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Zhou X, Liu H, Feng F, Kang GJ, Liu M, Guo Y, Dudley SC. Macrophage IL-1β mediates atrial fibrillation risk in diabetic mice. JCI Insight 2024; 9:e171102. [PMID: 38889387 PMCID: PMC11383594 DOI: 10.1172/jci.insight.171102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2024] [Indexed: 06/20/2024] Open
Abstract
Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). The mechanisms underlying DM-associated AF are unclear. AF and DM are both related to inflammation. We investigated whether DM-associated inflammation contributed to AF risk. Mice were fed with high-fat diet to induce type II DM and were subjected to IL-1β antibodies, macrophage depletion by clodronate liposomes, a mitochondrial antioxidant (mitoTEMPO), or a cardiac ryanodine receptor 2 (RyR2) stabilizer (S107). All tests were performed at 36-38 weeks of age. DM mice presented with increased AF inducibility, enhanced mitochondrial reactive oxygen species (mitoROS) generation, and activated innate immunity in the atria, as evidenced by enhanced monocyte chemoattractant protein-1 (MCP-1) expression, macrophage infiltration, and IL-1β levels. Signs of aberrant RyR2 Ca2+ leak were observed in the atria of DM mice. IL-1β neutralization, macrophage depletion, and exposure to mitoTEMPO and S107 significantly ameliorated the AF vulnerability in DM mice. Atrial overexpression of MCP-1 increased AF occurrence in normal mice through the same mechanistic signaling cascade as observed in DM mice. In conclusion, macrophage-mediated IL-1β contributed to DM-associated AF risk through mitoROS modulation of RyR2 Ca2+ leak.
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2
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Ripplinger CM, Glukhov AV, Kay MW, Boukens BJ, Chiamvimonvat N, Delisle BP, Fabritz L, Hund TJ, Knollmann BC, Li N, Murray KT, Poelzing S, Quinn TA, Remme CA, Rentschler SL, Rose RA, Posnack NG. Guidelines for assessment of cardiac electrophysiology and arrhythmias in small animals. Am J Physiol Heart Circ Physiol 2022; 323:H1137-H1166. [PMID: 36269644 PMCID: PMC9678409 DOI: 10.1152/ajpheart.00439.2022] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 01/09/2023]
Abstract
Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. Although recent advances in cell-based models, including human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM), are contributing to our understanding of electrophysiology and arrhythmia mechanisms, preclinical animal studies of cardiovascular disease remain a mainstay. Over the past several decades, animal models of cardiovascular disease have advanced our understanding of pathological remodeling, arrhythmia mechanisms, and drug effects and have led to major improvements in pacing and defibrillation therapies. There exist a variety of methodological approaches for the assessment of cardiac electrophysiology and a plethora of parameters may be assessed with each approach. This guidelines article will provide an overview of the strengths and limitations of several common techniques used to assess electrophysiology and arrhythmia mechanisms at the whole animal, whole heart, and tissue level with a focus on small animal models. We also define key electrophysiological parameters that should be assessed, along with their physiological underpinnings, and the best methods with which to assess these parameters.
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Affiliation(s)
- Crystal M Ripplinger
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
| | - Alexey V Glukhov
- Department of Medicine, Cardiovascular Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Matthew W Kay
- Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia
| | - Bastiaan J Boukens
- Department Physiology, University Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Medical Biology, University of Amsterdam, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis School of Medicine, Davis, California
- Department of Internal Medicine, University of California Davis School of Medicine, Davis, California
- Veterans Affairs Northern California Healthcare System, Mather, California
| | - Brian P Delisle
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Larissa Fabritz
- University Center of Cardiovascular Science, University Heart and Vascular Center, University Hospital Hamburg-Eppendorf with DZHK Hamburg/Kiel/Luebeck, Germany
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Thomas J Hund
- Department of Internal Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
- Department of Biomedical Engineering, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Na Li
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Katherine T Murray
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Steven Poelzing
- Virginia Tech Carilon School of Medicine, Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech, Roanoke, Virginia
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Stacey L Rentschler
- Cardiovascular Division, Department of Medicine, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nikki G Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, District of Columbia
- Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
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3
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Hennis K, Rötzer RD, Rilling J, Wu Y, Thalhammer SB, Biel M, Wahl-Schott C, Fenske S. In vivo and ex vivo electrophysiological study of the mouse heart to characterize the cardiac conduction system, including atrial and ventricular vulnerability. Nat Protoc 2022; 17:1189-1222. [PMID: 35314849 DOI: 10.1038/s41596-021-00678-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/09/2021] [Indexed: 01/05/2023]
Abstract
The mouse is a common and cost-effective animal model for basic research, and the number of genetically engineered mouse models with cardiac phenotype is increasing. In vivo electrophysiological study in mice is similar to that performed in humans. It is indispensable for acquiring intracardiac electrocardiogram recordings and determining baseline cardiac cycle intervals. Furthermore, the use of programmed electrical stimulation enables determination of parameters such as sinoatrial conduction time, sinus node recovery time, atrioventricular-nodal conduction properties, Wenckebach periodicity, refractory periods and arrhythmia vulnerability. This protocol describes specific procedures for determining these parameters that were adapted from analogous human protocols for use in mice. We include details of ex vivo electrophysiological study, which provides detailed insights into intrinsic cardiac electrophysiology without external influences from humoral and neural factors. In addition, we describe a heart preparation with intact innervation by the vagus nerve that can be used as an ex vivo model for vagal control of the cardiac conduction system. Data acquisition for in vivo and ex vivo electrophysiological study takes ~1 h per mouse, depending on the number of stimulation protocols applied during the procedure. The technique yields highly reliable results and can be used for phenotyping of cardiac disease models, elucidating disease mechanisms and confirming functional improvements in gene therapy approaches as well as for drug and toxicity testing.
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Affiliation(s)
- Konstantin Hennis
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - René D Rötzer
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Julia Rilling
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Yakun Wu
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stefan B Thalhammer
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Martin Biel
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | | | - Stefanie Fenske
- Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany.
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany.
