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Domingues N, Catarino S, Cristóvão B, Rodrigues L, Carvalho FA, Sarmento MJ, Zuzarte M, Almeida J, Ribeiro-Rodrigues T, Correia-Rodrigues Â, Fernandes F, Rodrigues-Santos P, Aasen T, Santos NC, Korolchuk VI, Gonçalves T, Milosevic I, Raimundo N, Girão H. Connexin43 promotes exocytosis of damaged lysosomes through actin remodelling. EMBO J 2024:10.1038/s44318-024-00177-3. [PMID: 39044100 DOI: 10.1038/s44318-024-00177-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024] Open
Abstract
A robust and efficient cellular response to lysosomal membrane damage prevents leakage from the lysosome lumen into the cytoplasm. This response is understood to happen through either lysosomal membrane repair or lysophagy. Here we report exocytosis as a third response mechanism to lysosomal damage, which is further potentiated when membrane repair or lysosomal degradation mechanisms are impaired. We show that Connexin43 (Cx43), a protein canonically associated with gap junctions, is recruited from the plasma membrane to damaged lysosomes, promoting their secretion and accelerating cell recovery. The effects of Cx43 on lysosome exocytosis are mediated by a reorganization of the actin cytoskeleton that increases plasma membrane fluidity and decreases cell stiffness. Furthermore, we demonstrate that Cx43 interacts with the actin nucleator Arp2, the activity of which was shown to be necessary for Cx43-mediated actin rearrangement and lysosomal exocytosis following damage. These results define a novel mechanism of lysosomal quality control whereby Cx43-mediated actin remodelling potentiates the secretion of damaged lysosomes.
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Affiliation(s)
- Neuza Domingues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
| | - Steve Catarino
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Beatriz Cristóvão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Lisa Rodrigues
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Filomena A Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria João Sarmento
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Mónica Zuzarte
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Jani Almeida
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Ânia Correia-Rodrigues
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
| | - Fábio Fernandes
- Institute for Bioengineering and Biosciences (IBB) and Associate Laboratory i4HB-Institute for Health and Bioeconomy, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Paulo Rodrigues-Santos
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Trond Aasen
- Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Viktor I Korolchuk
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK
| | - Teresa Gonçalves
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Univ Coimbra, Center for Neurosciences and Cell Biology (CNC), Coimbra, Portugal
| | - Ira Milosevic
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- University of Oxford, Centre for Human Genetics, Nuffield Department of Medicine, Oxford, UK
| | - Nuno Raimundo
- Multidisciplinary Institute of Ageing, University of Coimbra, Coimbra, Portugal
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Henrique Girão
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Faculty of Medicine, Coimbra, Portugal.
- Univ Coimbra, Centre for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal.
- Clinical and Academic Centre of Coimbra, Coimbra, Portugal.
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2
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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3
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Wu L, Jiang T, Fu Z, Wang L, You H, Xue J, Luo D. Connexin 43 dephosphorylation at serine 282 induces spontaneous arrhythmia and increases susceptibility to ischemia/reperfusion injury. Heliyon 2023; 9:e15879. [PMID: 37215881 PMCID: PMC10196788 DOI: 10.1016/j.heliyon.2023.e15879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 05/24/2023] Open
Abstract
Background Connexin 43 (Cx43), the predominant gap junction protein in hearts, is modified by specific (de)phosphorylation events under physiological and pathological states to affect myocardium function and structure. Previously we found that deficiency in Cx43 S282 phosphorylation could impair intercellular communication and contribute to cardiomyocyte apoptosis by activating p38 mitogen-activated protein kinase (p38 MAPK)/factor-associated suicide (Fas)/Fas-associating protein with a novel death domain (FADD) pathway, which is involved in myocardium injury in ischemia/reperfusion (I/R) heart. In addition, mutant at Cx43 S282 substituted with alanine heterozygous mice (S282A+/-) exhibited different degrees of ventricular arrhythmias and only some underwent myocardium apoptosis. In this study, we aimed to investigate the role of Cx43 pS282 in different cardiac pathological phenotypes. Methods We examined cardiac function, structure, and relevant protein expression in S282A+/- mice (aged 2, 10 and 30 weeks) by electrocardiograph, echocardiography, histological staining, and co-immunoprecipitation followed by Western blot. Intraperitoneal isoprenaline injection and I/R surgery were applied in S282A+/- mice as external stimulus. 2,3,5-triphenyltetrazolium chloride staining was used for myocardium infarction evaluation. Results Adult S282A+/- mice (aged 10 and 30 weeks) still exhibited spontaneous arrhythmia. Unlike neonatal stage (aged around 2 weeks), no apoptosis-related manifestations and the activation of p38 MAPK-Fas-FADD apoptotic pathway were observed in adult S282A+/- hearts. S282A+/- neonatal mice with cardiomyocytes apoptosis exhibited more than 60% dephosphorylation at Cx43 S282 than WT mice, while less than 40% S282 dephosphorylation were found in adult S282A+/- mice. In addition, although S282A+/- mice displayed normal cardiac function, they were highly susceptible to isoproterenol-induced ECG alternans and prone to cardiac injury and deaths upon I/R attack. Conclusions These results reinforce that Cx43 S282 dephosphorylation acts as a susceptibility factor in regulating cardiomyocyte survival and cardiac electrical homeostasis in basal conditions and contributes to myocardium injury in the setting of I/R. Cx43 S282 phosphorylation was competent to induce spontaneous arrhythmias, cardiomyocyte apoptosis and deaths based on the degree of S282 dephosphorylation.
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Affiliation(s)
- Lulin Wu
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Tianhui Jiang
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Zhiping Fu
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Luqi Wang
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Hongjie You
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Jingyi Xue
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
| | - Dali Luo
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, PR China
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4
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Marchal GA, Remme CA. Subcellular diversity of Nav1.5 in cardiomyocytes: distinct functions, mechanisms and targets. J Physiol 2023; 601:941-960. [PMID: 36469003 DOI: 10.1113/jp283086] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/24/2022] [Indexed: 12/11/2022] Open
Abstract
In cardiomyocytes, the rapid depolarisation of the membrane potential is mediated by the α-subunit of the cardiac voltage-gated Na+ channel (NaV 1.5), encoded by the gene SCN5A. This ion channel allows positively charged Na+ ions to enter the cardiomyocyte, resulting in the fast upstroke of the action potential and is therefore crucial for cardiac excitability and electrical propagation. This essential role is underscored by the fact that dysfunctional NaV 1.5 is associated with high risk for arrhythmias and sudden cardiac death. However, development of therapeutic interventions regulating NaV 1.5 has been limited due to the complexity of NaV 1.5 structure and function and its diverse roles within the cardiomyocyte. In particular, research from the last decade has provided us with increased knowledge on the subcellular distribution of NaV 1.5 as well as the proteins which it interacts with in distinct cardiomyocyte microdomains. We here review these insights, detailing the potential role of NaV 1.5 within subcellular domains as well as its dysfunction in the setting of arrhythmia disorders. We furthermore provide an overview of current knowledge on the pathways involved in (microdomain-specific) trafficking of NaV 1.5, and their potential as novel targets. Unravelling the complexity of NaV 1.5 (dys)function may ultimately facilitate the development of therapeutic strategies aimed at preventing lethal arrhythmias. This is not only of importance for pathophysiological conditions where sodium current is specifically decreased within certain subcellular regions, such as in arrhythmogenic cardiomyopathy and Duchenne muscular dystrophy, but also for other acquired and inherited disorders associated with NaV 1.5.
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Affiliation(s)
- Gerard A Marchal
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.,National Institute of Optics, National Research Council (CNR-INO), Sesto Fiorentino, Florence, Italy
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
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5
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Blackwell DJ, Schmeckpeper J, Knollmann BC. Animal Models to Study Cardiac Arrhythmias. Circ Res 2022; 130:1926-1964. [PMID: 35679367 DOI: 10.1161/circresaha.122.320258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac arrhythmias are a significant cause of morbidity and mortality worldwide, accounting for 10% to 15% of all deaths. Although most arrhythmias are due to acquired heart disease, inherited channelopathies and cardiomyopathies disproportionately affect children and young adults. Arrhythmogenesis is complex, involving anatomic structure, ion channels and regulatory proteins, and the interplay between cells in the conduction system, cardiomyocytes, fibroblasts, and the immune system. Animal models of arrhythmia are powerful tools for studying not only molecular and cellular mechanism of arrhythmogenesis but also more complex mechanisms at the whole heart level, and for testing therapeutic interventions. This review summarizes basic and clinical arrhythmia mechanisms followed by an in-depth review of published animal models of genetic and acquired arrhythmia disorders.
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Affiliation(s)
- Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Jeffrey Schmeckpeper
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
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6
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Connexin Mutations and Hereditary Diseases. Int J Mol Sci 2022; 23:ijms23084255. [PMID: 35457072 PMCID: PMC9027513 DOI: 10.3390/ijms23084255] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/04/2022] [Accepted: 04/09/2022] [Indexed: 02/01/2023] Open
Abstract
Inherited diseases caused by connexin mutations are found in multiple organs and include hereditary deafness, congenital cataract, congenital heart diseases, hereditary skin diseases, and X-linked Charcot–Marie–Tooth disease (CMT1X). A large number of knockout and knock-in animal models have been used to study the pathology and pathogenesis of diseases of different organs. Because the structures of different connexins are highly homologous and the functions of gap junctions formed by these connexins are similar, connexin-related hereditary diseases may share the same pathogenic mechanism. Here, we analyze the similarities and differences of the pathology and pathogenesis in animal models and find that connexin mutations in gap junction genes expressed in the ear, eye, heart, skin, and peripheral nerves can affect cellular proliferation and differentiation of corresponding organs. Additionally, some dominant mutations (e.g., Cx43 p.Gly60Ser, Cx32 p.Arg75Trp, Cx32 p.Asn175Asp, and Cx32 p.Arg142Trp) are identified as gain-of-function variants in vivo, which may play a vital role in the onset of dominant inherited diseases. Specifically, patients with these dominant mutations receive no benefits from gene therapy. Finally, the complete loss of gap junctional function or altered channel function including permeability (ions, adenosine triphosphate (ATP), Inositol 1,4,5-trisphosphate (IP3), Ca2+, glucose, miRNA) and electric activity are also identified in vivo or in vitro.
