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Gorman RA, Yakobov S, Polidovitch N, Debi R, Sanfrancesco VC, Hood DA, Lakin R, Backx PH. The effects of daily dose of intense exercise on cardiac responses and atrial fibrillation. J Physiol 2024; 602:569-596. [PMID: 38319954 DOI: 10.1113/jp285697] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 12/08/2023] [Indexed: 02/08/2024] Open
Abstract
Atrial fibrillation (AF) is a supraventricular tachyarrhythmia that is strongly associated with cardiovascular (CV) disease and sedentary lifestyles. Despite the benefits of exercise on overall health, AF incidence in high-level endurance athletes rivals that of CV disease patients, suggesting a J-shaped relationship with AF. To investigate the dependence of AF vulnerability on exercise, we varied daily swim durations (120, 180 or 240 min day-1 ) in 7-week-old male CD1 mice. We assessed mice after performing equivalent amounts of cumulative work during swimming (i.e. ∼700 L O2 kg-1 ), as determined from O2 consumption rates (V ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ ). The meanV ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ during exercise increased progressively throughout the training period and was indistinguishable between the swim groups. Consistent with similar improvements in aerobic conditioning induced by swimming, skeletal muscle mitochondria content increased (P = 0.027) indistinguishably between exercise groups. Physiological ventricular remodelling, characterized by mild hypertrophy and left ventricular dilatation, was also similar between exercised mice without evidence of ventricular arrhythmia inducibility. By contrast, prolongation of daily swim durations caused progressive and vagal-dependent heart rate reductions (P = 0.008), as well as increased (P = 0.005) AF vulnerability. As expected, vagal inhibition prolonged (P = 0.013) atrial refractoriness, leading to reduced AF vulnerability, although still inducible in the 180 and 240 min swim groups. Accordingly, daily swim dose progressively increased atrial hypertrophy (P = 0.003), fibrosis (P < 0.001) and macrophage accumulation (P = 0.006) without differentially affecting the ventricular tissue properties. Thus, increasing daily exercise duration drives progressively adverse atrial-specific remodelling and vagal-dependent AF vulnerability despite robust and beneficial aerobic conditioning and physiological remodelling of ventricles and skeletal muscle. KEY POINTS: Previous studies have suggested that a J-shaped dose-response relationship exists between physical activity and cardiovascular health outcomes, with moderate exercise providing protection against many cardiovascular disease conditions, whereas chronic endurance exercise can promote atrial fibrillation (AF). We found that AF vulnerability increased alongside elevated atrial hypertrophy, fibrosis and inflammation as daily swim exercise durations in mice were prolonged (i.e. ≥180 min day-1 for 6 weeks). The MET-h week-1 (based on O2 measurements during swimming) needed to induce increased AF vulnerability mirrored the levels linked to AF in athletes. These adverse atria effects associated with excessive daily exercise occurred despite improved aerobic conditioning, skeletal muscle adaptation and physiological ventricular remodelling. We suggest that atrial-specific changes observed with exercise arise from excessive elevations in venous filling pressures during prolonged exercise bouts, which we argue has implications for all AF patients because elevated atrial pressures occur in most cardiovascular disease conditions as well as ageing which are linked to AF.
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Affiliation(s)
- Renée A Gorman
- Department of Biology, York University, Toronto, ON, Canada
- Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Simona Yakobov
- Department of Biology, York University, Toronto, ON, Canada
- Muscle Health Research Centre, York University, Toronto, ON, Canada
| | | | - Ryan Debi
- Department of Biology, York University, Toronto, ON, Canada
| | - Victoria C Sanfrancesco
- Muscle Health Research Centre, York University, Toronto, ON, Canada
- Department of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - David A Hood
- Muscle Health Research Centre, York University, Toronto, ON, Canada
- Department of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, Canada
- Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada
- Muscle Health Research Centre, York University, Toronto, ON, Canada
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2
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Lakin R, Polidovitch N, Yang S, Parikh M, Liu X, Debi R, Gao X, Chen W, Guzman C, Yakobov S, Izaddoustdar F, Wauchop M, Lei Q, Xu W, Nedospasov SA, Christoffels VM, Backx PH. Cardiomyocyte and endothelial cells play distinct roles in the tumour necrosis factor (TNF)-dependent atrial responses and increased atrial fibrillation vulnerability induced by endurance exercise training in mice. Cardiovasc Res 2023; 119:2607-2622. [PMID: 37713664 PMCID: PMC10730243 DOI: 10.1093/cvr/cvad144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 06/22/2023] [Accepted: 07/18/2023] [Indexed: 09/17/2023] Open
Abstract
AIMS Endurance exercise is associated with an increased risk of atrial fibrillation (AF). We previously established that adverse atrial remodelling and AF susceptibility induced by intense exercise in mice require the mechanosensitive and pro-inflammatory cytokine tumour necrosis factor (TNF). The cellular and mechanistic basis for these TNF-mediated effects is unknown. METHODS AND RESULTS We studied the impact of Tnf excision, in either atrial cardiomyocytes or endothelial cells (using Cre-recombinase expression controlled by Nppa or Tie2 promoters, respectively), on the cardiac responses to six weeks of intense swim exercise training. TNF ablation, in either cell type, had no impact on the changes in heart rate, autonomic tone, or left ventricular structure and function induced by exercise training. Tnf excision in atrial cardiomyocytes did, however, prevent atrial hypertrophy, fibrosis, and macrophage infiltration as well as conduction slowing and increased AF susceptibility arising from exercise training. In contrast, endothelial-specific excision only reduced the training-induced atrial hypertrophy. Consistent with these cell-specific effects of Tnf excision, inducing TNF loss from atrial cardiomyocytes prevented activation of p38MAPKinase, a strain-dependent downstream mediator of TNF signalling, without affecting the atrial stretch as assessed by atrial pressures induced by exercise. Despite TNF's established role in innate immune responses and inflammation, neither acute nor chronic exercise training caused measurable NLRP3 inflammasome activation. CONCLUSIONS Our findings demonstrate that adverse atrial remodelling and AF vulnerability induced by intense exercise require TNF in atrial cardiomyocytes whereas the impact of endothelial-derived TNF is limited to hypertrophy modulation. The implications of the cell autonomous effects of TNF and crosstalk between cells in the atria are discussed.
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Affiliation(s)
- Robert Lakin
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Nazari Polidovitch
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Sibao Yang
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130022, China
| | - Mihir Parikh
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Xueyan Liu
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130022, China
| | - Ryan Debi
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Xiaodong Gao
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Wenliang Chen
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Camilo Guzman
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Simona Yakobov
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Farzad Izaddoustdar
- Department of Physiology, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Marianne Wauchop
- Department of Physiology, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Qian Lei
- Department of Anesthesiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Weimin Xu
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130022, China
| | - Sergei A Nedospasov
- Laboratory of Molecular Mechanisms of Immunity, Engelhardt Institute of Molecular Biology, Moscow 119991, Russia
- Division of Immunobiology and Biomedicine, Sirius University of Science and Technology, Sirius 354349, Russia
| | - Vincent M Christoffels
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Amsterdam, The Netherlands
| | - Peter H Backx
- Department of Biology, York University, 354 & 357 Farquharson Building, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
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3
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Li X, You J, Dai F, Wang S, Yang FH, Wang X, Ding Z, Huang J, Chen L, Abudureyimu M, Tang H, Yang X, Xiang Y, Backx PH, Ren J, Ge J, Zou Y, Wu J. TAK1 Activation by NLRP3 Deficiency Confers Cardioprotection Against Pressure Overload-Induced Cardiomyocyte Pyroptosis and Hypertrophy. JACC Basic Transl Sci 2023; 8:1555-1573. [PMID: 38205342 PMCID: PMC10774584 DOI: 10.1016/j.jacbts.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/16/2023] [Accepted: 05/16/2023] [Indexed: 01/12/2024]
Abstract
A comprehensive view of the role of NLRP3/caspase-1/GSDMD-mediated pyroptosis in pressure overload cardiac hypertrophy is presented in this study. Furthermore, mitigation of NLRP3 deficiency-induced pyroptosis confers cardioprotection against pressure overload through activation of TAK1, whereas this salutary effect is abolished by inhibition of TAK1 activity, highlighting a previously unrecognized reciprocally regulatory role of NLRP3-TAK1 governing inflammation-induced cell death and hypertrophic growth. Translationally, this study advocates strategies based on inflammation-induced cell death might be exploited therapeutically in other inflammatory and mechanical overload disorders, such as myocardial infarction and mitral regurgitation.
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Affiliation(s)
- Xuan Li
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jieyun You
- Department of Cardiovascular Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Fangjie Dai
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Department of Cardiology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Shijun Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Feng Hua Yang
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - Xingxu Wang
- Department of Cardiovascular Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Zhiwen Ding
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jiayuan Huang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - Liming Chen
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Miyesaier Abudureyimu
- Cardiovascular Department, Shanghai Xuhui Central Hospital, Fudan University, Shanghai, China
| | - Haiyang Tang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou, China
- Guangdong Key Laboratory of Vascular Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiangdong Yang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yaozu Xiang
- Shanghai East Hospital, Key Laboratory of Arrhythmias of the Ministry of Education of China, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Peter H. Backx
- Department of Biology, Faculty of Science, York University, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Jun Ren
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Junbo Ge
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
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4
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Zheng S, Tan W, Li X, Wang L, Zhu C, Pyle WG, Chen J, Wu J, Ren X, Chen H, Zou Y, Backx PH, Yang FH. Apelin receptor inhibition in ischemia-reperfused mouse hearts protected by endogenous n-3 polyunsaturated fatty acids. Front Pharmacol 2023; 14:1145413. [PMID: 37942483 PMCID: PMC10628527 DOI: 10.3389/fphar.2023.1145413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 09/27/2023] [Indexed: 11/10/2023] Open
Abstract
Background: While the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on cardiac ischemia-reperfusion (IR) injury have been previously reported, limited data are available regarding how these fatty acids affect membrane receptors and their downstream signaling following IR injury. We aimed to identify potential receptors activated by n-3 PUFAs in IR hearts to understand the regulatory mechanisms of these receptors. Methods: We used fat-1 mice, which naturally have elevated levels of n-3 PUFAs, and C57BL/6J mice as a control group to create a myocardial IR injury model through Langendorff perfusion. We assessed the impact of endogenous n-3 PUFAs on left ventricular function, myocardial infarct size, myocardial apoptosis, and ATP production. RNA sequencing (RNA-seq) and bioinformatics analysis were conducted to identify molecular targets affected by n-3 PUFAs. Based on these analyses we then treated IR hearts of WT and fat-1 mice with an antagonist (ML221) or an agonist (apelin-13) for the predicted receptor to assess cardiac contractile function and intracellular signaling pathways. An in vitro hypoxia-reoxygenation (HR) model was also used to confirm the effects of n-3 PUFAs on the examined intracellular signaling pathways. Results: Endogenous n-3 PUFAs protected cardiac structure and function in post-IR hearts, and modulated phosphorylation patterns in the PI3K-AKT-mTOR signaling pathways. RNA-seq analysis revealed that n-3 PUFAs affected multiple biological processes as well as levels of the apelin receptor (APLNR). Consistent with a role for the PLNNR, ML221 synchronized the activation of the PI3K-AKT-mTOR signaling axis, suppressed the expression of PKCδ and phosphorylated p38α, upregulated PKCε expression, upregulated or restored the phosphorylation of myofilaments, and prevented myocardial injury and contractile dysfunction in WT IR hearts. By contrast, apelin-13 disrupted the PI3K-AKT-mTOR signaling axis in post-IR fat-1 hearts. The phosphorylation signaling targeted by APLNR inhibition in post-IR fat-1 hearts was also observed after treating HR cells with eicosatetraenoic acid (EPA). Conclusion: Endogenous n-3 PUFAs protect against post-IR injury and preserve cardiac contractile function possibly through APLNR inhibition. This inhibition synchronizes the PI3K-AKT-mTOR axis, suppresses detrimental phosphorylation signaling, and restores or increases myofilament phosphorylation in post-IR hearts. The beneficial effects observed in fat-1 transgenic mouse hearts can be attributed, at least in part, to elevated EPA levels. This study is the first to demonstrate that n-3 PUFAs protect hearts against IR injury through APLNR inhibition.
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Affiliation(s)
- Shuang Zheng
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Weijiang Tan
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xiang Li
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Lijing Wang
- School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
| | - Caiyi Zhu
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - W. Glen Pyle
- IMPART Investigator Team, Dalhousie Medicine, Saint John, NB, Canada
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Jianxin Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xuecong Ren
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Honghua Chen
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Yunzeng Zou
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Peter H. Backx
- Department of Biology, York University, Toronto, ON, Canada
| | - Feng Hua Yang
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
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5
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Wauchop M, Rafatian N, Zhao Y, Chen W, Gagliardi M, Massé S, Cox BJ, Lai P, Liang T, Landau S, Protze S, Gao XD, Wang EY, Tung KC, Laksman Z, Lu RXZ, Keller G, Nanthakumar K, Radisic M, Backx PH. Maturation of iPSC-derived cardiomyocytes in a heart-on-a-chip device enables modeling of dilated cardiomyopathy caused by R222Q-SCN5A mutation. Biomaterials 2023; 301:122255. [PMID: 37651922 PMCID: PMC10942743 DOI: 10.1016/j.biomaterials.2023.122255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/17/2023] [Accepted: 07/23/2023] [Indexed: 09/02/2023]
Abstract
To better understand sodium channel (SCN5A)-related cardiomyopathies, we generated ventricular cardiomyocytes from induced pluripotent stem cells obtained from a dilated cardiomyopathy patient harbouring the R222Q mutation, which is only expressed in adult SCN5A isoforms. Because the adult SCN5A isoform was poorly expressed, without functional differences between R222Q and control in both embryoid bodies and cell sheet preparations (cultured for 29-35 days), we created heart-on-a-chip biowires which promote myocardial maturation. Indeed, biowires expressed primarily adult SCN5A with R222Q preparations displaying (arrhythmogenic) short action potentials, altered Na+ channel biophysical properties and lower contractility compared to corrected controls. Comprehensive RNA sequencing revealed differential gene regulation between R222Q and control biowires in cellular pathways related to sarcoplasmic reticulum and dystroglycan complex as well as biological processes related to calcium ion regulation and action potential. Additionally, R222Q biowires had marked reductions in actin expression accompanied by profound sarcoplasmic disarray, without differences in cell composition (fibroblast, endothelial cells, and cardiomyocytes) compared to corrected biowires. In conclusion, we demonstrate that in addition to altering cardiac electrophysiology and Na+ current, the R222Q mutation also causes profound sarcomere disruptions and mechanical destabilization. Possible mechanisms for these observations are discussed.
