated conduction changes.
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Affiliation(s)
- Bram P Prins
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, SW17 0RE, UK
- Department of Public Health and Primary Care, MRC/BHF Cardiovascular Epidemiology Unit, University of Cambridge, Strangeways Research Laboratory, Worts' Causeway, Cambridge, CB1 8RN, UK
| | - Timothy J Mead
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Jennifer A Brody
- Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA, 98101, USA
| | | | - Ioanna Ntalla
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- NIHR Barts Cardiovascular Biomedical Research Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Nathan A Bihlmeyer
- Predoctoral Training Program in Human Genetics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Marten van den Berg
- Department of Medical Informatics Erasmus MC - University Medical Center, P.O. Box 2040, Rotterdam, 3000, CA, The Netherlands
| | - Jette Bork-Jensen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Stefania Cappellani
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", 34137, Trieste, Italy
| | - Stefan Van Duijvenboden
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- Institute of Cardiovascular Science, University College London, London, WC1E 6BT, UK
| | - Nikolai T Klena
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - George C Gabriel
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Xiaoqin Liu
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Cagri Gulec
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Niels Grarup
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Jeffrey Haessler
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Leanne M Hall
- Department of Cardiovascular Sciences, University of Leicester, Cardiovascular Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
- Leicester NIHR Biomedical Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
| | - Annamaria Iorio
- Cardiovascular Department, Ospedali Riuniti and University of Trieste, 34100, Trieste, Italy
| | - Aaron Isaacs
- CARIM School for Cardiovascular Diseases, Maastricht Center for Systems Biology (MaCSBio), and Department of Biochemistry, Maastricht University, Universiteitssingel 60, Maastricht, 6229 ER, The Netherlands
- Department of Epidemiology, Genetic Epidemiology Unit, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ruifang Li-Gao
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
| | - Honghuang Lin
- Department of Medicine, Section of Computational Biomedicine, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Ching-Ti Liu
- Biostatistics Department, Boston University School of Public Health, Boston, MA, 02118, USA
| | - Leo-Pekka Lyytikäinen
- Department of Clinical Chemistry, Fimlab Laboratories, 33520, Tampere, Finland
- Department of Clinical Chemistry, Faculty of Medicine and Life Sciences, University of Tampere, 33014, Tampere, Finland
| | - Jonathan Marten
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Hao Mei
- Department of Data Science, School of Population Health, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Martina Müller-Nurasyid
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University, Munich, Germany
- German Centre for Cardiovascular Research (DZHK); partner site: Munich Heart Alliance, Munich, Germany
| | - Michele Orini
- Mechanical Engineering Department, University College London, London, WC1E 6BT, UK
- Barts Heart Centre, St Bartholomews Hospital, London, EC1A 7BE, UK
| | - Sandosh Padmanabhan
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, BHF GCRC, Glasgow, G12 8TA, UK
| | - Farid Radmanesh
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, 02114, USA
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Julia Ramirez
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- NIHR Barts Cardiovascular Biomedical Research Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Antonietta Robino
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", 34137, Trieste, Italy
| | - Molly Schwartz
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Jessica van Setten
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, University of Utrecht, Utrecht, the Netherlands
| | - Albert V Smith
- Icelandic Heart Association, 201, Kopavogur, Iceland
- Department of Cardiology, Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Niek Verweij
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Cardiovascular Research Center and Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, 2114.0, USA
| | - Helen R Warren
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- NIHR Barts Cardiovascular Biomedical Research Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Stefan Weiss
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt-University Greifswald, 17475, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research); Partner site Greifswald, 17475, Greifswald, Germany
| | - Alvaro Alonso
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - David O Arnar
- deCODE genetics/Amgen, Inc., 101, Reykjavik, Iceland
- Department of Medicine, Landspitali University Hospital, 101, Reykjavik, Iceland
| | - Michiel L Bots
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands
| | - Rudolf A de Boer
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Anna F Dominiczak
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Mark Eijgelsheim
- Erasmus MC - University Medical Center Rotterdam, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, 02114, USA
| | - Xiuqing Guo
- The Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Division of Genomic Outcomes, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, 90502, USA
| | - Stephan B Felix
- DZHK (German Centre for Cardiovascular Research); Partner site Greifswald, 17475, Greifswald, Germany
- Department of Internal Medicine B - Cardiology, Pneumology, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, 17475, Greifswald, Germany
| | - Tamara B Harris
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Caroline Hayward
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Susan R Heckbert
- Cardiovascular Health Research Unit and the Department of Epidemiology, University of Washington, Seattle, WA, 98101, USA
| | - Paul L Huang
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, 02114, USA
| | - J W Jukema
- Department of Cardiology, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
- Durrer Center for Cardiogenetic Research, Amsterdam, The Netherlands
- Interuniversity Cardiology Institute of The Netherlands, Utrecht, The Netherlands
| | - Mika Kähönen
- Department of Clinical Physiology, Tampere University Hospital, 33521, Tampere, Finland
- Department of Clinical Physiology, Faculty of Medicine and Life Sciences, University of Tampere, 33014, Tampere, Finland
| | - Jan A Kors
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, London, WC1E 6BT, UK
- Barts Heart Centre, St Bartholomews Hospital, London, EC1A 7BE, UK
| | - Lenore J Launer
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Man Li
- Division of Nephrology & Hypertension, Internal Medicine, School of Medicine, University of Utah, Salt Lake City, UT, 84109, USA
| | - Allan Linneberg
- Research Centre for Prevention and Health, Capital Region of Denmark, 2600, Glostrup, Denmark
- Department of Clinical Experimental Research, Rigshospitalet, 2600, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200.0, Copenhagen, Denmark
| | - Christopher P Nelson
- Department of Cardiovascular Sciences, University of Leicester, Cardiovascular Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
- Leicester NIHR Biomedical Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Marco Perez
- Division of Cardiovascular Medicine, Stanford University, Stanford, CA, 94305, USA
| | - Annette Peters
- German Centre for Cardiovascular Research (DZHK); partner site: Munich Heart Alliance, Munich, Germany
- Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research, Neuherberg, Germany
| | - Ozren Polasek
- Faculty of Medicine, University of Split, Split, Croatia
| | - Bruce M Psaty
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology, and Health Services, University of Washington, Seattle, WA, 98101, USA
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, 98101, USA
| | - Olli T Raitakari
- Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, 20521, Turku, Finland
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, 20014, Turku, Finland
| | - Kenneth M Rice
- Department of Biostatistics, University of Washington, Seattle, WA, 98195, USA
| | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences and Departments of Pediatrics and Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, 90502, USA
| | - Moritz F Sinner
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University, Munich, Germany
- German Centre for Cardiovascular Research (DZHK); partner site: Munich Heart Alliance, Munich, Germany
| | - Elsayed Z Soliman
- Epidemiological Cardiology Research Center (EPICARE), Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Tim D Spector
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Konstantin Strauch
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Chair of Genetic Epidemiology, IBE, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Unnur Thorsteinsdottir
- deCODE genetics/Amgen, Inc., 101, Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Andrew Tinker
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- NIHR Barts Cardiovascular Biomedical Research Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Stella Trompet
- Department of Cardiology, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
| | - André Uitterlinden
- Human Genotyping Facility Erasmus MC - University Medical Center Rotterdam, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Ilonca Vaartjes
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands
| | - Peter van der Meer
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt-University Greifswald, 17475, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research); Partner site Greifswald, 17475, Greifswald, Germany
