1
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He ZX, Gao G, Qiao H, Dong GJ, Dan Z, Li YL, Qi YR, Zhang Q, Yuan S, Liu HM, Dong J, Zhao W, Ma LY. Discovery of 1,2,4-Triazole-3-thione Derivatives as Potent and Selective DCN1 Inhibitors for Pathological Cardiac Fibrosis and Remodeling. J Med Chem 2024. [PMID: 39158077 DOI: 10.1021/acs.jmedchem.4c00713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
DCN1, a critical co-E3 ligase during the neddylation process, is overactivated in many diseases, such as cancers, heart failure as well as fibrotic diseases, and has been regarded as a new target for drug development. Herein, we designed and synthesized a new class of 1,2,4-triazole-3-thione-based DCN1 inhibitors based the hit HD1 identified from high-throughput screening and optimized through numerous structure-activity-relationship (SAR) explorations. HD2 (IC50= 2.96 nM) was finally identified and represented a highly potent and selective DCN1 inhibitor with favorable PK properties and low toxicity. Amazingly, HD2 effectively relieved Ang II/TGFβ-induced cardiac fibroblast activation in vitro, and reduced ISO-induced cardiac fibrosis as well as remodeling in vivo, which was linked to the inhibition of cullin 3 neddylation and its substrate Nrf2 accumulation. Our findings unveil a novel 1,2,4-triazole-3-thione-based derivative HD2, which can be recognized as a promising lead compound targeting DCN1 for cardiac fibrosis and remodeling.
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Affiliation(s)
- Zhang-Xu He
- Pharmacy College, Henan University of Chinese Medicine, 450046 Zhengzhou, PR China
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Ge Gao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Hui Qiao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Guan-Jun Dong
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Zengyangzong Dan
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Ya-Lan Li
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yu-Ruo Qi
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Qian Zhang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Shuo Yuan
- Henan Children's Hospital, Zhengzhou Children's Hospital, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou 450018, China
| | - Hong-Min Liu
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jianzeng Dong
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450000, China
| | - Wen Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Li-Ying Ma
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China
- China Meheco Topfond Pharmaceutical Co., Zhumadian 463000, China
- Key Laboratory of Cardiocerebrovascular Drugs, Zhumadian 463000, Henan Province, China
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2
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García-Mendívil L, Pérez-Zabalza M, Oliver-Gelabert A, Vallejo-Gil JM, Fañanás-Mastral J, Vázquez-Sancho M, Bellido-Morales JA, Vaca-Núñez AS, Ballester-Cuenca C, Diez E, Ordovás L, Pueyo E. Interindividual Age-Independent Differences in Human CX43 Impact Ventricular Arrhythmic Risk. RESEARCH (WASHINGTON, D.C.) 2023; 6:0254. [PMID: 38023417 PMCID: PMC10650968 DOI: 10.34133/research.0254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023]
Abstract
Connexin 43 (CX43) is one of the major components of gap junctions, the structures responsible for the intercellular communication and transmission of the electrical impulse in the left ventricle. There is limited information on the histological changes of CX43 with age and their effect on electrophysiology, especially in humans. Here, we analyzed left ventricular biopsies from living donors starting at midlife to characterize age-related CX43 remodeling. We assessed its quantity, degree of lateralization, and spatial heterogeneity together with fibrotic deposition. We observed no significant age-related remodeling of CX43. Only spatial heterogeneity increased slightly with age, and this increase was better explained by biological age than by chronological age. Importantly, we found that CX43 features varied considerably among individuals in our population with no relevant relationship to age or fibrosis content, in contrast to animal species. We used our experimental results to feed computational models of human ventricular electrophysiology and to assess the effects of interindividual differences in specific features of CX43 and fibrosis on conduction velocity, action potential duration, and arrhythmogenicity. We found that larger amounts of fibrosis were associated with the highest arrhythmic risk, with this risk being increased when fibrosis deposition was combined with a reduction in CX43 amount and/or with an increase in CX43 spatial heterogeneity. These mechanisms underlying high arrhythmic risk in some individuals were not associated with age in our study population. In conclusion, our data rule out CX43 remodeling as an age-related arrhythmic substrate in the population beyond midlife, but highlight its potential as a proarrhythmic factor at the individual level, especially when combined with increased fibrosis.
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Affiliation(s)
- Laura García-Mendívil
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - María Pérez-Zabalza
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Centro Universitario de la Defensa (CUD), Zaragoza 50090, Spain
| | - Antoni Oliver-Gelabert
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
| | - José María Vallejo-Gil
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Javier Fañanás-Mastral
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Manuel Vázquez-Sancho
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | | | | | - Carlos Ballester-Cuenca
- Department of Cardiovascular Surgery,
University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Emiliano Diez
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU), CONICET, Mendoza 5500, Argentina
| | - Laura Ordovás
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Fundación Agencia Aragonesa para la Investigación y el Desarrollo (ARAID), Zaragoza 50018, Spain
| | - Esther Pueyo
- Biomedical Signal Interpretation and Computational Simulation group (BSICoS), Aragón Institute of Engineering Research,
University of Zaragoza, Zaragoza 50018, Spain
- BSICoS, Instituto de Investigación Sanitaria Aragón (IISA), Zaragoza 50018, Spain
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza 50018, Spain
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3
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Guo YH, Yang YQ. Atrial Fibrillation: Focus on Myocardial Connexins and Gap Junctions. BIOLOGY 2022; 11:489. [PMID: 35453689 PMCID: PMC9029470 DOI: 10.3390/biology11040489] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Atrial fibrillation (AF) represents the most common type of clinical cardiac arrhythmia worldwide and contributes to substantial morbidity, mortality and socioeconomic burden. Aggregating evidence highlights the strong genetic basis of AF. In addition to chromosomal abnormalities, pathogenic mutations in over 50 genes have been causally linked to AF, of which the majority encode ion channels, cardiac structural proteins, transcription factors and gap junction channels. In the heart, gap junctions comprised of connexins (Cxs) form intercellular pathways responsible for electrical coupling and rapid coordinated action potential propagation between adjacent cardiomyocytes. Among the 21 isoforms of connexins already identified in the mammal genomes, 5 isoforms (Cx37, Cx40, Cx43, Cx45 and Cx46) are expressed in human heart. Abnormal electrical coupling between cardiomyocytes caused by structural remodeling of gap junction channels (alterations in connexin distribution and protein levels) has been associated with enhanced susceptibility to AF and recent studies have revealed multiple causative mutations or polymorphisms in 4 isoforms of connexins predisposing to AF. In this review, an overview of the genetics of AF is made, with a focus on the roles of mutant myocardial connexins and gap junctions in the pathogenesis of AF, to underscore the hypothesis that cardiac connexins are a major molecular target in the management of AF.