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4
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Jungen C, Scherschel K, Bork NI, Kuklik P, Eickholt C, Kniep H, Klatt N, Willems S, Nikolaev VO, Meyer C. Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System. J Vis Exp 2018. [PMID: 29889210 DOI: 10.3791/57617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Since its invention in the late 19th century, the Langendorff ex vivo heart perfusion system continues to be a relevant tool for studying a broad spectrum of physiological, biochemical, morphological, and pharmacological parameters in centrally denervated hearts. Here, we describe a setup for the modulation of the intracardiac autonomic nervous system and the assessment of its influence on basic electrophysiology, arrhythmogenesis, and cyclic adenosine monophosphate (cAMP) dynamics. The intracardiac autonomic nervous system is modulated by the mechanical dissection of atrial fat pads-in which murine ganglia are located mainly-or by the usage of global as well as targeted pharmacological interventions. An octapolar electrophysiological catheter is introduced into the right atrium and the right ventricle, and epicardial-placed multi-electrode arrays (MEA) for high-resolution mapping are used to determine cardiac electrophysiology and arrhythmogenesis. Förster resonance energy transfer (FRET) imaging is performed for the real-time monitoring of cAMP levels in different cardiac regions. Neuromorphology is studied by means of antibody-based staining of whole hearts using neuronal markers to guide the identification and modulation of specific targets of the intracardiac autonomic nervous system in the performed studies. The ex vivo Langendorff setup allows for a high number of reproducible experiments in a short time. Nevertheless, the partly open nature of the setup (e.g., during MEA measurements) makes constant temperature control difficult and should be kept to a minimum. This described method makes it possible to analyze and modulate the intracardiac autonomic nervous system in decentralized hearts.
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Affiliation(s)
- Christiane Jungen
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf; DZHK (German Center for Cardiovascular Research)
| | - Katharina Scherschel
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf; DZHK (German Center for Cardiovascular Research)
| | - Nadja I Bork
- DZHK (German Center for Cardiovascular Research); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf
| | - Pawel Kuklik
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf
| | - Christian Eickholt
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf
| | - Helge Kniep
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf
| | - Niklas Klatt
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf; DZHK (German Center for Cardiovascular Research)
| | - Stephan Willems
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf; DZHK (German Center for Cardiovascular Research)
| | - Viacheslav O Nikolaev
- DZHK (German Center for Cardiovascular Research); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf
| | - Christian Meyer
- Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf; DZHK (German Center for Cardiovascular Research);
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5
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Monteiro LM, Vasques-Nóvoa F, Ferreira L, Pinto-do-Ó P, Nascimento DS. Restoring heart function and electrical integrity: closing the circuit. NPJ Regen Med 2017; 2:9. [PMID: 29302345 PMCID: PMC5665620 DOI: 10.1038/s41536-017-0015-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/19/2017] [Accepted: 03/06/2017] [Indexed: 12/30/2022] Open
Abstract
Cardiovascular diseases are the main cause of death in the world and are often associated with the occurrence of arrhythmias due to disruption of myocardial electrical integrity. Pathologies involving dysfunction of the specialized cardiac excitatory/conductive tissue are also common and constitute an added source of morbidity and mortality since current standard therapies withstand a great number of limitations. As electrical integrity is essential for a well-functioning heart, innovative strategies have been bioengineered to improve heart conduction and/or promote myocardial repair, based on: (1) gene and/or cell delivery; or (2) conductive biomaterials as tools for cardiac tissue engineering. Herein we aim to review the state-of-art in the area, while briefly describing the biological principles underlying the heart electrical/conduction system and how this system can be disrupted in heart disease. Suggestions regarding targets for future studies are also presented.
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Affiliation(s)
- Luís Miguel Monteiro
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
- CNC—Center for Neuroscience and Cell Biology, Universidade de Coimbra, Coimbra, Portugal
| | - Francisco Vasques-Nóvoa
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
- Departamento de Fisiologia e Cirurgia Cardiotorácica, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Lino Ferreira
- CNC—Center for Neuroscience and Cell Biology, Universidade de Coimbra, Coimbra, Portugal
| | - Perpétua Pinto-do-Ó
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Diana Santos Nascimento
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
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Taniguchi T, Maruyama N, Ogata T, Kasahara T, Nakanishi N, Miyagawa K, Naito D, Hamaoka T, Nishi M, Matoba S, Ueyama T. PTRF/Cavin-1 Deficiency Causes Cardiac Dysfunction Accompanied by Cardiomyocyte Hypertrophy and Cardiac Fibrosis. PLoS One 2016; 11:e0162513. [PMID: 27612189 PMCID: PMC5017623 DOI: 10.1371/journal.pone.0162513] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/05/2016] [Indexed: 12/16/2022] Open
Abstract
Mutations in the PTRF/Cavin-1 gene cause congenital generalized lipodystrophy type 4 (CGL4) associated with myopathy. Additionally, long-QT syndrome and fatal cardiac arrhythmia are observed in patients with CGL4 who have homozygous PTRF/Cavin-1 mutations. PTRF/Cavin-1 deficiency shows reductions of caveolae and caveolin-3 (Cav3) protein expression in skeletal muscle, and Cav3 deficiency in the heart causes cardiac hypertrophy with loss of caveolae. However, it remains unknown how loss of PTRF/Cavin-1 affects cardiac morphology and function. Here, we present a characterization of the hearts of PTRF/Cavin-1-null (PTRF−/−) mice. Electron microscopy revealed the reduction of caveolae in cardiomyocytes of PTRF−/− mice. PTRF−/− mice at 16 weeks of age developed a progressive cardiomyopathic phenotype with wall thickening of left ventricles and reduced fractional shortening evaluated by echocardiography. Electrocardiography revealed that PTRF−/− mice at 24 weeks of age had low voltages and wide QRS complexes in limb leads. Histological analysis showed cardiomyocyte hypertrophy accompanied by progressive interstitial/perivascular fibrosis. Hypertrophy-related fetal gene expression was also induced in PTRF−/− hearts. Western blotting analysis and quantitative RT-PCR revealed that Cav3 expression was suppressed in PTRF−/− hearts compared with that in wild-type (WT) ones. ERK1/2 was activated in PTRF−/− hearts compared with that in WT ones. These results suggest that loss of PTRF/Cavin-1 protein expression is sufficient to induce a molecular program leading to cardiomyocyte hypertrophy and cardiomyopathy, which is partly attributable to Cav3 reduction in the heart.