| | - Henry Völzke
- DZHK (German Centre for Cardiovascular Research); Partner site Greifswald, 17475, Greifswald, Germany
- Institute for Community Medicine, University Medicine Greifswald, 17475, Greifswald, Germany
| | - Melanie Waldenberger
- German Centre for Cardiovascular Research (DZHK); partner site: Munich Heart Alliance, Munich, Germany
- Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Research unit of Molecular Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - James G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Zhijun Xie
- TCM Clinical Basis Institute, Zhejiang Chinese Medical University, Hangzhou, 310000, Zhejiang, China
| | - Folkert W Asselbergs
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, University of Utrecht, Utrecht, the Netherlands
- Durrer Center for Cardiovascular Research, Netherlands Heart Institute, Utrecht, the Netherlands
- Institute of Cardiovascular Science, Faculty of Population Health Sciences, University College London, London, UK
- Farr Institute of Health Informatics Research and Institute of Health Informatics, University College London, London, UK
| | - Marcus Dörr
- DZHK (German Centre for Cardiovascular Research); Partner site Greifswald, 17475, Greifswald, Germany
- Department of Internal Medicine B - Cardiology, Pneumology, Infectious Diseases, Intensive Care Medicine, University Medicine Greifswald, 17475, Greifswald, Germany
| | - Cornelia M van Duijn
- Department of Epidemiology, Genetic Epidemiology Unit, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Paolo Gasparini
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100, Trieste, Italy
- Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar
| | - Daniel F Gudbjartsson
- deCODE genetics/Amgen, Inc., 101, Reykjavik, Iceland
- School of Engineering and Natural Sciences, University of Iceland, 101, Reykjavik, Iceland
| | - Vilmundur Gudnason
- Icelandic Heart Association, 201, Kopavogur, Iceland
- Department of Cardiology, Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Stefan Kääb
- Department of Medicine I, University Hospital Munich, Ludwig-Maximilians University, Munich, Germany
- German Centre for Cardiovascular Research (DZHK); partner site: Munich Heart Alliance, Munich, Germany
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Charles Kooperberg
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories, 33520, Tampere, Finland
- Department of Clinical Chemistry, Faculty of Medicine and Life Sciences, University of Tampere, 33014, Tampere, Finland
| | - Henry J Lin
- The Institute for Translational Genomics and Population Sciences and Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Division of Medical Genetics, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, 90502, USA
| | - Steven A Lubitz
- Division of Genomic Outcomes, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, 90502, USA
| | - Dennis O Mook-Kanamori
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, 2300RC, The Netherlands
| | - Francesco J Conti
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | - Christopher H Newton-Cheh
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
- Center for Human Genetic Research and Cardiovascular Research Center, Harvard Medical School and Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Jonathan Rosand
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, 02114, USA
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Igor Rudan
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, EH8 9AG, UK
| | - Nilesh J Samani
- Department of Cardiovascular Sciences, University of Leicester, Cardiovascular Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
- Leicester NIHR Biomedical Research Centre, Glenfield Hospital, Leicester, LE3 9QP, UK
| | - Gianfranco Sinagra
- Cardiovascular Department, Ospedali Riuniti and University of Trieste, 34100, Trieste, Italy
| | - Blair H Smith
- Division of Population Health Sciences, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Hilma Holm
- deCODE genetics/Amgen, Inc., 101, Reykjavik, Iceland
| | - Bruno H Stricker
- Department of Epidemiology Erasmus MC - University Medical Center Rotterdam, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands
| | - Sheila Ulivi
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", 34137, Trieste, Italy
| | - Nona Sotoodehnia
- Division of Cardiology, Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, 98101, USA
| | - Suneel S Apte
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Pim van der Harst
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Durrer Center for Cardiovascular Research, Netherlands Heart Institute, Utrecht, the Netherlands
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Kari Stefansson
- deCODE genetics/Amgen, Inc., 101, Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, 101, Reykjavik, Iceland
| | - Patricia B Munroe
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- NIHR Barts Cardiovascular Biomedical Research Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Dan E Arking
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Yalda Jamshidi
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, SW17 0RE, UK.
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St George's University of London, London, UK.
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Zhong C, Chang H, Wu Y, Zhou L, Wang Y, Wang M, Wu P, Qi Z, Zou J. Up-regulated Cx43 phosphorylation at Ser368 prolongs QRS duration in myocarditis. J Cell Mol Med 2018; 22:3537-3547. [PMID: 29664174 PMCID: PMC6010859 DOI: 10.1111/jcmm.13631] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 03/14/2018] [Indexed: 01/26/2023] Open
Abstract
Prolongation of QRS duration in electrocardiogram is one of the risk factors for morbidity and mortality in many kinds of cardiac diseases. However, its molecular mechanism is unknown. In this study, utilizing experimental autoimmune myocarditis (EAM) as a disease model, we show that the prolongation of QRS duration is accompanied by elevated phosphorylation of connexin 43 (Cx43) at Ser368 (pS368Cx43). In cultured cells, inflammatory cytokine IL‐1β activates p38 MAPK to up‐regulate pS368Cx43 and impairs cell‐to‐cell communication. In isolated hearts of normal rats, perfusion of IL‐1β not only increases pS368Cx43 but also impairs cell‐to‐cell communication and prolongs QRS duration. Furthermore, blockade of p38 MAPK down‐regulates pS368Cx43, improves cell‐to‐cell communication and reduces QRS duration in EAM. These findings suggest that up‐regulation of pS368Cx43 by IL‐1β via p38 MAPK contributes to the prolongation of QRS duration and could be a therapeutic target for myocarditis‐induced prolongation of QRS duration.
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Affiliation(s)
- Chunlian Zhong
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - He Chang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Yang Wu
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Li Zhou
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Yan Wang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China.,Department of Cardiology, Affiliated Cardiovascular Hospital of Xiamen University, Xiamen, China
| | - Mingyan Wang
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Peng Wu
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
| | - Jun Zou
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen, China
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25
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van Eldik W, den Adel B, Monshouwer-Kloots J, Salvatori D, Maas S, van der Made I, Creemers EE, Frank D, Frey N, Boontje N, van der Velden J, Steendijk P, Mummery C, Passier R, Beqqali A. Z-disc protein CHAPb induces cardiomyopathy and contractile dysfunction in the postnatal heart. PLoS One 2017; 12:e0189139. [PMID: 29206857 PMCID: PMC5716575 DOI: 10.1371/journal.pone.0189139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 11/20/2017] [Indexed: 12/17/2022] Open
Abstract
Aims The Z-disc is a crucial structure of the sarcomere and is implicated in mechanosensation/transduction. Dysregulation of Z-disc proteins often result in cardiomyopathy. We have previously shown that the Z-disc protein Cytoskeletal Heart-enriched Actin-associated Protein (CHAP) is essential for cardiac and skeletal muscle development. Furthermore, the CHAP gene has been associated with atrial fibrillation in humans. Here, we studied the misregulated expression of CHAP isoforms in heart disease. Methods and results Mice that underwent transverse aortic constriction and calcineurin transgenic (Tg) mice, both models of experimental heart failure, displayed a significant increase in cardiac expression of fetal isoform CHAPb. To investigate whether increased expression of CHAPb postnatally is sufficient to induce cardiomyopathy, we generated CHAPb Tg mice under the control of the cardiac-specific αMHC promoter. CHAPb Tg mice displayed cardiac hypertrophy, interstitial fibrosis and enlargement of the left atrium at three months, which was more pronounced at the age of six months. Hypertrophy and fibrosis were confirmed by evidence of activation of the hypertrophic gene program (Nppa, Nppb, Myh7) and increased collagen expression, respectively. Connexin40 and 43 were downregulated in the left atrium, which was associated with delayed atrioventricular conduction. Tg hearts displayed both systolic and diastolic dysfunction partly caused by impaired sarcomere function evident from a reduced force generating capacity of single cardiomyocytes. This co-incided with activation of the actin signalling pathway leading to the formation of stress fibers. Conclusion This study demonstrated that the fetal isoform CHAPb initiates progression towards cardiac hypertrophy, which is accompanied by delayed atrioventricular conduction and diastolic dysfunction. Moreover, CHAP may be a novel therapeutic target or candidate gene for screening in cardiomyopathies and atrial fibrillation.