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Affiliation(s)
- Marianne Wauchop
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Yimu Zhao
- Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Wenliang Chen
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Mark Gagliardi
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Stéphane Massé
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Brian J Cox
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada; Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Patrick Lai
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Timothy Liang
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Shira Landau
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Stephanie Protze
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Xiao Dong Gao
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Erika Yan Wang
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Kelvin Chan Tung
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Zachary Laksman
- Department of Medicine, University of British Columbia, Vancouver, BC, V6E 1M7, Canada
| | - Rick Xing Ze Lu
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Gordon Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Kumaraswamy Nanthakumar
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada.
| | - Milica Radisic
- Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada, M5S 3E5.
| | - Peter H Backx
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada; Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
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6
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Teng ACT, Gu L, Di Paola M, Lakin R, Williams ZJ, Au A, Chen W, Callaghan NI, Zadeh FH, Zhou YQ, Fatah M, Chatterjee D, Jourdan LJ, Liu J, Simmons CA, Kislinger T, Yip CM, Backx PH, Gourdie RG, Hamilton RM, Gramolini AO. Tmem65 is critical for the structure and function of the intercalated discs in mouse hearts. Nat Commun 2022; 13:6166. [PMID: 36257954 PMCID: PMC9579145 DOI: 10.1038/s41467-022-33303-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/07/2022] [Indexed: 12/24/2022] Open
Abstract
The intercalated disc (ICD) is a unique membrane structure that is indispensable to normal heart function, yet its structural organization is not completely understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin43 (Cx43) localization and function in cultured mouse neonatal cardiomyocytes. Here, we investigate the functional and cellular effects of Tmem65 reductions on the myocardium in a mouse model by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 shRNA, which reduces Tmem65 expression by 90% in mouse ventricles compared to scrambled shRNA injection. Tmem65 knockdown (KD) results in increased mortality which is accompanied by eccentric hypertrophic cardiomyopathy within 3 weeks of injection and progression to dilated cardiomyopathy with severe cardiac fibrosis by 7 weeks post-injection. Tmem65 KD hearts display depressed hemodynamics as measured echocardiographically as well as slowed conduction in optical recording accompanied by prolonged PR intervals and QRS duration in electrocardiograms. Immunoprecipitation and super-resolution microscopy demonstrate a physical interaction between Tmem65 and sodium channel β subunit (β1) in mouse hearts and this interaction appears to be required for both the establishment of perinexal nanodomain structure and the localization of both voltage-gated sodium channel 1.5 (NaV1.5) and Cx43 to ICDs. Despite the loss of NaV1.5 at ICDs, whole-cell patch clamp electrophysiology did not reveal reductions in Na+ currents but did show reduced Ca2+ and K+ currents in Tmem65 KD cardiomyocytes in comparison to control cells. We conclude that disrupting Tmem65 function results in impaired ICD structure, abnormal cardiac electrophysiology, and ultimately cardiomyopathy.
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Affiliation(s)
- Allen C T Teng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
| | - Liyang Gu
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Michelle Di Paola
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Zachary J Williams
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA, 24016, USA
| | - Aaron Au
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Wenliang Chen
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Neal I Callaghan
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Farigol Hakem Zadeh
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Yu-Qing Zhou
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Meena Fatah
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Diptendu Chatterjee
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - L Jane Jourdan
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Jack Liu
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Craig A Simmons
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Christopher M Yip
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Robert G Gourdie
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Robert M Hamilton
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Anthony O Gramolini
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
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7
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Li X, Tan W, Zheng S, Pyle WG, Zhu C, Chen H, Kang L, Wu J, Zou Y, Backx PH, Yang FH. Differential mRNA Expression and Circular RNA-Based Competitive Endogenous RNA Networks in the Three Stages of Heart Failure in Transverse Aortic Constriction Mice. Front Physiol 2022; 13:777284. [PMID: 35330931 PMCID: PMC8940230 DOI: 10.3389/fphys.2022.777284] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/11/2022] [Indexed: 12/31/2022] Open
Abstract
Background The murine transverse aortic constriction (TAC) model is frequently used to investigate molecular mechanisms underlying heart failure. However, limited data is available regarding the expression of mRNAs and circRNAs in murine heart failure progression induced by pressure overload. Methods Transverse aortic constriction was used to induce pressure overload for 2, 4, and 8 weeks in mice. Echocardiographic measurements in B-mode and M-mode, as well as blood flow Doppler data were collected in mice without (sham) and with (2W-, 4W-, and 8W-post-TAC) pressure load. Hearts were excised and morphology, cardiomyocyte size, and fibrosis were determined. RNA sequencing, circRNA microarray, functional mRNA enrichment analysis, hub gene identification, target miRNA interaction, and competitive endogenous RNA (ceRNA) network construction were conducted. Results Heart weight, cardiomyocyte hypertrophy, and fibrosis gradually increased over time in the hearts with pressure overload. The 2W-post-TAC hearts displayed concentric hypertrophy, thickened left ventricular walls, and increased EF and FS. The 4W-post-TAC hearts were characterized by preserved EF and FS, dilated atria, and increased left ventricle (LV) systolic volume. The 8W-post-TAC hearts presented with ventricular and atrial dilation, increased LV systolic and diastolic volume, reduced EF and FS, and increased ejection time (MV ET). mRNA expression analysis suggested that cardiac remodeling, immune response dysregulation, and metabolic disorder were the key cellular events in heart failure progression. Depression in chemotaxis and mitochondrial function were predicted in 4W- and 8W-post-TAC myocardia, respectively. A ceRNA network analysis demonstrated that the circRNAs targeted the expression of genes enriched in metabolism dysregulation in the 2W-post-TAC hypertrophic hearts, while they targeted genes enriched in cardiac remodeling in the 4W-post-TAC EF-preserved hearts and in the suppression of oxidative phosphorylation and cardiac contraction in the 8W-post-TAC EF-reduced hearts. Conclusion Our work empirically demonstrates that distinctive features of heart failure, including ventricular hypertrophy, heart failure with preserved EF (HFpEF), and heart failure with reduced EF (HFrEF) are present in the murine pressure overload models. The three stages of heart failure vary in terms of mRNA and circRNA expression, as well as ceRNA regulation in a manner consistent with their structural, functional, and pathological differences.
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Affiliation(s)
- Xiang Li
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - Weijiang Tan
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China.,College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Shuang Zheng
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - W Glen Pyle
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Caiyi Zhu
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - Honghua Chen
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
| | - Le Kang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Peter H Backx
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Biology, York University, Toronto, ON, Canada
| | - Feng Hua Yang
- Guangdong Laboratory Animals Monitoring Institute, Guangdong Province Key Laboratory of Laboratory Animals, Guangzhou, China
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8
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Kim KH, Oh Y, Liu J, Dababneh S, Xia Y, Kim RY, Kim DK, Ban K, Husain M, Hui CC, Backx PH. Irx5 and transient outward K + currents contribute to transmural contractile heterogeneities in the mouse ventricle. Am J Physiol Heart Circ Physiol 2022; 322:H725-H741. [PMID: 35245131 DOI: 10.1152/ajpheart.00572.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have established that fast transmural gradients of transient outward K+ current (Ito,f) correlate with regional differences in action potential (AP) profile and excitation-contraction coupling (ECC) with high Ito,f expression in the epimyocardium (EPI) being associated with short APs and low contractility and vice versa. Herein, we investigated the effects of disrupted Ito,f gradient on contractile properties using mouse models of Irx5 knockout (Irx5-KO) for selective Ito,f elevation in the endomyocardium (ENDO) of the left ventricle (LV) and Kcnd2 ablation (KV4.2-KO) for selective Ito,freduction in the EPI. Irx5-KO mice exhibited decreased global LV contractility in association with reductions in cell shortening and Ca2+ transient amplitudes in isolated ENDO but not EPI cardiomyocytes. Moreover, transcriptional profiling revealed that the primary effect of Irx5 ablation on ECC-related genes was to increase Ito,f gene expression (i.e. Kcnd2 and Kcnip2) in the ENDO, but not the EPI. Indeed, KV4.2-KO mice showed selective increases in cell shortening and Ca2+ transients in isolated EPI cardiomyocytes, leading to enhanced ventricular contractility and mice lacking both Irx5 and Kcnd2 displayed elevated ventricular contractility comparable to KV4.2-KO mice. Our findings demonstrate that the transmural electromechanical heterogeneities in the healthy ventricles depend on the Irx5-dependent Ito,f gradients. These observations provide a useful framework for assessing the molecular mechanisms underlying the alterations in contractile heterogeneity seen in the diseased heart.
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Affiliation(s)
- Kyoung-Han Kim
- University of Ottawa Heart Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Yena Oh
- University of Ottawa Heart Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jie Liu
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Biology, Faculty of Science, York University, Toronto, ON, Canada
| | - Saif Dababneh
- University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Ying Xia
- University of Ottawa Heart Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Ri Youn Kim
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Dae-Kyum Kim
- University of Ottawa Heart Institute, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Kiwon Ban
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Mansoor Husain
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Chi-Chung Hui
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Peter H Backx
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Biology, Faculty of Science, York University, Toronto, ON, Canada.,Toronto General Research Institute, University Health Network, Toronto, ON, Canada
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9
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Li X, Tan W, Zheng S, Zhang J, Zhu C, Cai C, Chen H, Yang C, Kang L, Pan Z, Pyle WG, Backx PH, Zou Y, Yang FH. Cardioprotective Effects of n-3 Polyunsaturated Fatty Acids: Orchestration of mRNA Expression, Protein Phosphorylation, and Lipid Metabolism in Pressure Overload Hearts. Front Cardiovasc Med 2022; 8:788270. [PMID: 35047577 PMCID: PMC8761763 DOI: 10.3389/fcvm.2021.788270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/08/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Pressure overload can result in dilated cardiomyopathy. The beneficial effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) on heart disorders have been widely recognized. However, the molecular mechanisms underlying their protective effects against cardiomyopathy remain unclear. Methods: Pressure overload in mice induced by 8 weeks of transverse aortic constriction was used to induce dilated cardiomyopathy. A transgenic fat-1 mouse model carrying the n-3 fatty acid desaturase gene fat-1 gene from Caenorhabditis elegans was used to evaluate the mechanism of n-3 PUFAs in this disease. Echocardiography, transmission electron microscopy, and histopathological analyses were used to evaluate the structural integrity and function in pressure overloaded fat-1 hearts. mRNA sequencing, label-free phosphoprotein quantification, lipidomics, Western blotting, RT-qPCR, and ATP detection were performed to examine the effects of n-3 PUFAs in the heart. Results: Compared with wild-type hearts, left ventricular ejection fraction was significantly improved (C57BL/6J [32%] vs. fat-1 [53%]), while the internal diameters of the left ventricle at systole and diastole were reduced in the fat-1 pressure overload hearts. mRNA expression, protein phosphorylation and lipid metabolism were remodeled by pressure overload in wild-type and fat-1 hearts. Specifically, elevation of endogenous n-3 PUFAs maintained the phosphorylation states of proteins in the subcellular compartments of sarcomeres, cytoplasm, membranes, sarcoplasmic reticulum, and mitochondria. Moreover, transcriptomic analysis predicted that endogenous n-3 PUFAs restored mitochondrial respiratory chain function that was lost in the dilated hearts, and this was supported by reductions in detrimental oxylipins and protection of mitochondrial structure, oxidative phosphorylation, and ATP production. Conclusions: Endogenous n-3 PUFAs prevents dilated cardiomyopathy via orchestrating gene expression, protein phosphorylation, and lipid metabolism. This is the first study provides mechanistic insights into the cardioprotective effects of n-3 PUFAs in dilated cardiomyopathy through integrated multi-omics data analysis.
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Affiliation(s)
- Xiang Li
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Weijiang Tan
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China.,College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Shuang Zheng
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Junjie Zhang
- School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Caiyi Zhu
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Chun Cai
- School of Pharmacy, Guangdong Medical University, Dongguan, China
| | - Honghua Chen
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Chenqi Yang
- Faculty of Arts and Sciences, University of Toronto, Toronto, ON, Canada
| | - Le Kang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Zhanhong Pan
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - W Glen Pyle
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Peter H Backx
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Biology, York University, Toronto, ON, Canada
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Feng Hua Yang
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
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10
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Barazi N, Polidovitch N, Debi R, Yakobov S, Lakin R, Backx PH. Dissecting the Roles of the Autonomic Nervous System and Physical Activity on Circadian Heart Rate Fluctuations in Mice. Front Physiol 2021; 12:692247. [PMID: 34733171 PMCID: PMC8558381 DOI: 10.3389/fphys.2021.692247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 09/22/2021] [Indexed: 01/02/2023] Open
Abstract
Heart rate (HR) and blood pressure as well as adverse cardiovascular events show clear circadian patterns, which are linked to interdependent daily variations in physical activity and cardiac autonomic nerve system (ANS) activity. We set out to assess the relative contributions of the ANS (alone) and physical activity to circadian HR fluctuations. To do so, we measured HR (beats per minute, bpm) in mice that were either immobilized using isoflurane anesthesia or free-moving. Nonlinear fits of HR data to sine functions revealed that anesthetized mice display brisk circadian HR fluctuations with amplitudes of 47.1±7.4bpm with the highest HRs in middle of the dark (active) period (ZT 18: 589±46bpm) and lowest HRs in the middle of the light (rest) period (ZT 6: 497±54bpm). The circadian HR fluctuations were reduced by ~70% following blockade of cardiac parasympathetic nervous activity (PNA) with atropine while declining by <15% following cardiac sympathetic nerve activity (SNA) blockade with propranolol. Small HR fluctuation amplitudes (11.6±5.9bpm) remained after complete cardiac ANS blockade. Remarkably, circadian HR fluctuation amplitudes in freely moving, telemetrized mice were only ~32% larger than in anesthetized mice. However, after gaining access to running wheels for 1week, circadian HR fluctuations increase to 102.9±12.1bpm and this is linked directly to increased O2 consumption during running. We conclude that, independent of physical activity, the ANS is a major determinant of circadian HR variations with PNA playing a dominant role compared to SNA. The effects of physical activity to the daily HR variations are remarkably small unless mice get access to running wheels.
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Affiliation(s)
- Nour Barazi
- Department of Biology, York University, Toronto, ON, Canada
| | | | - Ryan Debi
- Department of Biology, York University, Toronto, ON, Canada
| | - Simona Yakobov
- Department of Biology, York University, Toronto, ON, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada
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11
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Tan W, Li X, Zheng S, Li X, Zhang X, Pyle WG, Chen H, Wu J, Sun H, Zou Y, Backx PH, Yang FH. A Porcine Model of Heart Failure With Preserved Ejection Fraction Induced by Chronic Pressure Overload Characterized by Cardiac Fibrosis and Remodeling. Front Cardiovasc Med 2021; 8:677727. [PMID: 34150870 PMCID: PMC8206269 DOI: 10.3389/fcvm.2021.677727] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/10/2021] [Indexed: 12/17/2022] Open
Abstract
Heart failure is induced by multiple pathological mechanisms, and current therapies are ineffective against heart failure with preserved ejection fraction (HFpEF). As there are limited animal models of HFpEF, its underlying mechanisms have not yet been elucidated. Here, we employed the descending aortic constriction (DAC) technique to induce chronic pressure overload in the left ventricles of Tibetan minipigs for 12 weeks. Cardiac function, pathological and cellular changes, fibrotic signaling activation, and gene expression profiles were explored. The left ventricles developed concentric hypertrophy from weeks 4 to 6 and transition to dilation starting in week 10. Notably, the left ventricular ejection fraction was maintained at >50% in the DAC group during the 12-week period. Pathological examination, biochemical analyses, and gene profile analysis revealed evidence of inflammation, fibrosis, cell death, and myofilament dephosphorylation in the myocardium of HFpEF model animals, together with gene expression shifts promoting cardiac remodeling and downregulating metabolic pathways. Furthermore, we noted the activation of several signaling proteins that impact cardiac fibrosis and remodeling, including transforming growth factor-β/SMAD family members 2/3, type I/III/V collagens, phosphatidylinositol 3-kinase, extracellular signal-regulated kinase, matrix metalloproteinases 2 and 9, tissue inhibitor of metalloproteinases 1 and 2, interleukins 6 and 1β, and inhibitor of κBα/nuclear factor-κB. Our findings demonstrate that this chronic pressure overload-induced porcine HFpEF model is a powerful tool to elucidate the mechanisms of this disease and translate preclinical findings.