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Affiliation(s)
- Takuya Taniguchi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Naoki Maruyama
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Takehiro Ogata
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Takeru Kasahara
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Naohiko Nakanishi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Kotaro Miyagawa
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Daisuke Naito
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Tetsuro Hamaoka
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Masahiro Nishi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Satoaki Matoba
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
| | - Tomomi Ueyama
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602–8566, Japan
- * E-mail:
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7
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Choy L, Yeo JM, Tse V, Chan SP, Tse G. Cardiac disease and arrhythmogenesis: Mechanistic insights from mouse models. IJC HEART & VASCULATURE 2016; 12:1-10. [PMID: 27766308 PMCID: PMC5064289 DOI: 10.1016/j.ijcha.2016.05.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022]
Abstract
The mouse is the second mammalian species, after the human, in which substantial amount of the genomic information has been analyzed. With advances in transgenic technology, mutagenesis is now much easier to carry out in mice. Consequently, an increasing number of transgenic mouse systems have been generated for the study of cardiac arrhythmias in ion channelopathies and cardiomyopathies. Mouse hearts are also amenable to physical manipulation such as coronary artery ligation and transverse aortic constriction to induce heart failure, radiofrequency ablation of the AV node to model complete AV block and even implantation of a miniature pacemaker to induce cardiac dyssynchrony. Last but not least, pharmacological models, despite being simplistic, have enabled us to understand the physiological mechanisms of arrhythmias and evaluate the anti-arrhythmic properties of experimental agents, such as gap junction modulators, that may be exert therapeutic effects in other cardiac diseases. In this article, we examine these in turn, demonstrating that primary inherited arrhythmic syndromes are now recognized to be more complex than abnormality in a particular ion channel, involving alterations in gene expression and structural remodelling. Conversely, in cardiomyopathies and heart failure, mutations in ion channels and proteins have been identified as underlying causes, and electrophysiological remodelling are recognized pathological features. Transgenic techniques causing mutagenesis in mice are extremely powerful in dissecting the relative contributions of different genes play in producing disease phenotypes. Mouse models can serve as useful systems in which to explore how protein defects contribute to arrhythmias and direct future therapy.
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Affiliation(s)
- Lois Choy
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Jie Ming Yeo
- School of Medicine, Imperial College London, SW7 2AZ, UK
| | - Vivian Tse
- Department of Physiology, McGill University, Canada
| | - Shing Po Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
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8
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Tse G, Tse V, Yeo JM, Sun B. Atrial Anti-Arrhythmic Effects of Heptanol in Langendorff-Perfused Mouse Hearts. PLoS One 2016; 11:e0148858. [PMID: 26872148 PMCID: PMC4752503 DOI: 10.1371/journal.pone.0148858] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 01/24/2016] [Indexed: 12/24/2022] Open
Abstract
Acute effects of heptanol (0.1 to 2 mM) on atrial electrophysiology were explored in Langendorff-perfused mouse hearts. Left atrial bipolar electrogram or monophasic action potential recordings were obtained during right atrial stimulation. Regular pacing at 8 Hz elicited atrial activity in 11 out of 11 hearts without inducing atrial arrhythmias. Programmed electrical stimulation using a S1S2 protocol provoked atrial tachy-arrhythmias in 9 of 17 hearts. In the initially arrhythmic group, 2 mM heptanol exerted anti-arrhythmic effects (Fisher’s exact test, P < 0.05) and increased atrial effective refractory period (ERP) from 26.0 ± 1.9 to 57.1 ± 2.5 ms (ANOVA, P < 0.001) despite increasing activation latency from 18.7 ± 1.1 to 28.9 ± 2.1 ms (P < 0.001) and leaving action potential duration at 90% repolarization (APD90) unaltered (25.6 ± 1.2 vs. 27.2 ± 1.2 ms; P > 0.05), which led to increases in ERP/latency ratio from 1.4 ± 0.1 to 2.1 ± 0.2 and ERP/APD90 ratio from 1.0 ± 0.1 to 2.1 ± 0.2 (P < 0.001). In contrast, in the initially non-arrhythmic group, heptanol did not alter arrhythmogenicity, increased AERP from 47.3 ± 5.3 to 54.5 ± 3.1 ms (P < 0.05) and activation latency from 23.7 ± 2.2 to 31.3 ± 2.5 ms and did not alter APD90 (24.1 ± 1.2 vs. 25.0 ± 2.3 ms; P > 0.05), leaving both AERP/latency ratio (2.1 ± 0.3 vs. 1.9 ± 0.2; P > 0.05) and ERP/APD90 ratio (2.0 ± 0.2 vs. 2.1 ± 0.1; P > 0.05) unaltered. Lower heptanol concentrations (0.1, 0.5 and 1 mM) did not alter arrhythmogenicity or the above parameters. The present findings contrast with known ventricular pro-arrhythmic effects of heptanol associated with decreased ERP/latency ratio, despite increased ERP/APD ratio observed in both the atria and ventricles.