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Affiliation(s)
- Willemijn van Eldik
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
- Interuniversity Cardiology Institute of the Netherlands (ICIN), Utrecht, The Netherlands
| | - Brigit den Adel
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Daniela Salvatori
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
- Central Laboratory Animal Facility, Leiden University Medical Center, Leiden, The Netherlands
| | - Saskia Maas
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
- Central Laboratory Animal Facility, Leiden University Medical Center, Leiden, The Netherlands
| | - Ingeborg van der Made
- Department of Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Esther E. Creemers
- Department of Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Derk Frank
- Department of Cardiology and Angiology, Universitätsklinikum Schleswig-Holstein (UKSH), University of Kiel, Kiel, Germany
| | - Norbert Frey
- Department of Cardiology and Angiology, Universitätsklinikum Schleswig-Holstein (UKSH), University of Kiel, Kiel, Germany
| | - Nicky Boontje
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Jolanda van der Velden
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Paul Steendijk
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Christine Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert Passier
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
| | - Abdelaziz Beqqali
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
- * E-mail:
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26
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Ren J, Xu Q, Chen X, Li W, Guo K, Zhao Y, Wang Q, Zhang Z, Peng H, Li YG. Superaligned Carbon Nanotubes Guide Oriented Cell Growth and Promote Electrophysiological Homogeneity for Synthetic Cardiac Tissues. Adv Mater 2017; 29:1702713. [PMID: 29024059 DOI: 10.1002/adma.201702713] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/19/2017] [Indexed: 05/21/2023]
Abstract
Cardiac engineering of patches and tissues is a promising option to restore infarcted hearts, by seeding cardiac cells onto scaffolds and nurturing their growth in vitro. However, current patches fail to fully imitate the hierarchically aligned structure in the natural myocardium, the fast electrotonic propagation, and the subsequent synchronized contractions. Here, superaligned carbon-nanotube sheets (SA-CNTs) are explored to culture cardiomyocytes, mimicking the aligned structure and electrical-impulse transmission behavior of the natural myocardium. The SA-CNTs not only induce an elongated and aligned cell morphology of cultured cardiomyocytes, but also provide efficient extracellular signal-transmission pathways required for regular and synchronous cell contractions. Furthermore, the SA-CNTs can reduce the beat-to-beat and cell-to-cell dispersion in repolarization of cultured cells, which is essential for a normal beating rhythm, and potentially reduce the occurrence of arrhythmias. Finally, SA-CNT-based flexible one-piece electrodes demonstrate a multipoint pacing function. These combined high properties make SA-CNTs promising in applications in cardiac resynchronization therapy in patients with heart failure and following myocardial infarctions.
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Affiliation(s)
- Jing Ren
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Quanfu Xu
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Xiaomeng Chen
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Wei Li
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Kai Guo
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Yang Zhao
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, and Laboratory of Advanced Materials, Fudan University, Shanghai, 200438, China
| | - Qian Wang
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Zhitao Zhang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, and Laboratory of Advanced Materials, Fudan University, Shanghai, 200438, China
| | - Huisheng Peng
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, and Laboratory of Advanced Materials, Fudan University, Shanghai, 200438, China
| | - Yi-Gang Li
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
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27
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Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
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28
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Tse G, Liu T, Li G, Keung W, Yeo JM, Fiona Chan YW, Yan BP, Chan YS, Wong SH, Li RA, Zhao J, Wu WKK, Wong WT. Effects of pharmacological gap junction and sodium channel blockade on S1S2 restitution properties in Langendorff-perfused mouse hearts. Oncotarget 2017; 8:85341-85352. [PMID: 29156723 PMCID: PMC5689613 DOI: 10.18632/oncotarget.19675] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 05/23/2017] [Indexed: 12/19/2022] Open
Abstract
Gap junctions and sodium channels are the major molecular determinants of normal and abnormal electrical conduction through the myocardium, however, their exact contributions to arrhythmogenesis are unclear. We examined conduction and recovery properties of regular (S1) and extrasystolic (S2) action potentials (APs), S1S2 restitution and ventricular arrhythmogenicity using the gap junction and sodium channel inhibitor heptanol (2 mM) in Langendorff-perfused mouse hearts (n=10). Monophasic action potential recordings obtained during S1S2 pacing showed that heptanol increased the proportion of hearts showing inducible ventricular tachycardia (0/10 vs. 5/8 hearts (Fisher’s exact test, P < 0.05), prolonged activation latencies of S1 and S2 APs, thereby decreasing S2/S1 activation latency ratio (ANOVA, P < 0.05) despite prolonged ventricular effective refractory period (VERP). It did not alter S1 action potential duration at 90% repolarization (APD90) but prolonged S2 APD90 (P < 0.05), thereby increasing S2/S1 APD90 ratio (P < 0.05). It did not alter maximum conduction velocity (CV) restitution gradient or maximum CV reductions but decreased the restitution time constant (P < 0.05). It increased maximal APD90 restitution gradient (P < 0.05) without altering critical diastolic interval or maximum APD90 reductions. Pro-arrhythmic effects of 2 mM heptanol are explicable by delayed conduction and abnormal electrical restitution. We concluded that gap junctions modulated via heptanol (0.05 mM) increased arrhythmogenicity through a delay in conduction, while sodium channel inhibition by a higher concentration of heptanol (2 mM) increased arrhythmogenicity via additional mechanisms, such as abnormalities in APDs and CV restitution.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.,Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Guangping Li
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Wendy Keung
- Dr. Li Dak-Sum Research Centre, The University of Hong Kong-Karolinska Institutet Collaboration in Regenerative Medicine, Hong Kong, China
| | - Jie Ming Yeo
- Faculty of Medicine, Imperial College London, London, UK
| | | | - Bryan P Yan
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Yat Sun Chan
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Sunny Hei Wong
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.,Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Ronald A Li
- Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, Solna, Sweden
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - William K K Wu
- Department of Anaesthesia and Intensive Care, State Key Laboratory of Digestive Disease, LKS Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wing Tak Wong
- School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
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29
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Lao S, Xu J, Liu Y, Cai S, Lin L, Zhang J, Cai D, Yin S. A comparative study of the influence of two types of PHEMA stents on the differentiation of ASCs to myocardial cells. Mol Med Rep 2017; 16:507-514. [PMID: 28586071 PMCID: PMC5482065 DOI: 10.3892/mmr.2017.6680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 02/07/2017] [Indexed: 01/16/2023] Open
Abstract
In the present study, subcutaneous fat was obtained from adult women that had undergone conventional liposuction surgery. A comparative study was performed to investigate the effect of transparent and white poly-β-hydroxyethyl methacrylate (PHEMA) stents, which have different surface and cross-sectional morphological characteristics, on the differentiation of adipose-derived stem cells (ASCs) into myocardial cells. The cell counting kit-8 assay revealed that cell growth increased at varying rates among the different treatment groups. The absorbance of the experimental transparent PHEMA treated group increased in a time-dependent manner with the duration of incubation. The highest levels of proliferation were observed in the transparent PHEMA group. In addition, the transparent PHEMA treated group exhibited the strongest cell adhesion ability, which was significantly different to that of the white PHEMA group (P<0.01 and P<0.05 for Matrigel and fibronectin assay, respectively). Comparisons between the two stent materials with the inducer control group revealed statistically significant differences in the rate of ASC differentiation (P<0.05). The level of differentiation was the greatest in the transparent PHEMA group, and was significantly different to the white PHEMA group (P<0.05) and the blank control group (P<0.01). The results suggest that the inducers 5-aza-2-deoxycytidin and laminin, and material microstructure stents effectively promote the proliferation, growth and adhesion of ASCs. However, the transparent material microstructure may be a more suitable candidate for ASC-associated injections. The present study provides further evidence that a PHEMA stent structure, comprised of a high number of matrixes and a low water content, induces a high level of ASC differentiation to myocardial cells.
