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Su L, Wang J, Liu B, Liu H, Chen Q, Liu J, Li S, Yuan L, An L, Lin H, Feng L, Zheng J, Ren J, Liang L, Li S. Construction of a Near-Infrared Fluorescent Probe for Dynamic Monitoring and Early Diagnosis of Heart Failure. ACS Sens 2024; 9:3075-3084. [PMID: 38807573 DOI: 10.1021/acssensors.4c00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Cardiac hypertrophy characterized by abnormal cardiomyocyte viscosity is a typical sign of heart failure (HF) with vital importance for early diagnosis. However, current biochemical and imaging diagnostic methods are unable to detect this subclinical manifestation. In this work, we developed a series of NIR-I fluorescence probes for detecting myocardial viscosity based on the pyridazinone scaffold. The probes showed weak fluorescence due to free intramolecular rotation under low-viscosity conditions, while they displayed strong fluorescence with limited intramolecular rotation in response to a high-viscosity environment. Among them, CarVis2 exhibited higher stability and photobleaching resistance than commercial dyes. Its specific response to viscosity was not influenced by the pH and biological species. Furthermore, CarVis2 showed rapid and accurate responses to the viscosity of isoproterenol (ISO)-treated H9C2 cardiomyocytes with good biocompatibility. More importantly, CarVis2 demonstrated excellent sensitivity in monitoring myocardial viscosity variation in HF mice in vivo, potentially enabling earlier noninvasive identification of myocardial abnormalities compared to traditional clinical imaging and biomarkers. These findings revealed that CarVis2 can serve as a powerful tool to monitor myocardial viscosity, providing the potential to advance insights into a pathophysiological mechanism and offering a new reference strategy for early visual diagnosis of HF.
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Affiliation(s)
- Lina Su
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
- Department of Cardiology, Beijing Key Laboratory of Early Prediction and Intervention of Acute Myocardial Infarction, Center for Cardiovascular Translational Research, Peking University People's Hospital, Beijing 100044, China
| | - Junda Wang
- Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Bowei Liu
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Hui Liu
- Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Qixin Chen
- Department of Cardiology, Beijing Key Laboratory of Early Prediction and Intervention of Acute Myocardial Infarction, Center for Cardiovascular Translational Research, Peking University People's Hospital, Beijing 100044, China
| | - Jiang Liu
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Shuolei Li
- Laboratory Animal Unit, Peking University People's Hospital, Beijing 100044, China
| | - Lan Yuan
- Medical and Healthy Analytical Center, Peking University, Beijing 100191, China
| | - Lihua An
- Medical and Healthy Analytical Center, Peking University, Beijing 100191, China
| | - Hang Lin
- Department of Cardiology, Beijing Key Laboratory of Early Prediction and Intervention of Acute Myocardial Infarction, Center for Cardiovascular Translational Research, Peking University People's Hospital, Beijing 100044, China
| | - Lina Feng
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jingang Zheng
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jingyi Ren
- Heart Failure Center, Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Lei Liang
- Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Sufang Li
- Department of Cardiology, Beijing Key Laboratory of Early Prediction and Intervention of Acute Myocardial Infarction, Center for Cardiovascular Translational Research, Peking University People's Hospital, Beijing 100044, China
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Guo C, Jardin BD, Lin J, Ambroise RL, Wang Z, Yang L, Mazumdar N, Lu F, Ma Q, Cao Y, Liu C, Liu X, Lan F, Zhao M, Xiao H, Dong E, Pu WT, Guo Y. In vivo proximity proteomics uncovers palmdelphin (PALMD) as a Z-line-associated mitigator of isoproterenol-induced cardiac injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570334. [PMID: 38106146 PMCID: PMC10723331 DOI: 10.1101/2023.12.06.570334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Z-lines are core ultrastructural organizers of cardiomyocytes that modulate many facets of cardiac pathogenesis. Yet a comprehensive proteomic atlas of Z-line-associated components remain incomplete. Here, we established an adeno-associated virus (AAV)-delivered, cardiomyocyte-specific, proximity-labeling approach to characterize the Z-line proteome in vivo. We found palmdelphin (PALMD) as a novel Z-line-associated protein in both adult murine cardiomyocytes and human pluripotent stem cell-derived cardiomyocytes. Germline and cardiomyocyte-specific palmd knockout mice were grossly normal at baseline but exhibited compromised cardiac hypertrophy and aggravated cardiac injury upon long-term isoproterenol treatment. By contrast, cardiomyocyte-specific PALMD overexpression was sufficient to mitigate isoproterenol-induced cardiac injury. PALMD ablation perturbed transverse tubules (T-tubules) and their association with sarcoplasmic reticulum, which formed the Z-line-associated junctional membrane complex (JMC) essential for calcium handling and cardiac function. These phenotypes were associated with disrupted localization of T-tubule markers caveolin-3 (CAV3) and junctophilin-2 (JPH2) and the reduction of nexilin (NEXN) protein, a crucial Z-line-associated protein that is essential for both Z-line and JMC structures and functions. PALMD was found to interact with NEXN and enhance its protein stability while the Nexn mRNA level was not affected. Together, this study discovered PALMD as a potential target for myocardial protection and highlighted in vivo proximity proteomics as a powerful approach to nominate novel players regulating cardiac pathogenesis. Highlights In vivo proximity proteomics uncover novel Z-line components that are undetected in in vitro proximity proteomics in cardiomyocytes.PALMD is a novel Z-line-associated protein that is dispensable for baseline cardiomyocyte function in vivo.PALMD mitigates cardiac dysfunction and myocardial injury after repeated isoproterenol insults.PALMD stabilizes NEXN, an essential Z-line-associated regulator of the junctional membrane complex and cardiac systolic function.
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Zhang X, Smith CER, Morotti S, Edwards AG, Sato D, Louch WE, Ni H, Grandi E. Mechanisms of spontaneous Ca 2+ release-mediated arrhythmia in a novel 3D human atrial myocyte model: II. Ca 2+ -handling protein variation. J Physiol 2023; 601:2685-2710. [PMID: 36114707 PMCID: PMC10017376 DOI: 10.1113/jp283602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/02/2022] [Indexed: 11/08/2022] Open
Abstract
Disruption of the transverse-axial tubule system (TATS) in diseases such as heart failure and atrial fibrillation occurs in combination with changes in the expression and distribution of key Ca2+ -handling proteins. Together this ultrastructural and ionic remodelling is associated with aberrant Ca2+ cycling and electrophysiological instabilities that underlie arrhythmic activity. However, due to the concurrent changes in TATs and Ca2+ -handling protein expression and localization that occur in disease it is difficult to distinguish their individual contributions to the arrhythmogenic state. To investigate this, we applied our novel 3D human atrial myocyte model with spatially detailed Ca2+ diffusion and TATS to investigate the isolated and interactive effects of changes in expression and localization of key Ca2+ -handling proteins and variable TATS density on Ca2+ -handling abnormality driven membrane instabilities. We show that modulating the expression and distribution of the sodium-calcium exchanger, ryanodine receptors and the sarcoplasmic reticulum (SR) Ca2+ buffer calsequestrin have varying pro- and anti-arrhythmic effects depending on the balance of opposing influences on SR Ca2+ leak-load and Ca2+ -voltage relationships. Interestingly, the impact of protein remodelling on Ca2+ -driven proarrhythmic behaviour varied dramatically depending on TATS density, with intermediately tubulated cells being more severely affected compared to detubulated and densely tubulated myocytes. This work provides novel mechanistic insight into the distinct and interactive consequences of TATS and Ca2+ -handling protein remodelling that underlies dysfunctional Ca2+ cycling and electrophysiological instability in disease. KEY POINTS: In our companion paper we developed a 3D human atrial myocyte model, coupling electrophysiology and Ca2+ handling with subcellular spatial details governed by the transverse-axial tubule system (TATS). Here we utilize this model to mechanistically examine the impact of TATS loss and changes in the expression and distribution of key Ca2+ -handling proteins known to be remodelled in disease on Ca2+ homeostasis and electrophysiological stability. We demonstrate that varying the expression and localization of these proteins has variable pro- and anti-arrhythmic effects with outcomes displaying dependence on TATS density. Whereas detubulated myocytes typically appear unaffected and densely tubulated cells seem protected, the arrhythmogenic effects of Ca2+ handling protein remodelling are profound in intermediately tubulated cells. Our work shows the interaction between TATS and Ca2+ -handling protein remodelling that underlies the Ca2+ -driven proarrhythmic behaviour observed in atrial fibrillation and may help to predict the effects of antiarrhythmic strategies at varying stages of ultrastructural remodelling.
