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Lahiri SK, Lu J, Aguilar-Sanchez Y, Li H, Moreira LM, Hulsurkar MM, Mendoza A, Turkieltaub Paredes MR, Navarro-Garcia JA, Munivez E, Horist B, Moore OM, Weninger G, Brandenburg S, Lenz C, Lehnart SE, Sayeed R, Krasopoulos G, Srivastava V, Zhang L, Karch JM, Reilly S, Wehrens XHT. Targeting calpain-2-mediated junctophilin-2 cleavage delays heart failure progression following myocardial infarction. J Mol Cell Cardiol 2024; 194:85-95. [PMID: 38960317 DOI: 10.1016/j.yjmcc.2024.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 06/18/2024] [Accepted: 06/29/2024] [Indexed: 07/05/2024]
Abstract
Coronary heart disease (CHD) is a prevalent cardiac disease that causes over 370,000 deaths annually in the USA. In CHD, occlusion of a coronary artery causes ischemia of the cardiac muscle, which results in myocardial infarction (MI). Junctophilin-2 (JPH2) is a membrane protein that ensures efficient calcium handling and proper excitation-contraction coupling. Studies have identified loss of JPH2 due to calpain-mediated proteolysis as a key pathogenic event in ischemia-induced heart failure (HF). Our findings show that calpain-2-mediated JPH2 cleavage yields increased levels of a C-terminal cleaved peptide (JPH2-CTP) in patients with ischemic cardiomyopathy and mice with experimental MI. We created a novel knock-in mouse model by removing residues 479-SPAGTPPQ-486 to prevent calpain-2-mediated cleavage at this site. Functional and molecular assessment of cardiac function post-MI in cleavage site deletion (CSD) mice showed preserved cardiac contractility and reduced dilation, reduced JPH2-CTP levels, attenuated adverse remodeling, improved T-tubular structure, and normalized SR Ca2+-handling. Adenovirus mediated calpain-2 knockdown in mice exhibited similar findings. Pulldown of CTP followed by proteomic analysis revealed valosin-containing protein (VCP) and BAG family molecular chaperone regulator 3 (BAG3) as novel binding partners of JPH2. Together, our findings suggest that blocking calpain-2-mediated JPH2 cleavage may be a promising new strategy for delaying the development of HF following MI.
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Affiliation(s)
- Satadru K Lahiri
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Jiao Lu
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA; Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine
| | - Yuriana Aguilar-Sanchez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Hui Li
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Lucia M Moreira
- Cardiovascular Medicine, Radcliffe Dept of Medicine, University of Oxford, UK
| | - Mohit M Hulsurkar
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Arielys Mendoza
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Mara R Turkieltaub Paredes
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Jose Alberto Navarro-Garcia
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Elda Munivez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Brooke Horist
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Oliver M Moore
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Gunnar Weninger
- Department of Physiology and Cellular Biophysics, Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Sören Brandenburg
- Department of Cardiology & Pneumology, Heart Research Center Göttingen; Cellular Biophysics and Translational Cardiology Section, University Medical Center Göttingen, Göttingen, Germany
| | - Christof Lenz
- Department of Clinical Chemistry, University Medical Center Göttingen, Germany; Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Stephan E Lehnart
- Department of Cardiology & Pneumology, Heart Research Center Göttingen; Cellular Biophysics and Translational Cardiology Section, University Medical Center Göttingen, Göttingen, Germany
| | - Rana Sayeed
- Cardiothoracic Unit, John Radcliffe Hospital, Oxford, UK
| | | | | | - Lilei Zhang
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jason M Karch
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Svetlana Reilly
- Cardiovascular Medicine, Radcliffe Dept of Medicine, University of Oxford, UK
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA; Department of Medicine/Cardiology, Baylor College of Medicine, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Center for Space Medicine, Baylor College of Medicine, Houston, TX, USA.
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Hall DD, Takeshima H, Song LS. Structure, Function, and Regulation of the Junctophilin Family. Annu Rev Physiol 2024; 86:123-147. [PMID: 37931168 PMCID: PMC10922073 DOI: 10.1146/annurev-physiol-042022-014926] [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] [Indexed: 11/08/2023]
Abstract
In both excitable and nonexcitable cells, diverse physiological processes are linked to different calcium microdomains within nanoscale junctions that form between the plasma membrane and endo-sarcoplasmic reticula. It is now appreciated that the junctophilin protein family is responsible for establishing, maintaining, and modulating the structure and function of these junctions. We review foundational findings from more than two decades of research that have uncovered how junctophilin-organized ultrastructural domains regulate evolutionarily conserved biological processes. We discuss what is known about the junctophilin family of proteins. Our goal is to summarize the current knowledge of junctophilin domain structure, function, and regulation and to highlight emerging avenues of research that help our understanding of the transcriptional, translational, and post-translational regulation of this gene family and its roles in health and during disease.
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Affiliation(s)
- Duane D Hall
- Department of Internal Medicine, Division of Cardiovascular Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; ,
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Long-Sheng Song
- Department of Internal Medicine, Division of Cardiovascular Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; ,
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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3
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Yang Q, Tadros HJ, Sun B, Bidzimou MT, Ezekian JE, Li F, Ludwig A, Wehrens XH, Landstrom AP. Junctional Ectopic Tachycardia Caused by Junctophilin-2 Expression Silencing Is Selectively Sensitive to Ryanodine Receptor Blockade. JACC Basic Transl Sci 2023; 8:1577-1588. [PMID: 38205351 PMCID: PMC10774596 DOI: 10.1016/j.jacbts.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/10/2023] [Accepted: 07/10/2023] [Indexed: 01/12/2024]
Abstract
Junctional ectopic tachycardia (JET) is a potentially fatal cardiac arrhythmia. Hcn4:shJph2 mice serve as a model of nodal arrhythmias driven by ryanodine type 2 receptor (RyR2)-mediated Ca2+ leak. EL20 is a small molecule that blocks RyR2 Ca2+ leak. In a novel in vivo model of JET, Hcn4:shJph2 mice demonstrated rapid conversion of JET to sinus rhythm with infusion of EL20. Primary atrioventricular nodal cells demonstrated increased Ca2+ transient oscillation frequency and increased RyR2-mediated stored Ca2+ leak which was normalized by EL20. EL20 was found to be rapidly degraded in mouse and human plasma, making it a potential novel therapy for JET.
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Affiliation(s)
- Qixin Yang
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hanna J. Tadros
- Section of Cardiology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Bo Sun
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Minu-Tshyeto Bidzimou
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jordan E. Ezekian
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Feng Li
- Center for Drug Discovery and Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie, und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Xander H.T. Wehrens
- Section of Cardiology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Cardiovascular Research Institute, Departments of Medicine (Cardiology), Molecular Physiology and Biophysics, and Neuroscience and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Andrew P. Landstrom
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
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Niloy SI, Shen Y, Guo L, O'Rourke ST, Sun C. Loss of IP3R-BK Ca Coupling Is Involved in Vascular Remodeling in Spontaneously Hypertensive Rats. Int J Mol Sci 2023; 24:10903. [PMID: 37446080 DOI: 10.3390/ijms241310903] [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: 06/05/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Mechanisms by which BKCa (large-conductance calcium-sensitive potassium) channels are involved in vascular remodeling in hypertension are not fully understood. Vascular smooth muscle cell (VSMC) proliferation and vascular morphology were compared between hypertensive and normotensive rats. BKCa channel activity, protein expression, and interaction with IP3R (inositol 1,4,5-trisphosphate receptor) were examined using patch clamp, Western blot analysis, and coimmunoprecipitation. On inside-out patches of VSMCs, the Ca2+-sensitivity and voltage-dependence of BKCa channels were similar between hypertensive and normotensive rats. In whole-cell patch clamp configuration, treatment of cells with the IP3R agonist, Adenophostin A (AdA), significantly increased BKCa channel currents in VSMCs of both strains of rats, suggesting IP3R-BKCa coupling; however, the AdA-induced increases in BKCa currents were attenuated in VSMCs of hypertensive rats, indicating possible IP3R-BKCa decoupling, causing BKCa dysfunction. Co-immunoprecipitation and Western blot analysis demonstrated that BKCa and IP3R proteins were associated together in VSMCs; however, the association of BKCa and IP3R proteins was dramatically reduced in VSMCs of hypertensive rats. Genetic disruption of IP3R-BKCa coupling using junctophilin-2 shRNA dramatically augmented Ang II-induced proliferation in VSMCs of normotensive rats. Subcutaneous infusion of NS1619, a BKCa opener, to reverse BKCa dysfunction caused by IP3R-BKCa decoupling significantly attenuated vascular hypertrophy in hypertensive rats. In summary, the data from this study demonstrate that loss of IP3R-BKCa coupling in VSMCs induces BKCa channel dysfunction, enhances VSMC proliferation, and thus, may contribute to vascular hypertrophy in hypertension.
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Affiliation(s)
- Sayeman Islam Niloy
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Yue Shen
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Lirong Guo
- School of Nursing, Jilin University, Changchun 130021, China
| | - Stephen T O'Rourke
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
| | - Chengwen Sun
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58105, USA
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Xu X, Elkenani M, Tan X, Hain JK, Cui B, Schnelle M, Hasenfuss G, Toischer K, Mohamed BA. DNA Methylation Analysis Identifies Novel Epigenetic Loci in Dilated Murine Heart upon Exposure to Volume Overload. Int J Mol Sci 2023; 24:ijms24065885. [PMID: 36982963 PMCID: PMC10059258 DOI: 10.3390/ijms24065885] [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: 02/16/2023] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Left ventricular (LV) dilatation, a prominent risk factor for heart failure (HF), precedes functional deterioration and is used to stratify patients at risk for arrhythmias and cardiac mortality. Aberrant DNA methylation contributes to maladaptive cardiac remodeling and HF progression following pressure overload and ischemic cardiac insults. However, no study has examined cardiac DNA methylation upon exposure to volume overload (VO) despite being relatively common among HF patients. We carried out global methylome analysis of LV harvested at a decompensated HF stage following exposure to VO induced by aortocaval shunt. VO resulted in pathological cardiac remodeling, characterized by massive LV dilatation and contractile dysfunction at 16 weeks after shunt. Although methylated DNA was not markedly altered globally, 25 differentially methylated promoter regions (DMRs) were identified in shunt vs. sham hearts (20 hypermethylated and 5 hypomethylated regions). The validated hypermethylated loci in Junctophilin-2 (Jph2), Signal peptidase complex subunit 3 (Spcs3), Vesicle-associated membrane protein-associated protein B (Vapb), and Inositol polyphosphate multikinase (Ipmk) were associated with the respective downregulated expression and were consistently observed in dilated LV early after shunt at 1 week after shunt, before functional deterioration starts to manifest. These hypermethylated loci were also detected peripherally in the blood of the shunt mice. Altogether, we have identified conserved DMRs that could be novel epigenetic biomarkers in dilated LV upon VO exposure.