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7
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Rivaud MR, Delmar M, Remme CA. Heritable arrhythmia syndromes associated with abnormal cardiac sodium channel function: ionic and non-ionic mechanisms. Cardiovasc Res 2021; 116:1557-1570. [PMID: 32251506 PMCID: PMC7341171 DOI: 10.1093/cvr/cvaa082] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/01/2020] [Accepted: 04/01/2020] [Indexed: 12/19/2022] Open
Abstract
The cardiac sodium channel NaV1.5, encoded by the SCN5A gene, is responsible for the fast upstroke of the action potential. Mutations in SCN5A may cause sodium channel dysfunction by decreasing peak sodium current, which slows conduction and facilitates reentry-based arrhythmias, and by enhancing late sodium current, which prolongs the action potential and sets the stage for early afterdepolarization and arrhythmias. Yet, some NaV1.5-related disorders, in particular structural abnormalities, cannot be directly or solely explained on the basis of defective NaV1.5 expression or biophysics. An emerging concept that may explain the large disease spectrum associated with SCN5A mutations centres around the multifunctionality of the NaV1.5 complex. In this alternative view, alterations in NaV1.5 affect processes that are independent of its canonical ion-conducting role. We here propose a novel classification of NaV1.5 (dys)function, categorized into (i) direct ionic effects of sodium influx through NaV1.5 on membrane potential and consequent action potential generation, (ii) indirect ionic effects of sodium influx on intracellular homeostasis and signalling, and (iii) non-ionic effects of NaV1.5, independent of sodium influx, through interactions with macromolecular complexes within the different microdomains of the cardiomyocyte. These indirect ionic and non-ionic processes may, acting alone or in concert, contribute significantly to arrhythmogenesis. Hence, further exploration of these multifunctional effects of NaV1.5 is essential for the development of novel preventive and therapeutic strategies.
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Affiliation(s)
- Mathilde R Rivaud
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University School of Medicine, 435 E 30th St, NSB 707, New York, NY 10016, USA
| | - Carol Ann Remme
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
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8
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Blok M, Boukens BJ. Mechanisms of Arrhythmias in the Brugada Syndrome. Int J Mol Sci 2020; 21:ijms21197051. [PMID: 32992720 PMCID: PMC7582368 DOI: 10.3390/ijms21197051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022] Open
Abstract
Arrhythmias in Brugada syndrome patients originate in the right ventricular outflow tract (RVOT). Over the past few decades, the characterization of the unique anatomy and electrophysiology of the RVOT has revealed the arrhythmogenic nature of this region. However, the mechanisms that drive arrhythmias in Brugada syndrome patients remain debated as well as the exact site of their occurrence in the RVOT. Identifying the site of origin and mechanism of Brugada syndrome would greatly benefit the development of mechanism-driven treatment strategies.
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Affiliation(s)
- Michiel Blok
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Bastiaan J. Boukens
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Correspondence: ; Tel.: +31-(0)20-566-4659
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9
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Scholman KT, Meijborg VMF, Gálvez-Montón C, Lodder EM, Boukens BJ. From Genome-Wide Association Studies to Cardiac Electrophysiology: Through the Maze of Biological Complexity. Front Physiol 2020; 11:557. [PMID: 32536879 PMCID: PMC7267057 DOI: 10.3389/fphys.2020.00557] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/04/2020] [Indexed: 12/19/2022] Open
Abstract
Genome Wide Association Studies (GWAS) have provided an enormous amount of data on genomic loci associated with cardiac electrophysiology and arrhythmias. Clinical relevance, however, remains unclear since GWAS do not provide a mechanistic explanation for this association. Determining the electrophysiological relevance of variants for arrhythmias would aid development of risk stratification models for patients with arrhythmias. In this review, we give an overview of genetic variants related to ECG intervals and arrhythmogenic pathologies and discuss how these variants may influence cardiac electrophysiology and the occurrence of arrhythmias.
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Affiliation(s)
- Koen T Scholman
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Veronique M F Meijborg
- Department of Experimental Cardiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Netherlands Heart Institute, Utrecht, Netherlands
| | - Carolina Gálvez-Montón
- ICREC Research Program, Germans Trias i Pujol Health Science Research Institute, Badalona, Spain.,CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Elisabeth M Lodder
- Department of Experimental Cardiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Bastiaan J Boukens
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Department of Experimental Cardiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
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10
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Lissoni A, Hulpiau P, Martins-Marques T, Wang N, Bultynck G, Schulz R, Witschas K, Girao H, De Smet M, Leybaert L. RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes. Cardiovasc Res 2019; 117:123-136. [PMID: 31841141 DOI: 10.1093/cvr/cvz340] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/14/2019] [Accepted: 12/11/2019] [Indexed: 12/16/2022] Open
Abstract
AIMS Connexin-based gap junctions are crucial for electrical communication in the heart; they are each composed of two docked hemichannels (HCs), supplied as unpaired channels via the sarcolemma. When open, an unpaired HC forms a large pore, high-conductance and Ca2+-permeable membrane shunt pathway that may disturb cardiomyocyte function. HCs composed of connexin 43 (Cx43), a major cardiac connexin, can be opened by electrical stimulation but only by very positive membrane potentials. Here, we investigated the activation of Cx43 HCs in murine ventricular cardiomyocytes voltage-clamped at -70 mV. METHODS AND RESULTS Using whole-cell patch-clamp, co-immunoprecipitation, western blot analysis, immunocytochemistry, proximity ligation assays, and protein docking studies, we found that stimulation of ryanodine receptors (RyRs) triggered unitary currents with a single-channel conductance of ∼220 pS, which were strongly reduced by Cx43 knockdown. Recordings under Ca2+-clamp conditions showed that both RyR activation and intracellular Ca2+ elevation were necessary for HC opening. Proximity ligation studies indicated close Cx43-RyR2 apposition (<40 nm), and both proteins co-immunoprecipitated indicating physical interaction. Molecular modelling suggested a strongly conserved RyR-mimicking peptide sequence (RyRHCIp), which inhibited RyR/Ca2+ HC activation but not voltage-triggered activation. The peptide also slowed down action potential repolarization. Interestingly, alterations in the concerned RyR sequence are known to be associated with primary familial hypertrophic cardiomyopathy. CONCLUSION Our results demonstrate that Cx43 HCs are intimately linked to RyRs, allowing them to open at negative diastolic membrane potential in response to RyR activation.
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Affiliation(s)
- Alessio Lissoni
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Paco Hulpiau
- Department of Bio-Medical Sciences, HOWEST University of Applied Sciences (Hogeschool West-Vlaanderen), Bruges, Belgium
| | - Tânia Martins-Marques
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
| | - Nan Wang
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Geert Bultynck
- Department of Molecular Cell Biology, Laboratory of Molecular and Cellular Signaling, KU Leuven, Leuven, Belgium
| | - Rainer Schulz
- Institut für Physiologie, JustusLiebig Universität Giessen, Giessen, Germany
| | - Katja Witschas
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
| | - Maarten De Smet
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences-Physiology Group, Ghent University, Ghent 9000, Belgium
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11
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Jin Y, Zhou T, Feng Q, Yang J, Cao J, Xu X, Yang C. Inhibition of MicroRNA-206 Ameliorates Ischemia-Reperfusion Arrhythmia in a Mouse Model by Targeting Connexin43. J Cardiovasc Transl Res 2019; 13:584-592. [PMID: 31792806 DOI: 10.1007/s12265-019-09940-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 11/15/2019] [Indexed: 01/10/2023]
Abstract
Reperfusion arrhythmias (RA) are an important cause of sudden cardiac death and is closely associated with gap junction protein in the heart, connexin 43 (Cx43). This study is aimed at elucidating the molecular association between microRNA-206 (miR-206) and Cx43 in ischemia-reperfusion arrhythmia using experimental animal model. Our results showed that miR-206 inhibitor alleviated ischemia-reperfusion-induced arrhythmias, indicated by the lower extent of changes in heart rate (HR), PR interval, rate pressure product (RPP), and mean arterial pressure (MAP). miR-206 inhibitor also downregulated the serum creatine kinase isoenzyme (CKMB) and cardiac troponin I (cTnI) levels in mice under myocardial ischemia-reperfusion (IR) process. The knockdown of Cx43 inversed the protective effects of miR-206 inhibitor on cardiac arrhythmias. These results supported that inhibition of miR-206 ameliorates ischemia-reperfusion arrhythmia by targeting Cx43, and this miR-206/Cx43 axis could serve as a potential target for the management of ischemic-perfusion arrhythmia.
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Affiliation(s)
- Yan Jin
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Tianyi Zhou
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Qiuting Feng
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Jun Yang
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Jianing Cao
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Xin Xu
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China
| | - Chengjian Yang
- Department of Cardiology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, No. 68 Zhongshan Road, Wuxi, 214002, Jiangsu, China.