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Affiliation(s)
- Xianwei Zhang
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | | | - Stefano Morotti
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | | | - Daisuke Sato
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Haibo Ni
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
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Zhang X, Ni H, Morotti S, Smith C, Sato D, Louch W, Edwards A, Grandi E. Mechanisms of spontaneous Ca 2+ release-mediated arrhythmia in a novel 3D human atrial myocyte model: I. Transverse-axial tubule variation. J Physiol 2023; 601:2655-2683. [PMID: 36094888 PMCID: PMC10008525 DOI: 10.1113/jp283363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/02/2022] [Indexed: 11/08/2022] Open
Abstract
Intracellular calcium (Ca2+ ) cycling is tightly regulated in the healthy heart ensuring effective contraction. This is achieved by transverse (t)-tubule membrane invaginations that facilitate close coupling of key Ca2+ -handling proteins such as the L-type Ca2+ channel and Na+ -Ca2+ exchanger (NCX) on the cell surface with ryanodine receptors (RyRs) on the intracellular Ca2+ store. Although less abundant and regular than in the ventricle, t-tubules also exist in atrial myocytes as a network of transverse invaginations with axial extensions known as the transverse-axial tubule system (TATS). In heart failure and atrial fibrillation, there is TATS remodelling that is associated with aberrant Ca2+ -handling and Ca2+ -induced arrhythmic activity; however, the mechanism underlying this is not fully understood. To address this, we developed a novel 3D human atrial myocyte model that couples electrophysiology and Ca2+ -handling with variable TATS organization and density. We extensively parameterized and validated our model against experimental data to build a robust tool examining TATS regulation of subcellular Ca2+ release. We found that varying TATS density and thus the localization of key Ca2+ -handling proteins has profound effects on Ca2+ handling. Following TATS loss, there is reduced NCX that results in increased cleft Ca2+ concentration through decreased Ca2+ extrusion. This elevated Ca2+ increases RyR open probability causing spontaneous Ca2+ releases and the promotion of arrhythmogenic waves (especially in the cell interior) leading to voltage instabilities through delayed afterdepolarizations. In summary, the present study demonstrates a mechanistic link between TATS remodelling and Ca2+ -driven proarrhythmic behaviour that probably reflects the arrhythmogenic state observed in disease. KEY POINTS: Transverse-axial tubule systems (TATS) modulate Ca2+ handling and excitation-contraction coupling in atrial myocytes, with TATS remodelling in heart failure and atrial fibrillation being associated with altered Ca2+ cycling and subsequent arrhythmogenesis. To investigate the poorly understood mechanisms linking TATS variation and spontaneous Ca2+ release, we built, parameterized and validated a 3D human atrial myocyte model coupling electrophysiology and spatially-detailed subcellular Ca2+ handling governed by the TATS. Simulated TATS loss causes diastolic Ca2+ and voltage instabilities through reduced Na+ -Ca2+ exchanger-mediated Ca2+ removal, cleft Ca2+ accumulation and increased ryanodine receptor open probability, resulting in spontaneous Ca2+ release and promotion of arrhythmogenic waves and delayed afterdepolarizations. At fast electrical rates typical of atrial tachycardia/fibrillation, spontaneous Ca2+ releases are larger and more frequent in the cell interior than at the periphery. Our work provides mechanistic insight into how atrial TATS remodelling can lead to Ca2+ -driven instabilities that may ultimately contribute to the arrhythmogenic state in disease.
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Affiliation(s)
- X. Zhang
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - H. Ni
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - S. Morotti
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - C.E.R. Smith
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - D. Sato
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - W.E. Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo Norway
| | - A.G. Edwards
- Department of Pharmacology, University of California Davis, Davis, CA, USA
- Simula Research Laboratory, Lysaker, Norway
| | - E. Grandi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
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5
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Chen B, Daneshgar N, Lee HC, Song LS, Dai DF. Mitochondrial Oxidative Stress Mediates Bradyarrhythmia in Leigh Syndrome Mitochondrial Disease Mice. Antioxidants (Basel) 2023; 12:antiox12051001. [PMID: 37237867 PMCID: PMC10215409 DOI: 10.3390/antiox12051001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023] Open
Abstract
Mitochondrial oxidative stress has been implicated in aging and several cardiovascular diseases, including heart failure and cardiomyopathy, ventricular tachycardia, and atrial fibrillation. The role of mitochondrial oxidative stress in bradyarrhythmia is less clear. Mice with a germline deletion of Ndufs4 subunit respiratory complex I develop severe mitochondrial encephalomyopathy resembling Leigh Syndrome (LS). Several types of cardiac bradyarrhythmia are present in LS mice, including a frequent sinus node dysfunction and episodic atrioventricular (AV) block. Treatment with the mitochondrial antioxidant Mitotempo or mitochondrial protective peptide SS31 significantly ameliorated the bradyarrhythmia and extended the lifespan of LS mice. Using an ex vivo Langendorff perfused heart with live confocal imaging of mitochondrial and total cellular reactive oxygen species (ROS), we showed increased ROS in the LS heart, which was potentiated by ischemia-reperfusion. A simultaneous ECG recording showed a sinus node dysfunction and AV block concurrent with the severity of the oxidative stress. Treatment with Mitotempo abolished ROS and restored the sinus rhythm. Our study reveals robust evidence of the direct mechanistic roles of mitochondrial and total ROS in bradyarrhythmia in the setting of LS mitochondrial cardiomyopathy. Our study also supports the potential clinical application of mitochondrial-targeted antioxidants or SS31 for the treatment of LS patients.