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Affiliation(s)
- Weijiang Tan
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xiang Li
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Shuang Zheng
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xiaohui Li
- Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Xiaoshen Zhang
- Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - W Glen Pyle
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Honghua Chen
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Huan Sun
- Cardiology Department, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Feng Hua Yang
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China.,Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
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12
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Kim KH, Backx PH. Understanding the role of Iroquois homeobox transcription factor 5 (IRX5) in cardiac function: getting to the (human) heart of the matter. Cardiovasc Res 2021; 117:1989-1991. [PMID: 33739382 DOI: 10.1093/cvr/cvab098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Kyoung-Han Kim
- University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 Smyth road, Ottawa, ON K1N 6N5, Canada
| | - Peter H Backx
- Department of Biology, York University, 4700 Keele St, Toronto, ON M3J 1P3, Canada.,Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, 101 College St, Toronto, ON M5G 1L7, Canada
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13
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Lakin R, Debi R, Yang S, Polidovitch N, Goodman JM, Backx PH. Differential negative effects of acute exhaustive swim exercise on the right ventricle are associated with disproportionate hemodynamic loading. Am J Physiol Heart Circ Physiol 2021; 320:H1261-H1275. [PMID: 33416456 DOI: 10.1152/ajpheart.00603.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute exhaustive endurance exercise can differentially impact the right ventricle (RV) versus the left ventricle (LV). However, the hemodynamic basis for these differences and its impact on postexercise recovery remain unclear. Therefore, we assessed cardiac structure and function along with hemodynamic properties of mice subjected to single bouts (216 ± 8 min) of exhaustive swimming (ES). One-hour after ES, LVs displayed mild diastolic impairment compared with that in sedentary (SED) mice. Following dobutamine administration to assess functional reserve, diastolic and systolic function were slightly impaired. Twenty-four hours after ES, LV function was largely indistinguishable from that in SED. By contrast, 1-h post swim, RVs showed pronounced impairment of diastolic and systolic function with and without dobutamine, which persisted 24 h later. The degree of RV impairment correlated with the time-to-exhaustion. To identify hemodynamic factors mediating chamber-specific responses to ES, LV pressure was recorded during swimming. Swimming initiated immediate increases in heart rates (HRs), systolic pressure, dP/dtmax and -dP/dtmin, which remained stable for ∼45 min. LV end-diastolic pressures (LVEDP) increased to ≥45 mmHg during the first 10 min and subsequently declined. After 45 min, HR and -dP/dtmin declined, which correlated with gradual elevations in LVEDP (to ∼45 mmHg) as mice approached exhaustion. All parameters rapidly normalized postexercise. Consistent with human studies, our findings demonstrate a disproportionate negative impact of acute exhaustive exercise on RVs that persisted for at least 24 h. We speculate that the differential effects of exhaustive exercise on the ventricles arise from a ∼2-fold greater hemodynamic load in the RV than in LV originating from profound elevations in LVEDPs as mice approach exhaustion.NEW & NOTEWORTHY Acute exhaustive exercise differentially impacts the right ventricle (RV) versus left ventricle (LV), yet the underlying hemodynamic basis remains unclear. Using pressure-volume analyses and pressure-telemetry implantation in mice, we confirmed a marked disproportionate and persistent negative impact of exhaustive exercise on the RV. These differences in responses of the ventricles to exhaustive exercise are of clinical relevance, reflecting ∼2-fold greater hemodynamic RV loads versus LVs arising from massive (∼45 mmHg) increases in LV end-diastolic pressures at exhaustion.
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Affiliation(s)
- Robert Lakin
- Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Ryan Debi
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Sibao Yang
- Department of Biology, York University, Toronto, Ontario, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Nazari Polidovitch
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Jack M Goodman
- Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
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14
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Oh Y, Yang S, Liu X, Jana S, Izaddoustdar F, Gao X, Debi R, Kim DK, Kim KH, Yang P, Kassiri Z, Lakin R, Backx PH. Transcriptomic Bioinformatic Analyses of Atria Uncover Involvement of Pathways Related to Strain and Post-translational Modification of Collagen in Increased Atrial Fibrillation Vulnerability in Intensely Exercised Mice. Front Physiol 2020; 11:605671. [PMID: 33424629 PMCID: PMC7793719 DOI: 10.3389/fphys.2020.605671] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Atrial Fibrillation (AF) is the most common supraventricular tachyarrhythmia that is typically associated with cardiovascular disease (CVD) and poor cardiovascular health. Paradoxically, endurance athletes are also at risk for AF. While it is well-established that persistent AF is associated with atrial fibrosis, hypertrophy and inflammation, intensely exercised mice showed similar adverse atrial changes and increased AF vulnerability, which required tumor necrosis factor (TNF) signaling, even though ventricular structure and function improved. To identify some of the molecular factors underlying the chamber-specific and TNF-dependent atrial changes induced by exercise, we performed transcriptome analyses of hearts from wild-type and TNF-knockout mice following exercise for 2 days, 2 or 6 weeks of exercise. Consistent with the central role of atrial stretch arising from elevated venous pressure in AF promotion, all 3 time points were associated with differential regulation of genes in atria linked to mechanosensing (focal adhesion kinase, integrins and cell-cell communications), extracellular matrix (ECM) and TNF pathways, with TNF appearing to play a permissive, rather than causal, role in gene changes. Importantly, mechanosensing/ECM genes were only enriched, along with tubulin- and hypertrophy-related genes after 2 days of exercise while being downregulated at 2 and 6 weeks, suggesting that early reactive strain-dependent remodeling with exercise yields to compensatory adjustments. Moreover, at the later time points, there was also downregulation of both collagen genes and genes involved in collagen turnover, a pattern mirroring aging-related fibrosis. By comparison, twofold fewer genes were differentially regulated in ventricles vs. atria, independently of TNF. Our findings reveal that exercise promotes TNF-dependent atrial transcriptome remodeling of ECM/mechanosensing pathways, consistent with increased preload and atrial stretch seen with exercise. We propose that similar preload-dependent mechanisms are responsible for atrial changes and AF in both CVD patients and athletes.
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Affiliation(s)
- Yena Oh
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Sibao Yang
- Department of Biology, York University, Toronto, ON, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Xueyan Liu
- Department of Biology, York University, Toronto, ON, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Sayantan Jana
- Department of Physiology, Cardiovascular Research Center, University of Alberta, Edmonton, AB, Canada
| | | | - Xiaodong Gao
- Department of Biology, York University, Toronto, ON, Canada
| | - Ryan Debi
- Department of Biology, York University, Toronto, ON, Canada
| | - Dae-Kyum Kim
- Donnelly Centre, University of Toronto, Toronto, ON, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada
| | - Kyoung-Han Kim
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Ping Yang
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Zamaneh Kassiri
- Department of Physiology, Cardiovascular Research Center, University of Alberta, Edmonton, AB, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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15
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Kim YM, Lakin R, Zhang H, Liu J, Sachedina A, Singh M, Wilson E, Perez M, Verma S, Quertermous T, Olgin J, Backx PH, Ashley EA. Apelin increases atrial conduction velocity, refractoriness, and prevents inducibility of atrial fibrillation. JCI Insight 2020; 5:126525. [PMID: 32879139 PMCID: PMC7526452 DOI: 10.1172/jci.insight.126525] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/22/2020] [Indexed: 11/17/2022] Open
Abstract
Previous studies have shown an association between elevated atrial NADPH-dependent oxidative stress and decreased plasma apelin in patients with atrial fibrillation (AF), though the basis for this relationship is unclear. In the current study, RT-PCR and immunofluorescence studies of human right atrial appendages (RAAs) showed expression of the apelin receptor, APJ, and reduced apelin content in the atria, but not in plasma, of patients with AF versus normal sinus rhythm. Disruption of the apelin gene in mice increased (2.4-fold) NADPH-stimulated superoxide levels and slowed atrial conduction velocities in optical mapping of a Langendorff-perfused isolated heart model, suggesting that apelin levels may influence AF vulnerability. Indeed, in mice with increased AF vulnerability (induced by chronic intense exercise), apelin administration reduced the incidence and duration of induced atrial arrhythmias in association with prolonged atrial refractory periods. Moreover, apelin decreased AF induction in isolated atria from exercised mice while accelerating conduction velocity and increasing action potential durations. At the cellular level, these changes were associated with increased atrial cardiomyocyte sodium currents. These findings support the conclusion that reduced atrial apelin is maladaptive in fibrillating human atrial myocardium and that increasing apelin bioavailability may be a worthwhile therapeutic strategy for treating and preventing AF.
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Affiliation(s)
- Young M Kim
- Division of Cardiovascular Medicine, Stanford Medicine, Stanford, California, USA
| | - Robert Lakin
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Hao Zhang
- Division of Cardiovascular Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Jack Liu
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Ayaaz Sachedina
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Maneesh Singh
- Division of Cardiovascular Medicine, Stanford Medicine, Stanford, California, USA
| | - Emily Wilson
- Division of Cardiovascular Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Marco Perez
- Division of Cardiovascular Medicine, Stanford Medicine, Stanford, California, USA
| | - Subodh Verma
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Thomas Quertermous
- Division of Cardiovascular Medicine, Stanford Medicine, Stanford, California, USA
| | - Jeffrey Olgin
- Division of Cardiovascular Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Peter H Backx
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Euan A Ashley
- Division of Cardiovascular Medicine, Stanford Medicine, Stanford, California, USA
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16
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Wang Y, Liu L, Lakin R, Polidovitch N, Liu G, Yang H, Yu M, Yan M, Zhao D, Backx PH, Sun H, He Y, Yang P. Revisiting right anterior oblique projections for the triangle of Koch: implications from computed tomography. BMC Cardiovasc Disord 2020; 20:383. [PMID: 32838758 PMCID: PMC7446209 DOI: 10.1186/s12872-020-01632-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 07/20/2020] [Indexed: 11/22/2022] Open
Abstract
Background Variability in the anatomy and orientation of the triangle of Koch (TK) complicates ablation procedures involving the atrioventricular (AV) node. We used CT angiography (CTA) to assess the anatomical TK orientation, the CS ostium direction, and the relationship between the two, and we validated an individualized CS-guided projection during ablation procedures. Methods In 104 patients without structural heart disease undergoing computed tomography (CT) angiography, TK orientations were determined in relation to the coronary sinus ostium (CSo) as well as two standard right anterior oblique (RAO) projection angles (30o and 45o) commonly used in ablation procedures. Results A CS-guided RAO projection (RAOCS) was shown to best track the orientation of the TK compared to RAO30° and 45°, with TK orientation strongly correlating with the CSo direction (r = 0.86, P < 0.001). In addition, the mean relative difference between the angle of the CSo and TK orientation was 5.54 ± 0.48°, consistent with a reduction in the degree of image shortening compared to traditional RAOs. Moreover, in vivo validation following ablation revealed that using a CS-guided projection limited the degree of on-screen image shortening compared to both the RAO30° and 45° in 25 patients with catheter ablation procedures. Conclusion In hearts with a normal structure, the CSo direction offers a reliable predictor of the TK orientation which can be used to guide the projection of the TK during ablation procedures.
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Affiliation(s)
- Yanjing Wang
- Radiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai street, Changchun, Jilin Province, 130033, China
| | - Lin Liu
- Radiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai street, Changchun, Jilin Province, 130033, China
| | - Robert Lakin
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, Canada
| | - Nazari Polidovitch
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, Canada
| | - Guohui Liu
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
| | - Hongliang Yang
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
| | - Ming Yu
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
| | - Mingzhou Yan
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
| | - Dong Zhao
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
| | - Peter H Backx
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, Canada
| | - Huan Sun
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China. .,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China. .,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China.
| | - Yuquan He
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China. .,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China. .,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China.
| | - Ping Yang
- Cardiology Department, China-Japan Union Hospital of Jilin University, 126 Xiantai Street, Changchun, Jilin Province, 130033, China.,Jilin Provincial Precision Medicine Key Laboratory for Cardiovascular Genetic Diagnosis, Changchun, Jilin Province, 130033, China.,Jilin Provincial Cardiovascular Research Institute, Changchun, 130033, China
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17
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Li X, Zheng S, Tan W, Chen H, Li X, Wu J, Luo T, Ren X, Pyle WG, Wang L, Backx PH, Huang R, Yang FH. Slit2 Protects Hearts Against Ischemia-Reperfusion Injury by Inhibiting Inflammatory Responses and Maintaining Myofilament Contractile Properties. Front Physiol 2020; 11:228. [PMID: 32292352 PMCID: PMC7135862 DOI: 10.3389/fphys.2020.00228] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 02/27/2020] [Indexed: 12/12/2022] Open
Abstract
Background The secreted glycoprotein Slit2, previously known as an axon guidance cue, has recently been found to protect tissues in pathological conditions; however, it is unknown whether Slit2 functions in cardiac ischemia-reperfusion (IR) injury. Methods Langendorff-perfused isolated hearts from Slit2-overexpressing (Slit2-Tg) mice and C57BL/6J mice (background strain) were subjected to 20 min of global ischemia followed by 40 min of reperfusion. We compared Slit2-Tg with C57BL/6J mice in terms of left ventricular function and infarct size of post-IR hearts along with tissue histological and biochemical assessments (mRNA and protein expression, phosphorylation status, and myofilament contractile properties). Results Slit2 played cardioprotective roles in maintaining contractile function and reducing infarct size in post-IR hearts. IR increased the expression of the Slit2 receptor Robo4 and the membrane receptor Slamf7, but these increases were suppressed by Slit2 overexpression post IR. This suppression was associated with inhibition of the nuclear translocation of NFκB p65 and reductions in IL-1β and IL-18 release into perfusates. Furthermore, Slit2 overexpression attenuated the increases in myofilament-associated PKCs and phosphorylation of cTnI at Ser43 in the post-IR myocardium. The myofilament calcium sensitivity and actomyosin MgATPase activity were preserved in the post-IR Slit2 myocardium. Conclusion Our work demonstrates that Slit2 inhibits inflammatory responses and maintains myofilament contractile properties, thus contributing, at least in part, to the prevention of structural and functional damage during IR.