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Affiliation(s)
- Yu-Han Guo
- Department of Cardiology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China;
| | - Yi-Qing Yang
- Department of Cardiology, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China;
- Cardiovascular Research Laboratory, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China
- Center Laboratory, Shanghai Fifth People’s Hospital, Fudan University, Shanghai 200240, China
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4
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Analysis of buccal mucosa as a prognostic tool in children with arrhythmogenic cardiomyopathy. PROGRESS IN PEDIATRIC CARDIOLOGY 2022; 64:None. [PMID: 35300203 PMCID: PMC8917042 DOI: 10.1016/j.ppedcard.2021.101458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/13/2021] [Accepted: 10/25/2021] [Indexed: 11/26/2022]
Abstract
Background The diagnosis of arrhythmogenic cardiomyopathy (ACM) is challenging especially in children at risk of adverse events. Analysis of cardiac myocyte junctional protein distribution may have diagnostic and prognostic implications, but its utility is limited by the need for a myocardial sample. We previously reported that buccal mucosa cells show junctional protein redistribution similar to that seen in cardiac myocytes of adult patients with ACM. Objectives We aimed to determine when junctional protein distribution abnormalities first occur in children with ACM variants and whether they correlate with progression of clinically apparent disease. Methods We analyzed buccal mucosa samples of children and adolescents with a family history of ACM (n = 13) and age-matched controls (n = 13). Samples were immunostained for plakoglobin, desmoplakin, plakophilin-1 and connexin43 and analyzed by confocal microscopy. All participants were swabbed at least twice with an average interval of 12–18 months between samplings. Results Junctional protein re-localization in buccal mucosa cells did not correlate with the presence of ACM-causing variants but instead occurred with clinical onset of disease. No changes in protein distribution were seen unless and until there was clinical evidence of disease. In addition, progressive shifts in the distribution of key proteins correlated with worsening of the disease phenotype. Finally, we observed restoration of junctional signal for Cx43 in patient with a favorable response to anti-arrhythmic therapy. Conclusions Due to ethical concerns about obtaining heart biopsies in children with no apparent disease, it has not been possible to analyze molecular changes in cardiac myocytes with the onset/progression of clinical disease. Using buccal smears as a surrogate for the myocardium may facilitate future studies of mechanisms and pathophysiological consequences of junctional protein redistribution in ACM. Buccal cells may also be a safe and inexpensive tool for risk stratification and potentially monitoring response to treatment in children bearing ACM variants.
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5
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González-Casanova JE, Durán-Agüero S, Caro-Fuentes NJ, Gamboa-Arancibia ME, Bruna T, Bermúdez V, Rojas-Gómez DM. New Insights on the Role of Connexins and Gap Junctions Channels in Adipose Tissue and Obesity. Int J Mol Sci 2021; 22:ijms222212145. [PMID: 34830025 PMCID: PMC8619175 DOI: 10.3390/ijms222212145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/05/2021] [Accepted: 11/05/2021] [Indexed: 12/20/2022] Open
Abstract
Due to the inability to curb the excessive increase in the prevalence of obesity and overweight, it is necessary to comprehend in more detail the factors involved in the pathophysiology and to appreciate more clearly the biochemical and molecular mechanisms of obesity. Thus, understanding the biological regulation of adipose tissue is of fundamental relevance. Connexin, a protein that forms intercellular membrane channels of gap junctions and unopposed hemichannels, plays a key role in adipogenesis and in the maintenance of adipose tissue homeostasis. The expression and function of Connexin 43 (Cx43) during the different stages of the adipogenesis are differentially regulated. Moreover, it has been shown that cell–cell communication decreases dramatically upon differentiation into adipocytes. Furthermore, inhibition of Cx43 degradation or constitutive overexpression of Cx43 blocks adipocyte differentiation. In the first events of adipogenesis, the connexin is highly phosphorylated, which is likely associated with enhanced Gap Junction (GJ) communication. In an intermediate state of adipocyte differentiation, Cx43 phosphorylation decreases, as it is displaced from the membrane and degraded through the proteasome; thus, Cx43 total protein is reduced. Cx is involved in cardiac disease as well as in obesity-related cardiovascular diseases. Different studies suggest that obesity together with a high-fat diet are related to the production of remodeling factors associated with expression and distribution of Cx43 in the atrium.
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Affiliation(s)
- Jorge Enrique González-Casanova
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile; (J.E.G.-C.); (N.J.C.-F.)
| | - Samuel Durán-Agüero
- Facultad de Ciencias Para el Cuidado de la Salud, Universidad San Sebastián, Sede Los Leones, Lota 2465, Providencia, Santiago 7500000, Chile;
| | - Nelson Javier Caro-Fuentes
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile; (J.E.G.-C.); (N.J.C.-F.)
| | - Maria Elena Gamboa-Arancibia
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. Libertador Bernardo O’higgins 3363, Estación Central, Santiago 9170022, Chile;
| | - Tamara Bruna
- Centro de Investigación Austral Biotech, Facultad de Ciencias, Universidad Santo Tomás, Avenida Ejercito 146, Santiago 8320000, Chile;
| | - Valmore Bermúdez
- Facultad de Ciencias de la Salud, Universidad Simón Bolívar, Barranquilla 080002, Colombia;
| | - Diana Marcela Rojas-Gómez
- Escuela de Nutrición y Dietética, Facultad de Medicina, Universidad Andres Bello, Santiago 8370321, Chile
- Correspondence: ; Tel.: +56-226618559
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Remodeling of Cardiac Gap Junctional Cell-Cell Coupling. Cells 2021; 10:cells10092422. [PMID: 34572071 PMCID: PMC8465208 DOI: 10.3390/cells10092422] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 12/29/2022] Open
Abstract
The heart works as a functional syncytium, which is realized via cell-cell coupling maintained by gap junction channels. These channels connect two adjacent cells, so that action potentials can be transferred. Each cell contributes a hexameric hemichannel (=connexon), formed by protein subuntis named connexins. These hemichannels dock to each other and form the gap junction channel. This channel works as a low ohmic resistor also allowing the passage of small molecules up to 1000 Dalton. Connexins are a protein family comprising of 21 isoforms in humans. In the heart, the main isoforms are Cx43 (the 43 kDa connexin; ubiquitous), Cx40 (mostly in atrium and specific conduction system), and Cx45 (in early developmental states, in the conduction system, and between fibroblasts and cardiomyocytes). These gap junction channels are mainly located at the polar region of the cardiomyocytes and thus contribute to the anisotropic pattern of cardiac electrical conductivity. While in the beginning the cell–cell coupling was considered to be static, similar to an anatomically defined structure, we have learned in the past decades that gap junctions are also subject to cardiac remodeling processes in cardiac disease such as atrial fibrillation, myocardial infarction, or cardiomyopathy. The underlying remodeling processes include the modulation of connexin expression by e.g., angiotensin, endothelin, or catecholamines, as well as the modulation of the localization of the gap junctions e.g., by the direction and strength of local mechanical forces. A reduction in connexin expression can result in a reduced conduction velocity. The alteration of gap junction localization has been shown to result in altered pathways of conduction and altered anisotropy. In particular, it can produce or contribute to non-uniformity of anisotropy, and thereby can pre-form an arrhythmogenic substrate. Interestingly, these remodeling processes seem to be susceptible to certain pharmacological treatment.