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Affiliation(s)
- Xingbo Xu
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
| | - Manar Elkenani
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
- Department of Clinical Pathology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Xiaoying Tan
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
- Department of Nephrology and Rheumatology, University Medical Center of Göttingen, 37075 Göttingen, Germany
| | - Jara Katharina Hain
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Baolong Cui
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
| | - Moritz Schnelle
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
- Department of Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Gerd Hasenfuss
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
| | - Karl Toischer
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
| | - Belal A Mohamed
- Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), 37075 Göttingen, Germany
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Calcium Handling in Inherited Cardiac Diseases: A Focus on Catecholaminergic Polymorphic Ventricular Tachycardia and Hypertrophic Cardiomyopathy. Int J Mol Sci 2023; 24:ijms24043365. [PMID: 36834774 PMCID: PMC9963263 DOI: 10.3390/ijms24043365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 02/10/2023] Open
Abstract
Calcium (Ca2+) is the major mediator of cardiac contractile function. It plays a key role in regulating excitation-contraction coupling and modulating the systolic and diastolic phases. Defective handling of intracellular Ca2+ can cause different types of cardiac dysfunction. Thus, the remodeling of Ca2+ handling has been proposed to be a part of the pathological mechanism leading to electrical and structural heart diseases. Indeed, to ensure appropriate electrical cardiac conduction and contraction, Ca2+ levels are regulated by several Ca2+-related proteins. This review focuses on the genetic etiology of cardiac diseases related to calcium mishandling. We will approach the subject by focalizing on two clinical entities: catecholaminergic polymorphic ventricular tachycardia (CPVT) as a cardiac channelopathy and hypertrophic cardiomyopathy (HCM) as a primary cardiomyopathy. Further, this review will illustrate the fact that despite the genetic and allelic heterogeneity of cardiac defects, calcium-handling perturbations are the common pathophysiological mechanism. The newly identified calcium-related genes and the genetic overlap between the associated heart diseases are also discussed in this review.
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7
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Landstrom AP, Yang Q, Sun B, Perelli RM, Bidzimou MT, Zhang Z, Aguilar-Sanchez Y, Alsina KM, Cao S, Reynolds JO, Word TA, van der Sangen NM, Wells Q, Kannankeril PJ, Ludwig A, Kim JJ, Wehrens XH. Reduction in Junctophilin 2 Expression in Cardiac Nodal Tissue Results in Intracellular Calcium-Driven Increase in Nodal Cell Automaticity. Circ Arrhythm Electrophysiol 2023; 16:e010858. [PMID: 36706317 PMCID: PMC9974897 DOI: 10.1161/circep.122.010858] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/06/2023] [Indexed: 01/29/2023]
Abstract
BACKGROUND Spontaneously depolarizing nodal cells comprise the pacemaker of the heart. Intracellular calcium (Ca2+) plays a critical role in mediating nodal cell automaticity and understanding this so-called Ca2+ clock is critical to understanding nodal arrhythmias. We previously demonstrated a role for Jph2 (junctophilin 2) in regulating Ca2+-signaling through inhibition of RyR2 (ryanodine receptor 2) Ca2+ leak in cardiac myocytes; however, its role in pacemaker function and nodal arrhythmias remains unknown. We sought to determine whether nodal Jph2 expression silencing causes increased sinoatrial and atrioventricular nodal cell automaticity due to aberrant RyR2 Ca2+ leak. METHODS A tamoxifen-inducible, nodal tissue-specific, knockdown mouse of Jph2 was achieved using a Cre-recombinase-triggered short RNA hairpin directed against Jph2 (Hcn4:shJph2). In vivo cardiac rhythm was monitored by surface ECG, implantable cardiac telemetry, and intracardiac electrophysiology studies. Intracellular Ca2+ imaging was performed using confocal-based line scans of isolated nodal cells loaded with fluorescent Ca2+ reporter Cal-520. Whole cell patch clamp was conducted on isolated nodal cells to determine action potential kinetics and sodium-calcium exchanger function. RESULTS Hcn4:shJph2 mice demonstrated a 40% reduction in nodal Jph2 expression, resting sinus tachycardia, and impaired heart rate response to pharmacologic stress. In vivo intracardiac electrophysiology studies and ex vivo optical mapping demonstrated accelerated junctional rhythm originating from the atrioventricular node. Hcn4:shJph2 nodal cells demonstrated increased and irregular Ca2+ transient generation with increased Ca2+ spark frequency and Ca2+ leak from the sarcoplasmic reticulum. This was associated with increased nodal cell AP firing rate, faster diastolic repolarization rate, and reduced sodium-calcium exchanger activity during repolarized states compared to control. Phenome-wide association studies of the JPH2 locus identified an association with sinoatrial nodal disease and atrioventricular nodal block. CONCLUSIONS Nodal-specific Jph2 knockdown causes increased nodal automaticity through increased Ca2+ leak from intracellular stores. Dysregulated intracellular Ca2+ underlies nodal arrhythmogenesis in this mouse model.
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Affiliation(s)
- Andrew P. Landstrom
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
- Dept of Cell Biology, Duke Univ School of Medicine, Durham, NC
| | - Qixin Yang
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
- Dept of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang Univ, Hangzhou, China
| | - Bo Sun
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
| | | | | | - Zhushan Zhang
- Dept of Cell Biology, Duke Univ School of Medicine, Durham, NC
| | - Yuriana Aguilar-Sanchez
- Integrative Molecular & Biomedical Sciences Program, Baylor College of Medicine, Houston, TX
| | - Katherina M. Alsina
- Integrative Molecular & Biomedical Sciences Program, Baylor College of Medicine, Houston, TX
| | - Shuyi Cao
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | - Julia O. Reynolds
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | - Tarah A. Word
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | | | - Quinn Wells
- Depts of Medicine, Pharmacology, and Biomedical Informatics, Vanderbilt Univ School of Medicine, Nashville, TN
| | - Prince J. Kannankeril
- Center for Pediatric Precision Medicine, Dept of Pediatrics, Vanderbilt Univ School of Medicine, Nashville, TN
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jeffrey J. Kim
- Dept of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, TX
| | - Xander H.T. Wehrens
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
- Dept of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, TX
- Depts of Neuroscience & Center for Space Medicine and the Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
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8
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Keefe JA, Moore OM, Ho KS, Wehrens XHT. Role of Ca 2+ in healthy and pathologic cardiac function: from normal excitation-contraction coupling to mutations that cause inherited arrhythmia. Arch Toxicol 2023; 97:73-92. [PMID: 36214829 PMCID: PMC10122835 DOI: 10.1007/s00204-022-03385-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/15/2022] [Indexed: 01/19/2023]
Abstract
Calcium (Ca2+) ions are a key second messenger involved in the rhythmic excitation and contraction of cardiomyocytes throughout the heart. Proper function of Ca2+-handling proteins is required for healthy cardiac function, whereas disruption in any of these can cause cardiac arrhythmias. This comprehensive review provides a broad overview of the roles of Ca2+-handling proteins and their regulators in healthy cardiac function and the mechanisms by which mutations in these proteins contribute to inherited arrhythmias. Major Ca2+ channels and Ca2+-sensitive regulatory proteins involved in cardiac excitation-contraction coupling are discussed, with special emphasis on the function of the RyR2 macromolecular complex. Inherited arrhythmia disorders including catecholaminergic polymorphic ventricular tachycardia, long QT syndrome, Brugada syndrome, short QT syndrome, and arrhythmogenic right-ventricular cardiomyopathy are discussed with particular emphasis on subtypes caused by mutations in Ca2+-handling proteins.
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Affiliation(s)
- Joshua A Keefe
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Oliver M Moore
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kevin S Ho
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA. .,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Center for Space Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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9
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Ji XY, Zheng D, Ni R, Wang JX, Shao JQ, Vue Z, Hinton A, Song LS, Fan GC, Chakrabarti S, Su ZL, Peng TQ. Sustained over-expression of calpain-2 induces age-dependent dilated cardiomyopathy in mice through aberrant autophagy. Acta Pharmacol Sin 2022; 43:2873-2884. [PMID: 35986214 PMCID: PMC9622835 DOI: 10.1038/s41401-022-00965-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 07/24/2022] [Indexed: 11/09/2022] Open
Abstract
Calpains have been implicated in heart diseases. While calpain-1 has been detrimental to the heart, the role of calpain-2 in cardiac pathology remains controversial. In this study we investigated whether sustained over-expression of calpain-2 had any adverse effects on the heart and the underlying mechanisms. Double transgenic mice (Tg-Capn2/tTA) were generated, which express human CAPN2 restricted to cardiomyocytes. The mice were subjected to echocardiography at age 3, 6, 8 and 12 months, and their heart tissues and sera were collected for analyses. We showed that transgenic mice over-expressing calpain-2 restricted to cardiomyocytes had normal heart function with no evidence of cardiac pathological remodeling at age 3 months. However, they exhibited features of dilated cardiomyopathy including increased heart size, enlarged heart chambers and heart dysfunction from age 8 months; histological analysis revealed loss of cardiomyocytes replaced by myocardial fibrosis and cardiomyocyte hypertrophy in transgenic mice from age 8 months. These cardiac alterations closely correlated with aberrant autophagy evidenced by significantly increased LC3BII and p62 protein levels and accumulation of autophagosomes in the hearts of transgenic mice. Notably, injection of 3-methyladenine, a well-established inhibitor of autophagy (30 mg/kg, i.p. once every 3 days starting from age 6 months for 2 months) prevented aberrant autophagy, attenuated myocardial injury and improved heart function in the transgenic mice. In cultured cardiomyocytes, over-expression of calpain-2 blocked autophagic flux by impairing lysosomal function. Furthermore, over-expression of calpain-2 resulted in lower levels of junctophilin-2 protein in the heart of transgenic mice and in cultured cardiomyocytes, which was attenuated by 3-methyladenine. In addition, blockade of autophagic flux by bafilomycin A (100 nM) induced a reduction of junctophilin-2 protein in cardiomyocytes. In summary, transgenic over-expression of calpain-2 induces age-dependent dilated cardiomyopathy in mice, which may be mediated through aberrant autophagy and a reduction of junctophilin-2. Thus, a sustained increase in calpain-2 may be detrimental to the heart.