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Affiliation(s)
- Xiang Li
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Shuang Zheng
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China.,School of Basic Medicine, Vascular Biology Institute, Guangdong Pharmaceutical University, Guanghzou, China
| | - Weijiang Tan
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Hongqi Chen
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xiaohui Li
- Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Ting Luo
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xuecong Ren
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - W Glen Pyle
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Lijing Wang
- School of Basic Medicine, Vascular Biology Institute, Guangdong Pharmaceutical University, Guanghzou, China
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
| | - Ren Huang
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Feng Hua Yang
- Guangdong Province Key Laboratory of Laboratory Animals, Cardiovascular Model Research Center, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China.,Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
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18
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Wu J, You J, Wang X, Wang S, Huang J, Xie Q, Gong B, Ding Z, Ye Y, Wang C, Kang L, Xu R, Li Y, Chen R, Sun A, Yang X, Jiang H, Yang F, Backx PH, Ge J, Zou Y. Left ventricular response in the transition from hypertrophy to failure recapitulates distinct roles of Akt, β-arrestin-2, and CaMKII in mice with aortic regurgitation. Ann Transl Med 2020; 8:219. [PMID: 32309366 PMCID: PMC7154424 DOI: 10.21037/atm.2020.01.51] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background Although aortic regurgitation (AR) is a clinically important condition that is becoming increasingly common, few relevant murine models and mechanistic studies exist for this condition. In this study, we attempted to delineate the pathological and molecular changes and address the roles of some potentially relevant molecules in an animal model of surgically induced AR. Methods AR was induced by puncturing the aortic valve leaflets in C57BL/6J mice under echocardiographic guidance. Results As early as 1 week following AR, the left ventricles (LV) displayed marked impairments in diastolic function and coronary flow reserve (CFR), as well as cardiac hypertrophy and chamber dilatation at both end-systole and end-diastole. LV free wall thickening and cardiomyocyte hypertrophy in LV were observed 2 weeks following of AR while a decline in ejection fraction was not seen until after 4 weeks. Nppa (natriuretic peptide A) and Nppb (natriuretic peptide B) increased over time, in conjunction with prominent Akt activation as well as slight CaMKII (Ca2+/calmodulin-dependent protein kinase II) activation and biphasic changes in β-arrestin-2 expression. Treatment of AR mice with Akt inhibition exacerbated the eccentric hypertrophy, while neither inhibition of CaMKII nor β-arrestin-2 overexpression influenced the response to AR. Conclusions Our structural, functional, molecular and therapeutic analyses reveal that Akt, but not CaMKII or β-arrestin-2, plays a regulatory role in the development of LV remodeling after AR in Mice. These results may shed important light on therapeutic targets for volume overloaded cardiomyopathy.
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Affiliation(s)
- Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Jieyun You
- Department of Cardiovascular Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Xiaoyan Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Shijun Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Jiayuan Huang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Qihai Xie
- Department of Cardiology, Shanghai Jiading District Central Hospital, Shanghai 201800, China
| | - Baoyong Gong
- Guangdong Laboratory Animal Monitoring Institute, Guangzhou 510663, China
| | - Zhiwen Ding
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yong Ye
- Department of Cardiovascular Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Cong Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Le Kang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Ran Xu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yang Li
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Ruizhen Chen
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Aijun Sun
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Xiangdong Yang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Hong Jiang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Fenghua Yang
- Guangdong Laboratory Animal Monitoring Institute, Guangzhou 510663, China
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Division of Cardiology, Peter Munk Heart Centre, University Health Network, Toronto, ON, Canada
| | - Junbo Ge
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
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19
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Zhao Y, Rafatian N, Wang EY, Feric NT, Lai BFL, Knee-Walden EJ, Backx PH, Radisic M. Engineering microenvironment for human cardiac tissue assembly in heart-on-a-chip platform. Matrix Biol 2020; 85-86:189-204. [PMID: 30981898 PMCID: PMC6788963 DOI: 10.1016/j.matbio.2019.04.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/19/2022]
Abstract
Organ-on-a-chip systems have the potential to revolutionize drug screening and disease modeling through the use of human stem cell-derived cardiomyocytes. The predictive power of these tissue models critically depends on the functional assembly and maturation of human cells that are used as building blocks for organ-on-a-chip systems. To resemble a more adult-like phenotype on these heart-on-a-chip systems, the surrounding micro-environment of individual cardiomyocyte needs to be controlled. Herein, we investigated the impact of four microenvironmental cues: cell seeding density, types and percentages of non-myocyte populations, the types of hydrogels used for tissue inoculation and the electrical conditioning regimes on the structural and functional assembly of human pluripotent stem cell-derived cardiac tissues. Utilizing a novel, plastic and open-access heart-on-a-chip system that is capable of continuous non-invasive monitoring of tissue contractions, we were able to study how different micro-environmental cues affect the assembly of the cardiomyocytes into a functional cardiac tissue. We have defined conditions that resulted in tissues exhibiting hallmarks of the mature human myocardium, such as positive force-frequency relationship and post-rest potentiation.
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Affiliation(s)
- Yimu Zhao
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5; Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network, Toronto, Ontario M5G 2N2, Canada
| | - Erika Y Wang
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Nicole T Feric
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; TARA Biosystems, Inc., New York, NY 10016, USA
| | - Benjamin F L Lai
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Ericka J Knee-Walden
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Peter H Backx
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network, Toronto, Ontario M5G 2N2, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada; Toronto General Research Institute, Toronto, Ontario M5G 2C4; Canada
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5; Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada; Toronto General Research Institute, Toronto, Ontario M5G 2C4; Canada.
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20
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Lidington D, Fares JC, Uhl FE, Dinh DD, Kroetsch JT, Sauvé M, Malik FA, Matthes F, Vanherle L, Adel A, Momen A, Zhang H, Aschar-Sobbi R, Foltz WD, Wan H, Sumiyoshi M, Macdonald RL, Husain M, Backx PH, Heximer SP, Meissner A, Bolz SS. CFTR Therapeutics Normalize Cerebral Perfusion Deficits in Mouse Models of Heart Failure and Subarachnoid Hemorrhage. JACC Basic Transl Sci 2019; 4:940-958. [PMID: 31909302 PMCID: PMC6939007 DOI: 10.1016/j.jacbts.2019.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/01/2023]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is a significant modulator of cerebrovascular reactivity; the loss of CFTR function enhances myogenic vasoconstriction. Heart failure and subarachnoid hemorrhage downregulate cerebrovascular CFTR protein expression; this leads to enhanced cerebral artery vasoconstriction, reduced cerebral perfusion, neuronal injury, and ultimately, neurologic deficits. CFTR therapeutics that maintain CFTR expression normalize the perfusion deficits, reduce neuronal injury, and improve neurologic function in these pathological settings.
Heart failure (HF) and subarachnoid hemorrhage (SAH) chronically reduce cerebral perfusion, which negatively affects clinical outcome. This work demonstrates a strong relationship between cerebral artery cystic fibrosis transmembrane conductance regulator (CFTR) expression and altered cerebrovascular reactivity in HF and SAH. In HF and SAH, CFTR corrector compounds (C18 or lumacaftor) normalize pathological alterations in cerebral artery CFTR expression, vascular reactivity, and cerebral perfusion, without affecting systemic hemodynamic parameters. This normalization correlates with reduced neuronal injury. Therefore, CFTR therapeutics have emerged as valuable clinical tools to manage cerebrovascular dysfunction, impaired cerebral perfusion, and neuronal injury.
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Key Words
- CBF, cerebral blood flow
- CFTR, cystic fibrosis transmembrane conductance regulator
- HF, heart failure
- MAP, mean arterial pressure
- MOPS, 3-morpholinopropanesulfonic acid
- MRI, magnetic resonance imaging
- NIH, National Institutes of Health
- PCA, posterior cerebral artery
- S1P, sphingosine-1-phosphate
- SAH, subarachnoid hemorrhage
- TNF, tumor necrosis factor
- TPR, total peripheral resistance
- cognitive impairment
- corrector compounds
- cystic fibrosis transmembrane conductance regulator (CFTR)
- myogenic vasoconstriction
- sphingosine-1-phosphate
- tumor necrosis factor
- vascular smooth muscle cells
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Affiliation(s)
- Darcy Lidington
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | - Jessica C Fares
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | - Franziska E Uhl
- Wallenberg Center for Molecular Medicine and Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Danny D Dinh
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | - Jeffrey T Kroetsch
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | - Meghan Sauvé
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | - Firhan A Malik
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Frank Matthes
- Wallenberg Center for Molecular Medicine and Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Lotte Vanherle
- Wallenberg Center for Molecular Medicine and Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Arman Adel
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Abdul Momen
- Division of Cell & Molecular Biology, Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Hangjun Zhang
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada
| | | | - Warren D Foltz
- STTARR Innovation Centre, Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Hoyee Wan
- Labatt Family Centre of Excellence in Brain Injury and Trauma Research, Keenan Research Centre for Biomedical Research and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Division of Neurosurgery, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Sunnybrook Research Institute, Physical Sciences Platform and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Manabu Sumiyoshi
- Division of Neurosurgery, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.,Institute of Health Biosciences, Department of Neurosurgery, University of Tokushima Graduate School, Tokushima, Japan
| | - R Loch Macdonald
- Labatt Family Centre of Excellence in Brain Injury and Trauma Research, Keenan Research Centre for Biomedical Research and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Division of Neurosurgery, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Mansoor Husain
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Division of Cell & Molecular Biology, Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Peter H Backx
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada.,Department of Biology, York University, Toronto, Ontario, Canada
| | - Scott P Heximer
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, Ontario, Canada
| | - Anja Meissner
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Wallenberg Center for Molecular Medicine and Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Steffen-Sebastian Bolz
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Toronto Centre for Microvascular Medicine at The Ted Rogers Centre for Heart Research Translational Biology and Engineering Program, University of Toronto, Ontario, Canada.,Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, Ontario, Canada
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21
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Wang E, Rafatian N, Zhao Y, Lee A, Lai BFL, Lu RX, Jekic D, Davenport Huyer L, Knee-Walden EJ, Bhattacharya S, Backx PH, Radisic M. Biowire Model of Interstitial and Focal Cardiac Fibrosis. ACS Cent Sci 2019; 5:1146-1158. [PMID: 31403068 PMCID: PMC6661857 DOI: 10.1021/acscentsci.9b00052] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Indexed: 05/07/2023]
Abstract
Myocardial fibrosis is a severe global health problem due to its prevalence in all forms of cardiac diseases and direct role in causing heart failure. The discovery of efficient antifibrotic compounds has been hampered due to the lack of a physiologically relevant disease model. Herein, we present a disease model of human myocardial fibrosis and use it to establish a compound screening system. In the Biowire II platform, cardiac tissues are suspended between a pair of poly(octamethylene maleate (anhydride) citrate) (POMaC) wires. Noninvasive functional readouts are realized on the basis of the deflection of the intrinsically fluorescent polymer. The disease model is constructed to recapitulate contractile, biomechanical, and electrophysiological complexities of fibrotic myocardium. Additionally, we constructed a heteropolar integrated model with fibrotic and healthy cardiac tissues coupled together. The integrated model captures the regional heterogeneity of scar lesion, border zone, and adjacent healthy myocardium. Finally, we demonstrate the utility of the system for the evaluation of antifibrotic compounds. The high-fidelity in vitro model system combined with convenient functional readouts could potentially facilitate the development of precision medicine strategies for cardiac fibrosis modeling and establish a pipeline for preclinical compound screening.
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Affiliation(s)
- Erika
Yan Wang
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Naimeh Rafatian
- Department
of Physiology, Faculty of Medicine, University
of Toronto, Toronto, Ontario M5S 1A8, Canada
- Toronto
General Research Institute, Toronto, Ontario M5G 2C4, Canada
| | - Yimu Zhao
- Department
of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Angela Lee
- RDM
Division of Cardiovascular Medicine and Wellcome Trust Centre for
Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Benjamin Fook Lun Lai
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Rick Xingze Lu
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Danica Jekic
- McGill University, Montreal, Quebec H3A 2K6, Canada
| | - Locke Davenport Huyer
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department
of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Ericka J. Knee-Walden
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Shoumo Bhattacharya
- RDM
Division of Cardiovascular Medicine and Wellcome Trust Centre for
Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Peter H. Backx
- Department
of Physiology, Faculty of Medicine, University
of Toronto, Toronto, Ontario M5S 1A8, Canada
- Toronto
General Research Institute, Toronto, Ontario M5G 2C4, Canada
- Department
of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | - Milica Radisic
- Institute
of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Toronto
General Research Institute, Toronto, Ontario M5G 2C4, Canada
- Department
of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
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22
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Polidovitch N, Yang S, Sun H, Lakin R, Ahmad F, Gao X, Turnbull PC, Chiarello C, Perry CG, Manganiello V, Yang P, Backx PH. Phosphodiesterase type 3A (PDE3A), but not type 3B (PDE3B), contributes to the adverse cardiac remodeling induced by pressure overload. J Mol Cell Cardiol 2019; 132:60-70. [DOI: 10.1016/j.yjmcc.2019.04.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/16/2019] [Accepted: 04/28/2019] [Indexed: 01/11/2023]
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23
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Lakin R, Polidovitch N, Yang S, Guzman C, Gao X, Wauchop M, Burns J, Izaddoustdar F, Backx PH. Inhibition of soluble TNFα prevents adverse atrial remodeling and atrial arrhythmia susceptibility induced in mice by endurance exercise. J Mol Cell Cardiol 2019; 129:165-173. [DOI: 10.1016/j.yjmcc.2019.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/17/2018] [Accepted: 01/15/2019] [Indexed: 10/27/2022]
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24
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Hughes MC, Ramos SV, Turnbull PC, Edgett BA, Huber JS, Polidovitch N, Schlattner U, Backx PH, Simpson JA, Perry CGR. Impairments in left ventricular mitochondrial bioenergetics precede overt cardiac dysfunction and remodelling in Duchenne muscular dystrophy. J Physiol 2019; 598:1377-1392. [PMID: 30674086 DOI: 10.1113/jp277306] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 01/22/2019] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Ninety-eight per cent of patients with Duchenne muscular dystrophy (DMD) develop cardiomyopathy, with 40% developing heart failure. While increased propensity for mitochondrial induction of cell death has been observed in left ventricle, it remains unknown whether this is linked to impaired mitochondrial respiratory control and elevated H2 O2 emission prior to the onset of cardiomyopathy. Classic mouse models of DMD demonstrate hyper-regeneration in skeletal muscle which may mask mitochondrial abnormalities. Using a model with less regenerative capacity that is more akin to DMD patients, we observed elevated left ventricular mitochondrial H2 O2 and impaired oxidative phosphorylation in the absence of cardiac remodelling or overt cardiac dysfunction at 4 weeks. These impairments were associated with dysfunctions at complex I, governance by ADP and creatine-dependent phosphate shuttling, which results in a less efficient response to energy demands. Mitochondria may be a therapeutic target for the treatment of cardiomyopathy in DMD. ABSTRACT In Duchenne muscular dystrophy (DMD), mitochondrial dysfunction is predicted as a response to numerous cellular stressors, yet the contribution of mitochondria to the onset of cardiomyopathy remains unknown. To resolve this uncertainty, we designed in vitro assessments of mitochondrial bioenergetics to model mitochondrial control parameters that influence cardiac function. Both left ventricular mitochondrial responsiveness to the central bioenergetic controller ADP and the ability of creatine to facilitate mitochondrial-cytoplasmic phosphate shuttling were assessed. These measurements were performed in D2.B10-DMDmdx /2J mice - a model that demonstrates skeletal muscle atrophy and weakness due to limited regenerative capacities and cardiomyopathy more akin to people with DMD than classic models. At 4 weeks of age, there was no evidence of cardiac remodelling or cardiac dysfunction despite impairments in ADP-stimulated respiration and ADP attenuation of H2 O2 emission. These impairments were seen at both submaximal and maximal ADP concentrations despite no reductions in mitochondrial content markers. The ability of creatine to enhance ADP's control of mitochondrial bioenergetics was also impaired, suggesting an impairment in mitochondrial creatine kinase-dependent phosphate shuttling. Susceptibly to permeability transition pore opening and the subsequent activation of cell death pathways remained unchanged. Mitochondrial H2 O2 emission was elevated despite no change in markers of irreversible oxidative damage, suggesting alternative redox signalling mechanisms should be explored. These findings demonstrate that selective mitochondrial dysfunction precedes the onset of overt cardiomyopathy in D2.mdx mice, suggesting that improving mitochondrial bioenergetics by restoring ADP, creatine-dependent phosphate shuttling and complex I should be considered for treating DMD patients.