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12
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Xue J, Yan X, Yang Y, Chen M, Wu L, Gou Z, Sun Z, Talabieke S, Zheng Y, Luo D. Connexin 43 dephosphorylation contributes to arrhythmias and cardiomyocyte apoptosis in ischemia/reperfusion hearts. Basic Res Cardiol 2019; 114:40. [DOI: 10.1007/s00395-019-0748-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/19/2019] [Indexed: 12/28/2022]
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13
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Yao J, Ke J, Zhou Z, Tan G, Yin Y, Liu M, Chen J, Wu W. Combination of HGF and IGF-1 promotes connexin 43 expression and improves ventricular arrhythmia after myocardial infarction through activating the MAPK/ERK and MAPK/p38 signaling pathways in a rat model. Cardiovasc Diagn Ther 2019; 9:346-354. [PMID: 31555539 DOI: 10.21037/cdt.2019.07.12] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background In this study, we hypothesized that the combination of hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) alters the expression of connexin 43 (Cx43) and results in a reduced frequency of induced ventricular arrhythmia in rats after myocardial infarction (MI) and explored the preliminary mechanisms involved. Methods Cardiomyocytes were cultured in vitro in medium with PBS, HGF, IGF-1, GFs (HGF + IGF-1), HGF + p38 inhibitor, HGF + ERK inhibitor, IGF-1 + p38 inhibitor or IGF-1 + ERK inhibitor. The expression of Cx43 was tested by real-time PCR and Western blotting after 48 hours. MI was induced in 48 male Sprague-Dawley rats. The rats were randomly divided into four groups and received an injection of PBS, HGF, IGF-1 or GFs into the infarct border zone two weeks after MI. Six weeks after injection, the expression levels of Cx43 and programmed stimulation-induced ventricular arrhythmias were examined. Results In vitro, the expression of Cx43 mRNA and the Cx43 protein in cardiomyocytes was higher in the HGF, IGF-1, and GFs groups than in the PBS group. GFs had a combinatorial effect on the Cx43 mRNA level but not on the Cx43 protein level. There was a significant reduction in Cx43 mRNA and Cx43 protein levels in the IGF-1 + p38 inhibitor group and IGF-1 + ERK inhibitor group compared to the IGF-1 group. In vivo, programmed stimulation significantly decreased the frequency of ventricular arrhythmia in the GFs, HGF and IGF-1 groups, and this effect was accompanied by increased immunohistochemical staining for Cx43, myocardial Cx43 protein levels and Cx43 mRNA levels in the infarct border zone of the left ventricle compared with those in the PBS group. The combinatorial effect of GFs on Cx43 expression was only observed at the mRNA level. Conclusions Both HGF and IGF-1 enhanced the expression of Cx43 and improved induced ventricular arrhythmia in rats with MI. Both synergistic and antagonistic effects of HGF and IGF-1 were not observed. In addition, IGF-1 may function through the MAPK/p38 and ERK1/2 signaling pathways to regulate Cx43 expression.
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Affiliation(s)
- Jierong Yao
- Department of Interventional Cardiovascular Medicine, Center for Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China.,Department of Cardiology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515000, China
| | - Jianting Ke
- Nephrology Department, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Zhijuan Zhou
- Department of Interventional Cardiovascular Medicine, Center for Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Guangyi Tan
- Department of Cardiology, Nanhai People's Hospital Affiliated to Southern Medical University, Foshan 528000, China
| | - Yuelan Yin
- Department of Interventional Cardiovascular Medicine, Center for Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Mao Liu
- Department of Cardiology, the Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, China
| | - Jian Chen
- Department of Interventional Cardiovascular Medicine, Center for Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China.,Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Wei Wu
- Department of Interventional Cardiovascular Medicine, Center for Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
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14
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Abstract
All proteins end with a carboxyl terminus that has unique biophysical properties and is often disordered. Although there are examples of important C-termini functions, a more global role for the C-terminus is not yet established. In this review, we summarize research on C-termini, a unique region in proteins that cells exploit. Alternative splicing and proteolysis increase the diversity of proteins and peptides in cells with unique C-termini. The C-termini of proteins contain minimotifs, short peptides with an encoded function generally characterized as binding, posttranslational modifications, and trafficking. Many of these activities are specific to minimotifs on the C-terminus. Approximately 13% of C-termini in the human proteome have a known minimotif, and the majority, if not all of the remaining termini have conserved motifs inferring a function that remains to be discovered. C-termini, their predictions, and their functions are collated in the C-terminome, Proteus, and Terminus Oriented Protein Function INferred Database (TopFIND) database/web systems. Many C-termini are well conserved, and some have a known role in health and disease. We envision that this summary of C-termini will guide future investigation of their biochemical and physiological significance.
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Affiliation(s)
- Surbhi Sharma
- a Nevada Institute of Personalized Medicine and School of Life Sciences , University of Nevada , Las Vegas , NV , USA
| | - Martin R Schiller
- a Nevada Institute of Personalized Medicine and School of Life Sciences , University of Nevada , Las Vegas , NV , USA
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15
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Lithium interacts with cardiac remodeling: the fundamental value in the pharmacotherapy of bipolar disorder. Prog Neuropsychopharmacol Biol Psychiatry 2019; 88:208-214. [PMID: 30053574 DOI: 10.1016/j.pnpbp.2018.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 06/18/2018] [Accepted: 07/23/2018] [Indexed: 12/13/2022]
Abstract
Patients with bipolar disorder (BD) have an increased risk of cardiovascular morbidity and mortality during the course of their illness. For over half a century, lithium has been the gold-standard medication used to treat the mood burdens of BD. In addition, lithium possesses several biological effects that may modulate cardiovascular risk in patients with BD. In this review, we update the current knowledge of cellular and molecular mechanisms underlying the possible cardiac actions of lithium. The mechanistic insights suggest that lithium at therapeutic levels potentially exerts cardioprotective effects on ischemic hearts by modulating structural and electrical remodeling. The possible cardioprotective actions of lithium may involve an extensive range of signaling pathways, including the Wnt/glycogen synthase kinase-3β, phosphatidylinositol-3-kinase/protein kinase B, phosphoinositide/protein kinase C, and mitogen-activated protein kinase/extracellular signal-regulated kinase cascades. Accordingly, understanding the cardioprotective effects of lithium may lead to the development of a potential strategy for reducing cardiovascular morbidity in patients with BD.
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16
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Abstract
Activation of the electrical signal and its transmission as a depolarizing wave in the whole heart requires highly organized myocyte architecture and cell-cell contacts. In addition, complex trafficking and anchoring intracellular machineries regulate the proper surface expression of channels and their targeting to distinct membrane domains. An increasing list of proteins, lipids, and second messengers can contribute to the normal targeting of ion channels in cardiac myocytes. However, their precise roles in the electrophysiology of the heart are far from been extensively understood. Nowadays, much effort in the field focuses on understanding the mechanisms that regulate ion channel targeting to sarcolemma microdomains and their organization into macromolecular complexes. The purpose of the present section is to provide an overview of the characterized partners of the main cardiac sodium channel, NaV1.5, involved in regulating the functional expression of this channel both in terms of trafficking and targeting into microdomains.
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17
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Delmar M, Laird DW, Naus CC, Nielsen MS, Verselis VK, White TW. Connexins and Disease. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a029348. [PMID: 28778872 DOI: 10.1101/cshperspect.a029348] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Inherited or acquired alterations in the structure and function of connexin proteins have long been associated with disease. In the present work, we review current knowledge on the role of connexins in diseases associated with the heart, nervous system, cochlea, and skin, as well as cancer and pleiotropic syndromes such as oculodentodigital dysplasia (ODDD). Although incomplete by virtue of space and the extent of the topic, this review emphasizes the fact that connexin function is not only associated with gap junction channel formation. As such, both canonical and noncanonical functions of connexins are fundamental components in the pathophysiology of multiple connexin related disorders, many of them highly debilitating and life threatening. Improved understanding of connexin biology has the potential to advance our understanding of mechanisms, diagnosis, and treatment of disease.
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Affiliation(s)
- Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, New York 10016
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A5C1, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Morten S Nielsen
- Department of Biological Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Vytautas K Verselis
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York 10461
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York 11790
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18
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Sorgen PL, Trease AJ, Spagnol G, Delmar M, Nielsen MS. Protein⁻Protein Interactions with Connexin 43: Regulation and Function. Int J Mol Sci 2018; 19:E1428. [PMID: 29748463 PMCID: PMC5983787 DOI: 10.3390/ijms19051428] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022] Open
Abstract
Connexins are integral membrane building blocks that form gap junctions, enabling direct cytoplasmic exchange of ions and low-molecular-mass metabolites between adjacent cells. In the heart, gap junctions mediate the propagation of cardiac action potentials and the maintenance of a regular beating rhythm. A number of connexin interacting proteins have been described and are known gap junction regulators either through direct effects (e.g., kinases) or the formation of larger multifunctional complexes (e.g., cytoskeleton scaffold proteins). Most connexin partners can be categorized as either proteins promoting coupling by stimulating forward trafficking and channel opening or inhibiting coupling by inducing channel closure, internalization, and degradation. While some interactions have only been implied through co-localization using immunohistochemistry, others have been confirmed by biophysical methods that allow detection of a direct interaction. Our understanding of these interactions is, by far, most well developed for connexin 43 (Cx43) and the scope of this review is to summarize our current knowledge of their functional and regulatory roles. The significance of these interactions is further exemplified by demonstrating their importance at the intercalated disc, a major hub for Cx43 regulation and Cx43 mediated effects.
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Affiliation(s)
- Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Andrew J Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Mario Delmar
- Leon H Charney Division of Cardiology, NYU School of Medicine, New York, NY 10016, USA.
| | - Morten S Nielsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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19
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Ribeiro-Rodrigues TM, Martins-Marques T, Morel S, Kwak BR, Girão H. Role of connexin 43 in different forms of intercellular communication - gap junctions, extracellular vesicles and tunnelling nanotubes. J Cell Sci 2017; 130:3619-3630. [PMID: 29025971 DOI: 10.1242/jcs.200667] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Communication is important to ensure the correct and efficient flow of information, which is required to sustain active social networks. A fine-tuned communication between cells is vital to maintain the homeostasis and function of multicellular or unicellular organisms in a community environment. Although there are different levels of complexity, intercellular communication, in prokaryotes to mammalians, can occur through secreted molecules (either soluble or encapsulated in vesicles), tubular structures connecting close cells or intercellular channels that link the cytoplasm of adjacent cells. In mammals, these different types of communication serve different purposes, may involve distinct factors and are mediated by extracellular vesicles, tunnelling nanotubes or gap junctions. Recent studies have shown that connexin 43 (Cx43, also known as GJA1), a transmembrane protein initially described as a gap junction protein, participates in all these forms of communication; this emphasizes the concept of adopting strategies to maximize the potential of available resources by reutilizing the same factor in different scenarios. In this Review, we provide an overview of the most recent advances regarding the role of Cx43 in intercellular communication mediated by extracellular vesicles, tunnelling nanotubes and gap junctions.