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7
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Papathanasiou KA, Giotaki SG, Vrachatis DA, Siasos G, Lambadiari V, Iliodromitis KE, Kossyvakis C, Kaoukis A, Raisakis K, Deftereos G, Papaioannou TG, Giannopoulos G, Avramides D, Deftereos SG. Molecular Insights in Atrial Fibrillation Pathogenesis and Therapeutics: A Narrative Review. Diagnostics (Basel) 2021; 11:diagnostics11091584. [PMID: 34573926 PMCID: PMC8470040 DOI: 10.3390/diagnostics11091584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022] Open
Abstract
The prevalence of atrial fibrillation (AF) is bound to increase globally in the following years, affecting the quality of life of millions of people, increasing mortality and morbidity, and beleaguering health care systems. Increasingly effective therapeutic options against AF are the constantly evolving electroanatomic substrate mapping systems of the left atrium (LA) and ablation catheter technologies. Yet, a prerequisite for better long-term success rates is the understanding of AF pathogenesis and maintenance. LA electrical and anatomical remodeling remains in the epicenter of current research for novel diagnostic and treatment modalities. On a molecular level, electrical remodeling lies on impaired calcium handling, enhanced inwardly rectifying potassium currents, and gap junction perturbations. In addition, a wide array of profibrotic stimuli activates fibroblast to an increased extracellular matrix turnover via various intermediaries. Concomitant dysregulation of the autonomic nervous system and the humoral function of increased epicardial adipose tissue (EAT) are established mediators in the pathophysiology of AF. Local atrial lymphomononuclear cells infiltrate and increased inflammasome activity accelerate and perpetuate arrhythmia substrate. Finally, impaired intracellular protein metabolism, excessive oxidative stress, and mitochondrial dysfunction deplete atrial cardiomyocyte ATP and promote arrhythmogenesis. These overlapping cellular and molecular alterations hinder us from distinguishing the cause from the effect in AF pathogenesis. Yet, a plethora of therapeutic modalities target these molecular perturbations and hold promise in combating the AF burden. Namely, atrial selective ion channel inhibitors, AF gene therapy, anti-fibrotic agents, AF drug repurposing, immunomodulators, and indirect cardiac neuromodulation are discussed here.
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Affiliation(s)
- Konstantinos A. Papathanasiou
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Sotiria G. Giotaki
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Dimitrios A. Vrachatis
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Gerasimos Siasos
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | - Vaia Lambadiari
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | | | - Charalampos Kossyvakis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Andreas Kaoukis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Konstantinos Raisakis
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Gerasimos Deftereos
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Theodore G. Papaioannou
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
| | | | - Dimitrios Avramides
- Department of Cardiology, “G. Gennimatas” General Hospital of Athens, 11527 Athens, Greece; (C.K.); (A.K.); (K.R.); (G.D.); (D.A.)
| | - Spyridon G. Deftereos
- Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (K.A.P.); (S.G.G.); (D.A.V.); (G.S.); (V.L.); (T.G.P.)
- Correspondence: ; Tel.: +30-21-0583-2355
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Li X, Cui X, Zhou S, Xing DL, Piao HR, Zhang QG, Zhao YQ, Liu LP. The novel ginsenoside AD2 prevents angiotensin II-induced connexin 40 and connexin 43 dysregulation by activating AMP kinase signaling in perfused beating rat atria. Chem Biol Interact 2021; 339:109430. [PMID: 33676887 DOI: 10.1016/j.cbi.2021.109430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 02/02/2021] [Accepted: 02/27/2021] [Indexed: 11/27/2022]
Abstract
Connexin-40 (Cx40) and Cx43 are the principal components of gap junctions. Dysregulation of connexin expression is clinically related to cardiac pathologies. 25-Hydroxy protopanaxadiol [25-OH-PPD, 20 (R)-dammarane-3β, 12β, 20, 25-tetrol], known as AD2, is a novel protopanaxadiol extracted from Panax ginseng that exhibits many pharmacological activities, but its effects on cardiac gap junctions are poorly understood. The aim of this study was to evaluate the effects of AD2 on angiotensin II (Ang II)-induced Cx40 and Cx43 dysregulation. In this study, isolated beating rat atria were perfused with Ang II (5 μM) for 1 h to induce Cx40 and Cx43 dysregulation. The effects of AD2 (1.6, 16, and 160 μg/100 g body weight) on Ang II-induced hemodynamics in rats were analyzed by biological recorder, and changes in proteins levels were analyzed by western blotting. The results showed that AD2 ameliorated Ang II-induced hyper hemodynamics and abnormal P-waves, and prevented fibrotic collagen deposition (3.77% ± 1.64%-26.31% ± 1.64% with Ang II, 5.76% ± 0.94% with AD2). Ang II upregulated expression of nuclear factor kappa B, activator protein 1, and transforming growth factor β1, and downregulated of Cx40 and Cx43 expression, which were inhibited by AD2 concomitantly with increased of AMP-activated protein kinase (AMPK) expression via liver kinase B1 activation. The present findings suggest that AD2 inhibited Ang II-induced dysregulation of Cx40 and Cx43 via activation of AMPK signaling, thus highlighting the promise and utility of AD2 for treatment of connexin dysregulation-related heart disease.
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Affiliation(s)
- Xiang Li
- Chronic Diseases Research Center, School of Medicine, Dalian University, Dalian, 116600, China; Department of Physiology and Pathophysiology, School of Medicine, Yanbian University, Yanji, 133002, China
| | - Xun Cui
- Department of Physiology and Pathophysiology, School of Medicine, Yanbian University, Yanji, 133002, China
| | - Shuai Zhou
- Department of Physiology and Pathophysiology, School of Medicine, Yanbian University, Yanji, 133002, China
| | - Da-Lin Xing
- Chronic Diseases Research Center, School of Medicine, Dalian University, Dalian, 116600, China
| | - Hu-Ri Piao
- Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules, Ministry of Education, Yanbian University College of Pharmacy, Yanji, 133002, China
| | - Qing-Gao Zhang
- Chronic Diseases Research Center, School of Medicine, Dalian University, Dalian, 116600, China.
| | - Yu-Qing Zhao
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, 110016, China.
| | - Li-Ping Liu
- Chronic Diseases Research Center, School of Medicine, Dalian University, Dalian, 116600, China.