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Affiliation(s)
- Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Nastaran Daneshgar
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Hsiang-Chun Lee
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Dao-Fu Dai
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Guo Y, Cao Y, Jardin BD, Zhang X, Zhou P, Guatimosim S, Lin J, Chen Z, Zhang Y, Mazumdar N, Lu F, Ma Q, Lu YW, Zhao M, Wang DZ, Dong E, Pu WT. Ryanodine receptor 2 (RYR2) dysfunction activates the unfolded protein response and perturbs cardiomyocyte maturation. Cardiovasc Res 2023; 119:221-235. [PMID: 35576474 PMCID: PMC10233305 DOI: 10.1093/cvr/cvac077] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 04/03/2022] [Accepted: 05/05/2022] [Indexed: 11/15/2022] Open
Abstract
AIMS Calcium-handling capacity is a major gauge of cardiomyocyte maturity. Ryanodine receptor 2 (RYR2) is the pre-dominant calcium channel that releases calcium from the sarcoplasmic reticulum/endoplasmic reticulum (SR/ER) to activate cardiomyocyte contraction. Although RYR2 was previously implied as a key regulator of cardiomyocyte maturation, the mechanisms remain unclear. The aim of this study is to solve this problem. METHODS AND RESULTS We performed Cas9/AAV9-mediated somatic mutagenesis to knockout RYR2 specifically in cardiomyocytes in mice. We conducted a genetic mosaic analysis to dissect the cell-autonomous function of RYR2 during cardiomyocyte maturation. We found that RYR2 depletion triggered ultrastructural and transcriptomic defects relevant to cardiomyocyte maturation. These phenotypes were associated with the drastic activation of ER stress pathways. The ER stress alleviator tauroursodeoxycholic acid partially rescued the defects in RYR2-depleted cardiomyocytes. Overexpression of ATF4, a key ER stress transcription factor, recapitulated defects in RYR2-depleted cells. Integrative analysis of RNA-Seq and bioChIP-Seq data revealed that protein biosynthesis-related genes are the major direct downstream targets of ATF4. CONCLUSION RYR2-regulated ER homeostasis is essential for cardiomyocyte maturation. Severe ER stress perturbs cardiomyocyte maturation primarily through ATF4 activation. The major downstream effector genes of ATF4 are related to protein biosynthesis.
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Affiliation(s)
- Yuxuan Guo
- Peking University Health Science Center, School of Basic Medical Sciences, Beijing 100191, China
- Institute of Cardiovascular Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Yangpo Cao
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Blake D Jardin
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Xiaoran Zhang
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Pingzhu Zhou
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte MG - CEP 31270-901, Brazil
| | - Junsen Lin
- Peking University Health Science Center, School of Basic Medical Sciences, Beijing 100191, China
- Institute of Cardiovascular Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Zhan Chen
- Peking University Health Science Center, School of Basic Medical Sciences, Beijing 100191, China
- Institute of Cardiovascular Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Yueyang Zhang
- Peking University Health Science Center, School of Basic Medical Sciences, Beijing 100191, China
- Institute of Cardiovascular Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Neil Mazumdar
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Fujian Lu
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Qing Ma
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Yao-Wei Lu
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Mingming Zhao
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Beijing 100191, China
- NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing 100191, China
| | - Da-Zhi Wang
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Erdan Dong
- Institute of Cardiovascular Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, Beijing 100191, China
- NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing 100191, China
| | - William T Pu
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA 02138, USA
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Lashgari M, Ravikumar N, Teh I, Li JR, Buckley DL, Schneider JE, Frangi AF. Three-dimensional micro-structurally informed in silico myocardium-Towards virtual imaging trials in cardiac diffusion weighted MRI. Med Image Anal 2022; 82:102592. [PMID: 36095906 DOI: 10.1016/j.media.2022.102592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022]
Abstract
In silico tissue models (viz. numerical phantoms) provide a mechanism for evaluating quantitative models of magnetic resonance imaging. This includes the validation and sensitivity analysis of imaging biomarkers and tissue microstructure parameters. This study proposes a novel method to generate a realistic numerical phantom of myocardial microstructure. The proposed method extends previous studies by accounting for the variability of the cardiomyocyte shape, water exchange between the cardiomyocytes (intercalated discs), disorder class of myocardial microstructure, and four sheetlet orientations. In the first stage of the method, cardiomyocytes and sheetlets are generated by considering the shape variability and intercalated discs in cardiomyocyte-cardiomyocyte connections. Sheetlets are then aggregated and oriented in the directions of interest. The morphometric study demonstrates no significant difference (p>0.01) between the distribution of volume, length, and primary and secondary axes of the numerical and real (literature) cardiomyocyte data. Moreover, structural correlation analysis validates that the in-silico tissue is in the same class of disorderliness as the real tissue. Additionally, the absolute angle differences between the simulated helical angle (HA) and input HA (reference value) of the cardiomyocytes (4.3°±3.1°) demonstrate a good agreement with the absolute angle difference between the measured HA using experimental cardiac diffusion tensor imaging (cDTI) and histology (reference value) reported by (Holmes et al., 2000) (3.7°±6.4°) and (Scollan et al. 1998) (4.9°±14.6°). Furthermore, the angular distance between eigenvectors and sheetlet angles of the input and simulated cDTI is much smaller than those between measured angles using structural tensor imaging (as a gold standard) and experimental cDTI. Combined with the qualitative results, these results confirm that the proposed method can generate richer numerical phantoms for the myocardium than previous studies.
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Affiliation(s)
- Mojtaba Lashgari
- Centre for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), School of Computing, University of Leeds, Leeds, UK; Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK.
| | - Nishant Ravikumar
- Centre for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), School of Computing, University of Leeds, Leeds, UK; Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK
| | - Irvin Teh
- Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK
| | - Jing-Rebecca Li
- INRIA Saclay, Equipe DEFI, CMAP, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex, France
| | - David L Buckley
- Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK
| | - Jurgen E Schneider
- Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK
| | - Alejandro F Frangi
- Centre for Computational Imaging and Simulation Technologies in Biomedicine (CISTIB), School of Computing, University of Leeds, Leeds, UK; Biomedical Imaging Science Department, Leeds Institute for Cardiovascular and Metabolic Medicine (LICAMM), School of Medicine, University of Leeds, Leeds, UK; INRIA Saclay, Equipe DEFI, CMAP, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex, France; Medical Imaging Research Center (MIRC), Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Medical Imaging Research Center (MIRC), Department of Electrical Engineering, KU Leuven, Leuven, Belgium; Alan Turing Institute, London, UK.
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8
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Wang J, Shi Q, Wang Y, Dawson LW, Ciampa G, Zhao W, Zhang G, Chen B, Weiss RM, Grueter CE, Hall DD, Song LS. Gene Therapy With the N-Terminus of Junctophilin-2 Improves Heart Failure in Mice. Circ Res 2022; 130:1306-1317. [PMID: 35317607 PMCID: PMC9050933 DOI: 10.1161/circresaha.121.320680] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Transcriptional remodeling is known to contribute to heart failure (HF). Targeting stress-dependent gene expression mechanisms may represent a clinically relevant gene therapy option. We recently uncovered a salutary mechanism in the heart whereby JP2 (junctophilin-2), an essential component of the excitation-contraction coupling apparatus, is site-specifically cleaved and releases an N-terminal fragment (JP2NT [N-terminal fragment of JP2]) that translocates into the nucleus and functions as a transcriptional repressor of HF-related genes. This study aims to determine whether JP2NT can be leveraged by gene therapy techniques for attenuating HF progression in a preclinical pressure overload model. METHODS We intraventricularly injected adeno-associated virus (AAV) (2/9) vectors expressing eGFP (enhanced green fluorescent protein), JP2NT, or DNA-binding deficient JP2NT (JP2NTΔbNLS/ARR) into neonatal mice and induced cardiac stress by transaortic constriction (TAC) 9 weeks later. We also treated mice with established moderate HF from TAC stress with either AAV-JP2NT or AAV-eGFP. RNA-sequencing analysis was used to reveal changes in hypertrophic and HF-related gene transcription by JP2NT gene therapy after TAC. Echocardiography, confocal imaging, and histology were performed to evaluate heart function and pathological myocardial remodeling following stress. RESULTS Mice preinjected with AAV-JP2NT exhibited ameliorated cardiac remodeling following TAC. The JP2NT DNA-binding domain is required for cardioprotection as its deletion within the AAV-JP2NT vector prevented improvement in TAC-induced cardiac dysfunction. Functional and histological data suggest that JP2NT gene therapy after the onset of cardiac dysfunction is effective at slowing the progression of HF. RNA-sequencing analysis further revealed a broad reversal of hypertrophic and HF-related gene transcription by JP2NT overexpression after TAC. CONCLUSIONS Our prevention- and intervention-based approaches here demonstrated that AAV-mediated delivery of JP2NT into the myocardium can attenuate stress-induced transcriptional remodeling and the development of HF when administered either before or after cardiac stress initiation. Our data indicate that JP2NT gene therapy holds great potential as a novel therapeutic for treating hypertrophy and HF.