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Affiliation(s)
- Xiao-Yun Ji
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China
- Lawson Health Research Institute, London Health Sciences Centre, London, ON, N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 5C1, Canada
| | - Dong Zheng
- Centre of Clinical Laboratory, the First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Rui Ni
- Lawson Health Research Institute, London Health Sciences Centre, London, ON, N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 5C1, Canada
| | - Jin-Xi Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Jian-Qiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Guo-Chang Fan
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Subrata Chakrabarti
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 5C1, Canada
| | - Zhao-Liang Su
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China.
| | - Tian-Qing Peng
- Lawson Health Research Institute, London Health Sciences Centre, London, ON, N6A 5W9, Canada.
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 5C1, Canada.
- Department of Medicine, Western University, London, ON, N6A 5W9, Canada.
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10
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Yu L, Hall DD, Zhao W, Song LS. NMR resonance assignments of the DNA binding domain of mouse Junctophilin-2. BIOMOLECULAR NMR ASSIGNMENTS 2022; 16:273-279. [PMID: 35665900 PMCID: PMC10394741 DOI: 10.1007/s12104-022-10091-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Junctophilin-2 (JP2) is a critical structural protein in the heart by stabilizing junctional membrane complexes between the plasma membrane and sarcoplasmic reticula responsible for precise Ca2+ regulation. Such complexes are essential for efficient cardiomyocyte contraction and adaptation to altered cardiac workload conditions. Mutations in the JPH2 gene that encodes JP2 are associated with inherited cardiomyopathies and arrhythmias, and disruption of JP2 function is lethal. Interestingly, cardiac stress promotes the proteolytic cleavage of JP2 that triggers the translocation of its N-terminal fragment into the nucleus to repress maladaptive gene transcription. We previously found that the central region of JP2 is responsible for mediating direct DNA binding interactions. Recent structural studies indicate that this region serves as a structural role in the cytosolic form of JP2 by folding into a single continuous α-helix. However, the structural basis of how this DNA-binding domain interacts with DNA is not known. Here, we report the backbone and sidechain assignments of the DNA-binding domain (residues 331-413) of mouse JP2. These assignments reveal that the JP2 DNA binding domain is an intrinsically disordered protein and contains two α-helices located in the C-terminal portion of the protein. Moreover, this protein binds to DNA in a similar manner to that shown previously by electrophoretic mobility shift assays. Therefore, these assignments provide a framework for further structural studies into the interaction of this JP2 domain with DNA for the elucidation of transcriptional regulation of stress-responsive genes as well as its role in the stabilization of junctional membrane complexes.
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Affiliation(s)
- Liping Yu
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, B291, CBRB, 285 Newton Road, Iowa City, IA, 52242, USA.
- CCOM NMR Core Facility, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
| | - Duane D Hall
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA
| | - Weiyang Zhao
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA
| | - Long-Sheng Song
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, B291, CBRB, 285 Newton Road, Iowa City, IA, 52242, USA.
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
- Iowa City Veterans Affairs Medical Center, Iowa City, IA, 52242, USA.
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11
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Weninger G, Pochechueva T, El Chami D, Luo X, Kohl T, Brandenburg S, Urlaub H, Guan K, Lenz C, Lehnart SE. Calpain cleavage of Junctophilin-2 generates a spectrum of calcium-dependent cleavage products and DNA-rich NT 1-fragment domains in cardiomyocytes. Sci Rep 2022; 12:10387. [PMID: 35725601 PMCID: PMC9209451 DOI: 10.1038/s41598-022-14320-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Calpains are calcium-activated neutral proteases involved in the regulation of key signaling pathways. Junctophilin-2 (JP2) is a Calpain-specific proteolytic target and essential structural protein inside Ca2+ release units required for excitation-contraction coupling in cardiomyocytes. While downregulation of JP2 by Calpain cleavage in heart failure has been reported, the precise molecular identity of the Calpain cleavage sites and the (patho-)physiological roles of the JP2 proteolytic products remain controversial. We systematically analyzed the JP2 cleavage fragments as function of Calpain-1 versus Calpain-2 proteolytic activities, revealing that both Calpain isoforms preferentially cleave mouse JP2 at R565, but subsequently at three additional secondary Calpain cleavage sites. Moreover, we identified the Calpain-specific primary cleavage products for the first time in human iPSC-derived cardiomyocytes. Knockout of RyR2 in hiPSC-cardiomyocytes destabilized JP2 resulting in an increase of the Calpain-specific cleavage fragments. The primary N-terminal cleavage product NT1 accumulated in the nucleus of mouse and human cardiomyocytes in a Ca2+-dependent manner, closely associated with euchromatic chromosomal regions, where NT1 is proposed to function as a cardio-protective transcriptional regulator in heart failure. Taken together, our data suggest that stabilizing NT1 by preventing secondary cleavage events by Calpain and other proteases could be an important therapeutic target for future studies.
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Affiliation(s)
- Gunnar Weninger
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Department of Physiology and Cellular Biophysics, Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Tatiana Pochechueva
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany
| | - Dana El Chami
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany
| | - Xiaojing Luo
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01307, Dresden, Germany
| | - Tobias Kohl
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany
| | - Sören Brandenburg
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany
| | - Henning Urlaub
- Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Proteomanalyse, Department of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01307, Dresden, Germany
| | - Christof Lenz
- Proteomanalyse, Department of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany.
| | - Stephan E Lehnart
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany. .,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany. .,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany. .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany.
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12
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Lopes ECP, Paim LR, Carvalho-Romano LFRS, Marques ER, Minin EOZ, Vegian CFL, Pio-Magalhães JA, Velloso LA, Coelho-Filho OR, Sposito AC, Matos-Souza JR, Nadruz W, Schreiber R. Relationship Between Circulating MicroRNAs and Left Ventricular Hypertrophy in Hypertensive Patients. Front Cardiovasc Med 2022; 9:798954. [PMID: 35498018 PMCID: PMC9043518 DOI: 10.3389/fcvm.2022.798954] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 03/24/2022] [Indexed: 12/29/2022] Open
Abstract
Objective Left ventricular hypertrophy (LVH) is a common complication of hypertension and microRNAs (miRNAs) are considered to play an important role in cardiac hypertrophy development. This study evaluated the relationship between circulating miRNAs and LVH in hypertensive patients. Methods Two cohorts [exploratory (n = 42) and validation (n = 297)] of hypertensive patients were evaluated by clinical, laboratory and echocardiography analysis. The serum expression of 754 miRNAs in the exploratory cohort and 6 miRNAs in the validation cohort was evaluated by the TaqMan OpenArray® system and quantitative polymerase chain reaction, respectively. Results Among the 754 analyzed miRNAs, ten miRNAs (miR-30a-5p, miR-let7c, miR-92a, miR-451, miR-145-5p, miR-185, miR-338, miR-296, miR-375, and miR-10) had differential expression between individuals with and without LVH in the exploratory cohort. Results of multivariable regression analysis adjusted for confounding variables showed that three miRNAs (miR-145-5p, miR-451, and miR-let7c) were independently associated with LVH and left ventricular mass index in the validation cohort. Functional enrichment analysis demonstrated that these three miRNAs can regulate various genes and pathways related to cardiac remodeling. Furthermore, in vitro experiments using cardiac myocytes demonstrated that miR-145-5p mimic transfection up-regulated the expression of brain and atrial natriuretic peptide genes, which are markers of cardiac hypertrophy, while anti-miR-145-5p transfection abrogated the expression of these genes in response to norepinephrine stimulus. Conclusions Our data demonstrated that circulating levels of several miRNAs, in particular miR-145-5p, miR-451, and let7c, were associated with LVH in hypertensive patients, indicating that these miRNAS may be potential circulating biomarkers or involved in hypertension-induced LV remodeling.
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Affiliation(s)
- Elisangela C P Lopes
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Layde R Paim
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Luís F R S Carvalho-Romano
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Edmilson R Marques
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Eduarda O Z Minin
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Camila F L Vegian
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - José A Pio-Magalhães
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Lício A Velloso
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Otavio R Coelho-Filho
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Andrei C Sposito
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - José R Matos-Souza
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Wilson Nadruz
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
| | - Roberto Schreiber
- Department of Internal Medicine, School of Medical Sciences, State University of Campinas, São Paulo, Brazil
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13
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Abstract
Junctophilins (JPHs) comprise a family of structural proteins that connect the plasma membrane to intracellular organelles such as the endo/sarcoplasmic reticulum. Tethering of these membrane structures results in the formation of highly organized subcellular junctions that play important signaling roles in all excitable cell types. There are four JPH isoforms, expressed primarily in muscle and neuronal cell types. Each JPH protein consists of 6 'membrane occupation and recognition nexus' (MORN) motifs, a joining region connecting these to another set of 2 MORN motifs, a putative alpha-helical region, a divergent region exhibiting low homology between JPH isoforms, and a carboxy-terminal transmembrane region anchoring into the ER/SR membrane. JPH isoforms play essential roles in developing and maintaining subcellular membrane junctions. Conversely, inherited mutations in JPH2 cause hypertrophic or dilated cardiomyopathy, while trinucleotide expansions in the JPH3 gene cause Huntington Disease-Like 2. Loss of JPH1 protein levels can cause skeletal myopathy, while loss of cardiac JPH2 levels causes heart failure and atrial fibrillation, among other disease. This review will provide a comprehensive overview of the JPH gene family, phylogeny, and evolutionary analysis of JPH genes and other MORN domain proteins. JPH biogenesis, membrane tethering, and binding partners will be discussed, as well as functional roles of JPH isoforms in excitable cells. Finally, potential roles of JPH isoform deficits in human disease pathogenesis will be reviewed.
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Affiliation(s)
- Stephan E Lehnart
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States; Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), Neuroscience, and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, United States
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14
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Bourque K, Hawey C, Jones-Tabah J, Pétrin D, Martin RD, Ling Sun Y, Hébert TE. Measuring hypertrophy in neonatal rat primary cardiomyocytes and human iPSC-derived cardiomyocytes. Methods 2021; 203:447-464. [PMID: 34933120 DOI: 10.1016/j.ymeth.2021.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
In the heart, left ventricular hypertrophy is initially an adaptive mechanism that increases wall thickness to preserve normal cardiac output and function in the face of coronary artery disease or hypertension. Cardiac hypertrophy develops in response to pressure and volume overload but can also be seen in inherited cardiomyopathies. As the wall thickens, it becomes stiffer impairing the distribution of oxygenated blood to the rest of the body. With complex cellular signalling and transcriptional networks involved in the establishment of the hypertrophic state, several model systems have been developed to better understand the molecular drivers of disease. Immortalized cardiomyocyte cell lines, primary rodent and larger animal models have all helped understand the pathological mechanisms underlying cardiac hypertrophy. Induced pluripotent stem cell-derived cardiomyocytes are also used and have the additional benefit of providing access to human samples with direct disease relevance as when generated from patients suffering from hypertrophic cardiomyopathies. Here, we briefly review in vitro and in vivo model systems that have been used to model hypertrophy and provide detailed methods to isolate primary neonatal rat cardiomyocytes as well as to generate cardiomyocytes from human iPSCs. We also describe how to model hypertrophy in a "dish" using gene expression analysis and immunofluorescence combined with automated high-content imaging.