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9
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Zhang Y, Hou MC, Li JJ, Qi Y, Zhang Y, She G, Ren YJ, Wu W, Pang ZD, Xie W, Deng XL, Du XJ. Cardiac β-adrenergic receptor activation mediates distinct and cell type-dependent changes in the expression and distribution of connexin 43. J Cell Mol Med 2020; 24:8505-8517. [PMID: 32578931 PMCID: PMC7412418 DOI: 10.1111/jcmm.15469] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/27/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Activation of the sympatho-β-adrenergic receptors (β-ARs) system is a hallmark of heart failure, leading to fibrosis and arrhythmias. Connexin 43 (Cx43) is the most abundant gap junctional protein in the myocardium. Current knowledge is limited regarding Cx43 remodelling in diverse cell types in the diseased myocardium and the underlying mechanism. We studied cell type-dependent changes in Cx43 remodelling due to β-AR overactivation and molecular mechanisms involved. Mouse models of isoproterenol stimulation or transgenic cardiomyocyte overexpression of β2 -AR were used, which exhibited cardiac fibrosis and up-regulated total Cx43 abundance. In both models, whereas Cx43 expression in cardiomyocytes was reduced and more laterally distributed, fibroblasts exhibited elevated Cx43 expression and enhanced gap junction communication. Mechanistically, activation of β2 -AR in fibroblasts in vitro elevated Cx43 expression, which was abolished by the β2 -antagonist ICI-118551 or protein kinase A inhibitor H-89, but simulated by the adenylyl cyclase activator forskolin. Our in vitro and in vivo data showed that β-AR activation-induced production of IL-18 sequentially stimulated Cx43 expression in fibroblasts in a paracrine fashion. In summary, our findings demonstrate a pivotal role of β-AR in mediating distinct and cell type-dependent changes in the expression and distribution of Cx43, leading to pathological gap junction remodelling in the myocardium.
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Affiliation(s)
- Yi Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Meng-Chen Hou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Department of Pathology, Xi'an Guangren Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Jing-Jing Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Ying Qi
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yu Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Gang She
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Yu-Jie Ren
- Department of Pathology, Xi'an Guangren Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Wei Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Zheng-Da Pang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xiu-Ling Deng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University Health Science Center, Shaanxi, China
| | - Xiao-Jun Du
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Experimental Cardiology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
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10
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Dai H, Yuan Y, Yin S, Zhang Y, Han Y, Sun L, Li T, Xu J, Sheng L, Gong Y, Li Y. Metoprolol Inhibits Profibrotic Remodeling of Epicardial Adipose Tissue in a Canine Model of Chronic Obstructive Sleep Apnea. J Am Heart Assoc 2020; 8:e011155. [PMID: 30686096 PMCID: PMC6405574 DOI: 10.1161/jaha.118.011155] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Whether chronic obstructive sleep apnea ( OSA ) could promote epicardial adipose tissue ( EAT ) secretion of profibrotic adipokines, and thereby contribute to atrial fibrosis, and the potential therapeutic effects of metoprolol remain unknown. Methods and Results A chronic OSA canine model was established by repeatedly clamping the endotracheal tube for and then reopening it for 4 hours every other day for 12 weeks. In a metoprolol treatment group, metoprolol succinate was administered daily for 12 weeks. The EAT infiltration and left atrial fibrosis were examined. The expressions of adipokines secreted by EAT and hypoxic 3T3-L1 adipocytes were detected. The changes in collagen synthesis, transforming growth factor-β1 expression, and cell differentiation and proliferation in cardiac fibroblasts induced by hypoxic 3T3-L1 adipocyte-derived conditioned medium were further analyzed. Chronic OSA induced infiltration of EAT into the left atrium. OSA enhanced the profibrotic effect of EAT on the adjacent atrial myocardium. Moreover, OSA induced profibrotic cytokine secretion from EAT . We also found that hypoxia induced adipokine secretion in cultured adipocytes, and the medium conditioned by the hypoxic adipocytes increased collagen and transforming growth factor-β1 protein expression and cell proliferation of cardiac fibroblasts. More importantly, metoprolol attenuated infiltration of EAT and alleviated the profibrotic effect of EAT by inhibiting adipokine secretion. Metoprolol also inhibited hypoxia-induced adipokine secretion in adipocytes and thereby blocked the hypoxic adipocyte-derived conditioned medium-induced fibrotic response of cardiac fibroblasts. Conclusions Chronic OSA enhanced the profibrotic effect of EAT on the neighboring atrial myocardium by stimulating the secretion of profibrotic adipokines from EAT , which was significantly attenuated by metoprolol. This study gives insights into mechanisms underlying OSA -induced atrial fibrillation and also provides experimental evidence for the protective effects of metoprolol.
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Affiliation(s)
- Hui Dai
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China.,2 Department of Emergency Xinhua Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yue Yuan
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Shuangli Yin
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Yun Zhang
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Yu Han
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Li Sun
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Tiankai Li
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Jicheng Xu
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Li Sheng
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Yongtai Gong
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
| | - Yue Li
- 1 Department of Cardiology the First Affiliated Hospital Harbin Medical University Harbin China
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11
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Involvement of sphingosine-1-phosphate receptors 2/3 in IR-induced sudden cardiac death. Heart Vessels 2019; 34:1052-1063. [DOI: 10.1007/s00380-018-01323-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 12/21/2018] [Indexed: 12/22/2022]
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12
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Li J, Wang S, Zhang YL, Bai J, Lin QY, Liu RS, Yu XH, Li HH. Immunoproteasome Subunit β5i Promotes Ang II (Angiotensin II)–Induced Atrial Fibrillation by Targeting ATRAP (Ang II Type I Receptor–Associated Protein) Degradation in Mice. Hypertension 2019; 73:92-101. [PMID: 30571551 DOI: 10.1161/hypertensionaha.118.11813] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and increases the risk of stroke, heart failure, and death. Ang II (angiotensin II) triggers AF, mainly through stimulation of the AT1R (Ang II type I receptor). The immunoproteasome is a highly efficient proteolytic machine derived from the constitutive proteasome, but the role it plays in regulating AT1R activation and triggering AF remains unknown. Here, we show that among the catalytic subunits, β5i (PSMB8) expression, and chymotrypsin-like activity were the most significantly upregulated in atrial tissue of Ang II–infused mice or serum from patients with AF. β5i KO (β5i knockout) in mice markedly attenuated Ang II-induced AF incidence, atrial fibrosis, inflammatory response, and oxidative stress compared with WT (wild type) animals, but injection with recombinant adeno-associated virus serotype 9–β5i increased these effects. Moreover, we found that ATRAP (AT1R-associated protein) was a target of β5i. Overexpression of ATRAP significantly attenuated Ang II-induced atrial remodeling and AF in recombinant adeno-associated virus serotype 9–β5i-injected mice. Mechanistically, Ang II upregulated β5i expression to promote ATRAP degradation, which resulted in activation of AT1R-mediated NF-κB signaling, increased NADPH oxidase activity, increased TGF (transforming growth factor)-β1/Smad signaling, and altered the expression of Kir2.1 and CX43 (connexin 43) in the atria, thereby affecting atrial remodeling and AF. In summary, this study identifies β5i as a negative regulator of ATRAP stability that contributes to AT1R activation and to AF, highlighting that targeting β5i activity may represent a potential therapeutic approach for the treatment of hypertensive AF.