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Affiliation(s)
- Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China
| | - Vivian Tse
- Department of Physiology, McGill University, Montreal, Canada
| | - Jie Ming Yeo
- Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bing Sun
- Department of Cardiology, Tongji University Affiliated Tongji Hospital, Shanghai, China
- * E-mail:
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9
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Quang KL, Maguy A, Qi XY, Naud P, Xiong F, Tadevosyan A, Shi YF, Chartier D, Tardif JC, Dobrev D, Nattel S. Loss of cardiomyocyte integrin-linked kinase produces an arrhythmogenic cardiomyopathy in mice. Circ Arrhythm Electrophysiol 2015; 8:921-32. [PMID: 26071395 DOI: 10.1161/circep.115.001668] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 06/05/2015] [Indexed: 01/26/2023]
Abstract
BACKGROUND Integrin-linked kinase (ILK), a serine/threonine protein kinase, has roles in cell signaling and molecular scaffolding. ILK mutation/deletion causes cardiomyopathic phenotypes, but the functional and electrophysiological features have not been characterized. This study investigated the structural, functional, ion channel, and electrophysiological changes associated with cardiomyocyte-directed ILK deletion in mice. METHODS AND RESULTS Adult mice with cardiomyocyte-directed ILK knockout were compared with littermate controls. Knockout mice showed markedly increased mortality, with sudden death beginning after 5 weeks and 100% mortality at 18 weeks. In 10-week-old knockout mice, spontaneous and inducible ventricular tachyarrhythmias were common, occurring in 60% and 86%, respectively, and absent in controls (P<0.001, P<0.05 versus knockout mice). Ventricular refractoriness was prolonged, along with both QRS and QT interval. Action potentials were prolonged and displayed triggered activity. A wide range of ion currents were downregulated, including total, fast and slow components of transient outward K(+) current and inward rectifier K(+) current, along with corresponding ion channel subunit genes, providing a plausible explanation of action potential prolongation. At 5 weeks, only voltage-dependent K(+) currents were reduced, possibly related to direct ILK-Kv4.2 subunit interactions. Action potentials were prolonged, but no arrhythmias or cardiac dysfunction were noted. Structural remodeling was prominent at 10 weeks: connexin-43 was downregulated and redistributed to lateral cell margins, and left ventricular fibrosis occurred, with a strong regional distribution (predominating in the basal left ventricle). Conduction was slowed. High-throughput quantitative polymerase reaction gene-expression studies in 10-week-old ILK knockout showed upregulation of structural, remodeling and fibrosis-related genes, and downregulation of a wide range of ion channel and transporter subunits. CONCLUSIONS Cardiomyocyte ILK deletion produces a lethal arrhythmogenic cardiomyopathy associated with important ion channel and structural remodeling.
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Affiliation(s)
- Khai Le Quang
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Ange Maguy
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Xiao-Yan Qi
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Patrice Naud
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Feng Xiong
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Artavazd Tadevosyan
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Yan-Fen Shi
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Denis Chartier
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Jean-Claude Tardif
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Dobromir Dobrev
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Stanley Nattel
- From the Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (K.L.Q., A.M., X.-Y.Q., P.N., F.X., A.T., Y.-F.S., D.C., C.T., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (F.X., S.N.); and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.).
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10
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Lin EC, Moungey BM, Lim E, Concannon SP, Anderson CL, Kyle JW, Makielski JC, Balijepalli SY, January CT. Mouse ERG K(+) channel clones reveal differences in protein trafficking and function. J Am Heart Assoc 2014; 3:e001491. [PMID: 25497881 PMCID: PMC4338741 DOI: 10.1161/jaha.114.001491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The mouse ether‐a‐go‐go‐related gene 1a (mERG1a, mKCNH2) encodes mERG K+ channels in mouse cardiomyocytes. The mERG channels and their human analogue, hERG channels, conduct IKr. Mutations in hERG channels reduce IKr to cause congenital long‐QT syndrome type 2, mostly by decreasing surface membrane expression of trafficking‐deficient channels. Three cDNA sequences were originally reported for mERG channels that differ by 1 to 4 amino acid residues (mERG‐London, mERG‐Waterston, and mERG‐Nie). We characterized these mERG channels to test the postulation that they would differ in their protein trafficking and biophysical function, based on previous findings in long‐QT syndrome type 2. Methods and Results The 3 mERG and hERG channels were expressed in HEK293 cells and neonatal mouse cardiomyocytes and were studied using Western blot and whole‐cell patch clamp. We then compared our findings with the recent sequencing results in the Welcome Trust Sanger Institute Mouse Genomes Project (WTSIMGP). Conclusions First, the mERG‐London channel with amino acid substitutions in regions of highly ordered structure is trafficking deficient and undergoes temperature‐dependent and pharmacological correction of its trafficking deficiency. Second, the voltage dependence of channel gating would be different for the 3 mERG channels. Third, compared with the WTSIMGP data set, the mERG‐Nie clone is likely to represent the wild‐type mouse sequence and physiology. Fourth, the WTSIMGP analysis suggests that substrain‐specific sequence differences in mERG are a common finding in mice. These findings with mERG channels support previous findings with hERG channel structure–function analyses in long‐QT syndrome type 2, in which sequence changes in regions of highly ordered structure are likely to result in abnormal protein trafficking.
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Affiliation(s)
- Eric C Lin
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Brooke M Moungey
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Evi Lim
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Sarah P Concannon
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Corey L Anderson
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - John W Kyle
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Jonathan C Makielski
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Sadguna Y Balijepalli
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
| | - Craig T January
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI (E.C.L., B.M.M., E.L., S.P.C., C.L.A., J.W.K., J.C.M., S.Y.B., C.T.J.)