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Affiliation(s)
- Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Cara Hawey
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Jace Jones-Tabah
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Yi Ling Sun
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
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15
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Setterberg IE, Le C, Frisk M, Li J, Louch WE. The Physiology and Pathophysiology of T-Tubules in the Heart. Front Physiol 2021; 12:718404. [PMID: 34566684 PMCID: PMC8458775 DOI: 10.3389/fphys.2021.718404] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/07/2021] [Indexed: 12/18/2022] Open
Abstract
In cardiomyocytes, invaginations of the sarcolemmal membrane called t-tubules are critically important for triggering contraction by excitation-contraction (EC) coupling. These structures form functional junctions with the sarcoplasmic reticulum (SR), and thereby enable close contact between L-type Ca2+ channels (LTCCs) and Ryanodine Receptors (RyRs). This arrangement in turn ensures efficient triggering of Ca2+ release, and contraction. While new data indicate that t-tubules are capable of exhibiting compensatory remodeling, they are also widely reported to be structurally and functionally compromised during disease, resulting in disrupted Ca2+ homeostasis, impaired systolic and/or diastolic function, and arrhythmogenesis. This review summarizes these findings, while highlighting an emerging appreciation of the distinct roles of t-tubules in the pathophysiology of heart failure with reduced and preserved ejection fraction (HFrEF and HFpEF). In this context, we review current understanding of the processes underlying t-tubule growth, maintenance, and degradation, underscoring the involvement of a variety of regulatory proteins, including junctophilin-2 (JPH2), amphiphysin-2 (BIN1), caveolin-3 (Cav3), and newer candidate proteins. Upstream regulation of t-tubule structure/function by cardiac workload and specifically ventricular wall stress is also discussed, alongside perspectives for novel strategies which may therapeutically target these mechanisms.
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Affiliation(s)
- Ingunn E Setterberg
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Christopher Le
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Jia Li
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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16
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Marian AJ, Asatryan B, Wehrens XHT. Genetic basis and molecular biology of cardiac arrhythmias in cardiomyopathies. Cardiovasc Res 2021; 116:1600-1619. [PMID: 32348453 DOI: 10.1093/cvr/cvaa116] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/09/2020] [Accepted: 04/21/2020] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias are common, often the first, and sometimes the life-threatening manifestations of hereditary cardiomyopathies. Pathogenic variants in several genes known to cause hereditary cardiac arrhythmias have also been identified in the sporadic cases and small families with cardiomyopathies. These findings suggest a shared genetic aetiology of a subset of hereditary cardiomyopathies and cardiac arrhythmias. The concept of a shared genetic aetiology is in accord with the complex and exquisite interplays that exist between the ion currents and cardiac mechanical function. However, neither the causal role of cardiac arrhythmias genes in cardiomyopathies is well established nor the causal role of cardiomyopathy genes in arrhythmias. On the contrary, secondary changes in ion currents, such as post-translational modifications, are common and contributors to the pathogenesis of arrhythmias in cardiomyopathies through altering biophysical and functional properties of the ion channels. Moreover, structural changes, such as cardiac hypertrophy, dilatation, and fibrosis provide a pro-arrhythmic substrate in hereditary cardiomyopathies. Genetic basis and molecular biology of cardiac arrhythmias in hereditary cardiomyopathies are discussed.
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Affiliation(s)
- Ali J Marian
- Department of Medicine, Center for Cardiovascular Genetics, Institute of Molecular Medicine, University of Texas Health Sciences Center at Houston, 6770 Bertner Street, Suite C900A, Houston, TX 77030, USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Xander H T Wehrens
- Department of Biophysics and Molecular Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
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17
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Targeting JP2: A New Treatment for Pulmonary Hypertension. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:2003446. [PMID: 34394822 PMCID: PMC8363443 DOI: 10.1155/2021/2003446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/21/2021] [Accepted: 07/27/2021] [Indexed: 12/16/2022]
Abstract
Pulmonary hypertension (PH) is a disease with a complex etiology and high mortality rate. Abnormal pulmonary vasoconstriction and pulmonary vascular remodeling lead to an increase in mean pulmonary arterial blood pressure for which, and there is currently no cure. Junctophilin-2 (JP2) is beneficial for the assembly of junctional membrane complexes, the structural basis for excitation-contraction coupling that tethers the plasma membrane to the sarcoplasmic reticulum/endoplasmic reticulum and is involved in maintaining intracellular calcium concentration homeostasis and normal muscle contraction function. Recent studies have shown that JP2 maintains normal contraction and relaxation of vascular smooth muscle. In some experimental studies of drug treatments for PH, JP2 expression was increased, which improved pulmonary vascular remodeling and right ventricular function. Based on JP2 research to date, this paper summarizes the current understanding of JP2 protein structure, function, and related heart diseases and mechanisms and analyzes the feasibility and possible therapeutic strategies for targeting JP2 in PH.
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18
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Piggott CA, Jin Y. Junctophilins: Key Membrane Tethers in Muscles and Neurons. Front Mol Neurosci 2021; 14:709390. [PMID: 34305529 PMCID: PMC8295595 DOI: 10.3389/fnmol.2021.709390] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/15/2021] [Indexed: 12/26/2022] Open
Abstract
Contacts between the endoplasmic reticulum (ER) and plasma membrane (PM) contain specialized tethering proteins that bind both ER and PM membranes. In excitable cells, ER–PM contacts play an important role in calcium signaling and transferring lipids. Junctophilins are a conserved family of ER–PM tethering proteins. They are predominantly expressed in muscles and neurons and known to simultaneously bind both ER- and PM-localized ion channels. Since their discovery two decades ago, functional studies using junctophilin-deficient animals have provided a deep understanding of their roles in muscles and neurons, including excitation-contraction coupling, store-operated calcium entry (SOCE), and afterhyperpolarization (AHP). In this review, we highlight key findings from mouse, fly, and worm that support evolutionary conservation of junctophilins.
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Affiliation(s)
- Christopher A Piggott
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
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19
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Val‐Blasco A, Gil‐Fernández M, Rueda A, Pereira L, Delgado C, Smani T, Ruiz Hurtado G, Fernández‐Velasco M. Ca 2+ mishandling in heart failure: Potential targets. Acta Physiol (Oxf) 2021; 232:e13691. [PMID: 34022101 DOI: 10.1111/apha.13691] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 12/14/2022]
Abstract
Ca2+ mishandling is a common feature in several cardiovascular diseases such as heart failure (HF). In many cases, impairment of key players in intracellular Ca2+ homeostasis has been identified as the underlying mechanism of cardiac dysfunction and cardiac arrhythmias associated with HF. In this review, we summarize primary novel findings related to Ca2+ mishandling in HF progression. HF research has increasingly focused on the identification of new targets and the contribution of their role in Ca2+ handling to the progression of the disease. Recent research studies have identified potential targets in three major emerging areas implicated in regulation of Ca2+ handling: the innate immune system, bone metabolism factors and post-translational modification of key proteins involved in regulation of Ca2+ handling. Here, we describe their possible contributions to the progression of HF.
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Affiliation(s)
| | | | - Angélica Rueda
- Department of Biochemistry Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV‐IPN) México City Mexico
| | - Laetitia Pereira
- INSERM UMR‐S 1180 Laboratory of Ca Signaling and Cardiovascular Physiopathology University Paris‐Saclay Châtenay‐Malabry France
| | - Carmen Delgado
- Instituto de Investigaciones Biomédicas Alberto Sols Madrid Spain
- Department of Metabolism and Cell Signalling Biomedical Research Institute "Alberto Sols" CSIC‐UAM Madrid Spain
| | - Tarik Smani
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) Madrid Spain
- Department of Medical Physiology and Biophysics University of Seville Seville Spain
- Group of Cardiovascular Pathophysiology Institute of Biomedicine of Seville University Hospital of Virgen del Rocío, University of Seville, CSIC Seville Spain
| | - Gema Ruiz Hurtado
- Cardiorenal Translational Laboratory Institute of Research i+12 University Hospital 12 de Octubre Madrid Spain
- CIBER‐CV University Hospita1 12 de Octubre Madrid Spain
| | - Maria Fernández‐Velasco
- La Paz University Hospital Health Research Institute IdiPAZ Madrid Spain
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) Madrid Spain
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20
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Remodeling of t-system and proteins underlying excitation-contraction coupling in aging versus failing human heart. NPJ Aging Mech Dis 2021; 7:16. [PMID: 34050186 PMCID: PMC8163749 DOI: 10.1038/s41514-021-00066-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/26/2021] [Indexed: 11/14/2022] Open
Abstract
It is well established that the aging heart progressively remodels towards a senescent phenotype, but alterations of cellular microstructure and their differences to chronic heart failure (HF) associated remodeling remain ill-defined. Here, we show that the transverse tubular system (t-system) and proteins underlying excitation-contraction coupling in cardiomyocytes are characteristically remodeled with age. We shed light on mechanisms of this remodeling and identified similarities and differences to chronic HF. Using left ventricular myocardium from donors and HF patients with ages between 19 and 75 years, we established a library of 3D reconstructions of the t-system as well as ryanodine receptor (RyR) and junctophilin 2 (JPH2) clusters. Aging was characterized by t-system alterations and sarcolemmal dissociation of RyR clusters. This remodeling was less pronounced than in HF and accompanied by major alterations of JPH2 arrangement. Our study indicates that targeting sarcolemmal association of JPH2 might ameliorate age-associated deficiencies of heart function.