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Affiliation(s)
- Shen Lao
- Department of Cardiothoracic Surgery, The Third Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Jing Xu
- Department of Ultrasonography, The First Affiliated Hospital, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510080, P.R. China
| | - Yunqi Liu
- Department of Cardiac Surgery, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Songwang Cai
- Department of Cardiothoracic Surgery, The Third Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Lin Lin
- Department of Cardiac Surgery, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Junhang Zhang
- Department of Cardiothoracic Surgery, The Third Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Dongmei Cai
- Department of Cardiac Surgery, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Shengli Yin
- Department of Cardiac Surgery, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
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30
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Le Dour C, Macquart C, Sera F, Homma S, Bonne G, Morrow JP, Worman HJ, Muchir A. Decreased WNT/β-catenin signalling contributes to the pathogenesis of dilated cardiomyopathy caused by mutations in the lamin a/C gene. Hum Mol Genet 2017; 26:333-343. [PMID: 28069793 PMCID: PMC6075603 DOI: 10.1093/hmg/ddw389] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/21/2016] [Accepted: 11/07/2016] [Indexed: 12/22/2022] Open
Abstract
Cardiomyopathy caused by lamin A/C gene (LMNA) mutations (hereafter referred as LMNA cardiomyopathy) is characterized by cardiac conduction abnormalities and left ventricular systolic dysfunction predisposing to heart failure. Previous cardiac transcriptional profiling of LmnaH222P/H222P mouse, a small animal model of LMNA cardiomyopathy, suggested decreased WNT/β-catenin signalling. We confirmed decreased WNT/β-catenin signalling in the hearts of these mice by demonstrating decreased β-catenin and WNT proteins. This was correlated with increased expression of soluble Frizzled-related proteins that modulate the WNT/β-catenin signalling pathway. Hearts of LmnaH222P/H222P mice also demonstrated lowered expression of the gap junction connexin 43. Activation of WNT/β-catenin activity with 6-bromoindirubin-3'-oxime improved cardiac contractility and ameliorated intraventricular conduction defects in LmnaH222P/H222P mice, which was associated with increased expression of myocardial connexin 43. These results indicate that decreased WNT/β-catenin contributes to the pathophysiology of LMNA cardiomyopathy and that drugs activating β-catenin may be beneficial in affected individuals.
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Affiliation(s)
- Caroline Le Dour
- Department of Medicine, College of Physicians and Surgeons
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Coline Macquart
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, G.H. Pitié Salpêtrière, F-75651 Paris Cedex 13, France
| | - Fusako Sera
- Department of Medicine, College of Physicians and Surgeons
| | - Shunichi Homma
- Department of Medicine, College of Physicians and Surgeons
| | - Gisele Bonne
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, G.H. Pitié Salpêtrière, F-75651 Paris Cedex 13, France
| | - John P. Morrow
- Department of Medicine, College of Physicians and Surgeons
| | - Howard J. Worman
- Department of Medicine, College of Physicians and Surgeons
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Antoine Muchir
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, G.H. Pitié Salpêtrière, F-75651 Paris Cedex 13, France
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31
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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32
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Tse G, Yeo JM, Tse V, Kwan J, Sun B. Gap junction inhibition by heptanol increases ventricular arrhythmogenicity by reducing conduction velocity without affecting repolarization properties or myocardial refractoriness in Langendorff-perfused mouse hearts. Mol Med Rep 2016; 14:4069-4074. [PMID: 27633494 PMCID: PMC5101880 DOI: 10.3892/mmr.2016.5738] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/18/2016] [Indexed: 12/31/2022] Open
Abstract
In the current study, arrhythmogenic effects of the gap junction inhibitor heptanol (0.05 mM) were examined in Langendorff-perfused mouse hearts. Monophasic action potential recordings were obtained from the left ventricular epicardium during right ventricular pacing. Regular activity was observed both prior and subsequent to application of heptanol in all of the 12 hearts studied during 8 Hz pacing. By contrast, induced ventricular tachycardia (VT) was observed after heptanol treatment in 6/12 hearts using a S1S2 protocol (Fisher's exact test; P<0.05). The arrhythmogenic effects of heptanol were associated with increased activation latencies from 13.2±0.6 to 19.4±1.3 msec (analysis of variance; P<0.001) and reduced conduction velocities (CVs) from 0.23±0.01 to 0.16±0.01 msec (analysis of variance; P<0.001) in an absence of alterations in action potential durations (ADPs) at x=90% (38.0±1.0 vs. 38.3±1.8 msec), 70% (16.8±1.0 vs. 19.5±0.9 msec), 50% (9.2±0.8 vs. 10.1±0.6 msec) or 30% (4.8±0.5 vs. 6.3±0.6 msec) repolarization (APDx) or in effective refractory period (ERPs) (39.6±1.9 vs. 40.6±3.0 msec) (all P>0.05). Consequently, excitation wavelengths (λ; CV x ERP) were reduced from 9.1±0.6 to 6.5±0.6 mm (P<0.01), however critical intervals for re‑excitation (APD90 ‑ ERP) were unaltered (‑1.1±2.4 vs. ‑2.3±1.8 msec; P>0.05). Together, these observations demonstrate for the first time, to the best of our knowledge, that inhibition of gap junctions alone using a low heptanol concentration (0.05 mM) was able to reduce CV, which alone was sufficient to permit the induction of VT using premature stimulation by reducing λ, which therefore appears central in the determination of arrhythmic tendency.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, P.R. China
| | - Jie Ming Yeo
- Faculty of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Vivian Tse
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Joseph Kwan
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Bing Sun
- Department of Cardiology, Tongji University Affiliated Tongji Hospital, Shanghai 200065, P.R. China
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33
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Tse G, Yeo JM, Chan YW, Lai ETHL, Yan BP. What Is the Arrhythmic Substrate in Viral Myocarditis? Insights from Clinical and Animal Studies. Front Physiol 2016; 7:308. [PMID: 27493633 PMCID: PMC4954848 DOI: 10.3389/fphys.2016.00308] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/06/2016] [Indexed: 01/25/2023] Open
Abstract
Sudden cardiac death (SCD) remains an unsolved problem in the twenty-first century. It is often due to rapid onset, ventricular arrhythmias caused by a number of different clinical conditions. A proportion of SCD patients have identifiable diseases such as cardiomyopathies, but for others, the causes are unknown. Viral myocarditis is becoming increasingly recognized as a contributor to unexplained mortality, and is thought to be a major cause of SCD in the first two decades of life. Myocardial inflammation, ion channel dysfunction, electrophysiological, and structural remodeling may play important roles in generating life-threatening arrhythmias. The aim of this review article is to examine the electrophysiology of action potential conduction and repolarization and the mechanisms by which their derangements lead to triggered and reentrant arrhythmogenesis. By synthesizing experimental evidence from pre-clinical and clinical studies, a framework of how host (inflammation), and viral (altered cellular signaling) factors can induce ion electrophysiological and structural remodeling is illustrated. Current pharmacological options are mainly supportive, which may be accompanied by mechanical circulatory support. Heart transplantation is the only curative option in the worst case scenario. Future strategies for the management of viral myocarditis are discussed.