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11
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Lujan HL, DiCarlo SE. Cardiac electrophysiology and the susceptibility to sustained ventricular tachycardia in intact, conscious mice. Am J Physiol Heart Circ Physiol 2014; 306:H1213-21. [PMID: 24561859 DOI: 10.1152/ajpheart.00780.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac electrophysiological dysfunction is a major cause of death in humans. Accordingly, electrophysiological testing is routinely performed in intact, conscious, humans to evaluate arrhythmias and disorders of cardiac conduction. However, to date, in vivo electrophysiological studies in mice are limited to anesthetized open-chest or closed-chest preparations. However, cardiac electrophysiology in anesthetized mice or mice with surgical trauma may not adequately represent what occurs in conscious mice. Accordingly, an intact, conscious murine model of cardiac electrophysiology has the potential to be of major importance for advancing the concepts and methods that drive cardiovascular therapies. Therefore, we describe, for the first time, the use of an intact, conscious, murine model of cardiac electrophysiology. The conscious mouse model permits measurements of atrioventricular interval, sinus cycle length, sinus node recovery time (SNRT), SNRT corrected for spontaneous sinus cycle, Wenckebach cycle length, the ventricular effective refractory period (VERP) and the electrical stimulation threshold to induce sustained ventricular tachyarrhythmias in an intact, complex model free of the confounding influences of anesthetics and surgical trauma. This is an important consideration because anesthesia and surgical trauma markedly reduced cardiac output and heart rate as well as altered cardiac electrophysiology parameters. Most importantly, anesthesia and surgical trauma significantly increased the VERP and virtually eliminated the ability to induce sustained ventricular tachyarrhythmias. Accordingly, the methodology allows for the accurate documentation of cardiac electrophysiology in complex, conscious mice and may be adopted for advancing the concepts and ideas that drive cardiovascular research.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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12
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Rajab M, Jin H, Welzig CM, Albano A, Aronovitz M, Zhang Y, Park HJ, Link MS, Noujaim SF, Galper JB. Increased inducibility of ventricular tachycardia and decreased heart rate variability in a mouse model for type 1 diabetes: effect of pravastatin. Am J Physiol Heart Circ Physiol 2013; 305:H1807-16. [PMID: 24163078 DOI: 10.1152/ajpheart.00979.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Although a reduction in the high-frequency (HF) component of heart rate variability (HRV) is a major complication of diabetes and a risk factor for sudden death, its relationship to ventricular tachycardia (VT) is unknown. We developed a mouse model for the study of VT and its relationship to changes in HRV in the Akita type 1 diabetic mouse. Programmed ventricular stimulation of anesthetized mice demonstrated that Akita mice were more inducible for VT compared with wild-type mice: 78.6% versus 28.6% (P = 0.007). Optical mapping of perfused hearts demonstrated multifocal breakthroughs that occasionally gave rise to short-lived rotors consistent with focal initiation and maintenance of VT. Treatment of Akita mice with pravastatin, which had been previously shown clinically to decrease ventricular ectopy and to increase HRV, decreased the inducibility of VT: 36.8% compared with 75.0% with placebo treatment (P = 0.022). The HF fraction of HRV was reduced in Akita mice (48.6 ± 5.2% vs. 70.9 ± 4.8% in wild-type mice, P = 0.005) and was increased compared with placebo treatment in pravastatin-treated mice. Pretreatment of Akita mice with the muscarinic agonist carbamylcholine or the β-adrenergic receptor blocker propranolol decreased the inducibility of VT (P = 0.001). In conclusion, the increased inducibility of focally initiated VT and reduced HF fraction in Akita mice were partially reversed by both pravastatin treatment and pharmacologic reversal of parasympathetic dysfunction. In this new animal model for the study of the pathogenesis of VT in type 1 diabetes, pravastatin may play a role in the prevention of VT by attenuating parasympathetic dysfunction.
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Affiliation(s)
- Mohammad Rajab
- Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
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13
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Hong EG, Kim BW, Jung DY, Kim JH, Yu T, Seixas Da Silva W, Friedline RH, Bianco SD, Seslar SP, Wakimoto H, Berul CI, Russell KS, Lee KW, Larsen PR, Bianco AC, Kim JK. Cardiac expression of human type 2 iodothyronine deiodinase increases glucose metabolism and protects against doxorubicin-induced cardiac dysfunction in male mice. Endocrinology 2013; 154:3937-46. [PMID: 23861374 PMCID: PMC4411365 DOI: 10.1210/en.2012-2261] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 07/09/2013] [Indexed: 12/16/2022]
Abstract
Altered glucose metabolism in the heart is an important characteristic of cardiovascular and metabolic disease. Because thyroid hormones have major effects on peripheral metabolism, we examined the metabolic effects of heart-selective increase in T3 using transgenic mice expressing human type 2 iodothyronine deiodinase (D2) under the control of the α-myosin heavy chain promoter (MHC-D2). Hyperinsulinemic-euglycemic clamps showed normal whole-body glucose disposal but increased hepatic insulin action in MHC-D2 mice as compared to wild-type (WT) littermates. Insulin-stimulated glucose uptake in heart was not altered, but basal myocardial glucose metabolism was increased by more than two-fold in MHC-D2 mice. Myocardial lipid levels were also elevated in MHC-D2 mice, suggesting an overall up-regulation of cardiac metabolism in these mice. The effects of doxorubicin (DOX) treatment on cardiac function and structure were examined using M-mode echocardiography. DOX treatment caused a significant reduction in ventricular fractional shortening and resulted in more than 50% death in WT mice. In contrast, MHC-D2 mice showed increased survival rate after DOX treatment, and this was associated with a six-fold increase in myocardial glucose metabolism and improved cardiac function. Myocardial activity and expression of AMPK, GLUT1, and Akt were also elevated in MHC-D2 and WT mice following DOX treatment. Thus, our findings indicate an important role of thyroid hormone in cardiac metabolism and further suggest a protective role of glucose utilization in DOX-mediated cardiac dysfunction.
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Affiliation(s)
- Eun-Gyoung Hong
- University of Massachusetts Medical School, Program in Molecular Medicine, 368 Plantation Street, Sherman Center, AS9.1041, Worcester, Massachusetts 01605.
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14
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Boukens BJ, Hoogendijk MG, Verkerk AO, Linnenbank A, van Dam P, Remme CA, Fiolet JW, Opthof T, Christoffels VM, Coronel R. Early repolarization in mice causes overestimation of ventricular activation time by the QRS duration. Cardiovasc Res 2012; 97:182-91. [DOI: 10.1093/cvr/cvs299] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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15
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Kaese S, Verheule S. Cardiac electrophysiology in mice: a matter of size. Front Physiol 2012; 3:345. [PMID: 22973235 PMCID: PMC3433738 DOI: 10.3389/fphys.2012.00345] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/09/2012] [Indexed: 12/27/2022] Open
Abstract
Over the last decade, mouse models have become a popular instrument for studying cardiac arrhythmias. This review assesses in which respects a mouse heart is a miniature human heart, a suitable model for studying mechanisms of cardiac arrhythmias in humans and in which respects human and murine hearts differ. Section I considers the issue of scaling of mammalian cardiac (electro) physiology to body mass. Then, we summarize differences between mice and humans in cardiac activation (section II) and the currents underlying the action potential in the murine working myocardium (section III). Changes in cardiac electrophysiology in mouse models of heart disease are briefly outlined in section IV, while section V discusses technical considerations pertaining to recording cardiac electrical activity in mice. Finally, section VI offers general considerations on the influence of cardiac size on the mechanisms of tachy-arrhythmias.