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Affiliation(s)
- Meghan C Hughes
- School of Kinesiology and Health Science and the Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Sofhia V Ramos
- School of Kinesiology and Health Science and the Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Patrick C Turnbull
- School of Kinesiology and Health Science and the Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Brittany A Edgett
- Department of Human Health and Nutritional Sciences and Cardiovascular Research Group, University of Guelph, Guelph, ON, Canada.,Department of Pharmacology, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada.,IMPART Team Canada Investigator Network, Saint John, New Brunswick, Canada
| | - Jason S Huber
- Department of Human Health and Nutritional Sciences and Cardiovascular Research Group, University of Guelph, Guelph, ON, Canada
| | - Nazari Polidovitch
- Department of Biology and the Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Uwe Schlattner
- Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), University Grenoble Alpes, Grenoble, France
| | - Peter H Backx
- Department of Biology and the Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences and Cardiovascular Research Group, University of Guelph, Guelph, ON, Canada.,IMPART Team Canada Investigator Network, Saint John, New Brunswick, Canada
| | - Christopher G R Perry
- School of Kinesiology and Health Science and the Muscle Health Research Centre, York University, Toronto, ON, Canada
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25
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Zhao Y, Rafatian N, Feric NT, Cox BJ, Aschar-Sobbi R, Wang EY, Aggarwal P, Zhang B, Conant G, Ronaldson-Bouchard K, Pahnke A, Protze S, Lee JH, Davenport Huyer L, Jekic D, Wickeler A, Naguib HE, Keller GM, Vunjak-Novakovic G, Broeckel U, Backx PH, Radisic M. A Platform for Generation of Chamber-Specific Cardiac Tissues and Disease Modeling. Cell 2019; 176:913-927.e18. [PMID: 30686581 PMCID: PMC6456036 DOI: 10.1016/j.cell.2018.11.042] [Citation(s) in RCA: 330] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/19/2018] [Accepted: 11/28/2018] [Indexed: 12/12/2022]
Abstract
Tissue engineering using cardiomyocytes derived from human pluripotent stem cells holds a promise to revolutionize drug discovery, but only if limitations related to cardiac chamber specification and platform versatility can be overcome. We describe here a scalable tissue-cultivation platform that is cell source agnostic and enables drug testing under electrical pacing. The plastic platform enabled on-line noninvasive recording of passive tension, active force, contractile dynamics, and Ca2+ transients, as well as endpoint assessments of action potentials and conduction velocity. By combining directed cell differentiation with electrical field conditioning, we engineered electrophysiologically distinct atrial and ventricular tissues with chamber-specific drug responses and gene expression. We report, for the first time, engineering of heteropolar cardiac tissues containing distinct atrial and ventricular ends, and we demonstrate their spatially confined responses to serotonin and ranolazine. Uniquely, electrical conditioning for up to 8 months enabled modeling of polygenic left ventricular hypertrophy starting from patient cells.
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Affiliation(s)
- Yimu Zhao
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada
| | - Nicole T Feric
- TARA Biosystems, Inc., New York, NY 10016, USA; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Brian J Cox
- Department of Physiology, Faculty of Medicine; University of Toronto; Toronto; Ontario, M5S 1A8, Canada; Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Roozbeh Aschar-Sobbi
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada; TARA Biosystems, Inc., New York, NY 10016, USA
| | - Erika Yan Wang
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Praful Aggarwal
- Section of Genomic Pediatrics, Department of Pediatrics and Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Boyang Zhang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Genevieve Conant
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Kacey Ronaldson-Bouchard
- TARA Biosystems, Inc., New York, NY 10016, USA; Department of Biomedical Engineering and Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Aric Pahnke
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Stephanie Protze
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Jee Hoon Lee
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada; BlueRock Therapeutics, MaRS Discovery District, Toronto, ON M5G 1L7, Canada
| | - Locke Davenport Huyer
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Danica Jekic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Department of Anatomy and Cell Biology, Faculty of Science, McGill University, Montreal, QC H3A 2K6, Canada
| | - Anastasia Wickeler
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
| | - Hani E Naguib
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
| | - Gordon M Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, ON M5G 1L7, Canada
| | - Gordana Vunjak-Novakovic
- Department of Biomedical Engineering and Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Ulrich Broeckel
- Section of Genomic Pediatrics, Department of Pediatrics and Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Peter H Backx
- Division of Cardiology and Peter Munk Cardiac Center, University of Health Network; Toronto, ON M5G 2N2, Canada; Department of Physiology, Faculty of Medicine; University of Toronto; Toronto; Ontario, M5S 1A8, Canada; Department of Biology; York University, Toronto, ON M3J 1P3, Canada; Toronto General Hospital Research Institute, Toronto, ON M5G 2C4, Canada.
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Toronto General Hospital Research Institute, Toronto, ON M5G 2C4, Canada.
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26
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Lakin R, Guzman C, Izaddoustdar F, Polidovitch N, Goodman JM, Backx PH. Changes in Heart Rate and Its Regulation by the Autonomic Nervous System Do Not Differ Between Forced and Voluntary Exercise in Mice. Front Physiol 2018; 9:841. [PMID: 30061838 PMCID: PMC6055008 DOI: 10.3389/fphys.2018.00841] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/14/2018] [Indexed: 12/20/2022] Open
Abstract
Most exercise studies in mice have relied on forced training which can introduce psychological stress. Consequently, the utility of mouse models for understanding exercise-mediated effects in humans, particularly autonomic nervous system (ANS) remodeling, have been challenged. We compared the effects of voluntary free-wheel running vs. non-voluntary swimming on heart function in mice with a focus on the regulation of heart rate (HR) by the ANS. Under conditions where the total excess O2 consumption associated with exercise was comparable, the two exercise models led to similar improvements in ventricular function as well as comparable reductions in HR and its control by parasympathetic nervous activity (PNA) and sympathetic nervous activity (SNA), compared to sedentary mice. Both exercise models also increased HR variability (HRV) by similar amounts, independent of HR reductions. In all mice, HRV depended primarily on PNA, with SNA weakly affecting HRV at low frequencies. The differences in both HR and HRV between exercised vs. sedentary mice were eliminated by autonomic blockade, consistent with the similar intrinsic beating rates observed in atria isolated from exercised vs. sedentary mice. In conclusion, both forced and voluntary exercise induce comparable ventricular physiological remodeling as well as HR reductions and HR-independent enhancements of HRV which were both primarily dependent on increased PNA. New and noteworthy -No previous mouse studies have compared the effects of forced and voluntary exercise on the heart function and its modulation by the autonomic nervous system (ANS).-Both voluntary free-wheel running and forced swimming induced similar improvements in ventricular contractile function, reductions in heart rate (HR) and enhancements of HR variability (HRV).-HR regulation in exercised mice was linked to increased parasympathetic nerve activity and reduced sympathetic nerve activity.- HRV was independent of HR and depended primarily on PNA in both exercised and sedentary mice.- Complete cardiac autonomic blockade eliminated differences in both HR and HRV between exercised and sedentary mice.
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Affiliation(s)
- Robert Lakin
- Department of Exercise Sciences, University of Toronto, Toronto, ON, Canada.,Division of Cardiology, Mount Sinai Hospital, University Health Network, Toronto, ON, Canada
| | - Camilo Guzman
- Department of Biology, York University, Toronto, ON, Canada
| | - Farzad Izaddoustdar
- Division of Cardiology, Mount Sinai Hospital, University Health Network, Toronto, ON, Canada
| | - Nazari Polidovitch
- Division of Cardiology, Mount Sinai Hospital, University Health Network, Toronto, ON, Canada.,Department of Biology, York University, Toronto, ON, Canada
| | - Jack M Goodman
- Department of Exercise Sciences, University of Toronto, Toronto, ON, Canada.,Division of Cardiology, Mount Sinai Hospital, University Health Network, Toronto, ON, Canada
| | - Peter H Backx
- Division of Cardiology, Mount Sinai Hospital, University Health Network, Toronto, ON, Canada.,Department of Biology, York University, Toronto, ON, Canada
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27
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Goodman JM, Banks L, Connelly KA, Yan AT, Backx PH, Dorian P. Excessive exercise in endurance athletes: Is atrial fibrillation a possible consequence? Appl Physiol Nutr Metab 2018; 43:973-976. [PMID: 29842800 DOI: 10.1139/apnm-2017-0764] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Moderate physical activity levels are associated with increased longevity and lower risk of atrial fibrillation (AF). However, the relative risk of lone AF is 3-5-fold higher in intensive endurance-trained athletes compared with healthy adults. There is growing concern that "excessive" endurance exercise may promote cardiac remodelling, leading to long-term adverse consequences. The pathogenesis of exercise-induced AF is thought to arise from an interplay of multiple acute and chronic factors, including atrial enlargement, pro-fibrotic tendency, high vagal tone, and genotypic profile, which collectively promote adverse atrial remodelling. Clinical management of athletes with AF, while challenging, can be achieved using various strategies that may allow continued, safe exercise. Based on the overall risk-benefit evidence, it is premature to suggest that excessive exercise is unsafe or should be curtailed. Evidence-based assessment and treatment guidelines are required to ensure optimal and safe exercise among the growing number of endurance athletes with AF.
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Affiliation(s)
- Jack M Goodman
- a Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2C9, Canada.,b Division of Cardiology, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Laura Banks
- a Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2C9, Canada
| | - Kim A Connelly
- c Division of Cardiology, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
| | - Andrew T Yan
- c Division of Cardiology, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
| | - Peter H Backx
- d Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Paul Dorian
- c Division of Cardiology, St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
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28
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Liu J, Bayer JD, Aschar-Sobbi R, Wauchop M, Spears D, Gollob M, Vigmond EJ, Tsushima R, Backx PH, Chauhan VS. Complex interactions in a novel SCN5A compound mutation associated with long QT and Brugada syndrome: Implications for Na+ channel blocking pharmacotherapy for de novo conduction disease. PLoS One 2018; 13:e0197273. [PMID: 29791480 PMCID: PMC5965851 DOI: 10.1371/journal.pone.0197273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 04/30/2018] [Indexed: 11/29/2022] Open
Abstract
Background The SCN5A mutation, P1332L, is linked to a malignant form of congenital long QT syndrome, type 3 (LQT3), and affected patients are highly responsive to the Na+ channel blocking drug, mexiletine. In contrast, A647D is an atypical SCN5A mutation causing Brugada syndrome. An asymptomatic male with both P1332L and A647D presented with varying P wave/QRS aberrancy and mild QTc prolongation which did not shorten measurably with mexiletine. Objective We characterized the biophysical properties of P1332L, A647D and wild-type (WT) Na+ channels as well as their combinations in order to understand our proband’s phenotype and to guide mexilitine therapy. Methods Na+ channel biophysics and mexilitine-binding kinetics were assessed using heterologous expression studies in CHO-K1 cells and human ventricular myocyte modeling. Results Compared to WT, P1332L channels displayed a hyperpolarizing shift in inactivation, slower inactivation and prominent late Na+ currents (INa). While A647D had no effect on the biophysical properties of INa, it reduced peak and late INa density when co-expressed with either WT or P1332L. Additionally, while P1332L channels had greater sensitivity to block by mexiletine compared to WT, this was reduced in the presence of A647D. Modelling studies revealed that mixing P1332L with A647D channels, action potential durations were shortened compared to P1332L, while peak INa was reduced compared to either A647D coexpressing with WT or WT alone. Conclusions While A647D mitigates the lethal LQT3 phenotype seen with P1332L, it also reduces mexilitine sensitivity and decreases INa density. These results explain our proband’s mild repolarization abnormality and prominent conduction defect in the atria and ventricles, but also suggest that expression of P1332L with A647D yields a novel disease phenotype for which mexiletine pharmacotherapy is no longer suitable.
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Affiliation(s)
- Jie Liu
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Jason D. Bayer
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University Foundation, Pessac, France
- University of Bordeaux, IMB, UMR 5251, Talance, France
| | | | - Marianne Wauchop
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Danna Spears
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Michael Gollob
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Edward J. Vigmond
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University Foundation, Pessac, France
- University of Bordeaux, IMB, UMR 5251, Talance, France
| | - Robert Tsushima
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Peter H. Backx
- Department of Biology, York University, Toronto, Ontario, Canada
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- * E-mail: (PB); (VC)
| | - Vijay S. Chauhan
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- * E-mail: (PB); (VC)
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29
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Lee JH, Protze SI, Laksman Z, Backx PH, Keller GM. Human Pluripotent Stem Cell-Derived Atrial and Ventricular Cardiomyocytes Develop from Distinct Mesoderm Populations. Cell Stem Cell 2018; 21:179-194.e4. [PMID: 28777944 DOI: 10.1016/j.stem.2017.07.003] [Citation(s) in RCA: 249] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 05/08/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023]
Abstract
The ability to direct the differentiation of human pluripotent stem cells (hPSCs) to the different cardiomyocyte subtypes is a prerequisite for modeling specific forms of cardiovascular disease in vitro and for developing novel therapies to treat them. Here we have investigated the development of the human atrial and ventricular lineages from hPSCs, and we show that retinoic acid signaling at the mesoderm stage of development is required for atrial specification. Analyses of early developmental stages revealed that ventricular and atrial cardiomyocytes derive from different mesoderm populations that can be distinguished based on CD235a and RALDH2 expression, respectively. Molecular and electrophysiological characterization of the derivative cardiomyocytes revealed that optimal specification of ventricular and atrial cells is dependent on induction of the appropriate mesoderm. Together these findings provide new insights into the development of the human atrial and ventricular lineages that enable the generation of highly enriched, functional cardiomyocyte populations for therapeutic applications.