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Affiliation(s)
- Jinxi Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Qian Shi
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Yihui Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Logan W. Dawson
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
| | - Grace Ciampa
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
| | - Weiyang Zhao
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Guangqin Zhang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Robert M. Weiss
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Chad E. Grueter
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Duane D. Hall
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
- Department of Veterans Affairs, Iowa City Medical Center, IA 52242
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9
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Lu F, Ma Q, Xie W, Liou CL, Zhang D, Sweat ME, Jardin BD, Naya FJ, Guo Y, Cheng H, Pu WT. CMYA5 establishes cardiac dyad architecture and positioning. Nat Commun 2022; 13:2185. [PMID: 35449169 PMCID: PMC9023524 DOI: 10.1038/s41467-022-29902-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 04/05/2022] [Indexed: 11/18/2022] Open
Abstract
Cardiac excitation-contraction coupling requires dyads, the nanoscopic microdomains formed adjacent to Z-lines by apposition of transverse tubules and junctional sarcoplasmic reticulum. Disruption of dyad architecture and function are common features of diseased cardiomyocytes. However, little is known about the mechanisms that modulate dyad organization during cardiac development, homeostasis, and disease. Here, we use proximity proteomics in intact, living hearts to identify proteins enriched near dyads. Among these proteins is CMYA5, an under-studied striated muscle protein that co-localizes with Z-lines, junctional sarcoplasmic reticulum proteins, and transverse tubules in mature cardiomyocytes. During cardiac development, CMYA5 positioning adjacent to Z-lines precedes junctional sarcoplasmic reticulum positioning or transverse tubule formation. CMYA5 ablation disrupts dyad architecture, dyad positioning at Z-lines, and junctional sarcoplasmic reticulum Ca2+ release, leading to cardiac dysfunction and inability to tolerate pressure overload. These data provide mechanistic insights into cardiomyopathy pathogenesis by demonstrating that CMYA5 anchors junctional sarcoplasmic reticulum to Z-lines, establishes dyad architecture, and regulates dyad Ca2+ release.
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Affiliation(s)
- Fujian Lu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Qing Ma
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Health and Rehabilitation Science, School of Life Science and Technology, Xi'an Jiaotong University, 710049, Xi'an, Shanxi, China
| | - Carter L Liou
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Donghui Zhang
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, 430062, Wuhan, Hubei, China
| | - Mason E Sweat
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Blake D Jardin
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Francisco J Naya
- Department of Biology, Program in Cell and Molecular Biology, Boston University, Boston, MA, 02215, USA
| | - Yuxuan Guo
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, 100191, Beijing, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, China
| | - William T Pu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA, 02138, USA.
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10
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Lin J, Chen Z, Yang L, Liu L, Yue P, Sun Y, Zhao M, Guo X, Hu X, Zhang Y, Zhang H, Li Y, Guo Y, Dong E. Cas9/AAV9-Mediated Somatic Mutagenesis Uncovered the Cell-Autonomous Role of Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 2 in Murine Cardiomyocyte Maturation. Front Cell Dev Biol 2022; 10:864516. [PMID: 35433671 PMCID: PMC9012521 DOI: 10.3389/fcell.2022.864516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/03/2022] [Indexed: 11/24/2022] Open
Abstract
Sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) is a key player in cardiomyocyte calcium handling and also a classic target in the gene therapy for heart failure. SERCA2 expression dramatically increases during cardiomyocyte maturation in the postnatal phase of heart development, which is essential for the heart to acquire its full function in adults. However, whether and how SERCA2 regulates cardiomyocyte maturation remains unclear. Here, we performed Cas9/AAV9-mediated somatic mutagenesis (CASAAV) in mice and achieved cardiomyocyte-specific knockout of Atp2a2, the gene coding SERCA2. Through a cardiac genetic mosaic analysis, we demonstrated the cell-autonomous role of SERCA2 in building key ultrastructures of mature ventricular cardiomyocytes, including transverse-tubules and sarcomeres. SERCA2 also exerts a profound impact on oxidative respiration gene expression and sarcomere isoform switching from Myh7/Tnni1 to Myh6/Tnni3, which are transcriptional hallmarks of cardiomyocyte maturation. Together, this study uncovered a pivotal role of SERCA2 in heart development and provided new insights about SERCA2-based cardiac gene therapy.
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Affiliation(s)
- Junsen Lin
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Zhan Chen
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Luzi Yang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Lei Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Peng Yue
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yueshen Sun
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
- Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Mingming Zhao
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, National Health Commission of China (NHC) Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research. Beijing, China
| | - Xiaoling Guo
- Basic Medical Research Center, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaomin Hu
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
- Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Yan Zhang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Hong Zhang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yuxuan Guo
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
- *Correspondence: Yuxuan Guo,
| | - Erdan Dong
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, National Health Commission of China (NHC) Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research. Beijing, China
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11
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Wright PT, Gorelik J, Harding SE. Electrophysiological Remodeling: Cardiac T-Tubules and ß-Adrenoceptors. Cells 2021; 10:cells10092456. [PMID: 34572106 PMCID: PMC8468945 DOI: 10.3390/cells10092456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 01/09/2023] Open
Abstract
Beta-adrenoceptors (βAR) are often viewed as archetypal G-protein coupled receptors. Over the past fifteen years, investigations in cardiovascular biology have provided remarkable insights into this receptor family. These studies have shifted pharmacological dogma, from one which centralized the receptor to a new focus on structural micro-domains such as caveolae and t-tubules. Important studies have examined, separately, the structural compartmentation of ion channels and βAR. Despite links being assumed, relatively few studies have specifically examined the direct link between structural remodeling and electrical remodeling with a focus on βAR. In this review, we will examine the nature of receptor and ion channel dysfunction on a substrate of cardiomyocyte microdomain remodeling, as well as the likely ramifications for cardiac electrophysiology. We will then discuss the advances in methodologies in this area with a specific focus on super-resolution microscopy, fluorescent imaging, and new approaches involving microdomain specific, polymer-based agonists. The advent of powerful computational modelling approaches has allowed the science to shift from purely empirical work, and may allow future investigations based on prediction. Issues such as the cross-reactivity of receptors and cellular heterogeneity will also be discussed. Finally, we will speculate as to the potential developments within this field over the next ten years.