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Affiliation(s)
- Jing Li
- From the Department of Cardiology, Institute of Heart and Vascular Diseases (J.L.), Second Affiliated Hospital of Dalian Medical University, China
| | - Shuai Wang
- Department of Ophthalmology (S.W.), Second Affiliated Hospital of Dalian Medical University, China
| | - Yun-Long Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, China (Y.-L.Z., J.B., H.-H.L.)
| | - Jie Bai
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, China (Y.-L.Z., J.B., H.-H.L.)
| | - Qiu-Yue Lin
- Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, China (Q.-Y. L., X.-H.Y., H.-H.L.)
| | - Rui-Sheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (R.-S.L.)
| | - Xiao-Hong Yu
- Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, China (Q.-Y. L., X.-H.Y., H.-H.L.)
| | - Hui-Hua Li
- Department of Cardiology, Institute of Cardiovascular Diseases, First Affiliated Hospital of Dalian Medical University, China (Q.-Y. L., X.-H.Y., H.-H.L.)
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, China (Y.-L.Z., J.B., H.-H.L.)
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13
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Radwański PB, Johnson CN, Györke S, Veeraraghavan R. Cardiac Arrhythmias as Manifestations of Nanopathies: An Emerging View. Front Physiol 2018; 9:1228. [PMID: 30233404 PMCID: PMC6131669 DOI: 10.3389/fphys.2018.01228] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022] Open
Abstract
A nanodomain is a collection of proteins localized within a specialized, nanoscale structural environment, which can serve as the functional unit of macroscopic physiologic processes. We are beginning to recognize the key roles of cardiomyocyte nanodomains in essential processes of cardiac physiology such as electrical impulse propagation and excitation–contraction coupling (ECC). There is growing appreciation of nanodomain dysfunction, i.e., nanopathy, as a mechanistic driver of life-threatening arrhythmias in a variety of pathologies. Here, we offer an overview of current research on the role of nanodomains in cardiac physiology with particular emphasis on: (1) sodium channel-rich nanodomains within the intercalated disk that participate in cell-to-cell electrical coupling and (2) dyadic nanodomains located along transverse tubules that participate in ECC. The beat to beat function of cardiomyocytes involves three phases: the action potential, the calcium transient, and mechanical contraction/relaxation. In all these phases, cell-wide function results from the aggregation of the stochastic function of individual proteins. While it has long been known that proteins that exist in close proximity influence each other’s function, it is increasingly appreciated that there exist nanoscale structures that act as functional units of cardiac biophysical phenomena. Termed nanodomains, these structures are collections of proteins, localized within specialized nanoscale structural environments. The nano-environments enable the generation of localized electrical and/or chemical gradients, thereby conferring unique functional properties to these units. Thus, the function of a nanodomain is determined by its protein constituents as well as their local structural environment, adding an additional layer of complexity to cardiac biology and biophysics. However, with the emergence of experimental techniques that allow direct investigation of structure and function at the nanoscale, our understanding of cardiac physiology and pathophysiology at these scales is rapidly advancing. Here, we will discuss the structure and functions of multiple cardiomyocyte nanodomains, and novel strategies that target them for the treatment of cardiac arrhythmias.
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Affiliation(s)
- Przemysław B Radwański
- Bob and Corinne Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, United States.,Division of Pharmacy Practice and Science, College of Pharmacy, The Ohio State University, Columbus, OH, United States
| | - Christopher N Johnson
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Vanderbilt Center for Arrhythmia Research and Therapeutics, Nashville, TN, United States
| | - Sándor Györke
- Bob and Corinne Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Rengasayee Veeraraghavan
- Bob and Corinne Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, United States.,Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
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14
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Omega-3 Index and Anti-Arrhythmic Potential of Omega-3 PUFAs. Nutrients 2017; 9:nu9111191. [PMID: 29084142 PMCID: PMC5707663 DOI: 10.3390/nu9111191] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/18/2017] [Accepted: 10/23/2017] [Indexed: 01/22/2023] Open
Abstract
Omega-3 polyunsaturated fatty acids (PUFAs), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are permanent subjects of interest in relation to the protection of cardiovascular health and the prevention of the incidence of both ventricular and atrial arrhythmias. The purpose of this updated review is to focus on the novel cellular and molecular effects of omega-3 PUFAs, in the context of the mechanisms and factors involved in the development of cardiac arrhythmias; to provide results of the most recent studies on the omega-3 PUFA anti-arrhythmic efficacy and to discuss the lack of the benefit in relation to omega-3 PUFA status. The evidence is in the favor of omega-3 PUFA acute and long-term treatment, perhaps with mitochondria-targeted antioxidants. However, for a more objective evaluation of the anti-arrhythmic potential of omega-3 PUFAs in clinical trials, it is necessary to monitor the basal pre-interventional omega-3 status of individuals, i.e., red blood cell content, omega-3 index and free plasma levels. In the view of evidence-based medicine, it seems to be crucial to aim to establish new approaches in the prevention of cardiac arrhythmias and associated morbidity and mortality that comes with these conditions.
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15
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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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16
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Kardiale „gap junctions“. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2017. [DOI: 10.1007/s00398-016-0106-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Connolly AJ, Bishop MJ. Computational Representations of Myocardial Infarct Scars and Implications for Arrhythmogenesis. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2016; 10:27-40. [PMID: 27486348 PMCID: PMC4962962 DOI: 10.4137/cmc.s39708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/17/2016] [Accepted: 05/27/2016] [Indexed: 11/30/2022]
Abstract
Image-based computational modeling is becoming an increasingly used clinical tool to provide insight into the mechanisms of reentrant arrhythmias. In the context of ischemic heart disease, faithful representation of the electrophysiological properties of the infarct region within models is essential, due to the scars known for arrhythmic properties. Here, we review the different computational representations of the infarcted region, summarizing the experimental measurements upon which they are based. We then focus on the two most common representations of the scar core (complete insulator or electrically passive tissue) and perform simulations of electrical propagation around idealized infarct geometries. Our simulations highlight significant differences in action potential duration and focal effective refractory period (ERP) around the scar, driven by differences in electrotonic loading, depending on the choice of scar representation. Finally, a novel mechanism for arrhythmia induction, following a focal ectopic beat, is demonstrated, which relies on localized gradients in ERP directly caused by the electrotonic sink effects of the neighboring passive scar.