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Affiliation(s)
- Teresa M Ribeiro-Rodrigues
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Tânia Martins-Marques
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Sandrine Morel
- Dept. of Pathology and Immunology, and Dept. of Medical Specialties - Cardiology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Brenda R Kwak
- Dept. of Pathology and Immunology, and Dept. of Medical Specialties - Cardiology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Henrique Girão
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal .,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
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20
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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] [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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21
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Basheer WA, Xiao S, Epifantseva I, Fu Y, Kleber AG, Hong T, Shaw RM. GJA1-20k Arranges Actin to Guide Cx43 Delivery to Cardiac Intercalated Discs. Circ Res 2017; 121:1069-1080. [PMID: 28923791 DOI: 10.1161/circresaha.117.311955] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 01/21/2023]
Abstract
RATIONALE Delivery of Cx43 (connexin 43) to the intercalated disc is a continuous and rapid process critical for intercellular coupling. By a pathway of targeted delivery involving microtubule highways, vesicles of Cx43 hemichannels are efficiently trafficked to adherens junctions at intercalated discs. It has also been identified that actin provides rest stops for Cx43 forward trafficking and that Cx43 has a 20 kDa internally translated small C terminus isoform, GJA1-20k (Gap Junction Protein Alpha 1- 20 kDa), which is required for full-length Cx43 trafficking, but by an unknown mechanism. OBJECTIVE We explored the mechanism by which the GJA1-20k isoform is required for full-length Cx43 forward trafficking to intercalated discs. METHODS AND RESULTS Using an in vivo Adeno-associated virus serotype 9-mediated gene transfer system, we confirmed in whole animal that GJA1-20k markedly increases endogenous myocardial Cx43 gap junction plaque size at the intercalated discs. In micropatterned cell pairing systems, we found that exogenous GJA1-20k expression stabilizes filamentous actin without affecting actin protein expression and that GJA1-20k complexes with both actin and tubulin. We also found that filamentous actin regulates microtubule organization as inhibition of actin polymerization with a low dose of latrunculin A disrupts the targeting of microtubules to cell-cell junctions. GJA1-20k protects actin filament from latrunculin A disruption, preserving microtubule trajectory to the cell-cell border. For therapeutic implications, we found that prior in vivo Adeno-associated virus serotype 9-mediated gene delivery of GJA1-20k to the heart protects Cx43 localization to the intercalated discs against acute ischemic injury. CONCLUSIONS The internally translated GJA1-20k isoform stabilizes actin filaments, which guides growth trajectories of the Cx43 microtubule trafficking machinery, increasing delivery of Cx43 hemichannels to cardiac intercalated discs. Exogenous GJA1-20k helps to maintain cell-cell coupling in instances of anticipated myocardial ischemia.
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Affiliation(s)
- Wassim A Basheer
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - Shaohua Xiao
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - Irina Epifantseva
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - Ying Fu
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - Andre G Kleber
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - TingTing Hong
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.)
| | - Robin M Shaw
- From the Cedars-Sinai Heart Institute (W.A.B., S.X., I.E., Y.F., T.H., R.M.S.) and Department of Medicine (T.H., R.M.S.), Cedars-Sinai Medical Center and UCLA, Los Angeles, CA; and Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (A.G.K.).
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22
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Cerrone M, Montnach J, Lin X, Zhao YT, Zhang M, Agullo-Pascual E, Leo-Macias A, Alvarado FJ, Dolgalev I, Karathanos TV, Malkani K, Van Opbergen CJM, van Bavel JJA, Yang HQ, Vasquez C, Tester D, Fowler S, Liang F, Rothenberg E, Heguy A, Morley GE, Coetzee WA, Trayanova NA, Ackerman MJ, van Veen TAB, Valdivia HH, Delmar M. Plakophilin-2 is required for transcription of genes that control calcium cycling and cardiac rhythm. Nat Commun 2017; 8:106. [PMID: 28740174 PMCID: PMC5524637 DOI: 10.1038/s41467-017-00127-0] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/02/2017] [Indexed: 12/19/2022] Open
Abstract
Plakophilin-2 (PKP2) is a component of the desmosome and known for its role in cell-cell adhesion. Mutations in human PKP2 associate with a life-threatening arrhythmogenic cardiomyopathy, often of right ventricular predominance. Here, we use a range of state-of-the-art methods and a cardiomyocyte-specific, tamoxifen-activated, PKP2 knockout mouse to demonstrate that in addition to its role in cell adhesion, PKP2 is necessary to maintain transcription of genes that control intracellular calcium cycling. Lack of PKP2 reduces expression of Ryr2 (coding for Ryanodine Receptor 2), Ank2 (coding for Ankyrin-B), Cacna1c (coding for CaV1.2) and Trdn (coding for triadin), and protein levels of calsequestrin-2 (Casq2). These factors combined lead to disruption of intracellular calcium homeostasis and isoproterenol-induced arrhythmias that are prevented by flecainide treatment. We propose a previously unrecognized arrhythmogenic mechanism related to PKP2 expression and suggest that mutations in PKP2 in humans may cause life-threatening arrhythmias even in the absence of structural disease.It is believed that mutations in desmosomal adhesion complex protein plakophilin 2 (PKP2) cause arrhythmia due to loss of cell-cell communication. Here the authors show that PKP2 controls the expression of proteins involved in calcium cycling in adult mouse hearts, and that lack of PKP2 can cause arrhythmia in a structurally normal heart.
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Affiliation(s)
- Marina Cerrone
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Jerome Montnach
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Xianming Lin
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Yan-Ting Zhao
- Center for Arrhythmia Research, Division of Cardiology, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Mingliang Zhang
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Esperanza Agullo-Pascual
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Alejandra Leo-Macias
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Francisco J Alvarado
- Department of Molecular and Integrative Physiology, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Igor Dolgalev
- Genome Technology Center, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Thomas V Karathanos
- Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, 3400N Charles St., Baltimore, MD, 21218, USA
| | - Kabir Malkani
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Chantal J M Van Opbergen
- Department of Medical Physiology Division of Heart & Lungs University Medical Centre Utrecht, Yalelaan 50, 3584CM, Utrecht, The Netherlands
| | - Joanne J A van Bavel
- Department of Medical Physiology Division of Heart & Lungs University Medical Centre Utrecht, Yalelaan 50, 3584CM, Utrecht, The Netherlands
| | - Hua-Qian Yang
- Department of Pediatrics, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Carolina Vasquez
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - David Tester
- Departments of Cardiovascular Diseases/Division of Heart Rhythm Services, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Department of Pediatric and Adolescent Medicine/Division of Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Steven Fowler
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Fengxia Liang
- Department of Cell Biology and Microscopy Core, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Adriana Heguy
- Genome Technology Center, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Gregory E Morley
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience and Biochemistry and Molecular Pharmacology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA
| | - Natalia A Trayanova
- Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, 3400N Charles St., Baltimore, MD, 21218, USA
| | - Michael J Ackerman
- Departments of Cardiovascular Diseases/Division of Heart Rhythm Services, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Department of Pediatric and Adolescent Medicine/Division of Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Toon A B van Veen
- Department of Medical Physiology Division of Heart & Lungs University Medical Centre Utrecht, Yalelaan 50, 3584CM, Utrecht, The Netherlands
| | - Hector H Valdivia
- Center for Arrhythmia Research, Division of Cardiology, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, NYU School of Medicine, 520 First Avenue, New York, NY, 10016, USA.
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23
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Moncayo-Arlandi J, Brugada R. Unmasking the molecular link between arrhythmogenic cardiomyopathy and Brugada syndrome. Nat Rev Cardiol 2017; 14:744-756. [DOI: 10.1038/nrcardio.2017.103] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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24
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Epifantseva I, Shaw RM. Intracellular trafficking pathways of Cx43 gap junction channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:40-47. [PMID: 28576298 DOI: 10.1016/j.bbamem.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
Abstract
Gap Junction (GJ) channels, including the most common Connexin 43 (Cx43), have fundamental roles in excitable tissues by facilitating rapid transmission of action potentials between adjacent cells. For instance, synchronization during each heartbeat is regulated by these ion channels at the cardiomyocyte cell-cell border. Cx43 protein has a short half-life, and rapid synthesis and timely delivery of those proteins to particular subdomains are crucial for the cellular organization of gap junctions and maintenance of intracellular coupling. Impairment in gap junction trafficking contributes to dangerous complications in diseased hearts such as the arrhythmias of sudden cardiac death. Of recent interest are the protein-protein interactions with the Cx43 carboxy-terminus. These interactions have significant impact on the full length Cx43 lifecycle and also contribute to trafficking of Cx43 as well as possibly other functions. We are learning that many of the known non-canonical roles of Cx43 can be attributed to the recently identified six endogenous Cx43 truncated isoforms which are produced by internal translation. In general, alternative translation is a new leading edge for proteome expansion and therapeutic drug development. This review highlights recent mechanisms identified in the trafficking of gap junction channels, involvement of other proteins contributing to the delivery of channels to the cell-cell border, and understanding of possible roles of the newly discovered alternatively translated isoforms in Cx43 biology. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Irina Epifantseva
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Robin M Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.; Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA..