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Affiliation(s)
- Peter T. Wright
- School of Life & Health Sciences, University of Roehampton, Holybourne Avenue, London SW15 4JD, UK;
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Julia Gorelik
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Sian E. Harding
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
- Correspondence:
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12
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Li S, Liu Z, Chen G, Qanmber G, Lu L, Zhang J, Ma S, Yang Z, Li F. Identification and Analysis of GhEXO Gene Family Indicated That GhEXO7_At Promotes Plant Growth and Development Through Brassinosteroid Signaling in Cotton ( Gossypium hirsutum L.). FRONTIERS IN PLANT SCIENCE 2021; 12:719889. [PMID: 34603349 PMCID: PMC8481617 DOI: 10.3389/fpls.2021.719889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/05/2021] [Indexed: 05/29/2023]
Abstract
Brassinosteroids (BRs), an efficient plant endogenous hormone, significantly promotes plant nutrient growth adapting to biological and abiotic adversities. BRs mainly promote plant cell elongation by regulating gene expression patterns. EXORDIUM (EXO) genes have been characterized as the indicators of BR response genes. Cotton, an ancient crop, is of great economic value and its fibers can be made into all kinds of fabrics. However, EXO gene family genes have not been full identified in cotton. 175 EXO genes were identified in nine plant species, of which 39 GhEXO genes in Gossypium hirsutum in our study. A phylogenetic analysis grouped all of the proteins encoded by the EXO genes into five major clades. Sequence identification of conserved amino acid residues among monocotyledonous and dicotyledonous species showed a high level of conservation across the N and C terminal regions. Only 25% the GhEXO genes contain introns besides conserved gene structure and protein motifs distribution. The 39 GhEXO genes were unevenly distributed on the 18 At and Dt sub-genome chromosomes. Most of the GhEXO genes were derived from gene duplication events, while only three genes showed evidence of tandem duplication. Homologous locus relationships showed that 15 GhEXO genes are located on collinear blocks and that all orthologous/paralogous gene pairs had Ka > Ks values, indicating purifying selection pressure. The GhEXO genes showed ubiquitous expression in all eight tested cotton tissues and following exposure to three phytohormones, IAA, GA, and BL. Furthermore, GhEXO7_At was mainly expressed in response to BL treatment, and was predominantly expressed in the fibers. GhEXO7_At was found to be a plasma membrane protein, and its ectopic expression in Arabidopsis mediated BR-regulated plant growth and development with altered expression of DWF4, CPD, KCS1, and EXP5. Additionally, the functions of GhEXO7_At were confirmed by virus-induced gene silencing (VIGS) in cotton. This study will provide important genetic resources for future cotton breeding programs.
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Affiliation(s)
- Shengdong Li
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Zhao Liu
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Guoquan Chen
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Ghulam Qanmber
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Lili Lu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Jiaxin Zhang
- Saint John Paul the Great Catholic High School, Dumfries, VA, United States
| | - Shuya Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Zuoren Yang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Fuguang Li
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
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13
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Sarcomeres regulate murine cardiomyocyte maturation through MRTF-SRF signaling. Proc Natl Acad Sci U S A 2021; 118:2008861118. [PMID: 33361330 DOI: 10.1073/pnas.2008861118] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The paucity of knowledge about cardiomyocyte maturation is a major bottleneck in cardiac regenerative medicine. In development, cardiomyocyte maturation is characterized by orchestrated structural, transcriptional, and functional specializations that occur mainly at the perinatal stage. Sarcomeres are the key cytoskeletal structures that regulate the ultrastructural maturation of other organelles, but whether sarcomeres modulate the signal transduction pathways that are essential for cardiomyocyte maturation remains unclear. To address this question, here we generated mice with cardiomyocyte-specific, mosaic, and hypomorphic mutations of α-actinin-2 (Actn2) to study the cell-autonomous roles of sarcomeres in postnatal cardiomyocyte maturation. Actn2 mutation resulted in defective structural maturation of transverse-tubules and mitochondria. In addition, Actn2 mutation triggered transcriptional dysregulation, including abnormal expression of key sarcomeric and mitochondrial genes, and profound impairment of the normal progression of maturational gene expression. Mechanistically, the transcriptional changes in Actn2 mutant cardiomyocytes strongly correlated with those in cardiomyocytes deleted of serum response factor (SRF), a critical transcription factor that regulates cardiomyocyte maturation. Actn2 mutation increased the monomeric form of cardiac α-actin, which interacted with the SRF cofactor MRTFA and perturbed its nuclear localization. Overexpression of a dominant-negative MRTFA mutant was sufficient to recapitulate the morphological and transcriptional defects in Actn2 and Srf mutant cardiomyocytes. Together, these data indicate that Actn2-based sarcomere organization regulates structural and transcriptional maturation of cardiomyocytes through MRTF-SRF signaling.
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14
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Wang S, Zhou Y, Luo Y, Kan R, Chen J, Xuan H, Wang C, Chen J, Xu T, Li D. SERCA2a ameliorates cardiomyocyte T-tubule remodeling via the calpain/JPH2 pathway to improve cardiac function in myocardial ischemia/reperfusion mice. Sci Rep 2021; 11:2037. [PMID: 33479390 PMCID: PMC7820433 DOI: 10.1038/s41598-021-81570-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 01/07/2021] [Indexed: 12/21/2022] Open
Abstract
Transverse-tubules (T-tubules) play pivotal roles in Ca2+-induced, Ca2+ release and excitation–contraction coupling in cardiomyocytes. The purpose of this study was to uncover mechanisms where sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) improved cardiac function through T-tubule regulation during myocardial ischemia/reperfusion (I/R). SERCA2a protein expression, cytoplasmic [Ca2+]i, calpain activity, junctophilin-2 (JPH2) protein expression and intracellular localization, cardiomyocyte T-tubules, contractility and calcium transients in single cardiomyocytes and in vivo cardiac functions were all examined after SERCA2a knockout and overexpression, and Calpain inhibitor PD150606 (PD) pretreatment, following myocardial I/R. This comprehensive approach was adopted to clarify SERCA2a mechanisms in improving cardiac function in mice. Calpain was activated during myocardial I/R, and led to the proteolytic cleavage of JPH2. This altered the T-tubule network, the contraction function/calcium transients in cardiomyocytes and in vivo cardiac functions. During myocardial I/R, PD pretreatment upregulated JPH2 expression and restored it to its intracellular location, repaired the T-tubule network, and contraction function/calcium transients of cardiomyocytes and cardiac functions in vivo. SERCA2a suppressed calpain activity via [Ca2+]i, and ameliorated these key indices. Our results suggest that SERCA2a ameliorates cardiomyocyte T-tubule remodeling via the calpain/JPH2 pathway, thereby improving cardiac function in myocardial I/R mice.
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Affiliation(s)
- Shuai Wang
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, 84 West Huaihai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - You Zhou
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, 84 West Huaihai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Yuanyuan Luo
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China
| | - Rongsheng Kan
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, 84 West Huaihai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Jingwen Chen
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, 84 West Huaihai Road, Xuzhou, 221002, Jiangsu, People's Republic of China
| | - Haochen Xuan
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China
| | - Chaofan Wang
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China
| | - Junhong Chen
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China
| | - Tongda Xu
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China.
| | - Dongye Li
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, 84 West Huaihai Road, Xuzhou, 221002, Jiangsu, People's Republic of China. .,Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221006, Jiangsu, People's Republic of China.