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21
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Gross P, Johnson J, Romero CM, Eaton DM, Poulet C, Sanchez-Alonso J, Lucarelli C, Ross J, Gibb AA, Garbincius JF, Lambert J, Varol E, Yang Y, Wallner M, Feldsott EA, Kubo H, Berretta RM, Yu D, Rizzo V, Elrod J, Sabri A, Gorelik J, Chen X, Houser SR. Interaction of the Joining Region in Junctophilin-2 With the L-Type Ca 2+ Channel Is Pivotal for Cardiac Dyad Assembly and Intracellular Ca 2+ Dynamics. Circ Res 2021; 128:92-114. [PMID: 33092464 PMCID: PMC7790862 DOI: 10.1161/circresaha.119.315715] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RATIONALE Ca2+-induced Ca2+ release (CICR) in normal hearts requires close approximation of L-type calcium channels (LTCCs) within the transverse tubules (T-tubules) and RyR (ryanodine receptors) within the junctional sarcoplasmic reticulum. CICR is disrupted in cardiac hypertrophy and heart failure, which is associated with loss of T-tubules and disruption of cardiac dyads. In these conditions, LTCCs are redistributed from the T-tubules to disrupt CICR. The molecular mechanism responsible for LTCCs recruitment to and from the T-tubules is not well known. JPH (junctophilin) 2 enables close association between T-tubules and the junctional sarcoplasmic reticulum to ensure efficient CICR. JPH2 has a so-called joining region that is located near domains that interact with T-tubular plasma membrane, where LTCCs are housed. The idea that this joining region directly interacts with LTCCs and contributes to LTCC recruitment to T-tubules is unknown. OBJECTIVE To determine if the joining region in JPH2 recruits LTCCs to T-tubules through direct molecular interaction in cardiomyocytes to enable efficient CICR. METHODS AND RESULTS Modified abundance of JPH2 and redistribution of LTCC were studied in left ventricular hypertrophy in vivo and in cultured adult feline and rat ventricular myocytes. Protein-protein interaction studies showed that the joining region in JPH2 interacts with LTCC-α1C subunit and causes LTCCs distribution to the dyads, where they colocalize with RyRs. A JPH2 with induced mutations in the joining region (mutPG1JPH2) caused T-tubule remodeling and dyad loss, showing that an interaction between LTCC and JPH2 is crucial for T-tubule stabilization. mutPG1JPH2 caused asynchronous Ca2+-release with impaired excitation-contraction coupling after β-adrenergic stimulation. The disturbed Ca2+ regulation in mutPG1JPH2 overexpressing myocytes caused calcium/calmodulin-dependent kinase II activation and altered myocyte bioenergetics. CONCLUSIONS The interaction between LTCC and the joining region in JPH2 facilitates dyad assembly and maintains normal CICR in cardiomyocytes.
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MESH Headings
- Animals
- Calcium/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism
- Cats
- Cells, Cultured
- Disease Models, Animal
- Excitation Contraction Coupling
- Humans
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Kinetics
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mitochondria, Heart/metabolism
- Mitochondria, Heart/pathology
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Mutation
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Organelle Biogenesis
- Protein Binding
- Protein Interaction Domains and Motifs
- Rats, Sprague-Dawley
- Ryanodine Receptor Calcium Release Channel
- Rats
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Affiliation(s)
- Polina Gross
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Jaslyn Johnson
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Carlos M. Romero
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Deborah M. Eaton
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Claire Poulet
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Jose Sanchez-Alonso
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Carla Lucarelli
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Jean Ross
- Bioimaging Center Research, Delaware Biotechnology Institute, Newark
| | - Andrew A. Gibb
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Joanne F. Garbincius
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Jonathan Lambert
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Erdem Varol
- Columbia University, Center for Theoretical Neuroscience, Department of Statistics, New York, NY
| | - Yijun Yang
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Markus Wallner
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
- Medical University of Graz, Division of Cardiology, Graz, Austria
- Center for Biomarker Research in Medicine, CBmed GmbH, Graz, Austria
| | - Eric A. Feldsott
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Hajime Kubo
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Remus M. Berretta
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Daohai Yu
- Clinical Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia
| | - Victor Rizzo
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - John Elrod
- Lewis Katz Temple University School of Medicine, Center for Translational Medicine, Department of Pharmacology, Philadelphia
| | - Abdelkarim Sabri
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Julia Gorelik
- Imperial College London, Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, London
| | - Xiongwen Chen
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
| | - Steven R. Houser
- Lewis Katz Temple University School of Medicine, Cardiovascular Research Center, Department of Physiology, Philadelphia
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22
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Luo T, Li L, Peng Y, Xie R, Yan N, Fan H, Zhang Q. The MORN domain of Junctophilin2 regulates functional interactions with small-conductance Ca 2+ -activated potassium channel subtype2 (SK2). Biofactors 2021; 47:69-79. [PMID: 31904168 DOI: 10.1002/biof.1608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/17/2019] [Indexed: 01/15/2023]
Abstract
Small-conductance Ca2+ -activated K+ channel subtype2 (SK2) are stable macromolecular complexes that regulate myocardial excitability and Ca2+ homeostasis. Junctophilin-2 (JP2) is a membrane-binding protein, which provides functional crosstalk by physically linking with the cell-surface and intracellular ion channels. We previously demonstrated that the MORN domain of JP2 interacts with SK2 channels. However, the roles of the JP2 MORN domain in regulating the precise subcellular localization and molecular modulation of SK2 have not yet been incompletely understood. In the present study, in vitro and in vivo assays were used to confirm the physical interactions between the SK2 channel and JP2 in H9c2 and HEK293 cells, with a concentration on the association between the C-terminus of SK2 channels and the MORN domain of JP2. Furthermore, the membrane expression of SK2 were found to be significantly impaired by the mutation or knockdown of JP2. Using immunofluorescence staining along with Golgi/early endosome markers, we studied the mechanisms of JP2-regulated SK2 membrane trafficking, which indicates that the JP2 MORN domain is probably necessary for the retrograde trafficking of SK2 channels. The functional study demonstrates that whole cell SK2 current densities recorded from the HEK293 cells co-expressing the JP2-MORN domain with SK2 were significantly augmented, compared with cells expressing SK2 alone. Our findings suggest that the MORN domain of JP2 directly modulates SK2 channel current amplitude and trafficking, through its interaction with an overlapping region of the JP2 MORN domain on the SK2 C-terminus.
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Affiliation(s)
- Tianxia Luo
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Liren Li
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yanghao Peng
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Rongrong Xie
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Ningning Yan
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Hongkun Fan
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Qian Zhang
- Department of Physiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
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23
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Poulet C, Sanchez-Alonso J, Swiatlowska P, Mouy F, Lucarelli C, Alvarez-Laviada A, Gross P, Terracciano C, Houser S, Gorelik J. Junctophilin-2 tethers T-tubules and recruits functional L-type calcium channels to lipid rafts in adult cardiomyocytes. Cardiovasc Res 2021; 117:149-161. [PMID: 32053184 PMCID: PMC7797210 DOI: 10.1093/cvr/cvaa033] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/08/2020] [Accepted: 02/06/2020] [Indexed: 12/19/2022] Open
Abstract
AIM In cardiomyocytes, transverse tubules (T-tubules) associate with the sarcoplasmic reticulum (SR), forming junctional membrane complexes (JMCs) where L-type calcium channels (LTCCs) are juxtaposed to Ryanodine receptors (RyR). Junctophilin-2 (JPH2) supports the assembly of JMCs by tethering T-tubules to the SR membrane. T-tubule remodelling in cardiac diseases is associated with downregulation of JPH2 expression suggesting that JPH2 plays a crucial role in T-tubule stability. Furthermore, increasing evidence indicate that JPH2 might additionally act as a modulator of calcium signalling by directly regulating RyR and LTCCs. This study aimed at determining whether JPH2 overexpression restores normal T-tubule structure and LTCC function in cultured cardiomyocytes. METHODS AND RESULTS Rat ventricular myocytes kept in culture for 4 days showed extensive T-tubule remodelling with impaired JPH2 localization and relocation of the scaffolding protein Caveolin3 (Cav3) from the T-tubules to the outer membrane. Overexpression of JPH2 restored T-tubule structure and Cav3 relocation. Depletion of membrane cholesterol by chronic treatment with methyl-β-cyclodextrin (MβCD) countered the stabilizing effect of JPH2 overexpression on T-tubules and Cav3. Super-resolution scanning patch-clamp showed that JPH2 overexpression greatly increased the number of functional LTCCs at the plasma membrane. Treatment with MβCD reduced LTCC open probability and activity. Proximity ligation assays showed that MβCD did not affect JPH2 interaction with RyR and the pore-forming LTCC subunit Cav1.2, but strongly impaired JPH2 association with Cav3 and the accessory LTCC subunit Cavβ2. CONCLUSIONS JPH2 promotes T-tubule structural stability and recruits functional LTCCs to the membrane, most likely by directly binding to the channel. Cholesterol is involved in the binding of JPH2 to T-tubules as well as in the modulation of LTCC activity. We propose a model where cholesterol and Cav3 support the assembly of lipid rafts which provide an anchor for JPH2 to form JMCs and a platform for signalling complexes to regulate LTCC activity.
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Affiliation(s)
- Claire Poulet
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Jose Sanchez-Alonso
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Pamela Swiatlowska
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Florence Mouy
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Carla Lucarelli
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
- Department of Cardiac Surgery, School of Medicine, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy
| | - Anita Alvarez-Laviada
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Polina Gross
- Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, 3500 N. Broad St., Philadelphia, PA 19140, USA
| | - Cesare Terracciano
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Steven Houser
- Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, 3500 N. Broad St., Philadelphia, PA 19140, USA
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
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24
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T-tubule remodeling in human hypertrophic cardiomyopathy. J Muscle Res Cell Motil 2020; 42:305-322. [PMID: 33222034 PMCID: PMC8332592 DOI: 10.1007/s10974-020-09591-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
The highly organized transverse T-tubule membrane system represents the ultrastructural substrate for excitation–contraction coupling in ventricular myocytes. While the architecture and function of T-tubules have been well described in animal models, there is limited morpho-functional data on T-tubules in human myocardium. Hypertrophic cardiomyopathy (HCM) is a primary disease of the heart muscle, characterized by different clinical presentations at the various stages of its progression. Most HCM patients, indeed, show a compensated hypertrophic disease (“non-failing hypertrophic phase”), with preserved left ventricular function, and only a small subset of individuals evolves into heart failure (“end stage HCM”). In terms of T-tubule remodeling, the “end-stage” disease does not differ from other forms of heart failure. In this review we aim to recapitulate the main structural features of T-tubules during the “non-failing hypertrophic stage” of human HCM by revisiting data obtained from human myectomy samples. Moreover, by comparing pathological changes observed in myectomy samples with those introduced by acute (experimentally induced) detubulation, we discuss the role of T-tubular disruption as a part of the complex excitation–contraction coupling remodeling process that occurs during disease progression. Lastly, we highlight how T-tubule morpho-functional changes may be related to patient genotype and we discuss the possibility of a primitive remodeling of the T-tubule system in rare HCM forms associated with genes coding for proteins implicated in T-tubule structural integrity, formation and maintenance.