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Affiliation(s)
- Gary Tse
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, University of Hong KongHong Kong, China
- Department of Medicine and Therapeutics, The Chinese University of Hong KongHong Kong, China
| | - Jie M. Yeo
- Faculty of Medicine, Imperial College LondonLondon, UK
| | - Yin Wah Chan
- Department of Psychology, School of Biological Sciences, University of CambridgeCambridge, UK
| | - Eric T. H. Lai Lai
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, University of Hong KongHong Kong, China
| | - Bryan P. Yan
- Department of Medicine and Therapeutics, The Chinese University of Hong KongHong Kong, China
- Department of Epidemiology and Preventive Medicine, Monash UniversityMelbourne, VIC, Australia
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34
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Abstract
Electrical remodeling involves alterations in the electrophysiologic milieu of myocardium in various disease states, such as ventricular hypertrophy, heart failure, atrial tachyarrhythmias, myocardial ischemia, and infarction that are associated with cardiac arrhythmias. Although research in this area dates back to early part of the 19th century, we still lack the exact knowledge of ionic remodeling, the role of various genes and channel proteins, and their relevance for the newer antiarrhythmic therapies. Structural remodeling may also have an impact on the electrical remodeling process, although differences in both structural and electrical remodeling are associated with different disease states. Various electrophysiologic, cellular, and structural alterations, including anisotropic conduction, increased intracellular calcium levels, and gap junction remodeling predispose to increased dispersion of action potential duration and refractoriness. This constitutes a favorable substrate for early and late afterdepolarizations and reentrant arrhythmias. Studying the role of ionic remodeling in the initiation and propagation of cardiac arrhythmias has significant relevance for developing newer antiarrhythmic therapies, for identifying patients at risk of developing fatal arrhythmias, and for implementing effective preventive measures. Further research is required to understand the specific effects of individual ion channel remodeling, to understand the signal transduction mechanisms, and to address whether detrimental effects of electrical remodeling can be altered.
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Affiliation(s)
- Sanjeev Wasson
- Division of Cardiology, University of Missouri Hospital, Columbia, Missouri 65212, USA
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35
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Tse G, Yeo JM. Conduction abnormalities and ventricular arrhythmogenesis: The roles of sodium channels and gap junctions. Int J Cardiol Heart Vasc 2015; 9:75-82. [PMID: 26839915 PMCID: PMC4695916 DOI: 10.1016/j.ijcha.2015.10.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/19/2015] [Indexed: 01/12/2023]
Abstract
Ventricular arrhythmias arise from disruptions in the normal orderly sequence of electrical activation and recovery of the heart. They can be categorized into disorders affecting predominantly cellular depolarization or repolarization, or those involving action potential (AP) conduction. This article briefly discusses the factors causing conduction abnormalities in the form of unidirectional conduction block and reduced conduction velocity (CV). It then examines the roles that sodium channels and gap junctions play in AP conduction. Finally, it synthesizes experimental results to illustrate molecular mechanisms of how abnormalities in these proteins contribute to such conduction abnormalities and hence ventricular arrhythmogenesis, in acquired pathologies such as acute ischaemia and heart failure, as well as inherited arrhythmic syndromes.
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Affiliation(s)
- Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Jie Ming Yeo
- School of Medicine, Imperial College London, SW7 2AZ, UK
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36
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Brandenburg S, Arakel EC, Schwappach B, Lehnart SE. The molecular and functional identities of atrial cardiomyocytes in health and disease. Biochim Biophys Acta 2015; 1863:1882-93. [PMID: 26620800 DOI: 10.1016/j.bbamcr.2015.11.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 12/28/2022]
Abstract
Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has become clear that the cell fate of atrial cardiomyocytes depends significantly on transcription programs that might control thousands of differentially expressed genes. Atrial muscle membranes propagate action potentials and activate myofilament force generation, producing overall faster contractions than ventricular muscles. While atria-specific excitation and contractility depend critically on intracellular Ca(2+) signalling, voltage-dependent L-type Ca(2+) channels and ryanodine receptor Ca(2+) release channels are each expressed at high levels similar to ventricles. However, intracellular Ca(2+) transients in atrial cardiomyocytes are markedly heterogeneous and fundamentally different from ventricular cardiomyocytes. In addition, differential atria-specific K(+) channel expression and trafficking confer unique electrophysiological and metabolic properties. Because diseased atria have the propensity to perpetuate fast arrhythmias, we discuss our understanding about the cell-specific mechanisms that lead to metabolic and/or mitochondrial dysfunction in atrial fibrillation. Interestingly, recent work identified potential atria-specific mechanisms that lead to early contractile dysfunction and metabolic remodelling, suggesting highly interdependent metabolic, electrical, and contractile pathomechanisms. Hence, the objective of this review is to provide an integrated model of atrial cardiomyocytes, from tissue-specific cell properties, intracellular metabolism, and excitation-contraction (EC) coupling to early pathological changes, in particular metabolic dysfunction and tissue remodelling due to atrial fibrillation and aging. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Sören Brandenburg
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Eric C Arakel
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Blanche Schwappach
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany
| | - Stephan E Lehnart
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany.
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37
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Sharma P, Abbasi C, Lazic S, Teng ACT, Wang D, Dubois N, Ignatchenko V, Wong V, Liu J, Araki T, Tiburcy M, Ackerley C, Zimmermann WH, Hamilton R, Sun Y, Liu PP, Keller G, Stagljar I, Scott IC, Kislinger T, Gramolini AO. Evolutionarily conserved intercalated disc protein Tmem65 regulates cardiac conduction and connexin 43 function. Nat Commun 2015; 6:8391. [PMID: 26403541 DOI: 10.1038/ncomms9391] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 08/18/2015] [Indexed: 02/07/2023] Open
Abstract
Membrane proteins are crucial to heart function and development. Here we combine cationic silica-bead coating with shotgun proteomics to enrich for and identify plasma membrane-associated proteins from primary mouse neonatal and human fetal ventricular cardiomyocytes. We identify Tmem65 as a cardiac-enriched, intercalated disc protein that increases during development in both mouse and human hearts. Functional analysis of Tmem65 both in vitro using lentiviral shRNA-mediated knockdown in mouse cardiomyocytes and in vivo using morpholino-based knockdown in zebrafish show marked alterations in gap junction function and cardiac morphology. Molecular analyses suggest that Tmem65 interaction with connexin 43 (Cx43) is required for correct localization of Cx43 to the intercalated disc, since Tmem65 deletion results in marked internalization of Cx43, a shorter half-life through increased degradation, and loss of Cx43 function. Our data demonstrate that the membrane protein Tmem65 is an intercalated disc protein that interacts with and functionally regulates ventricular Cx43.