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Affiliation(s)
- Sven Kaese
- Division of Experimental and Clinical Electrophysiology, Department of Cardiology and Angiology, University Hospital Münster Münster, Germany
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16
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Lujan HL, Janbaih H, Feng HZ, Jin JP, DiCarlo SE. Myocardial ischemia, reperfusion, and infarction in chronically instrumented, intact, conscious, and unrestrained mice. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1384-400. [PMID: 22538514 DOI: 10.1152/ajpregu.00095.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the United States alone, the National Heart, Lung, and Blood Institute (NHLBI) has invested several hundred million dollars in pursuit of myocardial infarct-sparing therapies. However, due largely to methodological limitations, this investment has not produced any notable clinical application or cardioprotective therapy. Among the major methodological limitations is the reliance on animal models that do not mimic the clinical situation. In this context, the limited use of conscious animal models is of major concern. In fact, whenever possible, studies of cardiovascular physiology and pathophysiology should be conducted in conscious, complex models to avoid the complications associated with the use of anesthesia and surgical trauma. The mouse has significant advantages over other experimental models for the investigation of infarct-sparing therapies. The mouse is inexpensive, has a high throughput, and presents the ability of one to create genetically modified models. However, successful infarct-sparing therapies in anesthetized mice or isolated mouse hearts may not be successful in more complex models, including conscious mice. Accordingly, a conscious mouse model of myocardial ischemia and reperfusion has the potential to be of major importance for advancing the concepts and methods that drive the development of infarct-sparing therapies. Therefore, we describe, for the first time, the use of an intact, conscious, and unrestrained mouse model of myocardial ischemia-reperfusion and infarction. The conscious mouse model permits occlusion and reperfusion of the left anterior descending coronary artery in an intact, complex model free of the confounding influences of anesthetics and surgical trauma. This methodology may be adopted for advancing the concepts and ideas that drive cardiovascular research.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Bolon B, Couto S, Fiette L, Perle KL. Internet and Print Resources to Facilitate Pathology Analysis When Phenotyping Genetically Engineered Rodents. Vet Pathol 2011; 49:224-35. [DOI: 10.1177/0300985811415709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Genetically engineered mice and rats are increasingly used as models for exploring disease progression and mechanisms. The full spectrum of anatomic, biochemical, and functional changes that develop in novel, genetically engineered mouse and rat lines must be cataloged before predictions regarding the significance of the mutation may be extrapolated to diseases in other vertebrate species, including humans. A growing list of reference materials, including books, journal articles, and websites, has been produced in the last 2 decades to assist researchers in phenotyping newly engineered rodent lines. This compilation provides an extensive register of materials related to the pathology component of rodent phenotypic analysis. In this article, the authors annotate the resources they use most often, to allow for quick determination of their relevance to research projects.
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Affiliation(s)
- B. Bolon
- The Ohio State University, Columbus, Ohio
| | - S. Couto
- Genentech, Inc., South San Francisco, California
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18
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Zigel Y, Mor M, Tzvi E, Tsviling V, Gil O, Katz A, Etzion Y. A Surface ECG-Based Algorithm to Determine the Atrial Refractoriness of Rodents During Electrophysiological Study. Cardiovasc Eng Technol 2011. [DOI: 10.1007/s13239-011-0055-5] [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: 10/18/2022]
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19
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Decher N, Wemhöner K, Rinné S, Netter MF, Zuzarte M, Aller MI, Kaufmann SG, Li XT, Meuth SG, Daut J, Sachse FB, Maier SK. Knock-Out of the Potassium Channel TASK-1 Leads to a Prolonged QT Interval and a Disturbed QRS Complex. Cell Physiol Biochem 2011; 28:77-86. [DOI: 10.1159/000331715] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2011] [Indexed: 01/13/2023] Open
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20
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Cruz-Adalia A, Jiménez-Borreguero LJ, Ramírez-Huesca M, Chico-Calero I, Barreiro O, López-Conesa E, Fresno M, Sánchez-Madrid F, Martín P. CD69 limits the severity of cardiomyopathy after autoimmune myocarditis. Circulation 2010; 122:1396-404. [PMID: 20855659 DOI: 10.1161/circulationaha.110.952820] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Experimental autoimmune myocarditis (EAM), a mouse model of post-infectious cardiomyopathy, reflects mechanisms of inflammatory cardiomyopathy in humans. EAM is characterized by an infiltration of inflammatory cells into the myocardium that can be followed by myocyte fibrosis, edema, and necrosis, leading to ventricular wall dysfunction and heart failure. Different data indicate that CD69 exerts an important immunoregulatory effect in vivo. However, the possible role of CD69 in autoimmune myocarditis has not been studied. METHODS AND RESULTS We have explored the role of the leukocyte regulatory molecule CD69 in the inflammation that leads to cardiac dysfunction after myocardial injury in EAM. We have found that after induction of EAM, the draining lymph nodes from CD69-deficient mice developed an exacerbated Th17 inflammatory response, resulting in increases in the numbers of infiltrating leukocytes in the myocardium. In the chronic phase of EAM, transthoracic echocardiography revealed a significantly reduced left ventricular fractional shortening and a decreased ejection fraction in CD69-deficient mice, indicative of an impaired cardiac contractility. This condition was accompanied by a greater extent of myocardial fibrosis, an elevated number of sinus pauses on ECG, and an enhanced ratio of heart weight to body weight in CD69-/- mice. Moreover, both bone marrow transplantation and adoptive transfer of Th17 cells isolated from immunized CD69-/- mice with EAM into naive wild-type recipients reproduced the severity of the disease, demonstrating that CD69 exerts its function within the lymphocyte compartment. CONCLUSION Our findings indicate that CD69 negatively regulates heart-specific Th17 responses, cardiac inflammation, and heart failure progression in EAM.