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15
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Yue P, Xia S, Wu G, Liu L, Zhou K, Liao H, Li J, Zheng X, Guo Y, Hua Y, Zhang D, Li Y. Attenuation of Cardiomyocyte Hypertrophy via Depletion Myh7 using CASAAV. Cardiovasc Toxicol 2020; 21:255-264. [PMID: 33098074 DOI: 10.1007/s12012-020-09617-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/16/2020] [Indexed: 10/23/2022]
Abstract
Myh7 is a classic biomarker for cardiac remodeling and a potential target to attenuate cardiomyocyte (CM) hypertrophy. This study aimed to identify the dominant function of Myh7 after birth and determine whether its removal would affect CM maturation or contribute to reversal of pathological hypertrophy phenotypes. The CASAAV (CRISPR/Cas9-AAV9-based somatic mutagenesis) technique was used to deplete Myh6 and Myh7, and an AAV dosage of 5 × 109 vg/g was used to generate a mosaic CM depletion model to explore the function of Myh7 in adulthood. CM hypertrophy was induced by transverse aortic constriction (TAC) in Rosa26Cas9-P2A-GFP mice at postnatal day 28 (PND28). Heart function was measured by echocardiography. Isolated CMs and in situ imaging were used to analyze the structure and morphology of CM. We discovered that CASAAV successfully silenced Myh6 and Myh7 in CMs, and early depletion of Myh7 led to mild adulthood lethality. However, the Myh7 PND28-knockout mice had normal heart phenotype and function, with normal cellular size and normal organization of sarcomeres and T-tubules. The TAC mice also received AAV-Myh7-Cre to produce Myh7-knockout CMs, which were also of normal size, and echocardiography demonstrated a reversal of cardiac hypertrophy. In conclusion, Myh7 has a role during the maturation period but rarely functions in adulthood. Thus, the therapeutic time should exceed the period of maturation. These results confirm Myh7 as a potential therapeutic target and indicate that its inhibition could help reverse CM hypertrophy.
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Affiliation(s)
- Peng Yue
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Shutao Xia
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, 430062, Hubei, China
| | - Gang Wu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lei Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Kaiyu Zhou
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Hongyu Liao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jiawen Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xiaolan Zheng
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yuxuan Guo
- Department of Cardiology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Yimin Hua
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Donghui Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, 430062, Hubei, China.
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
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16
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Affiliation(s)
- Barry London
- From the Division of Cardiovascular Medicine, University of Iowa, Iowa City.
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17
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Denham NC, Pearman CM, Caldwell JL, Madders GWP, Eisner DA, Trafford AW, Dibb KM. Calcium in the Pathophysiology of Atrial Fibrillation and Heart Failure. Front Physiol 2018; 9:1380. [PMID: 30337881 PMCID: PMC6180171 DOI: 10.3389/fphys.2018.01380] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/11/2018] [Indexed: 12/20/2022] Open
Abstract
Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship exists between the two-AF exacerbates heart failure causing a significant increase in heart failure symptoms, admissions to hospital and cardiovascular death, while pathological remodeling of the atria as a result of heart failure increases the risk of AF. A comprehensive understanding of the pathophysiology of AF is essential if we are to break this vicious circle. In this review, the latest evidence will be presented showing a fundamental role for calcium in both the induction and maintenance of AF. After outlining atrial electrophysiology and calcium handling, the role of calcium-dependent afterdepolarizations and atrial repolarization alternans in triggering AF will be considered. The atrial response to rapid stimulation will be discussed, including the short-term protection from calcium overload in the form of calcium signaling silencing and the eventual progression to diastolic calcium leak causing afterdepolarizations and the development of an electrical substrate that perpetuates AF. The role of calcium in the bidirectional relationship between heart failure and AF will then be covered. The effects of heart failure on atrial calcium handling that promote AF will be reviewed, including effects on both atrial myocytes and the pulmonary veins, before the aspects of AF which exacerbate heart failure are discussed. Finally, the limitations of human and animal studies will be explored allowing contextualization of what are sometimes discordant results.
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Affiliation(s)
- Nathan C. Denham
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | | | | | | | | | | | - Katharine M. Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
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18
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Guo Y, Jardin BD, Zhou P, Sethi I, Akerberg BN, Toepfer CN, Ai Y, Li Y, Ma Q, Guatimosim S, Hu Y, Varuzhanyan G, VanDusen NJ, Zhang D, Chan DC, Yuan GC, Seidman CE, Seidman JG, Pu WT. Hierarchical and stage-specific regulation of murine cardiomyocyte maturation by serum response factor. Nat Commun 2018; 9:3837. [PMID: 30242271 PMCID: PMC6155060 DOI: 10.1038/s41467-018-06347-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023] Open
Abstract
After birth, cardiomyocytes (CM) acquire numerous adaptations in order to efficiently pump blood throughout an animal's lifespan. How this maturation process is regulated and coordinated is poorly understood. Here, we perform a CRISPR/Cas9 screen in mice and identify serum response factor (SRF) as a key regulator of CM maturation. Mosaic SRF depletion in neonatal CMs disrupts many aspects of their maturation, including sarcomere expansion, mitochondrial biogenesis, transverse-tubule formation, and cellular hypertrophy. Maintenance of maturity in adult CMs is less dependent on SRF. This stage-specific activity is associated with developmentally regulated SRF chromatin occupancy and transcriptional regulation. SRF directly activates genes that regulate sarcomere assembly and mitochondrial dynamics. Perturbation of sarcomere assembly but not mitochondrial dynamics recapitulates SRF knockout phenotypes. SRF overexpression also perturbs CM maturation. Together, these data indicate that carefully balanced SRF activity is essential to promote CM maturation through a hierarchy of cellular processes orchestrated by sarcomere assembly.
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Affiliation(s)
- Yuxuan Guo
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Blake D Jardin
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Pingzhu Zhou
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Isha Sethi
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA, 02215, USA
| | - Brynn N Akerberg
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Christopher N Toepfer
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
- Radcliffe Department of Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Yulan Ai
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Yifei Li
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Qing Ma
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte, MG, CEP: 31270-901, Brazil
| | - Yongwu Hu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Wenzhou Medical University, School of Life Sciences, Wenzhou, China
| | - Grigor Varuzhanyan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, MC 114-96, Pasadena, CA, 91125, USA
| | - Nathan J VanDusen
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Donghui Zhang
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, 430062, Wuhan, China
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, MC 114-96, Pasadena, CA, 91125, USA
| | - Guo-Cheng Yuan
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA, 02215, USA
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD, 20815, USA
| | - Jonathan G Seidman
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - William T Pu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA, 02138, USA.
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Wang Y, Chen B, Huang CK, Guo A, Wu J, Zhang X, Chen R, Chen C, Kutschke W, Weiss RM, Boudreau RL, Margulies KB, Hong J, Song LS. Targeting Calpain for Heart Failure Therapy: Implications From Multiple Murine Models. JACC Basic Transl Sci 2018; 3:503-517. [PMID: 30175274 PMCID: PMC6115647 DOI: 10.1016/j.jacbts.2018.05.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/20/2018] [Accepted: 05/15/2018] [Indexed: 12/11/2022]
Abstract
Calpain is hyperactivated in human failing hearts and rodent heart failure models of different etiologies. Inhibition of calpain activity with MDL-28170 protects against cardiac dysfunction by preserving JP2 expression and T-tubule ultrastructural integrity in murine models of heart failure. Overexpression of JP2 delays the onset of early cardiac sudden death and heart failure, induced by calpain overactivation.