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Affiliation(s)
- Parveen Sharma
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Cynthia Abbasi
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Savo Lazic
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Allen C T Teng
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Dingyan Wang
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7
| | - Nicole Dubois
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Vladimir Ignatchenko
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Victoria Wong
- Departments of Molecular Genetics and Biochemistry, Donnelly Centre,, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Jun Liu
- Department of Mechanical and Industrial Engineering, Advanced Micro and Nanosystems Laboratory, University of Toronto, Toronto, Ontario, Canada M5S 3G8
| | - Toshiyuki Araki
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Malte Tiburcy
- Institute of Pharmacology, University Medical Center Göttingen and DZHK (German Center for Cardiovascular Research) partner site Göttingen, Göttingen 37075, Germany
| | - Cameron Ackerley
- The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | - Wolfram H Zimmermann
- Institute of Pharmacology, University Medical Center Göttingen and DZHK (German Center for Cardiovascular Research) partner site Göttingen, Göttingen 37075, Germany
| | - Robert Hamilton
- The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, Advanced Micro and Nanosystems Laboratory, University of Toronto, Toronto, Ontario, Canada M5S 3G8
| | - Peter P Liu
- Toronto General Hospital, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Gordon Keller
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada M5G 1L7
| | - Igor Stagljar
- Departments of Molecular Genetics and Biochemistry, Donnelly Centre,, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Ian C Scott
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.,The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada M5G 1L7.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada M5G 2M9
| | - Anthony O Gramolini
- Department of Physiology, University of Toronto, Toronto General Hospital Research Institute, Toronto, Ontario, Canada M5G 1L7.,Ted Rogers Centre for Heart Research, Toronto, Ontario, Canada M5G 1L7
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Opel A, Nobles M, Montaigne D, Finlay M, Anderson N, Breckenridge R, Tinker A. Absence of the Regulator of G-protein Signaling, RGS4, Predisposes to Atrial Fibrillation and Is Associated with Abnormal Calcium Handling. J Biol Chem 2015; 290:19233-44. [PMID: 26088132 PMCID: PMC4521044 DOI: 10.1074/jbc.m115.666719] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 06/15/2015] [Indexed: 01/11/2023] Open
Abstract
The description of potential molecular substrates for predisposition to atrial fibrillation (AF) is incomplete, and it is unknown what role regulators of G-protein signaling might play. We address whether the attenuation of RGS4 function may promote AF and the mechanism through which this occurs. For this purpose, we studied a mouse with global genetic deletion of RGS4 (RGS4(-/-)) and the normal littermate controls (RGS4(+/+)). In vivo electrophysiology using atrial burst pacing revealed that mice with global RGS4 deletion developed AF more frequently than control littermates. Isolated atrial cells from RGS4(-/-) mice show an increase in Ca(2+) spark frequency under basal conditions and after the addition of endothelin-1 and abnormal spontaneous Ca(2+) release events after field stimulation. Isolated left atria studied on a multielectrode array revealed modest changes in path length for re-entry but abnormal electrical events after a pacing train in RGS4(-/-) mice. RGS4 deletion results in a predisposition to atrial fibrillation from enhanced activity in the Gαq/11-IP3 pathway, resulting in abnormal Ca(2+) release and corresponding electrical events.
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Affiliation(s)
- Aaisha Opel
- From the British Heart Foundation Laboratories, Department of Medicine, University College London, Rayne Institute, London WC1E 6JJ, United Kingdom and the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
| | - Muriel Nobles
- the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
| | - David Montaigne
- the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
| | - Malcolm Finlay
- the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
| | - Naomi Anderson
- the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
| | - Ross Breckenridge
- From the British Heart Foundation Laboratories, Department of Medicine, University College London, Rayne Institute, London WC1E 6JJ, United Kingdom and
| | - Andrew Tinker
- From the British Heart Foundation Laboratories, Department of Medicine, University College London, Rayne Institute, London WC1E 6JJ, United Kingdom and the William Harvey Heart Centre, Barts & The London School of Medicine & Dentistry, London EC1M 6BQ, United Kingdom
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39
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Abstract
Optimal cardiac function depends on proper timing of excitation and contraction in various regions of the heart, as well as on appropriate heart rate. This is accomplished via specialized electrical properties of various components of the system, including the sinoatrial node, atria, atrioventricular node, His-Purkinje system, and ventricles. Here we review the major regionally determined electrical properties of these cardiac regions and present the available data regarding the molecular and ionic bases of regional cardiac function and dysfunction. Understanding these differences is of fundamental importance for the investigation of arrhythmia mechanisms and pharmacotherapy.
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Affiliation(s)
- Daniel C Bartos
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California Davis, Davis, California, USA
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George SA, Sciuto KJ, Lin J, Salama ME, Keener JP, Gourdie RG, Poelzing S. Extracellular sodium and potassium levels modulate cardiac conduction in mice heterozygous null for the Connexin43 gene. Pflugers Arch 2015; 467:2287-97. [PMID: 25771952 DOI: 10.1007/s00424-015-1698-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/18/2015] [Accepted: 03/02/2015] [Indexed: 11/27/2022]
Abstract
UNLABELLED Several studies have disagreed on measurements of cardiac conduction velocity (CV) in mice with a heterozygous knockout of the connexin gene Gja1--a mutation that reduces the gap junction (GJ) protein, Connexin43 (Cx43), by 50 %. We noted that perfusate ionic composition varied between studies and hypothesized that extracellular ionic concentration modulates CV dependence on GJs. CV was measured by optically mapping wild-type (WT) and heterozygous null (HZ) hearts serially perfused with solutions previously associated with no change (Solution 1) or CV slowing (Solution 2). In WT hearts, CV was similar for Solutions 1 and 2. However, consistent with the hypothesis, Solution 2 in HZ hearts slowed transverse CV (CVT) relative to Solution 1. Previously, we showed CV slowing in a manner consistent with ephaptic conduction correlated with increased perinexal inter-membrane width (W P) at GJ edges. Thus, W P was measured following perfusion with systematically adjusted [Na(+)]o and [K(+)]o in Solutions 1 and 2. A wider W P was associated with reduced CVT in WT and HZ hearts, with the greatest effect in HZ hearts. Increasing [Na(+)]o increased CVT only in HZ hearts. Increasing [K(+)]o slowed CVT in both WT and HZ hearts with large W P but only in HZ hearts with narrow W P. CONCLUSION When perinexi are wide, decreasing excitability by modulating [Na(+)]o and [K(+)]o increases CV sensitivity to reduced Cx43. By contrast, CV is less sensitive to Cx43 and ion composition when perinexi are narrow. These results are consistent with cardiac conduction dependence on both GJ and non-GJ (ephaptic) mechanisms.
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Affiliation(s)
- Sharon A George
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Center for Heart and Regenerative Medicine, Virginia Tech Carilion Research Institute, 2 Riverside Circle, Roanoke, VA, 24016, USA
| | - Katherine J Sciuto
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Joyce Lin
- Department of Mathematics, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Mohamed E Salama
- Department of Pathology, University of Utah and ARUP Reference Lab Institute of Research, Salt Lake City, UT, USA
| | - James P Keener
- Department of Mathematics, University of Utah, Salt Lake City, UT, USA
| | - Robert G Gourdie
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Center for Heart and Regenerative Medicine, Virginia Tech Carilion Research Institute, 2 Riverside Circle, Roanoke, VA, 24016, USA
| | - Steven Poelzing
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
- Center for Heart and Regenerative Medicine, Virginia Tech Carilion Research Institute, 2 Riverside Circle, Roanoke, VA, 24016, USA.