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25
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Leithe E, Mesnil M, Aasen T. The connexin 43 C-terminus: A tail of many tales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:48-64. [PMID: 28526583 DOI: 10.1016/j.bbamem.2017.05.008] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 10/19/2022]
Abstract
Connexins are chordate gap junction channel proteins that, by enabling direct communication between the cytosols of adjacent cells, create a unique cell signalling network. Gap junctional intercellular communication (GJIC) has important roles in controlling cell growth and differentiation and in tissue development and homeostasis. Moreover, several non-canonical connexin functions unrelated to GJIC have been discovered. Of the 21 members of the human connexin family, connexin 43 (Cx43) is the most widely expressed and studied. The long cytosolic C-terminus (CT) of Cx43 is subject to extensive post-translational modifications that modulate its intracellular trafficking and gap junction channel gating. Moreover, the Cx43 CT contains multiple domains involved in protein interactions that permit crosstalk between Cx43 and cytoskeletal and regulatory proteins. These domains endow Cx43 with the capacity to affect cell growth and differentiation independently of GJIC. Here, we review the current understanding of the regulation and unique functions of the Cx43 CT, both as an essential component of full-length Cx43 and as an independent signalling hub. We highlight the complex regulatory and signalling networks controlled by the Cx43 CT, including the extensive protein interactome that underlies both gap junction channel-dependent and -independent functions. We discuss these data in relation to the recent discovery of the direct translation of specific truncated forms of Cx43. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, University of Oslo, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0424 Oslo, Norway
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, France
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
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26
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Wu Q, Wu Y, Zhang L, Zheng J, Tang S, Cheng J. GJA1 gene variations in sudden unexplained nocturnal death syndrome in the Chinese Han population. Forensic Sci Int 2016; 270:178-182. [PMID: 27992820 DOI: 10.1016/j.forsciint.2016.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/09/2016] [Accepted: 12/03/2016] [Indexed: 10/20/2022]
Abstract
Sudden unexplained nocturnal death syndrome (SUNDS) is a conundrum to both forensic pathologists and physicians, more than 80% of which the molecular pathogenesis remains unclear. Reported studies on both clinical and genetic phenotypes suggest SUNDS is related to congenital and acquired arrhythmias. Recent researches have linked the mutations of gene gap junction alpha 1 (GJA1) with arrhythmogenic cardiac disorders. In the present study, we investigate the potential correlation between GJA1 gene variations and the occurrence of SUNDS. Genomic DNA was extracted from the blood samples of both 124 sporadic SUNDS patients and 125 healthy controls to screen GJA1 gene for candidate variants using polymerase chain reaction (PCR) and direct DNA sequencing. One novel homozygous variant c.169C>T and one heterozygous SNP c.624C>T (rs530633057) were determined in 124 SUNDS cases (one case for each detected variant) and none of the 125 healthy controls. Base C>T transition at nucleotide position 169 led to termination of protein production after glutamine (Q) at codon 57 which is very likely to result in decreased expression of Cx43 gap junction channels and cause arrhythmic sudden death. This is the first report of GJA1 gene variations in SUNDS in the Chinese Han population, which suggests a novel susceptibility gene for Chinese SUNDS.
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Affiliation(s)
- Qiuping Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yeda Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Liyong Zhang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Jinxiang Zheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Shuangbo Tang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
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27
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Abstract
Brugada syndrome is an inherited disease characterized by an increased risk of sudden cardiac death owing to ventricular arrhythmias in the absence of structural heart disease. Since the first description of the syndrome >20 years ago, considerable advances have been made in our understanding of the underlying mechanisms involved and the strategies to stratify at-risk patients. The development of repolarization-depolarization abnormalities in patients with Brugada syndrome can involve genetic alterations, abnormal neural crest cell migration, improper gap junctional communication, or connexome abnormalities. A common phenotype observed on the electrocardiogram of patients with Brugada syndrome might be the result of different pathophysiological mechanisms. Furthermore, risk stratification of this patient cohort is critical, and although some risk factors for Brugada syndrome have been frequently reported, several others remain unconfirmed. Current clinical guidelines offer recommendations for patients at high risk of developing sudden cardiac death, but the management of those at low risk has not yet been defined. In this Review, we discuss the proposed mechanisms that underlie the development of Brugada syndrome and the current risk stratification and therapeutic options available for these patients.
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Affiliation(s)
- Juan Sieira
- Heart Rhythm Management Centre, UZ Brussel-VUB, Brussels, Laarbeeklaan 101, 1090 Brussels, Belgium.,Cardiology Department, University Hospital Erasme, Route de Lennik 808, 1070 Brussels, Belgium
| | - Gregory Dendramis
- Heart Rhythm Management Centre, UZ Brussel-VUB, Brussels, Laarbeeklaan 101, 1090 Brussels, Belgium.,Cardiovascular Division, University Hospital "Paolo Giaccone", Via Del Vespro 127. 90127 Palermo, Italy
| | - Pedro Brugada
- Heart Rhythm Management Centre, UZ Brussel-VUB, Brussels, Laarbeeklaan 101, 1090 Brussels, Belgium
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28
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Wei N, Mori Y, Tolkacheva EG. The dual effect of ephaptic coupling on cardiac conduction with heterogeneous expression of connexin 43. J Theor Biol 2016; 397:103-14. [PMID: 26968493 DOI: 10.1016/j.jtbi.2016.02.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/25/2016] [Accepted: 02/19/2016] [Indexed: 11/30/2022]
Abstract
Decreased and heterogeneous expression of connexin 43 (Cx43) are common features in animal heart failure models. Ephpatic coupling, which relies on the presence of junctional cleft space between the ends of adjacent cells, has been suggested to play a more active role in mediating intercellular electrical communication when gap junctions are reduced. To better understand the interplay of Cx43 expression and ephaptic coupling on cardiac conduction during heart failure, we performed numerical simulations on our model when Cx43 expression is reduced and heterogeneous. Under severely reduced Cx43 expression, we identified three new phenomena in the presence of ephaptic coupling: alternating conduction, in which ephaptic and gap junction-mediated mechanisms alternate; instability of planar fronts; and small amplitude action potential (SAP), which has a smaller potential amplitude than the normal action potential. In the presence of heterogeneous Cx43 expression, ephaptic coupling can either prevent or promote conduction block (CB) depending on the Cx43 knockout (Cx43KO) content. When Cx43KO content is relatively high, ephaptic coupling reduces the probabilities of CB. However, ephaptic coupling promotes CB when Cx43KO and wild type cells are mixed in roughly equal proportion, which can be attributed to an increase in current-to-load mismatch.
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Affiliation(s)
- Ning Wei
- School of Mathematics, University of Minnesota, 206 Church St. SE, Minneapolis, MN 55455, United States
| | - Yoichiro Mori
- School of Mathematics, University of Minnesota, 206 Church St. SE, Minneapolis, MN 55455, United States
| | - Elena G Tolkacheva
- Department of Biomedical Engineering, University of Minnesota, 312 Church St. SE, 6-128 Nils Hasselmo Hall, Minneapolis, MN 55455, United States.
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29
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He Y, Yu S, Hu J, Cui Y, Liu P. Changes in the Anatomic and Microscopic Structure and the Expression of HIF-1α and VEGF of the Yak Heart with Aging and Hypoxia. PLoS One 2016; 11:e0149947. [PMID: 26914488 PMCID: PMC4767878 DOI: 10.1371/journal.pone.0149947] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 02/08/2016] [Indexed: 11/18/2022] Open
Abstract
The study aimed to identify the changes of anatomic and microscopic structure and the expression and localization of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) in the myocardium and coronary artery of the yak heart adapted to chronic hypoxia with aging. Thirty-two yaks (1 day, 6 months, 1 year, 2 years, and 5 year old) were included, and immunoelectronmicroscopy, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) were used. Right ventricular hypertrophy was not present in yaks with aging. There was no intima thickening phenomenon in the coronary artery. The ultrastructure of myofibrils, mitochondria, and collagen fibers and the diameter and quantity of collagen changed significantly with aging. The enzymatic activity of complexes I, II, and V increased with age. Immunogold labeling showed the localization of HIF-1α protein in the cytoplasm and nuclei of endothelial cells and cytoplasm of cardiac muscle cells, and VEGF protein in the nuclei and perinuclei areas of smooth muscle cells of coronary artery, and in the cytoplasm and nuclei of endothelial cells. ELISA results showed that HIF-1α secretion significantly increased in the myocardium and coronary artery from an age of 1 day to 2 years of yaks and decreased in old yaks. However, VEGF protein always increased with aging. The findings of this study suggest that 6 months is a key age of yak before which there are some adaptive changes to deal with low-oxygen environment, and there is a maturation of the yak heart from the age of 6 months to 2 years.
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Affiliation(s)
- Yanyu He
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Sijiu Yu
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Junwei Hu
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Yan Cui
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, Gansu, China
- * E-mail:
| | - Penggang Liu
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, Gansu, China
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30
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Leo-Macias A, Agullo-Pascual E, Delmar M. The cardiac connexome: Non-canonical functions of connexin43 and their role in cardiac arrhythmias. Semin Cell Dev Biol 2015; 50:13-21. [PMID: 26673388 DOI: 10.1016/j.semcdb.2015.12.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 12/01/2015] [Indexed: 12/17/2022]
Abstract
Connexin43 is the major component of gap junctions, an anatomical structure present in the cardiac intercalated disc that provides a low-resistance pathway for direct cell-to-cell passage of electrical charge. Recent studies have shown that in addition to its well-established function as an integral membrane protein that oligomerizes to form gap junctions, Cx43 plays other roles that are independent of channel (or perhaps even hemi-channel) formation. This article discusses non-canonical functions of Cx43. In particular, we focus on the role of Cx43 as a part of a protein interacting network, a connexome, where molecules classically defined as belonging to the mechanical junctions, the gap junctions and the sodium channel complex, multitask and work together to bring about excitability, electrical and mechanical coupling between cardiac cells. Overall, viewing Cx43 as a multi-functional protein, beyond gap junctions, opens a window to better understand the function of the intercalated disc and the pathological consequences that may result from changes in the abundance or localization of Cx43 in the intercalated disc subdomain.
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Affiliation(s)
- Alejandra Leo-Macias
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States
| | - Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States
| | - Mario Delmar
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States.
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George SA, Poelzing S. Cardiac conduction in isolated hearts of genetically modified mice--Connexin43 and salts. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:189-98. [PMID: 26627143 DOI: 10.1016/j.pbiomolbio.2015.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/13/2015] [Accepted: 11/23/2015] [Indexed: 10/22/2022]
Abstract
Physiologic variations in perfusate composition have been identified as a new and important modulator of cardiac conduction velocity (CV), particularly when gap junctions (GJ) are reduced. We recently demonstrated in ex vivo hearts that perfusates with low sodium and high potassium preferentially slow ventricular CV in mice genetically engineered to express 50% less of the gap junction protein, connexin43 (Cx43). We also reported the possible role of calcium in modulating CV. In this review we discuss previous murine studies that explored the CV-GJ relationship in isolated mouse heart preparations with approximately 50% reduced Cx43. Studies were grouped according to the type of perfusate utilized, and CV during GJ uncoupling was compared. Studies in Group A preferentially used perfusates with low sodium, high potassium and non-physiologic calcium, and found CV slows and arrhythmias increase in mouse hearts with reduced Cx43. Studies in Group B used solutions with high sodium, low potassium and physiologic calcium, and did not observe CV slowing nor increased arrhythmia risk with loss of Cx3. Studies in Group C used solutions with low sodium, low potassium, physiologic calcium, creatine, taurine, and insulin. CV slowing was not observed, nor was arrhythmia risk increased with loss of Cx43. We suggest that perfusate ion composition may be a major determinant of whether CV slows when Cx43 is reduced. Furthermore, the review of these studies highlights important theoretical developments in the understanding of cardiac conduction and suggests that ionic milieu can conceal electrophysiologic remodeling secondary to reduced Cx43 expression as occurs in many cardiac diseases.