Heart failure remains a major cause of morbidity and mortality in developed countries. There is still a strong need to devise new mechanism-based treatments for heart failure. Numerous studies have suggested the importance of the Ca2+-dependent protease calpain in cardiac physiology and pathology. However, no drugs are currently under development or testing in human patients to target calpain for heart failure treatment. Herein the data demonstrate that inhibition of calpain activity protects against deleterious ultrastructural remodeling and cardiac dysfunction in multiple rodent models of heart failure, providing compelling evidence that calpain inhibition is a promising therapeutic strategy for heart failure treatment.
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Key Words
- CAPN1-OE, calpain-1 overexpressing
- E-C coupling, excitation-contraction coupling
- EF, ejection fraction
- IP, intraperitoneally
- ISO, isoproterenol
- JP2, junctophilin-2
- JP2-OE, junctophilin-2 overexpressing
- LV, left ventricle/ventricular
- MI, myocardial infarction
- RV, right ventricular
- SR, sarcoplasmic reticulum
- T-tubule, transverse tubule
- T-tubules
- TAB, transverse aortic banding
- TTpower, strength of regularity of the T-tubule system
- WT, wild-type
- calcium
- calpain
- excitation-contraction coupling
- heart failure
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Affiliation(s)
- Yihui Wang
- Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China.,Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa.,Department of Veterans Affairs Medical Center, Iowa City, Iowa
| | - Chun-Kai Huang
- Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China.,Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Ang Guo
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Jennifer Wu
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Xiaoming Zhang
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Rong Chen
- Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China.,Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Cheng Chen
- Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China.,Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - William Kutschke
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Robert M Weiss
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Ryan L Boudreau
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa
| | - Kenneth B Margulies
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Jiang Hong
- Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine & François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine; Iowa City, Iowa.,Department of Veterans Affairs Medical Center, Iowa City, Iowa
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20
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Song Z, Liu MB, Qu Z. Transverse tubular network structures in the genesis of intracellular calcium alternans and triggered activity in cardiac cells. J Mol Cell Cardiol 2018; 114:288-299. [PMID: 29217432 PMCID: PMC5801147 DOI: 10.1016/j.yjmcc.2017.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/31/2017] [Accepted: 12/04/2017] [Indexed: 12/20/2022]
Abstract
RATIONALE The major role of a transverse-tubular (TT) network in a cardiac cell is to facilitate effective excitation-contraction coupling and signaling. The TT network structures are heterogeneous within a single cell, and vary between different types of cells and species. They are also remodeled in cardiac diseases. However, how different TT network structures predispose cardiac cells to arrhythmogenesis remains to be revealed. OBJECTIVE To systematically investigate the roles of TT network structure and the underlying mechanisms in the genesis of intracellular calcium (Ca2+) alternans and triggered activity (TA). METHODS AND RESULTS Based on recent experimental observations, different TT network structures, including uniformly and non-uniformly random TT distributions, were modeled in a cardiac cell model consisting of a three-dimensional network of Ca2+ release units (CRUs). Our simulations showed that both Ca2+ alternans and Ca2+ wave-mediated TA were promoted when the fraction of orphaned CRUs was in an intermediate range, but suppressed in cells exhibiting either well-organized TT networks or low TT densities. Ca2+ alternans and TA could be promoted by low TT densities when the cells were small or the CRU coupling was strong. Both alternans and TA occurred more easily in uniformly random TT networks than in non-uniformly random TT networks. Subcellular spatially discordant Ca2+ alternans was promoted by non-uniformly random TT networks but suppressed by increasing CRU coupling strength. These mechanistic insights provide a holistic understanding of the effects of TT network structure on the susceptibility to arrhythmogenesis. CONCLUSIONS The TT network plays important roles in promoting Ca2+ alternans and TA, and different TT network structures may predispose cardiac cells differently to arrhythmogenesis.
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Affiliation(s)
- Zhen Song
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
| | - Michael B Liu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Zhilin Qu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
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21
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Wu Z, Rademakers T, Kiessling F, Vogt M, Westein E, Weber C, Megens RT, van Zandvoort M. Multi-photon microscopy in cardiovascular research. Methods 2017; 130:79-89. [DOI: 10.1016/j.ymeth.2017.04.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/27/2017] [Accepted: 04/11/2017] [Indexed: 01/26/2023] Open
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22
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Guo Y, VanDusen NJ, Zhang L, Gu W, Sethi I, Guatimosim S, Ma Q, Jardin BD, Ai Y, Zhang D, Chen B, Guo A, Yuan GC, Song LS, Pu WT. Analysis of Cardiac Myocyte Maturation Using CASAAV, a Platform for Rapid Dissection of Cardiac Myocyte Gene Function In Vivo. Circ Res 2017; 120:1874-1888. [PMID: 28356340 PMCID: PMC5466492 DOI: 10.1161/circresaha.116.310283] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/22/2017] [Accepted: 03/29/2017] [Indexed: 11/16/2022]
Abstract
RATIONALE Loss-of-function studies in cardiac myocytes (CMs) are currently limited by the need for appropriate conditional knockout alleles. The factors that regulate CM maturation are poorly understood. Previous studies on CM maturation have been confounded by heart dysfunction caused by whole organ gene inactivation. OBJECTIVE To develop a new technical platform to rapidly characterize cell-autonomous gene function in postnatal murine CMs and apply it to identify genes that regulate transverse tubules (T-tubules), a hallmark of mature CMs. METHODS AND RESULTS We developed CRISPR/Cas9/AAV9-based somatic mutagenesis, a platform in which AAV9 delivers tandem guide RNAs targeting a gene of interest and cardiac troponin-T promoter-driven Cre to RosaCas9GFP/Cas9GFP neonatal mice. When directed against junctophilin-2 (Jph2), a gene previously implicated in T-tubule maturation, we achieved efficient, rapid, and CM-specific JPH2 depletion. High-dose AAV9 ablated JPH2 in 64% CMs and caused lethal heart failure, whereas low-dose AAV9 ablated JPH2 in 22% CMs and preserved normal heart function. In the context of preserved heart function, CMs lacking JPH2 developed T-tubules that were nearly morphologically normal, indicating that JPH2 does not have a major, cell-autonomous role in T-tubule maturation. However, in hearts with severe dysfunction, both adeno-associated virus-transduced and nontransduced CMs exhibited T-tubule disruption, which was more severe in the transduced subset. These data indicate that cardiac dysfunction disrupts T-tubule structure and that JPH2 protects T-tubules in this context. We then used CRISPR/Cas9/AAV9-based somatic mutagenesis to screen 8 additional genes for required, cell-autonomous roles in T-tubule formation. We identified RYR2 (Ryanodine Receptor-2) as a novel, cell-autonomously required T-tubule maturation factor. CONCLUSIONS CRISPR/Cas9/AAV9-based somatic mutagenesis is a powerful tool to study cell-autonomous gene functions. Genetic mosaics are invaluable to accurately define cell-autonomous gene function. JPH2 has a minor role in normal T-tubule maturation but is required to stabilize T-tubules in the failing heart. RYR2 is a novel T-tubule maturation factor.