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25
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Pretorius D, Kahn-Krell AM, LaBarge WC, Lou X, Kannappan R, Pollard AE, Fast VG, Berry JL, Eberhardt AW, Zhang J. Fabrication and characterization of a thick, viable bi-layered stem cell-derived surrogate for future myocardial tissue regeneration. Biomed Mater 2020; 16. [PMID: 33053512 DOI: 10.1088/1748-605x/abc107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
Cardiac tissue surrogates show promise for restoring mechanical and electrical function in infarcted left ventricular (LV) myocardium. For these cardiac surrogates to be useful in vivo, they are required to support synchronous and forceful contraction over the infarcted region. These design requirements necessitate a thickness sufficient to produce a useful contractile force, an area large enough to cover an infarcted region, and prevascularization to overcome diffusion limitations. Attempts to meet these requirements have been hampered by diffusion limits of oxygen and nutrients (100-200 μm) leading to necrotic regions.This study demonstrates a novel layer-by-layer (LbL) fabrication method used to produce tissue surrogates that meet these requirements and mimic normal myocardium in form and function. Thick (1.5-2 mm) LbL cardiac tissues created from human induced pluripotent stem cell-derived cardiomyocytes and endothelial cells were assessed, in vitro, over a four week period for viability (< 5.6 ± 1.4 % nectrotic cells), cell morphology, viscoelastic properties and functionality. Viscoelastic properties of the cardiac surrogates were determined via stress relaxation response modeling and compared to native murine LV tissue. Viscoelastic characterization showed that the generalized Maxwell model of order 4 described the samples well (0.7 < R2 < 0.98). Functional performance assessment showed enhanced t-tubule network development, gap junction communication as well as conduction velocity (16.9 ± 2.3 cm s-1). These results demonstrate that LbL fabrication can be utilized successfully in creating complex, functional cardiac surrogates for therapeutic applications.
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Affiliation(s)
- Danielle Pretorius
- Biomedical Engineering, The University of Alabama at Birmingham, Volker Hall Room G094, 1670 University Blvd, Birmingham, Alabama, 35294-2182, UNITED STATES
| | - Asher M Kahn-Krell
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Wesley C LaBarge
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Xi Lou
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Ramaswamy Kannappan
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Andrew E Pollard
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Vladimir G Fast
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Joel L Berry
- School of Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Alan W Eberhardt
- Department of Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
| | - Jianyi Zhang
- Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, UNITED STATES
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26
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Miura A, Kondo H, Yamamoto T, Okumura Y, Nishio H. Sudden Unexpected Death of Infantile Dilated Cardiomyopathy with JPH2 and PKD1 Gene Variants. Int Heart J 2020; 61:1079-1083. [PMID: 32879264 DOI: 10.1536/ihj.20-155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A Japanese girl with polycystic kidney disease (PKD) developed normally, but at 8 months of age, she was hospitalized for acute onset dyspnea. On the day after admission to hospital, her general condition suddenly became worse. An echocardiogram showed left ventricular dilatation with thin walls, severe mitral valve regurgitation, and a reduced ejection fraction. She died of acute cardiac failure 3 hours after the sudden change. Postmortem analysis with light microscopy showed disarray of cardiomyocytes without obvious infiltration of lymphocytes, and we diagnosed her heart failure as idiopathic dilated cardiomyopathy (DCM). Clinical exome sequencing showed compound heterozygous variants in JPH2 (p.T237A/p.I414L) and a heterozygous nonsense mutation in PKD1 (p.Q4193*). To date, several variants in the JPH2 gene have been reported to be pathogenic for adult-onset hypertrophic cardiomyopathy or DCM in an autosomal dominant manner and infantile-onset DCM in an autosomal recessive manner. Additionally, autosomal dominant polycystic kidney disease is a systemic disease associated with several extrarenal manifestations, such as cardiomyopathy. Here we report a sudden infant death case of DCM and discuss the genetic variants of DCM and PKD.
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Affiliation(s)
- Aya Miura
- Department of Legal Medicine, Hyogo College of Medicine
| | - Hidehito Kondo
- Department of Pediatrics, Japanese Red Cross Kyoto Daiichi Hospital
| | | | - Yasuko Okumura
- Department of Pediatrics, Japanese Red Cross Kyoto Daiichi Hospital
| | - Hajime Nishio
- Department of Legal Medicine, Hyogo College of Medicine
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27
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Lu F, Pu WT. The architecture and function of cardiac dyads. Biophys Rev 2020; 12:1007-1017. [PMID: 32661902 PMCID: PMC7429583 DOI: 10.1007/s12551-020-00729-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/03/2020] [Indexed: 12/28/2022] Open
Abstract
Cardiac excitation-contraction (EC) coupling, which links plasma membrane depolarization to activation of cardiomyocyte contraction, occurs at dyads, the nanoscopic microdomains formed by apposition of transverse (T)-tubules and junctional sarcoplasmic reticulum (jSR). In a dyadic junction, EC coupling occurs through Ca2+-induced Ca2+ release. Membrane depolarization opens voltage-gated L-type Ca2+ channels (LTCCs) in the T-tubule. The resulting influx of extracellular Ca2+ into the dyadic cleft opens Ca2+ release channels known as ryanodine receptors (RYRs) in the jSR, leading to the rapid increase in cytosolic Ca2+ that triggers sarcomere contraction. The efficacy of LTCC-RYR communication greatly affects a myriad of downstream intracellular signaling events, and it is controlled by many factors, including T-tubule and jSR structure, spatial distribution of ion channels, and regulatory proteins that closely regulate the activities of channels within dyads. Alterations in dyad architecture and/or channel activity are seen in many types of heart disease. This review will focus on the current knowledge regarding cardiac dyad structure and function, their alterations in heart failure, and new approaches to study the composition and function of dyads.
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Affiliation(s)
- Fujian Lu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA, 02115, USA
| | - 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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28
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Sarcoplasmic reticulum calcium mishandling: central tenet in heart failure? Biophys Rev 2020; 12:865-878. [PMID: 32696300 DOI: 10.1007/s12551-020-00736-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/08/2020] [Indexed: 12/17/2022] Open
Abstract
Excitation-contraction coupling links excitation of the sarcolemmal surface membrane to mechanical contraction. In the heart this link is established via a Ca2+-induced Ca2+ release process, which, following sarcolemmal depolarisation, prompts Ca2+ release from the sarcoplasmic reticulum (SR) though the ryanodine receptor (RyR2). This substantially raises the cytoplasmic Ca2+ concentration to trigger systole. In diastole, Ca2+ is removed from the cytoplasm, primarily via the sarcoplasmic-endoplasmic reticulum Ca2+-dependent ATPase (SERCA) pump on the SR membrane, returning Ca2+ to the SR store. Ca2+ movement across the SR is thus fundamental to the systole/diastole cycle and plays an essential role in maintaining cardiac contractile function. Altered SR Ca2+ homeostasis (due to disrupted Ca2+ release, storage, and reuptake pathways) is a central tenet of heart failure and contributes to depressed contractility, impaired relaxation, and propensity to arrhythmia. This review will focus on the molecular mechanisms that underlie asynchronous Ca2+ cycling around the SR in the failing heart. Further, this review will illustrate that the combined effects of expression changes and disruptions to RyR2 and SERCA2a regulatory pathways are critical to the pathogenesis of heart failure.
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29
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Jin B, Ji F, Zuo A, Liu H, Qi L, He Y, Wang Q, Zhao P. Destructive Role of TMAO in T-Tubule and Excitation-Contraction Coupling in the Adult Cardiomyocytes. Int Heart J 2020; 61:355-363. [PMID: 32173700 DOI: 10.1536/ihj.19-372] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heart failure (HF) is a disease with high morbidity and mortality. In patients with HF, decreased cardiac output and blood redistribution results in decreased intestinal perfusion and destruction of intestinal barrier. Microorganisms and endotoxins can migrate into the blood circulation, aggravating systemic inflammation and HF. Trimethylamine N-oxide (TMAO) is highly closed to the occurrence of HF. However, the exact mechanism between TMAO and HF remains unclear.To investigate the role of TMAO in transverse-tubule (T-tubule) in the cultured cardiomyocytes.T-tubule imaging and analysis detected T-tubule network in cardiomyocytes. Ca2+ handling dysfunction was identified by confocal Ca2+ imaging. Tubulin densification and polymerization were assessed by western blot and immunofluorescent staining of cardiomyocytes.TMAO induced T-tubule network damage in cardiomyocytes and Ca2+ handling dysfunction in cardiomyocytes under the TMAO stress via promoting tubulin densification and polymerization and therefore Junctophilin-2 (JPH2) redistribution. Mice treated with TMAO represented cardiac dysfunction and T-tubule network disorganization.TMAO impairs cardiac function via the promotion of tubulin polymerization, subsequent translocation of JPH2, and T-tubule remodeling, which provides a novel mechanism for the relationship between HF and elevated TMAO.
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Affiliation(s)
- Bu Jin
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
| | - Fangfang Ji
- The Medical Examination Center of Shandong Province Sanatorium
| | - Anjun Zuo
- Department of General Surgery, the Affiliated Hospital of Qingdao University
| | - Huiting Liu
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
| | - Lin Qi
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
| | - Yun He
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
| | - Qingyao Wang
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
| | - Peng Zhao
- Department of Pathology, the Affiliated Hospital of Qingdao University.,Department of Forensic Medicine, School of Basic Medicine, Qingdao University
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Chan BYH, Roczkowsky A, Cho WJ, Poirier M, Lee TYT, Mahmud Z, Schulz R. Junctophilin-2 is a target of matrix metalloproteinase-2 in myocardial ischemia-reperfusion injury. Basic Res Cardiol 2019; 114:42. [PMID: 31506724 DOI: 10.1007/s00395-019-0749-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/02/2019] [Indexed: 11/30/2022]
Abstract
Junctophilin-2 is a structural membrane protein that tethers T-tubules to the sarcoplasmic reticulum to allow for coordinated calcium-induced calcium release in cardiomyocytes. Defective excitation-contraction coupling in myocardial ischemia-reperfusion (IR) injury is associated with junctophilin-2 proteolysis. However, it remains unclear whether preventing junctophilin-2 proteolysis improves the recovery of cardiac contractile dysfunction in IR injury. Matrix metalloproteinase-2 (MMP-2) is a zinc and calcium-dependent protease that is activated by oxidative stress in myocardial IR injury and cleaves both intracellular and extracellular substrates. To determine whether junctophilin-2 is targeted by MMP-2, isolated rat hearts were perfused in working mode aerobically or subjected to IR injury with the selective MMP inhibitor ARP-100. IR injury impaired the recovery of cardiac contractile function which was associated with increased degradation of junctophilin-2 and damaged cardiac dyads. In IR hearts, ARP-100 improved the recovery of cardiac contractile function, attenuated junctophilin-2 proteolysis, and prevented ultrastructural damage to the dyad. MMP-2 was co-localized with junctophilin-2 in aerobic and IR hearts by immunoprecipitation and immunohistochemistry. In situ zymography showed that MMP activity was localized to the Z-disc and sarcomere in aerobic hearts and accumulated at sites where the striated JPH-2 staining was disrupted in IR hearts. In vitro proteolysis assays determined that junctophilin-2 is susceptible to proteolysis by MMP-2 and in silico analysis predicted multiple MMP-2 cleavage sites between the membrane occupation and recognition nexus repeats and within the divergent region of junctophilin-2. Degradation of junctophilin-2 by MMP-2 is an early consequence of myocardial IR injury which may initiate a cascade of sequelae leading to impaired contractile function.