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Affiliation(s)
- Sharon A George
- Department of Biomedical Engineering and Mechanics, Virginia Tech Carilion Research Institute, and Center for Heart and Regenerative Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Steven Poelzing
- Department of Biomedical Engineering and Mechanics, Virginia Tech Carilion Research Institute, and Center for Heart and Regenerative Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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Hou J, Yan P, Guo T, Xing Y, Zheng S, Zhou C, Huang H, Long H, Zhong T, Wu Q, Wang J, Wang T. Cardiac stem cells transplantation enhances the expression of connexin 43 via the ANG II/AT1R/TGF-beta1 signaling pathway in a rat model of myocardial infarction. Exp Mol Pathol 2015; 99:693-701. [PMID: 26554848 DOI: 10.1016/j.yexmp.2015.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 11/06/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND In this study, we hypothesized that CSCs mediated the expression of Cx43 after transplantation post MI via the ANG II/AT1R/TGF-beta1 signaling pathway. METHODS Myocardial infarction (MI) was induced in twenty male Sprague-Dawley rats. The rats were randomized into two groups and were then received the injection of 5 × 10(6) CSCs labeled with PKH26 in phosphate buffer solution (PBS) or equal PBS alone into the infarct anterior ventricular free wall two weeks after MI. Six weeks later, relevant signaling molecules involved were all examined. RESULTS In the CSCs group, an increased expression of Cx43 could be observed in different zones of the left ventricle (P<0.01). There was a significant reduction of the angiotensin II (ANG II) level in plasma and different regions of the left ventricular cardiac tissues (P<0.05; P<0.01). The angiotensin II type I receptor (AT1R) was decreased accompanied with an enhanced expression of angiotensin II type II receptor (AT2R) (P<0.01). Transforming growth factor beta-1(TGF-beta1) was downregulated (P<0.01). The expression of mothers against decapentaplegic homolog (SMAD) proteins including SMAD2 and SMAD3 was attenuated whereas SMAD7 was elevated (P<0.01, P<0.01, P<0.05). In addition, the expression of mitogen-activated protein kinases (MAPKs) including extracellular kinases 1/2 (ERK1/2) and p38 was also found to be reduced (P<0.01). CONCLUSION CSCs transplantation could enhance the level of Cx43 after MI. They might function through intervening the ANGII/AT1R/TGF-beta1 signaling pathway to regulate the expression of Cx43.
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Affiliation(s)
- Jingying Hou
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Ping Yan
- The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Tianzhu Guo
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Yue Xing
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China
| | - Shaoxin Zheng
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Changqing Zhou
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Hui Huang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Huibao Long
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Tingting Zhong
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Quanhua Wu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Jingfeng Wang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China
| | - Tong Wang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China; Department of Emergency, the Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 Yanjiang Xi Road, Guangzhou, Guangdong, China.
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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: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [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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Intracellular Cleavage of the Cx43 C-Terminal Domain by Matrix-Metalloproteases: A Novel Contributor to Inflammation? Mediators Inflamm 2015; 2015:257471. [PMID: 26424967 PMCID: PMC4573893 DOI: 10.1155/2015/257471] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 08/13/2015] [Indexed: 01/11/2023] Open
Abstract
The coordination of tissue function is mediated by gap junctions (GJs) that enable direct cell-cell transfer of metabolic and electric signals. GJs are formed by connexin (Cx) proteins of which Cx43 is most widespread in the human body. Beyond its role in direct intercellular communication, Cx43 also forms nonjunctional hemichannels (HCs) in the plasma membrane that mediate the release of paracrine signaling molecules in the extracellular environment. Both HC and GJ channel function are regulated by protein-protein interactions and posttranslational modifications that predominantly take place in the C-terminal domain of Cx43. Matrix metalloproteases (MMPs) are a major group of zinc-dependent proteases, known to regulate not only extracellular matrix remodeling, but also processing of intracellular proteins. Together with Cx43 channels, both GJs and HCs, MMPs contribute to acute inflammation and a small number of studies reports on an MMP-Cx43 link. Here, we build further on these reports and present a novel hypothesis that describes proteolytic cleavage of the Cx43 C-terminal domain by MMPs and explores possibilities of how such cleavage events may affect Cx43 channel function. Finally, we set out how aberrant channel function resulting from cleavage can contribute to the acute inflammatory response during tissue injury.
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Martins-Marques T, Anjo SI, Pereira P, Manadas B, Girão H. Interacting Network of the Gap Junction (GJ) Protein Connexin43 (Cx43) is Modulated by Ischemia and Reperfusion in the Heart. Mol Cell Proteomics 2015; 14:3040-55. [PMID: 26316108 DOI: 10.1074/mcp.m115.052894] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Indexed: 01/16/2023] Open
Abstract
The coordinated and synchronized cardiac muscle contraction relies on an efficient gap junction-mediated intercellular communication (GJIC) between cardiomyocytes, which involves the rapid anisotropic impulse propagation through connexin (Cx)-containing channels, namely of Cx43, the most abundant Cx in the heart. Expectedly, disturbing mechanisms that affect channel activity, localization and turnover of Cx43 have been implicated in several cardiomyopathies, such as myocardial ischemia. Besides gap junction-mediated intercellular communication, Cx43 has been associated with channel-independent functions, including modulation of cell adhesion, differentiation, proliferation and gene transcription. It has been suggested that the role played by Cx43 is dictated by the nature of the proteins that interact with Cx43. Therefore, the characterization of the Cx43-interacting network and its dynamics is vital to understand not only the molecular mechanisms underlying pathological malfunction of gap junction-mediated intercellular communication, but also to unveil novel and unanticipated biological functions of Cx43. In the present report, we applied a quantitative SWATH-MS approach to characterize the Cx43 interactome in rat hearts subjected to ischemia and ischemia-reperfusion. Our results demonstrate that, in the heart, Cx43 interacts with proteins related with various biological processes such as metabolism, signaling and trafficking. The interaction of Cx43 with proteins involved in gene transcription strengthens the emerging concept that Cx43 has a role in gene expression regulation. Importantly, our data shows that the interactome of Cx43 (Connexome) is differentially modulated in diseased hearts. Overall, the characterization of Cx43-interacting network may contribute to the establishment of new therapeutic targets to modulate cardiac function in physiological and pathological conditions. Data are available via ProteomeXchange with identifier PXD002331.
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Affiliation(s)
- Tania Martins-Marques
- From the ‡Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal
| | - Sandra Isabel Anjo
- §CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; ¶Faculty of Sciences and Technology, University of Coimbra, 3030-790 Coimbra, Portugal
| | - Paulo Pereira
- From the ‡Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal
| | - Bruno Manadas
- §CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; ‖Biocant - Biotechnology Innovation Center, 3060-197, Cantanhede, Portugal
| | - Henrique Girão
- From the ‡Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal;
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Abstract
Cardiomyocytes are connected by mechanical and electrical junctions located at the intercalated discs (IDs). Although these structures have long been known, it is becoming increasingly clear that their components interact. This review describes the involvement of the ID in electrical disturbances of the heart and focuses on the role of the gap junctional protein connexin 43 (Cx43). Current evidence shows that Cx43 plays a crucial role in organizing microtubules at the intercalated disc and thereby regulating the trafficking of the cardiac sodium channel NaV1.5 to the membrane.
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Lübkemeier I, Bosen F, Kim JS, Sasse P, Malan D, Fleischmann BK, Willecke K. Human Connexin43E42K Mutation From a Sudden Infant Death Victim Leads to Impaired Ventricular Activation and Neonatal Death in Mice. ACTA ACUST UNITED AC 2015; 8:21-9. [DOI: 10.1161/circgenetics.114.000793] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Sudden infant death syndrome (SIDS) describes the sudden, unexplained death of a baby during its first year of age and is the third leading cause of infant mortality. It is assumed that ≤20% of all SIDS cases are because of cardiac arrhythmias resulting from mutations in ion channel proteins. Besides ion channels also cardiac gap junction channels are important for proper conduction of cardiac electric activation. In the mammalian heart Connexin43 (Cx43) is the major gap junction protein expressed in ventricular cardiomyocytes. Recently, a novel Connexin43 loss-of-function mutation (Cx43E42K) was identified in a 2-month-old SIDS victim.
Methods and Results—
We have generated Cx43E42K-expressing mice as a model for SIDS. Heterozygous cardiac-restricted Cx43E42K-mutated mice die neonatally without major cardiac morphological defects. Electrocardiographic recordings of embryonic Cx43+/E42K mice reveal severely disturbed ventricular activation, whereas immunohistochemical analyses show normal localization and expression patterns of gap junctional Connexin43 protein in the Cx43E42K-mutated newborn mouse heart.
Conclusions—
Because we did not find heterogeneous gap junction loss in Cx43E42K mouse hearts, we conclude that the Cx43E42K gap junction channel creates an arrhythmogenic substrate leading to lethal ventricular arrhythmias. The strong cardiac phenotype of Cx43E42K expressing mice supports the association between the human Cx43E42K mutation and SIDS and indicates that Connexin43 mutations should be considered in future studies when SIDS cases are to be molecularly explained.