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Affiliation(s)
- Jee Hoon Lee
- McEwen Centre for Regenerative Medicine and Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7 Canada
| | - Stephanie I Protze
- McEwen Centre for Regenerative Medicine and Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7, Canada.
| | - Zachary Laksman
- Department of Medicine, University of British Columbia, Vancouver, BC V6E 1M7, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada; Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, Toronto, ON M5G 2N2, Canada
| | - Gordon M Keller
- McEwen Centre for Regenerative Medicine and Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7 Canada.
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30
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Zeng Y, Du WW, Wu Y, Yang Z, Awan FM, Li X, Yang W, Zhang C, Yang Q, Yee A, Chen Y, Yang F, Sun H, Huang R, Yee AJ, Li RK, Wu Z, Backx PH, Yang BB. A Circular RNA Binds To and Activates AKT Phosphorylation and Nuclear Localization Reducing Apoptosis and Enhancing Cardiac Repair. Am J Cancer Res 2017; 7:3842-3855. [PMID: 29109781 PMCID: PMC5667408 DOI: 10.7150/thno.19764] [Citation(s) in RCA: 270] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 05/01/2017] [Indexed: 02/06/2023] Open
Abstract
As central nodes in cardiomyocyte signaling, nuclear AKT appears to play a cardio-protective role in cardiovascular disease. Here we describe a circular RNA, circ-Amotl1 that is highly expressed in neonatal human cardiac tissue, and potentiates AKT-enhanced cardiomyocyte survival. We hypothesize that circ-Amotl1 binds to PDK1 and AKT1, leading to AKT1 phosphorylation and nuclear translocation. In primary cardiomyocytes, epithelial cells, and endothelial cells, we found that forced circ-Amotl1 expression increased the nuclear fraction of pAKT. We further detected increased nuclear pAKT in circ-Amotl1-treated hearts. In vivo, circ-Amotl1 expression was also found to be protective against Doxorubicin (Dox)-induced cardiomyopathy. Putative PDK1- and AKT1-binding sites were then identified in silico. Blocking oligonucleotides could reverse the effects of exogenous circ-Amotl1. We conclude that circ-Amotl1 physically binds to both PDK1 and AKT1, facilitating the cardio-protective nuclear translocation of pAKT.
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31
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Stanley-Hasnain S, Hauck L, Grothe D, Aschar-Sobbi R, Beca S, Butany J, Backx PH, Mak TW, Billia F. p53 and Mdm2 act synergistically to maintain cardiac homeostasis and mediate cardiomyocyte cell cycle arrest through a network of microRNAs. Cell Cycle 2017; 16:1585-1600. [PMID: 28745540 PMCID: PMC5587026 DOI: 10.1080/15384101.2017.1346758] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/07/2017] [Accepted: 06/21/2017] [Indexed: 01/07/2023] Open
Abstract
Defining the roadblocks responsible for cell cycle arrest in adult cardiomyocytes lies at the core of developing cardiac regenerative therapies. p53 and Mdm2 are crucial mediators of cell cycle arrest in proliferative cell types, however, little is known about their function in regulating homeostasis and proliferation in terminally differentiated cell types, like cardiomyocytes. To explore this, we generated a cardiac-specific conditional deletion of p53 and Mdm2 (DKO) in adult mice. Herein we describe the development of a dilated cardiomyopathy, in the absence of cardiac hypertrophy. In addition, DKO hearts exhibited a significant increase in cardiomyocyte proliferation. Further evaluation showed that proliferation was mediated by a significant increase in Cdk2 and cyclin E with downregulation of p21Cip1 and p27Kip1. Comparison of miRNA expression profiles from DKO mouse hearts and controls revealed 11 miRNAs that were downregulated in the DKO hearts and enriched for mRNA targets involved in cell cycle regulation. Knockdown of these miRNAs in neonatal rat cardiomyocytes significantly increased cytokinesis with an upregulation in the expression of crucial cell cycle regulators. These results illustrate the importance of the cooperative activities of p53 and Mdm2 in a network of miRNAs that function to impose a barrier against aberrant cardiomyocyte cell cycle re-entry to maintain cardiac homeostasis.
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Affiliation(s)
- Shanna Stanley-Hasnain
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, Toronto, Ontario, Canada
| | - Ludger Hauck
- Toronto General Research Institute, Toronto, Ontario, Canada
| | - Daniela Grothe
- Toronto General Research Institute, Toronto, Ontario, Canada
| | | | - Sanja Beca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jagdish Butany
- Department of Pathology, University Health Network, Toronto, Ontario, Canada
| | - Peter H. Backx
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Biology, York University, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
| | - Tak W. Mak
- Campbell Family Cancer Research Institute, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Filio Billia
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology and Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada
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Huang J, Wu J, Wang S, You J, Ye Y, Ding Z, Yang F, Wang X, Guo J, Ma L, Yuan J, Shen Y, Yang X, Sun A, Jiang H, Bu L, Backx PH, Ge J, Zou Y. Ultrasound biomicroscopy validation of a murine model of cardiac hypertrophic preconditioning: comparison with a hemodynamic assessment. Am J Physiol Heart Circ Physiol 2017; 313:H138-H148. [PMID: 28455286 DOI: 10.1152/ajpheart.00004.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/23/2017] [Accepted: 04/06/2017] [Indexed: 01/09/2023]
Abstract
In mice, myocardial hypertrophic preconditioning (HP), which is produced by the removal of short-term transverse aortic constriction (TAC), was recently reported to render the heart resistant to hypertrophic responses induced by subsequent reconstriction (Re-TAC). However, there is no efficient noninvasive method for ensuring that the repeated aortic manipulations were successfully performed. We previously demonstrated that ultrasound biomicroscopy (UBM) is a noninvasive and effective approach for predicting TAC success. Here, we investigated the value of UBM for serial predictions of load conditions in establishing a murine HP model. C57BL/6J mice were subjected to a sham operation, TAC, or Re-TAC, and the peak flow velocity at the aortic banding site (PVb) was measured by UBM. Left ventricular end-systolic pressure (LVESP) was examined by micromanometric catheterization. The PVb was positively associated with LVESP (R2 = 0.8204, P < 0.001, for TAC at 3 days and R2 = 0.7746, P < 0.001, for Re-TAC at 4 wk). PVb and LVESP values were markedly elevated after aortic banding, became attenuated to the sham-operated level after debanding, and increased after aortic rebanding. The cardiac hypertrophic responses were examined by UBM, histology, RT-PCR, and Western blot analysis. Four weeks after the last operation, with PVb ≥ 3.5 m/s as an indicator of successful aortic constriction, Re-TAC mice showed less cardiac hypertrophy, fetal gene expression, and ERK1/2 activation than TAC mice. Therefore, we successfully established a UBM protocol for the serial assessment of aortic flow and the prediction of LVESP during repeated aortic manipulations in mice, which might be useful for noninvasive evaluations of the murine HP model.NEW & NOTEWORTHY We successfully developed an ultrasound biomicroscopy protocol for the serial assessment of aortic bandings and the relevant left ventricular pressure in a murine model of cardiac hypertrophic preconditioning. The protocol may be of great importance in the successful establishment of the hypertrophic preconditioning model for further mechanistic and pharmacological studies.
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Affiliation(s)
- Jiayuan Huang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Shijun Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Jieyun You
- Department of Cardiovascular Medicine, East Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China
| | - Yong Ye
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Zhiwen Ding
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Fenghua Yang
- Guangdong Laboratory Animal Monitoring Institute, Guangzhou, People's Republic of China
| | - Xingxu Wang
- Department of Cardiovascular Medicine, East Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China
| | - Junjie Guo
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China.,Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China
| | - Leilei Ma
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Jie Yuan
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Yunli Shen
- Department of Cardiovascular Medicine, East Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China
| | - Xiangdong Yang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Aijun Sun
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Hong Jiang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Liping Bu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Peter H Backx
- Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario; and.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Junbo Ge
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China;
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Kroetsch JT, Levy AS, Zhang H, Aschar-Sobbi R, Lidington D, Offermanns S, Nedospasov SA, Backx PH, Heximer SP, Bolz SS. Constitutive smooth muscle tumour necrosis factor regulates microvascular myogenic responsiveness and systemic blood pressure. Nat Commun 2017; 8:14805. [PMID: 28378814 PMCID: PMC5382284 DOI: 10.1038/ncomms14805] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 02/01/2017] [Indexed: 01/04/2023] Open
Abstract
Tumour necrosis factor (TNF) is a ubiquitously expressed cytokine with functions beyond the immune system. In several diseases, the induction of TNF expression in resistance artery smooth muscle cells enhances microvascular myogenic vasoconstriction and perturbs blood flow. This pathological role prompted our hypothesis that constitutively expressed TNF regulates myogenic signalling and systemic haemodynamics under non-pathological settings. Here we show that acutely deleting the TNF gene in smooth muscle cells or pharmacologically scavenging TNF with etanercept (ETN) reduces blood pressure and resistance artery myogenic responsiveness; the latter effect is conserved across five species, including humans. Changes in transmural pressure are transduced into intracellular signals by membrane-bound TNF (mTNF) that connect to a canonical myogenic signalling pathway. Our data positions mTNF 'reverse signalling' as an integral element of a microvascular mechanosensor; pathologic or therapeutic perturbations of TNF signalling, therefore, necessarily affect microvascular tone and systemic haemodynamics.
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Affiliation(s)
- Jeffrey T Kroetsch
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8.,Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, 661 University Avenue, 14th floor, Toronto, Ontario, Canada M5G 1M1
| | - Andrew S Levy
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8.,Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, 661 University Avenue, 14th floor, Toronto, Ontario, Canada M5G 1M1.,Keenan Research Centre at St. Michael's Hospital, 30 Bond Street, Toronto, Ontario, Canada M5B 1W8
| | - Hangjun Zhang
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8
| | - Roozbeh Aschar-Sobbi
- Division of Cardiology, University Health Network, R. Fraser Elliott Building, 1st Floor, 190 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Darcy Lidington
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8.,Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, 661 University Avenue, 14th floor, Toronto, Ontario, Canada M5G 1M1
| | - Stefan Offermanns
- Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany.,Centre for Molecular Medicine, University of Frankfurt, Theodor-Stern-Kai 7, Frankfurt am Main 60590, Germany
| | - Sergei A Nedospasov
- Engelhardt Institute of Molecular Biology and Lemonosov Moscow State University, 32 Vavilov Street, Moscow 119991, Russia.,German Rheumatism Research Center, a Leibniz Institute, Chariteplatz 1, Berlin 10117, Germany
| | - Peter H Backx
- Division of Cardiology, University Health Network, R. Fraser Elliott Building, 1st Floor, 190 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4.,Heart &Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, C. David Naylor Building, 6 Queens Park Cresc. West, Toronto, Ontario, Canada M5S 3H2.,Department of Biology, York University, Farquharson Building, 110 Campus Walk, Toronto, Ontario, Canada M3J 2S5
| | - Scott P Heximer
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8.,Heart &Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, C. David Naylor Building, 6 Queens Park Cresc. West, Toronto, Ontario, Canada M5S 3H2
| | - Steffen-Sebastian Bolz
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8.,Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, 661 University Avenue, 14th floor, Toronto, Ontario, Canada M5G 1M1.,Keenan Research Centre at St. Michael's Hospital, 30 Bond Street, Toronto, Ontario, Canada M5B 1W8.,Heart &Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, C. David Naylor Building, 6 Queens Park Cresc. West, Toronto, Ontario, Canada M5S 3H2
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34
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Protze SI, Liu J, Nussinovitch U, Ohana L, Backx PH, Gepstein L, Keller GM. Sinoatrial node cardiomyocytes derived from human pluripotent cells function as a biological pacemaker. Nat Biotechnol 2016; 35:56-68. [PMID: 27941801 DOI: 10.1038/nbt.3745] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 11/10/2016] [Indexed: 12/13/2022]
Abstract
The sinoatrial node (SAN) is the primary pacemaker of the heart and controls heart rate throughout life. Failure of SAN function due to congenital disease or aging results in slowing of the heart rate and inefficient blood circulation, a condition treated by implantation of an electronic pacemaker. The ability to produce pacemaker cells in vitro could lead to an alternative, biological pacemaker therapy in which the failing SAN is replaced through cell transplantation. Here we describe a transgene-independent method for the generation of SAN-like pacemaker cells (SANLPCs) from human pluripotent stem cells by stage-specific manipulation of developmental signaling pathways. SANLPCs are identified as NKX2-5- cardiomyocytes that express markers of the SAN lineage and display typical pacemaker action potentials, ion current profiles and chronotropic responses. When transplanted into the apex of rat hearts, SANLPCs are able to pace the host tissue, demonstrating their capacity to function as a biological pacemaker.
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Affiliation(s)
- Stephanie I Protze
- McEwen Centre for Regenerative Medicine and Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Ontario, Canada
| | - Jie Liu
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada
| | - Udi Nussinovitch
- The Sohnis Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Internal Medicine A, Rappaport Faculty of Medicine and Research Institute and Rambam Health Care Campus, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lily Ohana
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology and the Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada
| | - Lior Gepstein
- The Sohnis Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Cardiology, Rappaport Faculty of Medicine and Research Institute and Rambam Health Care Campus, Technion-Israel Institute of Technology, Haifa, Israel
| | - Gordon M Keller
- McEwen Centre for Regenerative Medicine and Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Ontario, Canada
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35
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Oudit GY, Backx PH. Amlodipine Therapy for Iron-Overload Cardiomyopathy: The Enduring Value of Translational Research. Can J Cardiol 2016; 32:938-40. [DOI: 10.1016/j.cjca.2015.11.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022] Open
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36
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Kim KH, Rosen A, Hussein SMI, Puviindran V, Korogyi AS, Chiarello C, Nagy A, Hui CC, Backx PH. Irx3 is required for postnatal maturation of the mouse ventricular conduction system. Sci Rep 2016; 6:19197. [PMID: 26786475 PMCID: PMC4726432 DOI: 10.1038/srep19197] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 12/07/2015] [Indexed: 12/17/2022] Open
Abstract
The ventricular conduction system (VCS) orchestrates the harmonious contraction in every heartbeat. Defects in the VCS are often associated with life-threatening arrhythmias and also promote adverse remodeling in heart disease. We have previously established that the Irx3 homeobox gene regulates rapid electrical propagation in the VCS by modulating the transcription of gap junction proteins Cx40 and Cx43. However, it is unknown whether other factors contribute to the conduction defects observed in Irx3 knockout (Irx3(-/-)) mice. In this study, we show that during the early postnatal period, Irx3(-/-) mice develop morphological defects in the VCS which are temporally dissociated from changes in gap junction expression. These morphological defects were accompanied with progressive changes in the cardiac electrocardiogram including right bundle branch block. Hypoplastic VCS was not associated with increased apoptosis of VCS cardiomyocytes but with a lack of recruitment and maturation of ventricular cardiomyocytes into the VCS. Computational analysis followed by functional verification revealed that Irx3 promotes VCS-enriched transcripts targeted by Nkx2.5 and/or Tbx5. Altogether, these results indicate that, in addition to ensuring the appropriate expression of gap junctional channels in the VCS, Irx3 is necessary for the postnatal maturation of the VCS, possibly via its interactions with Tbx5 and Nkx2.5.