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Affiliation(s)
- Brandon Y H Chan
- Departments of Pediatrics and Pharmacology, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Andrej Roczkowsky
- Departments of Pediatrics and Pharmacology, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Woo Jung Cho
- Faculty of Medicine and Dentistry Cell Imaging Centre, University of Alberta, Edmonton, AB, Canada
| | - Mathieu Poirier
- Departments of Pediatrics and Pharmacology, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Tim Y T Lee
- Departments of Pediatrics and Pharmacology, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Zabed Mahmud
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Richard Schulz
- Departments of Pediatrics and Pharmacology, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, University of Alberta, Edmonton, AB, T6G 2S2, Canada.
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Molecular determinants of homo- and heteromeric interactions of Junctophilin-1 at triads in adult skeletal muscle fibers. Proc Natl Acad Sci U S A 2019; 116:15716-15724. [PMID: 31315980 DOI: 10.1073/pnas.1820980116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In adult skeletal muscles, 2 junctophilin isoforms (JPH1 and JPH2) tether the sarcoplasmic reticulum (SR) to transverse tubule (T-tubule) membranes, generating stable membrane contact sites known as triads. JPHs are anchored to the membrane of the SR by a C-terminal transmembrane domain (TMD) and bind the T-tubule membrane through their cytosolic N-terminal region, which contains 8 lipid-binding (MORN) motifs. By combining expression of GFP-JPH1 deletion mutants in skeletal muscle fibers with in vitro biochemical experiments, we investigated the molecular determinants of JPH1 recruitment at triads in adult skeletal muscle fibers. We found that MORN motifs bind PI(4,5)P2 in the sarcolemma, but do not mediate the selective localization of JPH1 at the T-tubule compartment of triads. On the contrary, fusion proteins containing only the TMD of JPH1 were able to localize at the junctional SR compartment of the triad. Bimolecular fluorescence complementation experiments indicated that the TMD of JPH1 can form dimers, suggesting that the observed localization at triads may result from dimerization with the TMDs of resident JPH1. A second domain, capable of mediating homo- and heterodimeric interactions between JPH1 and JPH2 was identified in the cytosolic region. FRAP experiments revealed that removal of either one of these 2 domains in JPH1 decreases the association of the resulting mutant proteins with triads. Altogether, these results suggest that the ability to establish homo- and heterodimeric interactions with resident JPHs may support the recruitment and stability of newly synthesized JPHs at triads in adult skeletal muscle fibers.
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Jones EG, Mazaheri N, Maroofian R, Zamani M, Seifi T, Sedaghat A, Shariati G, Jamshidi Y, Allen HD, Wehrens XHT, Galehdari H, Landstrom AP. Analysis of enriched rare variants in JPH2-encoded junctophilin-2 among Greater Middle Eastern individuals reveals a novel homozygous variant associated with neonatal dilated cardiomyopathy. Sci Rep 2019; 9:9038. [PMID: 31227780 PMCID: PMC6588559 DOI: 10.1038/s41598-019-44987-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 05/24/2019] [Indexed: 02/07/2023] Open
Abstract
Junctophilin-2 (JPH2) is a part of the junctional membrane complex that facilitates calcium-handling in the cardiomyocyte. Previously, missense variants in JPH2 have been linked to hypertrophic cardiomyopathy; however, pathogenic "loss of function" (LOF) variants have not been described. Family-based genetic analysis of GME individuals with cardiomyopathic disease identified an Iranian patient with dilated cardiomyopathy (DCM) as a carrier of a novel, homozygous single nucleotide insertion in JPH2 resulting in a stop codon (JPH2-p.E641*). A second Iranian family with consanguineous parents hosting an identical heterozygous variant had 2 children die in childhood from cardiac failure. To characterize ethnicity-dependent genetic variability in JPH2 and to identify homozygous JPH2 variants associated with cardiac disease, we identified variants in JPH2 in a worldwide control cohort (gnomAD) and 2 similar cohorts from the Greater Middle East (GME Variome, Iranome). These were compared against ethnicity-matched clinical whole exome sequencing (WES) referral tests and a case cohort of individuals with hypertrophic cardiomyopathy (HCM) based on comprehensive review of the literature. Worldwide, 1.45% of healthy individuals hosted a rare JPH2 variant with a significantly higher proportion among GME individuals (4.45%); LOF variants were rare overall (0.04%) yet were most prevalent in GME (0.21%). The increased prevalence of LOF variants in GME individuals was corroborated among region-specific, clinical WES cohorts. In conclusion, we report ethnic-specific differences in JPH2 rare variants, with GME individuals being at higher risk of hosting homozygous LOF variants. This conclusion is supported by the identification of a novel JPH2 LOF variant confirmed by segregation analysis resulting in autosomal recessive pediatric DCM due to presumptive JPH2 truncation.
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Affiliation(s)
- Edward G Jones
- Department of Pediatrics, Section of Pediatric Cardiology, Baylor College of Medicine, Houston, Texas, United States
| | - Neda Mazaheri
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.,Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Reza Maroofian
- Molecular and Clinical Sciences Institute, St George's University of London, London, United Kingdom
| | - Mina Zamani
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.,Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Tahereh Seifi
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.,Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Alireza Sedaghat
- Diabetes Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Gholamreza Shariati
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Yalda Jamshidi
- Molecular and Clinical Sciences Institute, St George's University of London, London, United Kingdom
| | - Hugh D Allen
- Department of Pediatrics, Section of Pediatric Cardiology, Baylor College of Medicine, Houston, Texas, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States.,Department of Molecular Physiology and Biophysics, Department of Medicine, Section of Cardiology, Center for Space Medicine, Baylor College of Medicine, Houston, Texas, United States
| | - Hamid Galehdari
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
| | - Andrew P Landstrom
- Department of Pediatrics, Section of Pediatric Cardiology, Baylor College of Medicine, Houston, Texas, United States. .,Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States. .,Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, United States.
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Brandenburg S, Pawlowitz J, Eikenbusch B, Peper J, Kohl T, Mitronova GY, Sossalla S, Hasenfuss G, Wehrens XH, Kohl P, Rog-Zielinska EA, Lehnart SE. Junctophilin-2 expression rescues atrial dysfunction through polyadic junctional membrane complex biogenesis. JCI Insight 2019; 4:127116. [PMID: 31217359 DOI: 10.1172/jci.insight.127116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/16/2019] [Indexed: 12/28/2022] Open
Abstract
Atrial dysfunction is highly prevalent and associated with increased severity of heart failure. While rapid excitation-contraction coupling depends on axial junctions in atrial myocytes, the molecular basis of atrial loss of function remains unclear. We identified approximately 5-fold lower junctophilin-2 levels in atrial compared with ventricular tissue in mouse and human hearts. In atrial myocytes, this resulted in subcellular expression of large junctophilin-2 clusters at axial junctions, together with highly phosphorylated ryanodine receptor (RyR2) channels. To investigate the contribution of junctophilin-2 to atrial pathology in adult hearts, we developed a cardiomyocyte-selective junctophilin-2-knockdown model with 0 mortality. Junctophilin-2 knockdown in mice disrupted atrial RyR2 clustering and contractility without hypertrophy or interstitial fibrosis. In contrast, aortic pressure overload resulted in left atrial hypertrophy with decreased junctophilin-2 and RyR2 expression, disrupted axial junctions, and atrial fibrosis. Whereas pressure overload accrued atrial dysfunction and heart failure with 40% mortality, additional junctophilin-2 knockdown greatly exacerbated atrial dysfunction with 100% mortality. Strikingly, transgenic junctophilin-2 overexpression restored atrial contractility and survival through de novo biogenesis of polyadic junctional membrane complexes maintained after pressure overload. Our data show a central role of junctophilin-2 cluster disruption in atrial hypertrophy and identify transgenic augmentation of junctophilin-2 as a disease-mitigating rationale to improve atrial dysfunction and prevent heart failure deterioration.
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Affiliation(s)
- Sören Brandenburg
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Jan Pawlowitz
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Benjamin Eikenbusch
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Jonas Peper
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Tobias Kohl
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Gyuzel Y Mitronova
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Samuel Sossalla
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Gerd Hasenfuss
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Xander Ht Wehrens
- Cardiovascular Research Institute - Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Peter Kohl
- University Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Eva A Rog-Zielinska
- University Heart Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Stephan E Lehnart
- Heart Research Center Göttingen, Department of Cardiology & Pneumology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany.,BioMET, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Chung YJ, Luo A, Park KC, Loonat AA, Lakhal-Littleton S, Robbins PA, Swietach P. Iron-deficiency anemia reduces cardiac contraction by downregulating RyR2 channels and suppressing SERCA pump activity. JCI Insight 2019; 4:125618. [PMID: 30779710 PMCID: PMC6483648 DOI: 10.1172/jci.insight.125618] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/14/2019] [Indexed: 12/20/2022] Open
Abstract
Iron deficiency is present in ~50% of heart failure (HF) patients. Large multicenter trials have shown that treatment of iron deficiency with i.v. iron benefits HF patients, but the underlying mechanisms are not known. To investigate the actions of iron deficiency on the heart, mice were fed an iron-depleted diet, and some received i.v. ferric carboxymaltose (FCM), an iron supplementation used clinically. Iron-deficient animals became anemic and had reduced ventricular ejection fraction measured by magnetic resonance imaging. Ca2+ signaling, a pathway linked to the contractile deficit in failing hearts, was also significantly affected. Ventricular myocytes isolated from iron-deficient animals produced smaller Ca2+ transients from an elevated diastolic baseline but had unchanged sarcoplasmic reticulum (SR) Ca2+ load, trigger L-type Ca2+ current, or cytoplasmic Ca2+ buffering. Reduced fractional release from the SR was due to downregulated RyR2 channels, detected at protein and message levels. The constancy of diastolic SR Ca2+ load is explained by reduced RyR2 permeability in combination with right-shifted SERCA activity due to dephosphorylation of its regulator phospholamban. Supplementing iron levels with FCM restored normal Ca2+ signaling and ejection fraction. Thus, 2 Ca2+-handling proteins previously implicated in HF become functionally impaired in iron-deficiency anemia, but their activity is rescued by i.v. iron supplementation.