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41
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Kessler EL, Boulaksil M, van Rijen HVM, Vos MA, van Veen TAB. Passive ventricular remodeling in cardiac disease: focus on heterogeneity. Front Physiol 2014; 5:482. [PMID: 25566084 PMCID: PMC4273631 DOI: 10.3389/fphys.2014.00482] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/24/2014] [Indexed: 12/20/2022] Open
Abstract
Passive ventricular remodeling is defined by the process of molecular ventricular adaptation to different forms of cardiac pathophysiology. It includes changes in tissue architecture, such as hypertrophy, fiber disarray, alterations in cell size and fibrosis. Besides that, it also includes molecular remodeling of gap junctions, especially those composed by Connexin43 proteins (Cx43) in the ventricles that affect cell-to-cell propagation of the electrical impulse, and changes in the sodium channels that modify excitability. All those alterations appear mainly in a heterogeneous manner, creating irregular and inhomogeneous electrical and mechanical coupling throughout the heart. This can predispose to reentry arrhythmias and adds to a further deterioration into heart failure. In this review, passive ventricular remodeling is described in Hypertrophic Cardiomyopathy (HCM), Dilated Cardiomyopathy (DCM), Ischemic Cardiomyopathy (ICM), and Arrhythmogenic Cardiomyopathy (ACM), with a main focus on the heterogeneity of those alterations mentioned above.
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Affiliation(s)
- Elise L Kessler
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Mohamed Boulaksil
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands ; Department of Cardiology, Radboud University Medical Center Nijmegen, Netherlands
| | - Harold V M van Rijen
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Marc A Vos
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Toon A B van Veen
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
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42
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Bacharova L, Ugander M. Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging. Ann Noninvasive Electrocardiol 2014; 19:524-33. [PMID: 25367364 PMCID: PMC6932615 DOI: 10.1111/anec.12223] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow-Lyon, Romhilt-Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging with echocardiography or cardiovascular magnetic resonance imaging (CMR). However, LVH can be the result of diverse etiologies, and LVH is also characterized by pathological changes in myocardial tissue characteristics on the genetic, molecular, cellular, and tissue level beyond a pure increase in the number of otherwise normal cardiomyocytes. For example, slowed conduction velocity through the myocardium, which can be due to diffuse myocardial fibrosis, has been shown to be an important determinant of conventional ECG LVH criteria regardless of LV mass. Myocardial tissue characterization by CMR has emerged to not only quantify LV mass, but also detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, myocarditis, fatty replacement, myocardial disarray, and myocardial deposition of amyloid proteins (amyloidosis), glycolipids (Fabry disease), or iron (siderosis). This can be undertaken using CMR techniques including late gadolinium enhancement (LGE), T1 mapping, T2 mapping, T2* mapping, extracellular volume fraction (ECV) mapping, fat/water-weighted imaging, and diffusion tensor CMR. This review presents an overview of current and emerging concepts regarding the diagnostic possibilities of both ECG and CMR for LVH in an attempt to narrow gaps in our knowledge regarding the ECG diagnosis of LVH.
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Affiliation(s)
- Ljuba Bacharova
- International Laser CenterBratislavaSlovak Republic
- Institute of PathophysiologyMedical SchoolComenius UniversityBratislavaSlovak Republic
| | - Martin Ugander
- Department of Clinical PhysiologyKarolinska Institute and Karolinska University HospitalStockholmSweden
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43
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Abstract
With each heartbeat, billions of cardiomyocytes work in concert to propagate the electrical excitation needed to effectively circulate blood. Regulated expression and timely delivery of connexin proteins to form gap junctions at the specialized cell-cell contact region, known as the intercalated disc, is essential to ventricular cardiomyocyte coupling. We focus this review on several regulatory mechanisms that have been recently found to govern the lifecycle of connexin 43 (Cx43), the short-lived and most abundantly expressed connexin in cardiac ventricular muscle. The Cx43 lifecycle begins with gene expression, followed by oligomerization into hexameric channels, and then cytoskeletal-based transport toward the disc region. Once delivered, hemichannels interact with resident disc proteins and are organized to effect intercellular coupling. We highlight recent studies exploring regulation of Cx43 localization to the intercalated disc, with emphasis on alternatively translated Cx43 isoforms and cytoskeletal transport machinery that together regulate Cx43 gap junction coupling between cardiomyocytes.
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44
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Burnham MP, Sharpe PM, Garner C, Hughes R, Pollard CE, Bowes J. Investigation of connexin 43 uncoupling and prolongation of the cardiac QRS complex in preclinical and marketed drugs. Br J Pharmacol 2014; 171:4808-19. [PMID: 24328991 DOI: 10.1111/bph.12554] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 11/13/2013] [Accepted: 11/22/2013] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Prolongation of the cardiac QRS complex is linked to increased mortality and may result from drug-induced inhibition of cardiac sodium channels (hNaV 1.5). There has been no systematic evaluation of preclinical and marketed drugs for their additional potential to cause QRS prolongation via gap junction uncoupling. EXPERIMENTAL APPROACH Using the human cardiac gap junction connexin 43 (hCx43), a dye transfer 'parachute' assay to determine IC50 values for compound ranking was validated with compounds known to uncouple gap junctions. Uncoupling activity (and hNaV 1.5 inhibition by automated patch clamp) was determined in a set of marketed drugs and preclinical candidate drugs, each with information regarding propensity to prolong QRS. KEY RESULTS The potency of known gap junction uncouplers to uncouple hCx43 was ranked (according to IC50 ) as phorbol ester>digoxin>meclofenamic acid>carbenoxolone>heptanol. Among the drugs associated with QRS prolongation, 29% were found to uncouple hCx43 (IC50 < 50 μM), whereas no uncoupling activity was observed in drugs not associated with QRS prolongation. In preclinical candidate drugs, hCx43 and hNaV 1.5 IC50 values were similar (within threefold). No consistent margin over preclinical Cmax (free) was apparent for QRS prolongation associated with Cx43 inhibition. However, instances were found of QRS prolonging compounds that uncoupled hCx43 with significantly less activity at hNaV 1.5. CONCLUSION AND IMPLICATIONS These results demonstrate that off-target uncoupling activity is apparent in drug and drug-like molecules. Although the full ramifications of Cx inhibition remain to be established, screening for hCx43 off-target activity could reduce the likelihood of developing candidate drugs with a risk of causing QRS prolongation.
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Affiliation(s)
- M P Burnham
- Safety Assessment, AstraZeneca R&D, Macclesfield, UK; Discovery Sciences, AstraZeneca R&D, Macclesfield, UK
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45
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Osbourne A, Calway T, Broman M, McSharry S, Earley J, Kim GH. Downregulation of connexin43 by microRNA-130a in cardiomyocytes results in cardiac arrhythmias. J Mol Cell Cardiol 2014; 74:53-63. [PMID: 24819345 DOI: 10.1016/j.yjmcc.2014.04.024] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 01/17/2023]
Abstract
MicroRNAs (miRNAs) are now recognized as critical regulators of diverse physiological and pathological processes; however, studies of miRNAs and arrhythmogenesis remain sparse. Connexin43 (Cx43), a major cardiac gap junction protein, has elicited great interest in its role in arrhythmias. Additionally, Cx43 was a potential target for miR-130a as predicted by several computational algorithms. This study investigates the effect of miR-130a overexpression in the adult heart and its effect on cardiac rhythm. Using a cardiac-specific inducible system, transgenic mice demonstrated both atrial and ventricular arrhythmias. We performed ventricular-programmed electrical stimulation and found that the αMHC-miR130a mice developed sustained ventricular tachycardia beginning 6weeks after overexpression. Western blot analysis demonstrated a steady decline in Cx43 after 2weeks of overexpression with over a 90% reduction in Cx43 levels by 10weeks. Immunofluorescent staining confirmed a near complete loss of Cx43 throughout the heart. To validate Cx43 as a direct target of miR-130a, we performed in vitro target assays in 3T3 fibroblasts and HL-1 cardiomyocytes, both known to endogenously express miR-130a. Using a luciferase reporter fused to the 3'UTR of Cx43, we found a 52.9% reduction in luciferase activity in 3T3 cells (p<0.0001) and a 47.6% reduction in HL-1 cells (p=0.0056) compared to controls. Addition of an antisense miR-130a inhibitor resulted in a loss of inhibitory activity of the Cx43 3'UTR reporter. We have identified an unappreciated role for miR-130a as a direct regulator of Cx43. Overexpression of miR-130a may contribute importantly to gap junction remodeling and to the pathogenesis of atrial and ventricular arrhythmias.