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Affiliation(s)
- Kyoung-Han Kim
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Anna Rosen
- The Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, ON M5S 3E2, Canada
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Samer M. I. Hussein
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
- Centre Hospitalier Universitaire de Québec Research Center and Faculty of Medicine, Laval University, Quebec City, QC G1V 4G2, Canada
| | - Vijitha Puviindran
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Adam S. Korogyi
- The Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, ON M5S 3E2, Canada
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Carmelina Chiarello
- The Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, ON M5S 3E2, Canada
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Andras Nagy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
- Institute of Medical Science and Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario M5T 3H7, Canada
| | - Chi-chung Hui
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Peter H. Backx
- The Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, ON M5S 3E2, Canada
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Peter Munk Cardiac Centre and Division of Cardiology, University Health Network, Toronto ON
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37
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Liu J, Laksman Z, Backx PH. The electrophysiological development of cardiomyocytes. Adv Drug Deliv Rev 2016; 96:253-73. [PMID: 26788696 DOI: 10.1016/j.addr.2015.12.023] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/23/2015] [Accepted: 12/31/2015] [Indexed: 02/07/2023]
Abstract
The generation of human cardiomyocytes (CMs) from human pluripotent stem cells (hPSCs) has become an important resource for modeling human cardiac disease and for drug screening, and also holds significant potential for cardiac regeneration. Many challenges remain to be overcome however, before innovation in this field can translate into a change in the morbidity and mortality associated with heart disease. Of particular importance for the future application of this technology is an improved understanding of the electrophysiologic characteristics of CMs, so that better protocols can be developed and optimized for generating hPSC-CMs. Many different cell culture protocols are currently utilized to generate CMs from hPSCs and all appear to yield relatively “developmentally” immature CMs with highly heterogeneous electrical properties. These hPSC-CMs are characterized by spontaneous beating at highly variable rates with a broad range of depolarization-repolarization patterns, suggestive of mixed populations containing atrial, ventricular and nodal cells. Many recent studies have attempted to introduce approaches to promote maturation and to create cells with specific functional properties. In this review, we summarize the studies in which the electrical properties of CMs derived from stem cells have been examined. In order to place this information in a useful context, we also review the electrical properties of CMs as they transition from the developing embryo to the adult human heart. The signal pathways involved in the regulation of ion channel expression during development are also briefly considered.
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Panama BK, Korogyi AS, Aschar-Sobbi R, Oh Y, Gray CBB, Gang H, Brown JH, Kirshenbaum LA, Backx PH. Reductions in the Cardiac Transient Outward K+ Current Ito Caused by Chronic β-Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor κB. J Biol Chem 2016; 291:4156-65. [PMID: 26742842 DOI: 10.1074/jbc.m115.694984] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Indexed: 12/27/2022] Open
Abstract
The fast transient outward potassium current (Ito,f) plays a critical role in the electrical and contractile properties of the myocardium. Ito,f channels are formed by the co-assembly of the pore-forming α-subunits, Kv4.2 and Kv4.3, together with the accessory β-subunit KChIP2. Reductions of Ito,f are common in the diseased heart, which is also associated with enhanced stimulation of β-adrenergic receptors (β-ARs). We used cultured neonatal rat ventricular myocytes to examine how chronic β-AR stimulation decreases Ito,f. To determine which downstream pathways mediate these Ito,f changes, adenoviral infections were used to inhibit CaMKIIδc, CaMKIIδb, calcineurin, or nuclear factor κB (NF-κB). We observed that chronic β-AR stimulation with isoproterenol (ISO) for 48 h reduced Ito,f along with mRNA expression of all three of its subunits (Kv4.2, Kv4.3, and KChIP2). Inhibiting either CaMKIIδc nor CaMKIIδb did not prevent the ISO-mediated Ito,f reductions, even though CaMKIIδc and CaMKIIδb clearly regulated Ito,f and the mRNA expression of its subunits. Likewise, calcineurin inhibition did not prevent the Ito,f reductions induced by β-AR stimulation despite strongly modulating Ito,f and subunit mRNA expression. In contrast, NF-κB inhibition partly rescued the ISO-mediated Ito,f reductions in association with restoration of KChIP2 mRNA expression. Consistent with these observations, KChIP2 promoter activity was reduced by p65 as well as β-AR stimulation. In conclusion, NF-κB, and not CaMKIIδ or calcineurin, partly mediates the Ito,f reductions induced by chronic β-AR stimulation. Both mRNA and KChIP2 promoter data suggest that the ISO-induced Ito,f reductions are, in part, mediated through reduced KChIP2 transcription caused by NF-κB activation.
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Affiliation(s)
- Brian K Panama
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada, the Masonic Medical Research Laboratory, Department of Experimental Cardiology, Utica, New York 13501, and
| | - Adam S Korogyi
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | - Roozbeh Aschar-Sobbi
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | - Yena Oh
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
| | - Charles B B Gray
- the Department of Pharmacology, University of California, San Diego, California 92161
| | - Hongying Gang
- The Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R2H 2A6, Canada
| | - Joan Heller Brown
- the Department of Pharmacology, University of California, San Diego, California 92161
| | - Lorrie A Kirshenbaum
- The Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R2H 2A6, Canada
| | - Peter H Backx
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada, the Division of Cardiology, University Health Network, University of Toronto, Toronto, Ontario M5G 1L7, Canada,
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Cordeiro JM, Calloe K, Aschar-Sobbi R, Kim KH, Korogyi A, Occhipinti D, Backx PH, Panama BK. Physiological roles of the transient outward current Ito in normal and diseased hearts. Front Biosci (Schol Ed) 2016; 8:143-159. [PMID: 26709904 DOI: 10.2741/s454] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Ca(2+)-independent transient outward K(+) current (I(to)) plays a critical role in underlying phase 1 of repolarization of the cardiac action potential and, as a result, is central to modulating excitation-contraction coupling and propensity for arrhythmia. Additionally, I(to) and its molecular constituents are consistently reduced in cardiac hypertrophy and heart failure. In this review, we discuss the physiological role of I(to) as well as the molecular basis of this current in human and canine hearts, in which I(to) has been thoroughly studied. In particular, we discuss the role of Ito; in the action potential and the mechanisms by which I(to) modulates excitation-contraction coupling. We also describe the effects of mutations in the subunits constituting the Ito channel as well as the role of I(to) in the failing myocardium. Finally, we review pharmacological modulation of I(to) and discuss the evidence supporting the hypothesis that restoration of I(to) in the setting of heart failure may be therapeutically beneficial by enhancing excitation-contraction coupling and cardiac function.
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Affiliation(s)
- Jonathan M Cordeiro
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, New York, 13501 USA
| | - Kirstine Calloe
- Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Veterinary Clinical and Animal Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Denmark
| | - Roozbeh Aschar-Sobbi
- Departments of Physiology and Medicine, University Health Network, University of Toronto. 1 King\'s College Circle, Toronto, Ontario, M5S 1A8 Canada
| | - Kyoung-Han Kim
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, M5G 1X8 Canada
| | - Adam Korogyi
- Departments of Physiology and Medicine, University Health Network, University of Toronto. 1 King\'s College Circle, Toronto, Ontario, M5S 1A8 Canada
| | - Dona Occhipinti
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, New York, 13501 USA
| | - Peter H Backx
- Departments of Physiology and Medicine, University Health Network, University of Toronto. 1 King\'s College Circle, Toronto, Ontario, M5S 1A8 Canada
| | - Brian K Panama
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, New York, 13501 USA,
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40
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Abstract
Gradients of the fast transient outward K+ current (Ito,f) contribute to heterogeneity of ventricular repolarization in a number of species. Cardiac Ito,f levels and gradients change notably with heart disease. Human cardiac Ito,f appears to be encoded by the Kv4.3 pore-forming α-subunit plus the auxiliary KChIP2 β-subunit while mouse cardiac Ito,f requires Kv4.2 and Kv4.3 α-subunits plus KChIP2. Regional differences in cardiac Ito,f are associated with expression differences in Kv4.2 and KChIP2. Although Ito,f was reported to be absent in mouse ventricular cardiomyocytes lacking the Kv4.2 gene (Kv4.2-/-) when short depolarizing voltage pulses were used to activate voltage-gated K+ currents, in the present study, we showed that the use of long depolarization steps revealed a heteropodatoxin-sensitive Ito,f (at ~40% of the wild-type levels). Immunohistological studies further demonstrated membrane expression of Kv4.3 in Kv4.2-/- cardiomyocytes. Transmural Ito,f gradients across the left ventricular wall were reduced by ~3.5-fold in Kv4.2-/- heart, compared to wild-type. The Ito,f gradient in Kv4.2-/- hearts was associated with gradients in KChIP2 mRNA expression while in wild-type there was also a gradient in Kv4.2 expression. In conclusion, we found that Kv4.3-based Ito,f exists in the absence of Kv4.2, although with a reduced transmural gradient. Kv4.2-/- mice may be a useful animal model for studying Kv4.3-based Ito,f as observed in humans.
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Affiliation(s)
- Jie Liu
- The Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Kyoung-Han Kim
- The Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael J. Morales
- Department of Physiology & Biophysics, University at Buffalo, the State University of New York, Buffalo, New York, United States of America
| | - Scott P. Heximer
- The Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Chi-chung Hui
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- The Departments of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (CCH); (PHB)
| | - Peter H. Backx
- The Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- * E-mail: (CCH); (PHB)
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Dadson K, Turdi S, Hashemi S, Zhao J, Polidovitch N, Beca S, Backx PH, McDermott JC, Sweeney G. Adiponectin is required for cardiac MEF2 activation during pressure overload induced hypertrophy. J Mol Cell Cardiol 2015. [PMID: 26196305 DOI: 10.1016/j.yjmcc.2015.06.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cardiomyocyte (CM) hypertrophy and increased heart mass in response to pressure overload are associated with hyper-activation of the myocyte enhancer factor-2 (MEF2) family of transcriptional regulators, and concomitant initiation of the fetal gene program. Adiponectin, an adipokine that is reduced in individuals with obesity and diabetes, has been characterized both as a negative regulator or permissive factor in cardiac hypertrophy. We therefore sought to analyze temporal regulation of MEF2 activity in response to pressure overload (PO) and changes in adiponectin status. To address this we crossed a well characterized transgenic MEF2 "sensor" mouse (MEF2-lacZ) with adiponectin null mice (Ad-KO) to create compound MEF2 lacZ/Ad-KO mice. Initially, we established that transverse aortic banding induced PO in wild-type (WT) mice increased heart mass and CM hypertrophy from 1 to 4weeks following surgery, indicated by increased CM diameter and heart weight/tibia length ratio. This was associated with cardiac dysfunction determined by echocardiography. Hypertrophic changes and dysfunction were observed in Ad-KO mice 4weeks following surgery. MEF2 lacZ activity and endogenous ANF mRNA levels, used as indicators of hypertrophic gene activation, were both robustly increased in WT mice after MTAB but attenuated in the Ad-KO background. Furthermore, activation of the pro-hypertrophic molecule p38 was increased following MTAB surgery in WT mice, but not in Ad-KO animals, and treatment of primary isolated CM with recombinant adiponectin induced p38 phosphorylation in a time dependent manner. Adiponectin also increased MEF2 activation in primary cardiomyocytes, an effect attenuated by p38 MAPK inhibition. In conclusion, our data indicate that robust hypertrophic MEF2 activation in the heart in vivo requires a background of adiponectin signaling and that adiponectin signaling in primary isolated CM directly enhances MEF2 activity through activation of p38 MAPK. We conclude that adiponectin is required for full induction of cardiomyocyte MEF2 activation, thus contributing to the myocardial hypertrophic gene expression program in response to PO.
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Affiliation(s)
- Keith Dadson
- Department of Biology, York University, Toronto, Canada
| | - Subat Turdi
- Department of Biology, York University, Toronto, Canada
| | - Sarah Hashemi
- Department of Biology, York University, Toronto, Canada
| | | | - Nazar Polidovitch
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Sanja Beca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Peter H Backx
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Peter Munk Cardiac Centre and the Division of Cardiology, University Health Network,Toronto, Ontario, Canada
| | | | - Gary Sweeney
- Department of Biology, York University, Toronto, Canada.
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Backx PH. Complexity, confusion and controversy continue complicating the contribution of RyR2 channel phosphorylation to heart function. J Physiol 2015; 592:1911-2. [PMID: 24786150 DOI: 10.1113/jphysiol.2014.272575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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43
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Aschar-Sobbi R, Izaddoustdar F, Korogyi AS, Wang Q, Farman GP, Yang F, Yang W, Dorian D, Simpson JA, Tuomi JM, Jones DL, Nanthakumar K, Cox B, Wehrens XHT, Dorian P, Backx PH. Increased atrial arrhythmia susceptibility induced by intense endurance exercise in mice requires TNFα. Nat Commun 2015; 6:6018. [PMID: 25598495 DOI: 10.1038/ncomms7018] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/02/2014] [Indexed: 12/13/2022] Open
Abstract
Atrial fibrillation (AF) is the most common supraventricular arrhythmia that, for unknown reasons, is linked to intense endurance exercise. Our studies reveal that 6 weeks of swimming or treadmill exercise improves heart pump function and reduces heart-rates. Exercise also increases vulnerability to AF in association with inflammation, fibrosis, increased vagal tone, slowed conduction velocity, prolonged cardiomyocyte action potentials and RyR2 phosphorylation (CamKII-dependent S2814) in the atria, without corresponding alterations in the ventricles. Microarray results suggest the involvement of the inflammatory cytokine, TNFα, in exercised-induced atrial remodelling. Accordingly, exercise induces TNFα-dependent activation of both NFκB and p38MAPK, while TNFα inhibition (with etanercept), TNFα gene ablation, or p38 inhibition, prevents atrial structural remodelling and AF vulnerability in response to exercise, without affecting the beneficial physiological changes. Our results identify TNFα as a key factor in the pathology of intense exercise-induced AF.