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Affiliation(s)
- Yuxuan Guo
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Nathan J VanDusen
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Lina Zhang
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Weiliang Gu
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Isha Sethi
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Silvia Guatimosim
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Qing Ma
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Blake D Jardin
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Yulan Ai
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Donghui Zhang
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Biyi Chen
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Ang Guo
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Guo-Cheng Yuan
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - Long-Sheng Song
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.)
| | - William T Pu
- From the Cardiology, Boston Children's Hospital, MA (Y.G., N.J.V., Q.M., B.D.J., Y.A., D.Z., W.T.P.); Institute of Basic Medicine (L.Z.) and Pharmacology, School of Pharmacy (W.G.), Shanghai University of Traditional Chinese Medicine, China; Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA (I.S., G.-C.Y.); Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil (S.G.); Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City (B.C., A.G., L.-S.S.); Veterans Affairs Medical Center, Iowa City (L.-S.S.); and Harvard Stem Cell Institute, Cambridge, MA (W.T.P.).
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Crocini C, Ferrantini C, Coppini R, Sacconi L. Electrical defects of the transverse-axial tubular system in cardiac diseases. J Physiol 2017; 595:3815-3822. [PMID: 27981580 PMCID: PMC5471422 DOI: 10.1113/jp273042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/21/2016] [Indexed: 01/20/2023] Open
Abstract
Electrical excitability is an essential feature of cardiomyocytes and the homogenous propagation of the action potential is guaranteed by a complex network of membrane invaginations called the transverse-axial tubular system (TATS). TATS structural remodelling is a hallmark of cardiac diseases and we demonstrated that this can be accompanied by electrical defects at single T-tubular level. Using a random-access multi-photon (RAMP) microscope, we found that pathological T-tubules can fail to conduct action potentials, which delays local Ca2+ release. Although the underlying causes for T-tubular electrical failure are still unknown, our findings suggest that they are likely to be related to local ultrastructural alterations. Here, we first review the experimental approach that allowed us to observe and dissect the consequences of TATS electrical dysfunction and then propose two different strategies to unveil the reasons for T-tubular electrical failures. The first strategy consists in a correlative approach, in which the failing T-tubule identified with the RAMP microscope is then imaged with electron microscopy. The second approach exploits the diffusion of molecules within TATS to gain insights into the local TATS structure, even without a thorough reconstruction of the tubular network. Although challenging, the local electrical failure occurring at single T-tubules is a fundamental question that needs to be addressed and could provide novel insights in cardiac pathophysiology.
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Affiliation(s)
- Claudia Crocini
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, 50125, Florence, Italy
| | - Cecilia Ferrantini
- Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, 50134, Florence, Italy
| | - Raffaele Coppini
- Division of Pharmacology, Department 'NeuroFarBa', University of Florence, 50139, Florence, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, 50019, Sesto Fiorentino, Italy.,National Institute of Optics, National Research Council, 50125, Florence, Italy
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Arora R, Aistrup GL, Supple S, Frank C, Singh J, Tai S, Zhao A, Chicos L, Marszalec W, Guo A, Song LS, Wasserstrom JA. Regional distribution of T-tubule density in left and right atria in dogs. Heart Rhythm 2016; 14:273-281. [PMID: 27670628 DOI: 10.1016/j.hrthm.2016.09.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND The peculiarities of transverse tubule (T-tubule) morphology and distribution in the atrium-and how they contribute to excitation-contraction coupling-are just beginning to be understood. OBJECTIVES The objectives of this study were to determine T-tubule density in the intact, live right and left atria in a large animal and to determine intraregional differences in T-tubule organization within each atrium. METHODS Using confocal microscopy, T-tubules were imaged in both atria in intact, Langendorf-perfused normal dog hearts loaded with di-4-ANEPPS. T-tubules were imaged in large populations of myocytes from the endocardial surface of each atrium. Computerized data analysis was performed using a new MatLab (Mathworks, Natick, MA) routine, AutoTT. RESULTS There was a large percentage of myocytes that had no T-tubules in both atria with a higher percentage in the right atrium (25.1%) than in the left atrium (12.5%) (P < .02). The density of transverse and longitudinal T-tubule elements was low in cells that did contain T-tubules, but there were no significant differences in density between the left atrial appendage, the pulmonary vein-posterior left atrium, the right atrial appendage, and the right atrial free wall. In contrast, there were significant differences in sarcomere spacing and cell width between different regions of the atria. CONCLUSION There is a sparse T-tubule network in atrial myocytes throughout both dog atria, with significant numbers of myocytes in both atria-the right atrium more so than the left atrium-having no T-tubules at all. These regional differences in T-tubule distribution, along with differences in cell width and sarcomere spacing, may have implications for the emergence of substrate for atrial fibrillation.
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Affiliation(s)
- Rishi Arora
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois,.
| | - Gary L Aistrup
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Stephen Supple
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Caleb Frank
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Jasleen Singh
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Shannon Tai
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Anne Zhao
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Laura Chicos
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - William Marszalec
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ang Guo
- Division of Cardiology, University of Iowa School of Medicine, Iowa City, Iowa
| | - Long-Sheng Song
- Division of Cardiology, University of Iowa School of Medicine, Iowa City, Iowa
| | - J Andrew Wasserstrom
- Division of Cardiology, Department of Medicine, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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25
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Zhu Y, Zhang C, Chen B, Chen R, Guo A, Hong J, Song LS. Cholesterol is required for maintaining T-tubule integrity and intercellular connections at intercalated discs in cardiomyocytes. J Mol Cell Cardiol 2016; 97:204-12. [PMID: 27255730 PMCID: PMC5002380 DOI: 10.1016/j.yjmcc.2016.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/25/2016] [Accepted: 05/25/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUNDS Low serum cholesterol levels are associated with cardiac arrhythmias and poor prognosis in patients with chronic heart failure. However, the underlying mechanisms by which decreases in cholesterol content lead to cardiac dysfunction remain unclear. Multiple studies have implicated damage to cardiac transverse (T)-tubules as a key mediator of excitation-contraction (E-C) coupling dysfunction and heart failure. Since the T-tubule membrane system is enriched in cholesterol, we hypothesized that depletion of membrane cholesterol promotes T-tubule remodeling and E-C coupling dysfunction. METHODS AND RESULTS We first examined the impact of membrane cholesterol depletion on T-tubule architecture by treating isolated C57BL/6 murine cardiomyocytes with methyl-β-cyclodextrin (MβCD). T-tubule structural integrity was progressively decreased by MβCD in a concentration- and time-dependent manner. Membrane cholesterol depletion also promoted a severe decrease in the amplitude of Ca(2+) transients and an increase in Ca(2+) release dyssynchrony as well as a significant increase in the frequency of spontaneous Ca(2+) sparks. Reintroduction of cholesterol restored T-tubule integrity and partially restored Ca(2+) handling properties in acutely-treated myocytes and slowed T-tubule deterioration in response to chronic MβCD exposure. Studies were extended to determine the impact of membrane cholesterol depletion on T-tubule structure in intact hearts. In addition to T-tubule remodeling, Langendorff perfusion of MβCD resulted in rapid and severe disruption of the intercellular connections between cardiomyocytes, in particular at intercalated disc regions in intact hearts. CONCLUSIONS These data provide the first evidence that cholesterol plays a critical role in maintaining cardiac T-tubule structure as well as the integrity of intercalated discs.
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Affiliation(s)
- Yanqi Zhu
- Department of Cardiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China; Division of Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Caimei Zhang
- Division of Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Rong Chen
- Department of Cardiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China; Department of Pharmacy, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Ang Guo
- Division of Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jiang Hong
- Department of Cardiology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China; Department of Pharmacy, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, François M. Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Veterans Affairs Medical Center, Iowa City, IA 52242, USA.
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