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Affiliation(s)
- Adam J Connolly
- Department of Imaging Sciences and Bioengineering, King's College London, St Thomas' Hospital, London, UK
| | - Martin J Bishop
- Department of Imaging Sciences and Bioengineering, King's College London, St Thomas' Hospital, London, UK
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Hou S, Lu Y, Huang D, Luo X, Yue D, Zhang J. Association of atrial fibrillation with gene polymorphisms of connexin 40 and angiotensin II receptor type 1 in Chongming adults of Shanghai. Int J Clin Exp Med 2015; 8:11803-11810. [PMID: 26380021 PMCID: PMC4565404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/10/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To characterized the gene polymorphisms of connexin 40 (cx40) and angiotensin II receptor type 1 (AT1R) in Chongming adults with atrial fibrillation (AF) and to explore their relationships with AF. METHODS 82 patients with AF, and 82 subjects without AF were enrolled. Polymorphisms of cx40 G-44A and AT1 A1166C were detected. Moreover, several samples were randomly selected to validate the gene polymorphisms of cx40 and AT1. RESULTS Genotypes AA, AG and GG of cx40 G-44A were found in both AF patients and controls. The frequencies of genotypes AA, AG and GG were 39%, 29% and 32%, respectively, in AF patients and 31%, 35% and 34%, respectively in controls. The frequencies of alleles A and G were 54% and 46%, respectively in AF patients and 48% and 52%, respectively, in controls (P < 0.05). The risk for AF in patients with allele A increased 1.31 times (OR = 1.31, P < 0.05). The frequencies of genotypes AA, AC and CC were 88%, 8% and 4%, respectively in AF patients and 93%, 6% and 1%, respectively in controls. The frequencies of alleles A and C were 92% and 8%, respectively in AF patients and 96% and 4%, respectively in controls (P < 0.05). More AF patients had allele C as compared to controls. The risk for AF increased by 1.43 times in patients with allele C (OR = 1.43, P < 0.05). CONCLUSION There were relationships between gene polymorphisms of cx40 and AT1 and AF in Chongming adults. Allele A of cx40 G-44A and allele C of AT1 A1166C significantly increase the risk for AF.
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Affiliation(s)
- Shuxin Hou
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
| | - Yingmin Lu
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
| | - Damin Huang
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
| | - Xiaohan Luo
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
| | - Dongmei Yue
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
| | - Jinchun Zhang
- Department of Cardiology, Xinhua (Chongming) Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai 202150, China
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Can we protect from malignant arrhythmias by modulation of cardiac cell-to-cell coupling? J Electrocardiol 2015; 48:434-40. [PMID: 25732099 DOI: 10.1016/j.jelectrocard.2015.02.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Indexed: 01/04/2023]
Abstract
Defects in intercellular coupling in the heart play a key role in the initiation and persistence of malignant arrhythmias. Such disorders result from abnormal expression and distribution of connexins, the major constituents of cardiac gap junction channels. The alterations of myocardial connexin are well established as a consistent feature of both human and animal heart disease and aging. Following these facts, the modulation of connexin mediated intercellular coupling is suggested as a new antiarrhythmic approach. This review provides recent data supporting this concept. It can be challenging for the development of new antiarrhythmic drugs. Moreover, findings point out the implication of some endogenous compounds in protection from life-threatening arrhythmias via preservation of myocardial connexin.
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Dhein S, Seidel T, Salameh A, Jozwiak J, Hagen A, Kostelka M, Hindricks G, Mohr FW. Remodeling of cardiac passive electrical properties and susceptibility to ventricular and atrial arrhythmias. Front Physiol 2014; 5:424. [PMID: 25404918 PMCID: PMC4217357 DOI: 10.3389/fphys.2014.00424] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 10/13/2014] [Indexed: 11/13/2022] Open
Abstract
Coordinated electrical activation of the heart is essential for the maintenance of a regular cardiac rhythm and effective contractions. Action potentials spread from one cell to the next via gap junction channels. Because of the elongated shape of cardiomyocytes, longitudinal resistivity is lower than transverse resistivity causing electrical anisotropy. Moreover, non-uniformity is created by clustering of gap junction channels at cell poles and by non-excitable structures such as collagenous strands, vessels or fibroblasts. Structural changes in cardiac disease often affect passive electrical properties by increasing non-uniformity and altering anisotropy. This disturbs normal electrical impulse propagation and is, consequently, a substrate for arrhythmia. However, to investigate how these structural changes lead to arrhythmias remains a challenge. One important mechanism, which may both cause and prevent arrhythmia, is the mismatch between current sources and sinks. Propagation of the electrical impulse requires a sufficient source of depolarizing current. In the case of a mismatch, the activated tissue (source) is not able to deliver enough depolarizing current to trigger an action potential in the non-activated tissue (sink). This eventually leads to conduction block. It has been suggested that in this situation a balanced geometrical distribution of gap junctions and reduced gap junction conductance may allow successful propagation. In contrast, source-sink mismatch can prevent spontaneous arrhythmogenic activity in a small number of cells from spreading over the ventricle, especially if gap junction conductance is enhanced. Beside gap junctions, cell geometry and non-cellular structures strongly modulate arrhythmogenic mechanisms. The present review elucidates these and other implications of passive electrical properties for cardiac rhythm and arrhythmogenesis.