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Affiliation(s)
- Roozbeh Aschar-Sobbi
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - Farzad Izaddoustdar
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - Adam S Korogyi
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - Qiongling Wang
- Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Gerrie P Farman
- Department of Physiology and Biophysics, Boston University, 700 Albany St, Boston, Massachusetts 02118-2526, USA
| | - FengHua Yang
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - Wallace Yang
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - David Dorian
- Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G2W1
| | - Jari M Tuomi
- Department of Physiology and Pharmacology, Western University, Medical Science Building, London, Ontario, Canada N6A5C1
| | - Douglas L Jones
- Department of Physiology and Pharmacology, Western University, Medical Science Building, London, Ontario, Canada N6A5C1
| | - Kumaraswamy Nanthakumar
- 1] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Division of Cardiology, Peter Munk Cardiac Centre, University Health Network, 200 Elizabeth St, Toronto, Ontario, Canada M5G2C4
| | - Brian Cox
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Program in Developmental and Stem Cell Biology, Hospital for Sick Children Research Institute, 555 University Ave, Toronto, Ontario, Canada M5G 1X9
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Paul Dorian
- 1] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Division of Cardiology, St Michael's Hospital, 2300 Yonge St, Toronto, Ontario, Canada M4P1E4
| | - Peter H Backx
- 1] Department of Physiology, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [2] Department of Medicine, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8 [3] Division of Cardiology, Peter Munk Cardiac Centre, University Health Network, 200 Elizabeth St, Toronto, Ontario, Canada M5G2C4 [4] Heart &Stroke Richard Lewar Centre of Excellence, University of Toronto, 1 King's College Cir., Toronto, Ontario, Canada M5S1A8
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44
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Song Z, Adam K, Backx PH, Qu Z. Subcellular Ca Channel Distribution and Ca Alternans in Atrial Myocytes. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.1444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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45
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Wang DY, Abbasi C, El-Rass S, Li JY, Dawood F, Naito K, Sharma P, Bousette N, Singh S, Backx PH, Cox B, Wen XY, Liu PP, Gramolini AO. Endoplasmic reticulum resident protein 44 (ERp44) deficiency in mice and zebrafish leads to cardiac developmental and functional defects. J Am Heart Assoc 2014; 3:e001018. [PMID: 25332179 PMCID: PMC4323785 DOI: 10.1161/jaha.114.001018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Endoplasmic reticulum (ER) resident protein 44 (ERp44) is a member of the protein disulfide isomerase family, is induced during ER stress, and may be involved in regulating Ca(2+) homeostasis. However, the role of ERp44 in cardiac development and function is unknown. The aim of this study was to investigate the role of ERp44 in cardiac development and function in mice, zebrafish, and embryonic stem cell (ESC)-derived cardiomyocytes to determine the underlying role of ERp44. METHODS AND RESULTS We generated and characterized ERp44(-/-) mice, ERp44 morphant zebrafish embryos, and ERp44(-/-) ESC-derived cardiomyocytes. Deletion of ERp44 in mouse and zebrafish caused significant embryonic lethality, abnormal heart development, altered Ca(2+) dynamics, reactive oxygen species generation, activated ER stress gene profiles, and apoptotic cell death. We also determined the cardiac phenotype in pressure overloaded, aortic-banded ERp44(+/-) mice: enhanced ER stress activation and increased mortality, as well as diastolic cardiac dysfunction with a significantly lower fractional shortening. Confocal and LacZ histochemical staining showed a significant transmural gradient for ERp44 in the adult heart, in which high expression of ERp44 was observed in the outer subepicardial region of the myocardium. CONCLUSIONS ERp44 plays a critical role in embryonic heart development and is crucial in regulating cardiac cell Ca(2+) signaling, ER stress, ROS-induced oxidative stress, and activation of the intrinsic mitochondrial apoptosis pathway.
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Affiliation(s)
- Ding-Yan Wang
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Cynthia Abbasi
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Suzan El-Rass
- Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.) Keenan Research Center for Biomedical Science and Zebrafish Center for Advanced Drug Discovery, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada (S.E.R., X.Y.W.)
| | - Jamie Yuanjun Li
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Fayez Dawood
- Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.)
| | - Kotaro Naito
- Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.)
| | - Parveen Sharma
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Nicolas Bousette
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Shalini Singh
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Peter H Backx
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.) Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.)
| | - Brian Cox
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.)
| | - Xiao-Yan Wen
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.) Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.) Keenan Research Center for Biomedical Science and Zebrafish Center for Advanced Drug Discovery, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada (S.E.R., X.Y.W.)
| | - Peter P Liu
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.) Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.)
| | - Anthony O Gramolini
- Department of Physiology, University of Toronto, Ontario, Canada (D.Y.W., C.A., J.Y.L., P.S., N.B., S.S., P.H.B., B.C., X.Y.W., P.P.L., A.O.G.) Faculty of Medicine and Institute of Medical Science, University of Toronto, Ontario, Canada (S.E.R., F.D., K.N., P.H.B., X.Y.W., P.P.L., A.O.G.)
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46
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Perrin MJ, Adler A, Green S, Al-Zoughool F, Doroshenko P, Orr N, Uppal S, Healey JS, Birnie D, Sanatani S, Gardner M, Champagne J, Simpson C, Ahmad K, van den Berg MP, Chauhan V, Backx PH, van Tintelen JP, Krahn AD, Gollob MH. Evaluation of genes encoding for the transient outward current (Ito) identifies the KCND2 gene as a cause of J-wave syndrome associated with sudden cardiac death. ACTA ACUST UNITED AC 2014; 7:782-9. [PMID: 25214526 DOI: 10.1161/circgenetics.114.000623] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND J-wave ECG patterns are associated with an increased risk of sudden arrhythmic death, and experimental evidence supports a transient outward current (I(to))-mediated mechanism of J-wave formation. This study aimed to determine the frequency of genetic mutations in genes encoding the I(to) in patients with J waves on ECG. METHODS AND RESULTS Comprehensive mutational analysis was performed on I(to)-encoding KCNA4, KCND2, and KCND3 genes, as well as the previously described J-wave-associated KCNJ8 gene, in 51 unrelated patients with ECG evidence defining a J-wave syndrome. Only patients with a resuscitated cardiac arrest or type 1 Brugada ECG pattern were included for analysis. A rare genetic mutation of the KCND2 gene, p.D612N, was identified in a single patient. Co-expression of mutant and wild-type KCND2 with KChIP2 in HEK293 cells demonstrated a gain-of-function phenotype, including an increase in peak I(to) density of 48% (P<0.05) in the heterozygous state. Using computer modeling, this increase in Ito resulted in loss of the epicardial action potential dome, predicting an increased ventricular transmural Ito gradient. The previously described KCNJ8-S422L mutation was not identified in this cohort of patients with ECG evidence of J-wave syndrome. CONCLUSIONS These findings are the first to implicate the KCND2 gene as a novel cause of J-wave syndrome associated with sudden cardiac arrest. However, genetic defects in I(to)-encoding genes seem to be an uncommon cause of sudden cardiac arrest in patients with apparent J-wave syndromes.
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Affiliation(s)
- Mark J Perrin
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Arnon Adler
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Sharon Green
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Foad Al-Zoughool
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Petro Doroshenko
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Nathan Orr
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Shaheen Uppal
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Jeff S Healey
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - David Birnie
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Shubhayan Sanatani
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Martin Gardner
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Jean Champagne
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Chris Simpson
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Kamran Ahmad
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Maarten P van den Berg
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Vijay Chauhan
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Peter H Backx
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - J Peter van Tintelen
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Andrew D Krahn
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Michael H Gollob
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.).
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Diaz RJ, Harvey K, Boloorchi A, Hossain T, Hinek A, Backx PH, Wilson GJ. Enhanced cell volume regulation: a key mechanism in local and remote ischemic preconditioning. Am J Physiol Cell Physiol 2014; 306:C1191-9. [DOI: 10.1152/ajpcell.00259.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously shown that ischemic preconditioning (IPC) protection against necrosis in whole hearts and in both fresh and cultured cardiomyocytes, as well as the improved regulatory volume decrease to hypoosmotic swelling in cardiomyocytes, is abrogated through Cl− channel blockade, pointing to a role for enhanced cell volume regulation in IPC. To further define this cardioprotective mechanism, cultured rabbit ventricular cardiomyocytes were preconditioned either by 10-min simulated ischemia (SI) followed by 10-min simulated reperfusion (SR), by 10-min exposure/10-min washout of remote IPC (rIPC) plasma dialysate (from rabbits subjected to repetitive limb ischemia), or by adenoviral transfection with the constitutively active PKC-ε gene. These interventions were done before cardiomyocytes were subjected to either 60- or 75-min SI/60-min SR to assess cell necrosis (by trypan blue staining), 30-min SI to assess ischemic cell swelling, or 30-min hypoosmotic (200 mosM) stress to assess cell volume regulation. Necrosis after SI/SR and both SI- and hypoosmotic stress-induced swelling was reduced in preconditioned cardiomyocytes compared with control cardiomyocytes (neither preconditioned nor transfected). These effects on necrosis and cell swelling were blocked by either Cl− channel blockade or dominant negative knockdown of inwardly rectifying K+ channels with adenoviruses, suggesting that Cl− and K+ movements across the sarcolemma are critical for cell volume regulation and, thereby, cell survival under hypoxic/ischemic conditions. Our results define enhanced cell volume regulation as a key common mechanism of cardioprotection by preconditioning in cardiomyocytes.
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Affiliation(s)
- Roberto J. Diaz
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Pediatric Laboratory Medicine and Pathology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kordan Harvey
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; and
| | - Azadeh Boloorchi
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; and
| | - Taneya Hossain
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Alina Hinek
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Peter H. Backx
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Gregory J. Wilson
- Division of Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Pediatric Laboratory Medicine and Pathology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; and
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Abstract
ESC-derived cardiomyocytes are excitable cells that express many of the ion channels also found in adult cardiomyocytes. The patch-clamp technique is a powerful technique to characterize both the electrophysiological properties of excitable cells as well as the underlying ion channel currents responsible for these electrophysiological properties. The technique also allows rapid and accurate screening of the pharmacological actions of agents used to modulate cardiomyocyte properties. In this chapter we illustrate the use of the whole-cell patch clamp technique by recording hERG (human ether-à-go-go-related gene) currents and action potentials in ESC-derived cardiomyocytes and also examine the effects of hERG channel blocker, dofetilide.
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Affiliation(s)
- Jie Liu
- Departments of Physiology and Medicine, University of Toronto, Medical Science Building, Rm 3247, 1 King's College Circle, Toronto, ON, Canada, M5S 1A8
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Strandberg LS, Cui X, Rath A, Liu J, Silverman ED, Liu X, Siragam V, Ackerley C, Su BB, Yan JY, Capecchi M, Biavati L, Accorroni A, Yuen W, Quattrone F, Lung K, Jaeggi ET, Backx PH, Deber CM, Hamilton RM. Congenital heart block maternal sera autoantibodies target an extracellular epitope on the α1G T-type calcium channel in human fetal hearts. PLoS One 2013; 8:e72668. [PMID: 24039792 PMCID: PMC3767782 DOI: 10.1371/journal.pone.0072668] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/17/2013] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Congenital heart block (CHB) is a transplacentally acquired autoimmune disease associated with anti-Ro/SSA and anti-La/SSB maternal autoantibodies and is characterized primarily by atrioventricular (AV) block of the fetal heart. This study aims to investigate whether the T-type calcium channel subunit α1G may be a fetal target of maternal sera autoantibodies in CHB. METHODOLOGY/PRINCIPAL FINDINGS We demonstrate differential mRNA expression of the T-type calcium channel CACNA1G (α1G gene) in the AV junction of human fetal hearts compared to the apex (18-22.6 weeks gestation). Using human fetal hearts (20-22 wks gestation), our immunoprecipitation (IP), Western blot analysis and immunofluorescence (IF) staining results, taken together, demonstrate accessibility of the α1G epitope on the surfaces of cardiomyocytes as well as reactivity of maternal serum from CHB affected pregnancies to the α1G protein. By ELISA we demonstrated maternal sera reactivity to α1G was significantly higher in CHB maternal sera compared to controls, and reactivity was epitope mapped to a peptide designated as p305 (corresponding to aa305-319 of the extracellular loop linking transmembrane segments S5-S6 in α1G repeat I). Maternal sera from CHB affected pregnancies also reacted more weakly to the homologous region (7/15 amino acids conserved) of the α1H channel. Electrophysiology experiments with single-cell patch-clamp also demonstrated effects of CHB maternal sera on T-type current in mouse sinoatrial node (SAN) cells. CONCLUSIONS/SIGNIFICANCE Taken together, these results indicate that CHB maternal sera antibodies readily target an extracellular epitope of α1G T-type calcium channels in human fetal cardiomyocytes. CHB maternal sera also show reactivity for α1H suggesting that autoantibodies can target multiple fetal targets.
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Affiliation(s)
- Linn S. Strandberg
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Xuezhi Cui
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Arianna Rath
- Division of Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jie Liu
- Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Earl D. Silverman
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Xiaoru Liu
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Vinayakumar Siragam
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Cameron Ackerley
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brenda Bin Su
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jane Yuqing Yan
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | - William Yuen
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Kalvin Lung
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Edgar T. Jaeggi
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Peter H. Backx
- Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Charles M. Deber
- Division of Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Robert M. Hamilton
- Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- * E-mail:
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50
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Lai PFH, Panama BK, Massé S, Li G, Zhang Y, Kusha M, Farid TA, Asta J, Backx PH, Yau TM, Nanthakumar K. Mesenchymal stem cell transplantation mitigates electrophysiological remodeling in a rat model of myocardial infarction. J Cardiovasc Electrophysiol 2013; 24:813-21. [PMID: 23647964 DOI: 10.1111/jce.12162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/26/2013] [Accepted: 02/12/2013] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Transplantation of mesenchymal stem cells (MSCs) has shown therapeutic potential for cardiovascular diseases, but the electrophysiological implications are not understood. The purpose of this study was to evaluate the impact of MSC transplantation on adverse electrophysiological remodeling in the heart following myocardial infarction (MI). METHODS AND RESULTS Three weeks after coronary ligation to induce MI in rats, MSCs or culture medium were directly injected into each infarct. One to two weeks later, hearts were excised, Langendorff-perfused, and optically mapped using the potentiometric fluorescent dye Di-4-ANEPPS. Quantitative real-time PCR was also performed to assess gene expression. Optical mapping showed that post-MI reduction in conduction velocity (from 0.70 ± 0.04 m/s in 12 normal controls to 0.47 ± 0.02 m/s in 11 infarcted hearts, P < 0.05) was attenuated with MSC transplantation (0.65 ± 0.04 m/s, n = 18, P < 0.05). Electrophysiological changes correlated with higher vascular density and better-preserved ventricular geometry in MSC-transplanted hearts. A number of ion channel genes showed changes in RNA expression following infarction. In particular, the expression of Kir2.1, which mediates the inward rectifier potassium current, I(K1), was reduced in infarcted tissues (n = 7) to 13.8 ± 3.7% of normal controls, and this post-MI reduction was attenuated with MSC transplantation (44.4 ± 11.2%, n = 7, P < 0.05). CONCLUSION In addition to promoting angiogenesis and limiting adverse structural remodeling in infarcted hearts, MSC transplantation also alters ion channel expression and mitigates electrophysiological remodeling. Further understanding of the electrophysiological impact of MSC transplantation to the heart may lead to the development of cell-based therapies for post-MI arrhythmias.
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Affiliation(s)
- Patrick F H Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Division of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada
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