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Affiliation(s)
- Aranzazu Cruz-Adalia
- Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro, Madrid, Spain
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Abstract
Arrhythmogenic cardiomyopathies are a heterogeneous group of pathological conditions that give rise to myocardial dysfunction with an increased risk for atrial or ventricular arrhythmias. Inherited defects in cardiomyocyte proteins in the sarcomeric contractile apparatus, the cytoskeleton and desmosomal cell-cell contact junctions are becoming recognized increasingly as major causes of sudden cardiac death in the general population. Animal models have been developed for the systematic dissection of the genetic pathways involved in the pathogenesis of arrhythmogenic cardiomyopathies. This review presents an overview of current animal models for arrhythmogenic right ventricular cardiomyopathy (ARVC), hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) associated with cardiac arrhythmias and sudden cardiac death.
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Affiliation(s)
- Mark D McCauley
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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Etzion Y, Mor M, Shalev A, Dror S, Etzion O, Dagan A, Beharier O, Moran A, Katz A. New insights into the atrial electrophysiology of rodents using a novel modality: the miniature-bipolar hook electrode. Am J Physiol Heart Circ Physiol 2008; 295:H1460-9. [PMID: 18660446 DOI: 10.1152/ajpheart.00414.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Studies of atrial electrophysiology (EP) in rodents are challenging, and available data are sparse. Herein, we utilized a novel type of bipolar electrode to evaluate the atrial EP of rodents through small lateral thoracotomy. In anesthetized rats and mice, we attached two bipolar electrodes to the right atrium and a third to the right ventricle. This standard setup enabled high-resolution EP studies. Moreover, a permanent implantation procedure enabled EP studies in conscious freely moving rats. Atrial EP was evaluated in anesthetized rats, anesthetized mice (ICR and C57BL6 strains), and conscious rats. Signal resolution enabled atrial effective refractory period (AERP) measurements and first time evaluation of the failed 1:1 atrial capture, which was unexpectedly longer than the AERP recorded at near normal cycle length by 27.2+/-2.3% in rats (P<0.0001; n=35), 31.7+/-8.3% in ICR mice (P=0.0001; n=13), and 57.7+/-13.7% in C57BL6 mice (P=0.015; n=4). While AERP rate adaptation was noted when 10 S1s at near normal basic cycle lengths were followed by S2 at varying basic cycle length and S3 for AERP evaluation, such rate adaptation was absent using conventional S1S2 protocols. Atrial tachypacing in rats shortened the AERP values on a timescale of hours, but a reverse remodeling phase was noted thereafter. Comparison of left vs. right atrial pacing in rats was also feasible with the current technique, resulting in similar AERP values recorded in the low right atrium. In conclusion, our findings indicate that in vivo rate adaptation of the rodent atria is different than expected based on previous ex vivo recordings. In addition, atrial electrical remodeling of rats shows unique remodeling-reverse remodeling characteristics that are described here for the first time. Further understanding of these properties should help to determine the clinical relevance as well as limitations of atrial arrhythmia models in rodents.
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Affiliation(s)
- Yoram Etzion
- Cardiac Arrhythmia Research Laboratory, Soroka University Medical Center, Beer-Sheva, Israel.
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Thomas G, Gurung IS, Killeen MJ, Hakim P, Goddard CA, Mahaut-Smith MP, Colledge WH, Grace AA, Huang CLH. Effects of L-type Ca2+ channel antagonism on ventricular arrhythmogenesis in murine hearts containing a modification in the Scn5a gene modelling human long QT syndrome 3. J Physiol 2006; 578:85-97. [PMID: 17110414 PMCID: PMC2075124 DOI: 10.1113/jphysiol.2006.121921] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Ventricular arrhythmogenesis in long QT 3 syndrome (LQT3) involves both triggered activity and re-entrant excitation arising from delayed ventricular repolarization. Effects of specific L-type Ca2+ channel antagonism were explored in a gain-of-function murine LQT3 model produced by a DeltaKPQ 1505-1507 deletion in the SCN5A gene. Monophasic action potentials (MAPs) were recorded from epicardial and endocardial surfaces of intact, Langendorff-perfused Scn5a+/Delta hearts. In untreated Scn5a+/Delta hearts, epicardial action potential duration at 90% repolarization (APD90) was 60.0 +/- 0.9 ms compared with 46.9 +/- 1.6 ms in untreated wild-type (WT) hearts (P < 0.05; n = 5). The corresponding endocardial APD(90) values were 52.0 +/- 0.7 ms and 53.7 +/- 1.6 ms in Scn5a+/Delta and WT hearts, respectively (P > 0.05; n = 5). Epicardial early afterdepolarizations (EADs), often accompanied by spontaneous ventricular tachycardia (VT), occurred in 100% of MAPs from Scn5a+/Delta but not in any WT hearts (n = 10). However, EAD occurrence was reduced to 62 +/- 7.1%, 44 +/- 9.7%, 10 +/- 10% and 0% of MAPs following perfusion with 10 nm, 100 nm, 300 nm and 1 mum nifedipine, respectively (P < 0.05; n = 5), giving an effective IC50 concentration of 79.3 nm. Programmed electrical stimulation (PES) induced VT in all five Scn5a+/Delta hearts (n = 5) but not in any WT hearts (n = 5). However, repeat PES induced VT in 3, 2, 2 and 0 out of 5 Scn5a+/Delta hearts following perfusion with 10 nm, 100 nm, 300 nm and 1 mum nifedipine, respectively. Patch clamp studies in isolated ventricular myocytes from Scn5a+/Delta and WT hearts confirmed that nifedipine (300 nm) completely suppressed the inward Ca2+ current but had no effect on inward Na+ currents. No significant effects were seen on epicardial APD90, endocardial APD90 or ventricular effective refractory period in Scn5a+/Delta and WT hearts following perfusion with nifedipine at 1 nm, 10 nm, 100 nm, 300 nm and 1 microm nifedipine concentrations. We conclude that L-type Ca2+ channel antagonism thus exerts specific anti-arrhythmic effects in Scn5a+/Delta hearts through suppression of EADs.