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Affiliation(s)
- Stefan Dhein
- Clinic for Cardiac Surgery, Heart Center Leipzig, University Leipzig Leipzig, Germany
| | - Thomas Seidel
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Salt Lake City, UT, USA
| | - Aida Salameh
- Clinic for Pediatric Cardiology, Heart Center Leipzig, University Leipzig Leipzig, Germany
| | - Joanna Jozwiak
- Clinic for Cardiology, Heart Center Leipzig, University Leipzig Leipzig, Germany
| | - Anja Hagen
- Hospital for Children and Adolescents, University of Leipzig Leipzig, Germany
| | - Martin Kostelka
- Clinic for Cardiac Surgery, Heart Center Leipzig, University Leipzig Leipzig, Germany
| | - Gerd Hindricks
- Clinic for Cardiology, Heart Center Leipzig, University Leipzig Leipzig, Germany
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21
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Kharche SR, Stary T, Colman MA, Biktasheva IV, Workman AJ, Rankin AC, Holden AV, Zhang H. Effects of human atrial ionic remodelling by β-blocker therapy on mechanisms of atrial fibrillation: a computer simulation. Europace 2014; 16:1524-33. [PMID: 25085203 DOI: 10.1093/europace/euu084] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Atrial anti-arrhythmic effects of β-adrenoceptor antagonists (β-blockers) may involve both a suppression of pro-arrhythmic effects of catecholamines, and an adaptational electrophysiological response to chronic β-blocker use; so-called 'pharmacological remodelling'. In human atrium, such remodelling decreases the transient outward (Ito) and inward rectifier (IK1) K(+) currents, and increases the cellular action potential duration (APD) and effective refractory period (ERP). However, the consequences of these changes on mechanisms of genesis and maintenance of atrial fibrillation (AF) are unknown. Using mathematical modelling, we tested the hypothesis that the long-term adaptational decrease in human atrial Ito and IK1 caused by chronic β-blocker therapy, i.e. independent of acute electrophysiological effects of β-blockers, in an otherwise un-remodelled atrium, could suppress AF. METHODS AND RESULTS Contemporarily, biophysically detailed human atrial cell and tissue models were used to investigate effects of the β-blocker-based pharmacological remodelling. Chronic β-blockade remodelling prolonged atrial cell APD and ERP. The incidence of small amplitude APD alternans in the CRN model was reduced. At the 1D tissue level, β-blocker remodelling decreased the maximum pacing rate at which APs could be conducted. At the three-dimensional organ level, β-blocker remodelling reduced the life span of re-entry scroll waves. CONCLUSION This study improves our understanding of the electrophysiological mechanisms of AF suppression by chronic β-blocker therapy. Atrial fibrillation suppression may involve a reduced propensity for maintenance of re-entrant excitation waves, as a consequence of increased APD and ERP.
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Affiliation(s)
- Sanjay R Kharche
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - Tomas Stary
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK
| | - Michael A Colman
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
| | - Irina V Biktasheva
- Department of Computer Sciences, University of Liverpool, Liverpool, L69 3BX, UK
| | - Antony J Workman
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, 126 University Place, Glasgow G12 8TA, UK
| | - Andrew C Rankin
- School of Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Arun V Holden
- School of Biomedical Sciences, University of Leeds, Leeds, LS6 9JT, UK
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK
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22
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Heijman J, Voigt N, Nattel S, Dobrev D. Cellular and molecular electrophysiology of atrial fibrillation initiation, maintenance, and progression. Circ Res 2014; 114:1483-99. [PMID: 24763466 DOI: 10.1161/circresaha.114.302226] [Citation(s) in RCA: 478] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common clinically relevant arrhythmia and is associated with increased morbidity and mortality. The incidence of AF is expected to continue to rise with the aging of the population. AF is generally considered to be a progressive condition, occurring first in a paroxysmal form, then in persistent, and then long-standing persistent (chronic or permanent) forms. However, not all patients go through every phase, and the time spent in each can vary widely. Research over the past decades has identified a multitude of pathophysiological processes contributing to the initiation, maintenance, and progression of AF. However, many aspects of AF pathophysiology remain incompletely understood. In this review, we discuss the cellular and molecular electrophysiology of AF initiation, maintenance, and progression, predominantly based on recent data obtained in human tissue and animal models. The central role of Ca(2+)-handling abnormalities in both focal ectopic activity and AF substrate progression is discussed, along with the underlying molecular basis. We also deal with the ionic determinants that govern AF initiation and maintenance, as well as the structural remodeling that stabilizes AF-maintaining re-entrant mechanisms and finally makes the arrhythmia refractory to therapy. In addition, we highlight important gaps in our current understanding, particularly with respect to the translation of these concepts to the clinical setting. Ultimately, a comprehensive understanding of AF pathophysiology is expected to foster the development of improved pharmacological and nonpharmacological therapeutic approaches and to greatly improve clinical management.
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Affiliation(s)
- Jordi Heijman
- From the Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany (J.H., N.V., D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (S.N.); and Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (S.N.)
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23
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Cheng N, Gao C. Prophylactic Effects of Metoprolol on the Prevention of Atrial Fibrillation after Cardiac Surgery Are Dose Dependent. Heart Surg Forum 2014; 17:E54-60. [DOI: 10.1532/hsf98.2013286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Atrial fibrillation (AF) is one of the most common complications after cardiac surgery. Many studies have reported an incidence of 20%-40% in patients undergoing open heart surgery, and the peak incidence usually occurs between the postoperative days [Fuller 1989; Aranki 1996; Svedjeholm 2000; Maisel 2001]. AF is commonly self-limited and rarely results in postoperative death. However, postoperative AF (POAF) is often associated with complications, including stroke, heart failure, prolonged hospital stay, and increased costs [Maisel 2001; Bramer 2010]. Many pharmacological methods have been used to prevent this complication, and beta-blockers, which have been investigated in several studies, have demonstrated effectiveness [Ali 1997; Connolly 2003; Crystal 2004; Halonen 2006; Imren 2007]. There is currently a consensus in the use of beta-blockers for the prevention of POAF. However, whether the effect of beta-blockers on POAF is dose dependent has not been widely studied [Coleman 2004; Lucio 2004]. In addition, patients with different racial backgrounds have a different response to metoprolol based on body shape. In addition, the CYP2D6 genotypes are different among white and Asian patients. In this study dose-dependent prophylactic effects of beta-blockers, which were obtained in a single center.
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24
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Jennings MM, Donahue JK. Connexin Remodeling Contributes to Atrial Fibrillation. J Atr Fibrillation 2013; 6:839. [PMID: 28496873 DOI: 10.4022/jafib.839] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 11/10/2022]
Abstract
Atrial fibrillation significantly contributes to mortality and morbidity through increased risk of stroke, heart failure and myocardial infarction. Investigations of mechanisms responsible for the development and maintenance of atrial fibrillation have highlighted the importance of gap junctional remodeling. Connexins 40 and 43, the major atrial gap junctional proteins, undergo considerable alterations in expression and localization in atrial fibrillation, creating an environment conducive to sustained reentry. Atrial fibrillation is initiated and/or maintained in this reentrant substrate. This review will focus on connexin remodeling in the context of underlying mechanism and possible therapeutic target for atrial fibrillation.