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46
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Kusmic C, Barsanti C, Matteucci M, Vesentini N, Pelosi G, Abraham NG, L'Abbate A. Up-regulation of heme oxygenase-1 after infarct initiation reduces mortality, infarct size and left ventricular remodeling: experimental evidence and proof of concept. J Transl Med 2014; 12:89. [PMID: 24708733 PMCID: PMC4022338 DOI: 10.1186/1479-5876-12-89] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 03/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Up-regulation of HO-1 by genetic manipulation or pharmacological pre-treatment has been reported to provide benefits in several animal models of myocardial infarction (MI). However, its efficacy following MI initiation (as in clinical reality) remains to be tested. Therefore, this study investigated whether HO-1 over-expression, by cobalt protoporphyrin (CoPP) administered after LAD ligation, is still able to improve functional and structural changes in left ventricle (LV) in a rat model of 4-week MI. METHODS A total of 144 adult male Wistar rats were subjected to either left anterior coronary artery ligation or sham-operation. The effect of CoPP treatment (5 mg/kg i.p. at the end of the surgical session and, then, once a week for 4 weeks) was evaluated on the basis of survival, electro- and echocardiography, plasma levels of B-type natriuretic peptide (BNP), endothelin-1 and prostaglandin E2, coronary microvascular reactivity, MI size, LV wall thickness and vascularity. Besides, the expression of HO-1 and connexin-43 in different LV territories was assessed by western blot analysis and immunohistochemistry, respectively. RESULTS CoPP induced an increased expression of HO-1 protein with >16 h delay. CoPP treatment significantly reduced mortality, MI size, BNP concentration, ECG alterations, LV dysfunction, microvascular constriction, capillary rarefaction and restored connexin-43 expression as compared to untreated MI. These functional and structural changes were paralleled by increased HO-1 expression in all LV territories. HO activity inhibition by tin-mesoporphyrin abolished the differences between CoPP-treated and untreated MI animals. CONCLUSIONS This is the first report demonstrating the putative role of pharmacological induction of HO-1 following coronary occlusion to benefit infarcted and remote territories, leading to better cardiac function in a 4-week MI outcome.
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Affiliation(s)
- Claudia Kusmic
- CNR Institute of Clinical Physiology, Via G Moruzzi 1, 56124 Pisa, Italy.
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47
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Hartman ME, Librande JR, Medvedev IO, Ahmad RN, Moussavi-Harami F, Gupta PP, Chien WM, Chin MT. An optimized and simplified system of mouse embryonic stem cell cardiac differentiation for the assessment of differentiation modifiers. PLoS One 2014; 9:e93033. [PMID: 24667642 PMCID: PMC3965510 DOI: 10.1371/journal.pone.0093033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 02/28/2014] [Indexed: 12/19/2022] Open
Abstract
Generating cardiomyocytes from embryonic stem cells is an important technique for understanding cardiovascular development, the origins of cardiovascular diseases and also for providing potential reagents for cardiac repair. Numerous methods have been published but often are technically challenging, complex, and are not easily adapted to assessment of specific gene contributions to cardiac myocyte differentiation. Here we report the development of an optimized protocol to induce the differentiation of mouse embryonic stem cells to cardiac myocytes that is simplified and easily adapted for genetic studies. Specifically, we made four critical findings that distinguish our protocol: 1) mouse embryonic stem cells cultured in media containing CHIR99021 and PD0325901 to maintain pluripotency will efficiently form embryoid bodies containing precardiac mesoderm when cultured in these factors at a reduced dosage, 2) low serum conditions promote cardiomyocyte differentiation and can be used in place of commercially prepared StemPro nutrient supplement, 3) the Wnt inhibitor Dkk-1 is dispensable for efficient cardiac differentiation and 4) tracking differentiation efficiency may be done with surface expression of PDGFRα alone. In addition, cardiac mesodermal precursors generated by this system can undergo lentiviral infection to manipulate the expression of specific target molecules to assess effects on cardiac myocyte differentiation and maturation. Using this approach, we assessed the effects of CHF1/Hey2 on cardiac myocyte differentiation, using both gain and loss of function. Overexpression of CHF1/Hey2 at the cardiac mesoderm stage had no apparent effect on cardiac differentiation, while knockdown of CHF1/Hey2 resulted in increased expression of atrial natriuretic factor and connexin 43, suggesting an alteration in the phenotype of the cardiomyocytes. In summary we have generated a detailed and simplified protocol for generating cardiomyocytes from mES cells that is optimized for investigating factors that affect cardiac differentiation.
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Affiliation(s)
- Matthew E. Hartman
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jason R. Librande
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Ivan O. Medvedev
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Rabiah N. Ahmad
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Farid Moussavi-Harami
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Pritha P. Gupta
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Wei-Ming Chien
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Michael T. Chin
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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48
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Choi S, Hong Y, Lee I, Huh D, Jeon TJ, Kim SM. Effects of various extracellular matrix proteins on the growth of HL-1 cardiomyocytes. Cells Tissues Organs 2014; 198:349-56. [PMID: 24662367 DOI: 10.1159/000358755] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2014] [Indexed: 11/19/2022] Open
Abstract
We present the physical and biochemical effects of extracellular matrixes (ECMs) on HL-1 cardiomyocytes. ECMs play major roles in cell growth, adhesion and the maintenance of native cell functions. We investigated the effects of 6 different cell culture systems: 5 different ECM-treated surfaces (fibronectin, laminin, collagen I, gelatin and a gelatin/fibronectin mixture) and 1 nontreated surface. Surface morphology was scanned and analyzed using atomic force microscopy in order to investigate the physical effects of ECMs. The attachment, growth, viability, proliferation and phenotype of the cells were analyzed using phase-contrast microscopy and immunocytochemistry to elucidate the biochemical effects of ECMs. Our study provides basic information for understanding cell-ECM interactions and should be utilized in future cardiac cell research and tissue engineering.
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Affiliation(s)
- Seongkyun Choi
- Department of Mechanical Engineering, Inha University, Incheon, Republic of Korea
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49
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Zhang SS, Hong S, Kléber AG, Lee LP, Shaw RM. A micropatterning approach for imaging dynamic Cx43 trafficking to cell-cell borders. FEBS Lett 2014; 588:1439-45. [PMID: 24444605 DOI: 10.1016/j.febslet.2014.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 12/31/2013] [Accepted: 01/04/2014] [Indexed: 11/22/2022]
Abstract
The precise expression and timely delivery of connexin 43 (Cx43) proteins to form gap junctions are essential for electrical coupling of cardiomyocytes. Growing evidence supports a cytoskeletal-based trafficking paradigm for Cx43 delivery directly to adherens junctions at the intercalated disc. A limitation of Cx43 localization assays in cultured cells, in which cell-cell contacts are essential, is the inability to control for cell geometry or reproducibly generate contact points. Here we present a micropatterned cell pairing system well suited for live microscopy to examine how the microtubule and actin cytoskeleton confer specificity to Cx43 trafficking to precisely defined cell-cell junctions. This system can be adapted for other cell types and used to study dynamic intracellular movements of other proteins important for cell-cell communication.
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50
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Abstract
Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease.
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Affiliation(s)
- Morten Schak Nielsen
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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