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Affiliation(s)
- Glyn Thomas
- Section of Cardiovascular Biology, Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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Lindsey ML, Escobar GP, Mukherjee R, Goshorn DK, Sheats NJ, Bruce JA, Mains IM, Hendrick JK, Hewett KW, Gourdie RG, Matrisian LM, Spinale FG. Matrix metalloproteinase-7 affects connexin-43 levels, electrical conduction, and survival after myocardial infarction. Circulation 2006; 113:2919-28. [PMID: 16769909 DOI: 10.1161/circulationaha.106.612960] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Matrix metalloproteinases (MMPs) contribute to left ventricular remodeling after myocardial infarction (MI). Specific causative roles of particular MMPs, however, remain unclear. MMP-7 is abundant in cardiomyocytes and macrophages, but MMP-7 function after MI has not been defined. METHODS AND RESULTS Wild-type (WT; n=55) and MMP-7-null (MMP-7-/-; n=32) mice underwent permanent coronary artery ligation for 7 days. MI sizes were similar, but survival was greatly improved in MMP-7-/- mice. The survival difference could not be attributed to differences in left ventricular dilation because end-diastolic volumes increased similarly. ECG analysis revealed a prolonged PR interval in WT but not in MMP-7-/- post-MI mice. Post-MI conduction velocity, determined by optically mapping electrical wavefront propagation, decreased to 78+/-6% of control for WT and was normalized in MMP-7-/- mice. In WT mice, slower conduction velocity correlated with a 53% reduction in the gap junction protein connexin-43. Direct binding of MMP-7 to connexin-43, determined by surface plasmon resonance technology, occurred in a dose-dependent manner. Connexin-43 processing by MMP-7 was confirmed by in silico and in vitro substrate analyses and MMP-7 infusion induced arrhythmias in vivo. CONCLUSIONS MMP-7 deletion results in improved survival and myocardial conduction patterns after MI. This is the first report to implicate MMP-7 in post-MI remodeling and to demonstrate that connexin-43 is a novel MMP-7 substrate.
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Affiliation(s)
- Merry L Lindsey
- Cardiology Division, Department of Medicine, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr, Mail Code 7872, San Antonio, TX 78229-3900, USA.
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Howell RR, Byrne B, Darras BT, Kishnani P, Nicolino M, van der Ploeg A. Diagnostic challenges for Pompe disease: An under-recognized cause of floppy baby syndrome. Genet Med 2006; 8:289-96. [PMID: 16702878 DOI: 10.1097/01.gim.0000204462.42910.b8] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Pompe disease, a disorder caused by a deficiency in the lysosomal enzyme acid alpha glucosidase, is frequently overlooked as a cause of floppy baby syndrome. The accurate diagnosis of floppy baby syndrome requires the sequential evaluation of medical causes (e.g., hypothyroidism, sepsis, malnutrition, malabsorption, congenital heart disease), neurologic etiologies (central [cerebral] and peripheral [lower motor unit]) and anatomic characteristics of the abnormality. Cardiomegaly on chest x-ray in a patient with floppy baby syndrome should alert the pediatrician to suspect Pompe disease. Based on this finding, further work-up or referral to a specialist can be considered. Pompe disease requires immediate attention. Symptomatic intervention of this disorder should be initiated at the earliest time possible to maximize the potential benefit from therapy and to prevent irreversible organ damage. Moreover, early diagnosis is important for providing parents with realistic information about their child's prognosis, and where appropriate, professional genetic counseling. Enzyme replacement therapy (ERT) with recombinant human GAA is currently being evaluated in clinical trials; the future availability of this option makes early identification of this condition even more critical. This article presents a unified view on the optimal approach to the accurate diagnosis of Pompe disease and to its recognition as one of the possible and treatable causes of floppy baby syndrome.
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Affiliation(s)
- R Rodney Howell
- Department of Pediatrics, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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Mangoni ME, Couette B, Marger L, Bourinet E, Striessnig J, Nargeot J. Voltage-dependent calcium channels and cardiac pacemaker activity: from ionic currents to genes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2005; 90:38-63. [PMID: 15979127 DOI: 10.1016/j.pbiomolbio.2005.05.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The spontaneous activity of pacemaker cells in the sino-atrial node controls the heart rhythm and rate under physiological conditions. Compared to working myocardial cells, pacemaker cells express a specific array of ionic channels. The functional importance of different ionic channels in the generation and regulation of cardiac automaticity is currently subject of an extensive research effort and has long been controversial. Among families of ionic channels, Ca(2+) channels have been proposed to substantially contribute to pacemaking. Indeed, Ca(2+) channels are robustly expressed in pacemaker cells, and influence the cell beating rate. Furthermore, they are regulated by the activity of the autonomic nervous system in both a positive and negative way. In this manuscript, we will first discuss how the concept of the involvement of Ca(2+) channels in cardiac pacemaking has been proposed and then subsequently developed by the recent advent in the domain of cardiac physiology of gene-targeting techniques. Secondly, we will indicate how the specific profile of Ca(2+) channels expression in pacemaker tissue can help design drugs which selectively regulate the heart rhythm in the absence of concomitant negative inotropism. Finally, we will indicate how the new possibility to assign a specific gene activity to a given ionic channel involved in cardiac pacemaking could implement the current postgenomic research effort in the construction of the cardiac Physiome.
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Affiliation(s)
- Matteo E Mangoni
- Departement de Physiologie, Institut de Génomique Fonctionnelle, University of Montpellier I, CNRS UMR 5203, Montpellier F-34094, France.
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Glueck S. Note from the Deputy Editor: reviews in mouse CV phenotyping. Physiol Genomics 2003. [DOI: 10.1152/physiolgenomics.00046.2003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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