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Affiliation(s)
| | - J Kevin Donahue
- Case Western Reserve University School of Medicine, MetroHealth Campus
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25
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Salameh A, Blanke K, Daehnert I. Role of connexins in human congenital heart disease: the chicken and egg problem. Front Pharmacol 2013; 4:70. [PMID: 23760510 PMCID: PMC3669755 DOI: 10.3389/fphar.2013.00070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/15/2013] [Indexed: 01/15/2023] Open
Abstract
Inborn cardiac diseases are among the most frequent congenital anomalies and are the main cause of death in infants within the first year of age in industrialized countries when not adequately treated. They can be divided into simple and complex cardiac malformations. The former ones, for instance atrial and ventricular septal defects, valvular or subvalvular stenosis or insufficiency account for up to 80% of cardiac abnormalities. The latter ones, for example transposition of the great vessels, Tetralogy of Fallot or Shone’s anomaly often do not involve only the heart, but also the great vessels and although occurring less frequently, these severe cardiac malformations will become symptomatic within the first months of age and have a high risk of mortality if the patients remain untreated. In the last decade, there is increasing evidence that cardiac gap junction proteins, the connexins (Cx), might have an impact on cardiac anomalies. In the heart, mainly three of them (Cx40, Cx43, and Cx45) are differentially expressed with regard to temporal organogenesis and to their spatial distribution in the heart. These proteins, forming gap junction channels, are most important for a normal electrical conduction and coordinated synchronous heart muscle contraction and also for the normal embryonic development of the heart. Animal and also some human studies revealed that at least in some cardiac malformations alterations in certain gap junction proteins are present but until today no particular gap junction mutation could be assigned to a specific cardiac anomaly. As gap junctions have often been supposed to transmit growth and differentiation signals from cell to cell it is reasonable to assume that they are somehow involved in misdirected growth present in many inborn heart diseases playing a primary or contributory role. This review addresses the potentional role of gap junctions in the development of inborn heart anomalies like the conotruncal heart defects.
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Affiliation(s)
- Aida Salameh
- Clinic for Pediatric Cardiology, Heart Centre, University of Leipzig Leipzig, Germany
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26
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Schmitt H, Liang BT, Pickett C. Ischemic Conditioning and Atrial Fibrillation: Hope for a NewTherapy? J Atr Fibrillation 2013; 5:753. [PMID: 28496825 PMCID: PMC5153171 DOI: 10.4022/jafib.753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 03/05/2013] [Accepted: 03/06/2013] [Indexed: 06/07/2023]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia.It is accompanied by both structural and ion channel remodeling which underlie the propensity to perpetuate AF.The prevalence of AF is expected to increase as population ages and as more patients survival myocardial infarction. Despite pharmacological and nonpharmacological (such as ablation) therapies for AF, more effective therapy is needed. Ischemic or pharmacological conditioning offers a potential novel approach to patients with AF. This review will focus on the basic biology of ischemic pre- and postconditioning, patho-physiology of AF, potentially novel AF treatment approachs based on conditioning, and clinical situations that may be amenable to a conditioning strategy.
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Affiliation(s)
- Heiko Schmitt
- Pat and Jim Calhoun Cardiology Center, University of Connecticut School of Medicine
| | - Bruce T Liang
- Pat and Jim Calhoun Cardiology Center, University of Connecticut School of Medicine
| | - Christopher Pickett
- Pat and Jim Calhoun Cardiology Center, University of Connecticut School of Medicine
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On the different roles of AT1 and AT2 receptors in stretch-induced changes of connexin43 expression and localisation. Pflugers Arch 2012; 464:535-47. [PMID: 23007463 DOI: 10.1007/s00424-012-1161-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 10/27/2022]
Abstract
Cyclic mechanical stretch (CMS) and angiotensin II (ATII) play an important role in cardiac remodelling. Thus, we aimed to examine how ATII affects CMS-induced changes in localisation and expression of the gap junction protein connexin43 (Cx43). Neonatal rat cardiomyocytes cultured on gelatin-coated Flexcell cell culture plates were kept static or were exposed to CMS (110 % of resting length, 1 Hz) for 24 h with or without additional ATII (0.1 μmol/L). Moreover, inhibitors of ATII receptors (AT-R) were used (for AT(1)-R: losartan 0.1 μmol/L, for AT(2)-R: PD123177 0.1 μmol/L). Thereafter, the cardiomyocytes were investigated by immunohistology, PCR and Western blot. After 24 h of CMS, cardiomyocytes were significantly elongated and orientated 75 ± 1.6° nearly perpendicular to the stretch axis. Furthermore, CMS significantly accentuated Cx43 at the cell poles (ratio Cx43 polar/lateral static: 2.32 ± 0.17; CMS: 10.08 ± 3.2). Additional ATII application significantly reduced Cx43 polarisation (ratio Cx43 polar/lateral ATII: 4.61 ± 0.42). The combined administration of ATII and losartan to CMS further reduced Cx43 polarisation to control levels, whilst the AT(2)-R blocker PD123177 restored polarisation. Moreover, CMS and ATII application resulted in a significant Cx43 protein and Cx43 mRNA up-regulation which could be blocked by losartan but not by PD123177. Thus, CMS results in a self-organisation of the cardiomyocytes leading to elongated cells orientated transversely towards the stretch axis with enhanced Cx43 expression and Cx43 accentuation at the cell poles. ATII enhances total Cx43 mRNA and protein expression probably via AT(1)-R (=inhibitory effect of losartan) and reduces Cx43 polarisation presumably via AT(2)-R, since PD123177 (but not losartan) inhibited the negative effects of ATII on polarisation.
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Current World Literature. Curr Opin Cardiol 2012; 27:318-26. [DOI: 10.1097/hco.0b013e328352dfaf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Salameh A, Dhein S. Effects of mechanical forces and stretch on intercellular gap junction coupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:147-56. [PMID: 22245380 DOI: 10.1016/j.bbamem.2011.12.030] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/17/2011] [Accepted: 12/27/2011] [Indexed: 01/27/2023]
Abstract
Mechanical forces provide fundamental physiological stimulus in living organisms. Recent investigations demonstrated how various types of mechanical load, like strain, pressure, shear stress, or cyclic stretch can affect cell biology and gap junction intercellular communication (GJIC). Depending on the cell type, the type of mechanical load and on strength and duration of application, these forces can induce hypertrophic processes and modulate the expression and function of certain connexins such as Cx43, while others such as Cx37 or Cx40 are reported to be less mechanosensitive. In particular, not only expression but also subcellular localization of Cx43 is altered in cardiomyocytes submitted to cyclic mechanical stretch resulting in the typical elongated cell shape with an accentuation of Cx43 at the cell poles. In the heart both cardiomyocytes and fibroblasts can alter their GJIC in response to mechanical load. In the vasculature both endothelial cells and smooth muscle cells are subject to strain and cyclic stretch resulting from the pulsatile flow. In addition, vascular endothelial cells are mainly affected by shear stress resulting from the blood flow parallel to their surface. These mechanical forces lead to a regulation of GJIC in vascular tissue. In bones, osteocytes and osteoblasts are coupled via gap junctions, which also react to mechanical forces. Since gap junctions are involved in regulation of cell growth and differentiation, the mechanosensitivity of the regulation of these channels might open new perspectives to explain how cells can respond to mechanical load, and how stretch induces self-organization of a cell layer which might have implications for embryology and the development of organs. This article is part of a Special Issue entitled: The Communicating junctions, roles and dysfunctions.
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Affiliation(s)
- Aida Salameh
- Clinic for Pediatric Cardiology, University of Leipzig, Heart Centre, Germany
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