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Affiliation(s)
- Indra Lübkemeier
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Felicitas Bosen
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Jung-Sun Kim
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Philipp Sasse
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Daniela Malan
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Bernd K. Fleischmann
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Klaus Willecke
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
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Gillet L, Shy D, Abriel H. Elucidating sodium channel NaV1.5 clustering in cardiac myocytes using super-resolution techniques. Cardiovasc Res 2014; 104:231-3. [DOI: 10.1093/cvr/cvu221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gerner L, Youssef G, O'Shaughnessy RFL. The protein phosphatase 2A regulatory subunit Ppp2r2a is required for Connexin-43 dephosphorlyation during epidermal barrier acquisition. Exp Dermatol 2014; 22:754-6. [PMID: 24433183 DOI: 10.1111/exd.12234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2013] [Indexed: 12/28/2022]
Abstract
Epidermal barrier acquisition during late mammalian development is a prerequisite for terrestrial existence. Over a 24-h period, the epidermis goes from being a barrier-deficient, dye permeable epithelium to a barrier-competent epithelium. We have previously shown that Akt signalling is necessary for barrier acquisition in the mouse and that the protein phosphatase 2A regulatory subunit Ppp2r2a causes barrier acquisition by dephosphorylation of cJun. Here, we demonstrate that there is transient interaction between the gap junction protein Connexin 43 (Cx43) and Zonula occludins-1 (Zo-1) during epidermal barrier acquisition. Ppp2r2a knockdown prevented plasma membrane co-localisation and interaction between the two proteins. Ppp2r2a knockdown also increased phosphorylation at Serine 368 of Connexin 43. Cx43 phosphorlyation at Serine368 occurred just prior to the interaction between Connexin 43 and Zo-1. We therefore propose a model in which Ppp2r2a is required both for the initial interaction between Zo-1 and Cx43 and the consequent dephosphorylation of Connexin 43, preventing interaction of Zo-1 and allowing Zo-1 to initiate tight junction formation and barrier acquisition.
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Affiliation(s)
- Lisa Gerner
- Immunobiology and Dermatology, UCL Institute of Child Health, London, UK; Prostate Cancer Research Group, Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
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Zhang SS, Shaw RM. Trafficking highways to the intercalated disc: new insights unlocking the specificity of connexin 43 localization. ACTA ACUST UNITED AC 2014; 21:43-54. [PMID: 24460200 DOI: 10.3109/15419061.2013.876014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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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Lin X, O'Malley H, Chen C, Auerbach D, Foster M, Shekhar A, Zhang M, Coetzee W, Jalife J, Fishman GI, Isom L, Delmar M. Scn1b deletion leads to increased tetrodotoxin-sensitive sodium current, altered intracellular calcium homeostasis and arrhythmias in murine hearts. J Physiol 2014; 593:1389-407. [PMID: 25772295 DOI: 10.1113/jphysiol.2014.277699] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/07/2014] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Na(+) current (INa) results from the integrated function of a molecular aggregate (the voltage-gated Na(+) channel complex) that includes the β subunit family. Mutations or rare variants in Scn1b (encoding the β1 and β1B subunits) have been associated with various inherited arrhythmogenic syndromes, including Brugada syndrome and sudden unexpected death in patients with epilepsy. We used Scn1b null mice to understand better the relation between Scn1b expression, and cardiac electrical function. Loss of Scn1b caused, among other effects, increased amplitude of tetrodotoxin-sensitive INa, delayed after-depolarizations, triggered beats, delayed Ca(2+) transients, frequent spontaneous calcium release events and increased susceptibility to polymorphic ventricular arrhythmias. Most alterations in Ca(2+) homeostasis were prevented by 100 nM tetrodotoxin. We propose that life-threatening arrhythmias in patients with mutations in Scn1b, a gene classically defined as ancillary to the Na(+) channel α subunit, can be partly consequent to disrupted intracellular Ca(2+) homeostasis. ABSTRACT Na(+) current (INa) is determined not only by the properties of the pore-forming voltage-gated Na(+) channel (VGSC) α subunit, but also by the integrated function of a molecular aggregate (the VGSC complex) that includes the VGSC β subunit family. Mutations or rare variants in Scn1b (encoding the β1 and β1B subunits) have been associated with various inherited arrhythmogenic syndromes, including cases of Brugada syndrome and sudden unexpected death in patients with epilepsy. Here, we have used Scn1b null mouse models to understand better the relation between Scn1b expression, and cardiac electrical function. Using a combination of macropatch and scanning ion conductance microscopy we show that loss of Scn1b in juvenile null animals resulted in increased tetrodotoxin-sensitive INa but only in the cell midsection, even before full T-tubule formation; the latter occurred concurrent with increased message abundance for the neuronal Scn3a mRNA, suggesting increased abundance of tetrodotoxin-sensitive NaV 1.3 protein and yet its exclusion from the region of the intercalated disc. Ventricular myocytes from cardiac-specific adult Scn1b null animals showed increased Scn3a message, prolonged action potential repolarization, presence of delayed after-depolarizations and triggered beats, delayed Ca(2+) transients and frequent spontaneous Ca(2+) release events and at the whole heart level, increased susceptibility to polymorphic ventricular arrhythmias. Most alterations in Ca(2+) homeostasis were prevented by 100 nM tetrodotoxin. Our results suggest that life-threatening arrhythmias in patients with mutations in Scn1b, a gene classically defined as ancillary to the Na(+) channel α subunit, can be partly consequent to disrupted intracellular Ca(2+) homeostasis in ventricular myocytes.
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Affiliation(s)
- Xianming Lin
- Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, NY, USA
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Agullo-Pascual E, Lin X, Leo-Macias A, Zhang M, Liang FX, Li Z, Pfenniger A, Lübkemeier I, Keegan S, Fenyö D, Willecke K, Rothenberg E, Delmar M. Super-resolution imaging reveals that loss of the C-terminus of connexin43 limits microtubule plus-end capture and NaV1.5 localization at the intercalated disc. Cardiovasc Res 2014; 104:371-81. [PMID: 25139742 DOI: 10.1093/cvr/cvu195] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AIMS It is well known that connexin43 (Cx43) forms gap junctions. We recently showed that Cx43 is also part of a protein-interacting network that regulates excitability. Cardiac-specific truncation of Cx43 C-terminus (mutant 'Cx43D378stop') led to lethal arrhythmias. Cx43D378stop localized to the intercalated disc (ID); cell-cell coupling was normal, but there was significant sodium current (INa) loss. We proposed that the microtubule plus-end is at the crux of the Cx43-INa relation. Yet, specific localization of relevant molecular players was prevented due to the resolution limit of fluorescence microscopy. Here, we use nanoscale imaging to establish: (i) the morphology of clusters formed by the microtubule plus-end tracking protein 'end-binding 1' (EB1), (ii) their position, and that of sodium channel alpha-subunit NaV1.5, relative to N-cadherin-rich sites, and (iii) the role of Cx43 C-terminus on the above-mentioned parameters and on the location-specific function of INa. METHODS AND RESULTS Super-resolution fluorescence localization microscopy in murine adult cardiomyocytes revealed EB1 and NaV1.5 as distinct clusters preferentially localized to N-cadherin-rich sites. Extent of co-localization decreased in Cx43D378stop cells. Macropatch and scanning patch clamp showed reduced INa exclusively at cell end, without changes in unitary conductance. Experiments in Cx43-modified HL1 cells confirmed the relation between Cx43, INa, and microtubules. CONCLUSIONS NaV1.5 and EB1 localization at the cell end is Cx43-dependent. Cx43 is part of a molecular complex that determines capture of the microtubule plus-end at the ID, facilitating cargo delivery. These observations link excitability and electrical coupling through a common molecular mechanism.
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Affiliation(s)
- Esperanza Agullo-Pascual
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Xianming Lin
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Alejandra Leo-Macias
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Mingliang Zhang
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Feng-Xia Liang
- Office of Collaborative Science Microscopy Core, NYU-SoM, New York, NY, USA
| | - Zhen Li
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Anna Pfenniger
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Indra Lübkemeier
- Life and Medical Sciences Institute, Molecular Genetics, University of Bonn, Bonn, Germany
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA Center for Health Informatics and Bioinformatics, NYU-SoM, New York, NY, USA
| | - David Fenyö
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA Center for Health Informatics and Bioinformatics, NYU-SoM, New York, NY, USA
| | - Klaus Willecke
- Life and Medical Sciences Institute, Molecular Genetics, University of Bonn, Bonn, Germany
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
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Shy D, Gillet L, Ogrodnik J, Albesa M, Verkerk AO, Wolswinkel R, Rougier JS, Barc J, Essers MC, Syam N, Marsman RF, van Mil AM, Rotman S, Redon R, Bezzina CR, Remme CA, Abriel H. PDZ domain-binding motif regulates cardiomyocyte compartment-specific NaV1.5 channel expression and function. Circulation 2014; 130:147-60. [PMID: 24895455 DOI: 10.1161/circulationaha.113.007852] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sodium channel NaV1.5 underlies cardiac excitability and conduction. The last 3 residues of NaV1.5 (Ser-Ile-Val) constitute a PDZ domain-binding motif that interacts with PDZ proteins such as syntrophins and SAP97 at different locations within the cardiomyocyte, thus defining distinct pools of NaV1.5 multiprotein complexes. Here, we explored the in vivo and clinical impact of this motif through characterization of mutant mice and genetic screening of patients. METHODS AND RESULTS To investigate in vivo the regulatory role of this motif, we generated knock-in mice lacking the SIV domain (ΔSIV). ΔSIV mice displayed reduced NaV1.5 expression and sodium current (INa), specifically at the lateral myocyte membrane, whereas NaV1.5 expression and INa at the intercalated disks were unaffected. Optical mapping of ΔSIV hearts revealed that ventricular conduction velocity was preferentially decreased in the transversal direction to myocardial fiber orientation, leading to increased anisotropy of ventricular conduction. Internalization of wild-type and ΔSIV channels was unchanged in HEK293 cells. However, the proteasome inhibitor MG132 rescued ΔSIV INa, suggesting that the SIV motif is important for regulation of NaV1.5 degradation. A missense mutation within the SIV motif (p.V2016M) was identified in a patient with Brugada syndrome. The mutation decreased NaV1.5 cell surface expression and INa when expressed in HEK293 cells. CONCLUSIONS Our results demonstrate the in vivo significance of the PDZ domain-binding motif in the correct expression of NaV1.5 at the lateral cardiomyocyte membrane and underline the functional role of lateral NaV1.5 in ventricular conduction. Furthermore, we reveal a clinical relevance of the SIV motif in cardiac disease.
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Affiliation(s)
- Diana Shy
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Ludovic Gillet
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Jakob Ogrodnik
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Maxime Albesa
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Arie O Verkerk
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Rianne Wolswinkel
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Jean-Sébastien Rougier
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Julien Barc
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Maria C Essers
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Ninda Syam
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Roos F Marsman
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Anneke M van Mil
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Samuel Rotman
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Richard Redon
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Connie R Bezzina
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Carol Ann Remme
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.)
| | - Hugues Abriel
- From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
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Smyth JW, Zhang SS, Sanchez JM, Lamouille S, Vogan JM, Hesketh GG, Hong T, Tomaselli GF, Shaw RM. A 14-3-3 mode-1 binding motif initiates gap junction internalization during acute cardiac ischemia. Traffic 2014; 15:684-99. [PMID: 24612377 PMCID: PMC4278178 DOI: 10.1111/tra.12169] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 02/03/2023]
Abstract
Altered phosphorylation and trafficking of connexin 43 (Cx43) during acute ischemia contributes to arrhythmogenic gap junction remodeling, yet the critical sequence and accessory proteins necessary for Cx43 internalization remain unresolved. 14-3-3 proteins can regulate protein trafficking, and a 14-3-3 mode-1 binding motif is activated upon phosphorylation of Ser373 of the Cx43 C-terminus. We hypothesized that Cx43(Ser373) phosphorylation is important to pathological gap junction remodeling. Immunofluorescence in human heart reveals the enrichment of 14-3-3 proteins at intercalated discs, suggesting interaction with gap junctions. Knockdown of 14-3-3τ in cell lines increases gap junction plaque size at cell-cell borders. Cx43(S373A) mutation prevents Cx43/14-3-3 complexing and stabilizes Cx43 at the cell surface, indicating avoidance of degradation. Using Langendorff-perfused mouse hearts, we detect phosphorylation of newly internalized Cx43 at Ser373 and Ser368 within 30 min of no-flow ischemia. Phosphorylation of Cx43 at Ser368 by protein kinase C and Ser255 by mitogen-activated protein kinase has previously been implicated in Cx43 internalization. The Cx43(S373A) mutant is resistant to phosphorylation at both these residues and does not undergo ubiquitination, revealing Ser373 phosphorylation as an upstream gatekeeper of a posttranslational modification cascade necessary for Cx43 internalization. Cx43(Ser373) phosphorylation is a potent target for therapeutic interventions to preserve gap junction coupling in the stressed myocardium.
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Affiliation(s)
- James W. Smyth
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center
| | - Shan-Shan Zhang
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center
| | - Jose M. Sanchez
- Department of Medicine, University of California San Francisco
| | - Samy Lamouille
- Department of Medicine, University of California San Francisco
| | - Jacob M. Vogan
- Department of Medicine, University of California San Francisco
| | | | - TingTing Hong
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center
- Department of Medicine, University of California Los Angeles
| | | | - Robin M. Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center
- Department of Medicine, University of California Los Angeles
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Protein LUMA is a cytoplasmic plaque constituent of various epithelial adherens junctions and composite junctions of myocardial intercalated disks: a unifying finding for cell biology and cardiology. Cell Tissue Res 2014; 357:159-72. [PMID: 24770932 DOI: 10.1007/s00441-014-1865-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 03/06/2014] [Indexed: 10/25/2022]
Abstract
In a series of recent reports, mutations in the gene encoding a protein called LUMA (or TMEM43), widely speculated to be a tetraspan transmembrane protein of the nuclear envelope, have been associated with a specific subtype of cardiomyopathy (arrhythmogenic cardiomyopathies) and cases of sudden death. However, using antibodies of high specificity in immunolocalization experiments, we have discovered that, in mammals, LUMA is a component of zonula adhaerens and punctum adhaerens plaques of diverse epithelia and epithelial cell cultures and is also located in (or in some species associated with) the plaques of composite junctions (CJs) in myocardiac intercalated disks (IDs). In CJs, LUMA often colocalizes with several other CJ marker proteins. In all these cells, LUMA has not been detected in the nuclear envelope. Surprisingly, under certain conditions, similar CJ localizations have also been seen with some antibodies commercially available for some time. The identification of LUMA as a plaque component of myocardiac CJs leads to reconsiderations of the molecular composition and architecture, the development, the functions, and the pathogenic states of CJs and IDs. These findings now also allow the general conclusion that LUMA has to be added to the list of mutations of cardiomyocyte junction proteins that may be involved in cardiomyopathies.
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46
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Bai D. Atrial fibrillation-linked GJA5/connexin40 mutants impaired gap junctions via different mechanisms. FEBS Lett 2014; 588:1238-43. [PMID: 24656738 DOI: 10.1016/j.febslet.2014.02.064] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 01/08/2023]
Abstract
The gap junctions (GJs) formed by Cx40 and Cx43 provide a low resistance passage allowing for rapid propagation of action potentials. Sporadic somatic mutations in GJA5 (encoding Cx40) have been identified in lone atrial fibrillation (AF) patients. More recently germline autosomal dominantly inherited mutations in GJA5 have been found in early onset lone AF patients in several families over generations. Characterizations of these AF-linked Cx40 mutants in model cells and in patient tissues revealed that some of the mutants reduced GJ channel function due to an impaired trafficking or channel formation. While others showed a gain-of-function in hemichannels. These functional alterations in GJs or hemichannel may play an important role in the pathogenesis of AF in the mutant carriers.
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Affiliation(s)
- Donglin Bai
- Department of Physiology and Pharmacology, Western University, London, Ontario N6A 5C1, Canada.
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47
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Mezzano V, Pellman J, Sheikh F. Cell junctions in the specialized conduction system of the heart. ACTA ACUST UNITED AC 2014; 21:149-59. [PMID: 24738884 DOI: 10.3109/15419061.2014.905928] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Anchoring cell junctions are integral in maintaining electro-mechanical coupling of ventricular working cardiomyocytes; however, their role in cardiomyocytes of the cardiac conduction system (CCS) remains less clear. Recent studies in genetic mouse models and humans highlight the appearance of these cell junctions alongside gap junctions in the CCS and also show that defects in these structures and their components are associated with conduction impairments in the CCS. Here we outline current evidence supporting an integral relationship between anchoring and gap junctions in the CCS. Specifically we focus on (1) molecular and ultrastructural evidence for cell-cell junctions in specialized cardiomyocytes of the CCS, (2) genetic mouse models specifically targeting cell-cell junction components in the heart which exhibit CCS conduction defects and (3) human clinical studies from patients with cell-cell junction-based diseases that exhibit CCS electrophysiological defects.
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Affiliation(s)
- Valeria Mezzano
- Leon H. Charney Division of Cardiology, New York University School of Medicine , New York , New York
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48
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Veeraraghavan R, Poelzing S, Gourdie RG. Intercellular electrical communication in the heart: a new, active role for the intercalated disk. ACTA ACUST UNITED AC 2014; 21:161-7. [PMID: 24735129 DOI: 10.3109/15419061.2014.905932] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cardiac conduction is the propagation of electrical excitation through the heart and is responsible for triggering individual myocytes to contract in synchrony. Canonically, this process has been thought to occur electrotonically, by means of direct flow of ions from cell to cell. The intercalated disk (ID), the site of contact between adjacent myocytes, has been viewed as a structure composed of mechanical junctions that stabilize the apposition of cell membranes and gap junctions which constitute low resistance pathways between cells. However, emerging evidence suggests a more active role for structures within the ID in mediating intercellular electrical communication by means of non-canonical ephaptic mechanisms. This review will discuss the role of the ID in the context of the canonical, electrotonic view of conduction and highlight new, emerging possibilities of its playing a more active role in ephaptic coupling between cardiac myocytes.
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Affiliation(s)
- Rengasayee Veeraraghavan
- Center for Cardiovascular and Regenerative Biology, Virginia Tech Carilion Research Institute , Roanoke, VA , USA
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49
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Nerbonne JM. Mouse models of arrhythmogenic cardiovascular disease: challenges and opportunities. Curr Opin Pharmacol 2014; 15:107-14. [PMID: 24632325 DOI: 10.1016/j.coph.2014.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 02/04/2014] [Accepted: 02/05/2014] [Indexed: 12/27/2022]
Abstract
Arrhythmogenic cardiovascular disease is associated with significant morbidity and mortality and, in spite of therapeutic advances, remains an enormous public health burden. The scope of this problem motivates efforts to delineate the molecular, cellular and systemic mechanisms underlying increased arrhythmia risk in inherited and acquired cardiac and systemic disease. The mouse is used increasingly in these efforts owing to the ease with which genetic strategies can be exploited and mechanisms can be probed. The question then arises whether the mouse has proven to be a useful model system to delineate arrhythmogenic cardiovascular disease mechanisms. Rather than trying to provide a definite answer, the goal here is to consider the issues that arise when using mouse models and to highlight the opportunities.
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Affiliation(s)
- Jeanne M Nerbonne
- Department of Developmental Biology, Washington University Medical School, St. Louis, MO 63110, USA; Department of Internal Medicine, Washington University Medical School, St. Louis, MO 63110, USA.
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50
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Agullo-Pascual E, Cerrone M, Delmar M. Arrhythmogenic cardiomyopathy and Brugada syndrome: diseases of the connexome. FEBS Lett 2014; 588:1322-30. [PMID: 24548564 DOI: 10.1016/j.febslet.2014.02.008] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/06/2014] [Accepted: 02/06/2014] [Indexed: 11/30/2022]
Abstract
This review summarizes data in support of the notion that the cardiac intercalated disc is the host of a protein interacting network, called "the connexome", where molecules classically defined as belonging to one particular structure (e.g., desmosomes, gap junctions, sodium channel complex) actually interact with others, and together, control excitability, electrical coupling and intercellular adhesion in the heart. The concept of the connexome is then translated into the understanding of the mechanisms leading to two inherited arrhythmia diseases: arrhythmogenic cardiomyopathy, and Brugada syndrome. The cross-over points in these two diseases are addressed to then suggest that, though separate identifiable clinical entities, they represent "bookends" of a spectrum of manifestations that vary depending on the effect that a particular mutation has on the connexome as a whole.
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Affiliation(s)
- Esperanza Agullo-Pascual
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States
| | - Marina Cerrone
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States.
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