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Affiliation(s)
- Yu Jin Chung
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Antao Luo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.,Medical College, Wuhan University of Science and Technology, Wuhan, China
| | - Kyung Chan Park
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Aminah A Loonat
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Samira Lakhal-Littleton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Peter A Robbins
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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35
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Jones PP, MacQuaide N, Louch WE. Dyadic Plasticity in Cardiomyocytes. Front Physiol 2018; 9:1773. [PMID: 30618792 PMCID: PMC6298195 DOI: 10.3389/fphys.2018.01773] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/23/2018] [Indexed: 11/13/2022] Open
Abstract
Contraction of cardiomyocytes is dependent on sub-cellular structures called dyads, where invaginations of the surface membrane (t-tubules) form functional junctions with the sarcoplasmic reticulum (SR). Within each dyad, Ca2+ entry through t-tubular L-type Ca2+ channels (LTCCs) elicits Ca2+ release from closely apposed Ryanodine Receptors (RyRs) in the SR membrane. The efficiency of this process is dependent on the density and macroscale arrangement of dyads, but also on the nanoscale organization of LTCCs and RyRs within them. We presently review accumulating data demonstrating the remarkable plasticity of these structures. Dyads are known to form gradually during development, with progressive assembly of both t-tubules and junctional SR terminals, and precise trafficking of LTCCs and RyRs. While dyads can exhibit compensatory remodeling when required, dyadic degradation is believed to promote impaired contractility and arrythmogenesis in cardiac disease. Recent data indicate that this plasticity of dyadic structure/function is dependent on the regulatory proteins junctophilin-2, amphiphysin-2 (BIN1), and caveolin-3, which critically arrange dyadic membranes while stabilizing the position and activity of LTCCs and RyRs. Indeed, emerging evidence indicates that clustering of both channels enables "coupled gating", implying that nanoscale localization and function are intimately linked, and may allow fine-tuning of LTCC-RyR crosstalk. We anticipate that improved understanding of dyadic plasticity will provide greater insight into the processes of cardiac compensation and decompensation, and new opportunities to target the basic mechanisms underlying heart disease.
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Affiliation(s)
- Peter P. Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- HeartOtago, University of Otago, Dunedin, New Zealand
| | - Niall MacQuaide
- Institute of Cardiovascular Sciences, University of Glasgow, Glasgow, United Kingdom
- Clyde Biosciences, Glasgow, United Kingdom
| | - William E. Louch
- Institute for Experimental Medical Research, Oslo University Hospital, University of Oslo, Oslo, Norway
- KG Jebsen Center for Cardiac Research, University of Oslo, Oslo, Norway
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36
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Fan HK, Luo TX, Zhao WD, Mu YH, Yang Y, Guo WJ, Tu HY, Zhang Q. Functional interaction of Junctophilin 2 with small- conductance Ca 2+ -activated potassium channel subtype 2(SK2) in mouse cardiac myocytes. Acta Physiol (Oxf) 2018; 222. [PMID: 29055091 PMCID: PMC6084295 DOI: 10.1111/apha.12986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 10/15/2017] [Accepted: 10/15/2017] [Indexed: 12/17/2022]
Abstract
Aim Junctophilins (JPs), a protein family of the junctional membrane complex, maintain the close conjunction between cell surface and intracellular membranes in striate muscle cells mediating the crosstalk between extracellular Ca2+ entry and intracellular Ca2+ release. The small‐conductance Ca2+‐activated K+ channels are activated by the intracellular calcium and play an essential role in the cardiac action potential profile. Molecular mechanisms of regulation of the SK channels are still uncertain. Here, we sought to determine whether there is a functional interaction of junctophilin type 2 (JP2) with the SK channels and whether JP2 gene silencing might modulate the function of SK channels in cardiac myocytes. Methods Association of JP2 with SK2 channel in mouse heart tissue as well as HEK293 cells was studied using in vivo and in vitro approaches. siRNA knockdown of JP2 gene was assessed by real‐time PCR. The expression of proteins was analysed by Western blotting. Ca2+‐activated K+ current (IK,Ca) in infected adult mouse cardiac myocytes was recorded using whole‐cell voltage‐clamp technique. The intracellular Ca2+ transient was measured using an IonOptix photometry system. Results We showed for the first time that JP2 associates with the SK2 channel in native cardiac tissue. JP2, via the membrane occupation and recognition nexus (MORN motifs) in its N‐terminus, directly interacted with SK2 channels. A colocalization of the SK2 channel with its interaction protein of JP2 was found in the cardiac myocytes. Moreover, we demonstrated that JP2 is necessary for the proper cell surface expression of the SK2 channel in HEK293. Functional experiments indicated that knockdown of JP2 caused a significant decrease in the density of IK,Ca and reduced the amplitude of the Ca2+ transient in infected cardiomyocytes. Conclusion The present data provide evidence that the functional interaction between JP2 and SK2 channels is present in the native mouse heart tissue. Junctophilin 2, as junctional membrane complex (JMC) protein, is an important regulator of the cardiac SK channels.
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Affiliation(s)
- H. K. Fan
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
| | - T. X. Luo
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
| | - W. D. Zhao
- Faculty of Medicine; KU Leuven; Leuven Belgium
| | - Y. H. Mu
- Department of Pathophysiology; School of Medicine; Xinxiang Medical College; Xinxiang China
| | - Y. Yang
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
| | - W. J. Guo
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
| | - H. Y. Tu
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
| | - Q. Zhang
- Department of Physiology; School of Medicine; Zhengzhou University; Zhengzhou China
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37
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Schobesberger S, Wright P, Tokar S, Bhargava A, Mansfield C, Glukhov AV, Poulet C, Buzuk A, Monszpart A, Sikkel M, Harding SE, Nikolaev VO, Lyon AR, Gorelik J. T-tubule remodelling disturbs localized β2-adrenergic signalling in rat ventricular myocytes during the progression of heart failure. Cardiovasc Res 2018; 113:770-782. [PMID: 28505272 PMCID: PMC5437368 DOI: 10.1093/cvr/cvx074] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/11/2017] [Indexed: 11/12/2022] Open
Abstract
Aims Cardiomyocyte β2-adrenergic receptor (β2AR) cyclic adenosine monophosphate (cAMP) signalling is regulated by the receptors' subcellular location within transverse tubules (T-tubules), via interaction with structural and regulatory proteins, which form a signalosome. In chronic heart failure (HF), β2ARs redistribute from T-tubules to the cell surface, which disrupts functional signalosomes and leads to diffuse cAMP signalling. However, the functional consequences of structural changes upon β2AR-cAMP signalling during progression from hypertrophy to advanced HF are unknown. Methods and results Rat left ventricular myocytes were isolated at 4-, 8-, and 16-week post-myocardial infarction (MI), β2ARs were stimulated either via whole-cell perfusion or locally through the nanopipette of the scanning ion conductance microscope. cAMP release was measured via a Förster Resonance Energy Transfer-based sensor Epac2-camps. Confocal imaging of di-8-ANNEPS-stained cells and immunoblotting were used to determine structural alterations. At 4-week post-MI, T-tubule regularity, density and junctophilin-2 (JPH2) expression were significantly decreased. The amplitude of local β2AR-mediated cAMP in T-tubules was reduced and cAMP diffused throughout the cytosol instead of being locally confined. This was accompanied by partial caveolin-3 (Cav-3) dissociation from the membrane. At 8-week post-MI, the β2AR-mediated cAMP response was observed at the T-tubules and the sarcolemma (crest). Finally, at 16-week post-MI, the whole cell β2AR-mediated cAMP signal was depressed due to adenylate cyclase dysfunction, while overall Cav-3 levels were significantly increased and a substantial portion of Cav-3 dissociated into the cytosol. Overexpression of JPH2 in failing cells in vitro or AAV9.SERCA2a gene therapy in vivo did not improve β2AR-mediated signal compartmentation or reduce cAMP diffusion. Conclusion Although changes in T-tubule structure and β2AR-mediated cAMP signalling are significant even at 4-week post-MI, progression to the HF phenotype is not linear. At 8-week post-MI the loss of β2AR-mediated cAMP is temporarily reversed. Complete disorganization of β2AR-mediated cAMP signalling due to changes in functional receptor localization and cellular structure occurs at 16-week post-MI.
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Affiliation(s)
- Sophie Schobesberger
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12 0NN, UK.,Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Martinistraße, Hamburg D-20246, Germany
| | - Peter Wright
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Sergiy Tokar
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Anamika Bhargava
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12 0NN, UK.,Department of Biotechnology, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram, 502205 Telangana, India
| | - Catherine Mansfield
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Alexey V Glukhov
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Claire Poulet
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Andrey Buzuk
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Aron Monszpart
- Department of Computer Science, University College London, Gower Street, London WC1E 6BT, UK
| | - Markus Sikkel
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Sian E Harding
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Martinistraße, Hamburg D-20246, Germany
| | - Alexander R Lyon
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12 0NN, UK.,NIHR Cardiovascular Biomedical Research Unit, Department of Cardiology, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| | - Julia Gorelik
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College, Du Cane Road, London W12?0NN, UK
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Highly variable contractile performance correlates with myocyte content in trabeculae from failing human hearts. Sci Rep 2018; 8:2957. [PMID: 29440728 PMCID: PMC5811450 DOI: 10.1038/s41598-018-21199-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/16/2018] [Indexed: 12/24/2022] Open
Abstract
Heart failure (HF) is defined by compromised contractile function and is associated with changes in excitation-contraction (EC) coupling and cardiomyocyte organisation. Tissue level changes often include fibrosis, while changes within cardiomyocytes often affect structures critical to EC coupling, including the ryanodine receptor (RyR), the associated protein junctophilin-2 (JPH2) and the transverse tubular system architecture. Using a novel approach, we aimed to directly correlate the influence of structural alterations with force development in ventricular trabeculae from failing human hearts. Trabeculae were excised from explanted human hearts in end-stage failure and immediately subjected to force measurements. Following functional experiments, each trabecula was fixed, sectioned and immuno-stained for structural investigations. Peak stress was highly variable between trabeculae from both within and between failing hearts and was strongly correlated with the cross-sectional area occupied by myocytes (MCSA), rather than total trabecula cross-sectional area. At the cellular level, myocytes exhibited extensive microtubule densification which was linked via JPH2 to time-to-peak stress. Trabeculae fractional MCSA variability was much higher than that in adjacent free wall samples. Together, these findings identify several structural parameters implicated in functional impairment in human HF and highlight the structural variability of ventricular trabeculae which should be considered when interpreting functional data.
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Calpena E, López Del Amo V, Chakraborty M, Llamusí B, Artero R, Espinós C, Galindo MI. The Drosophila junctophilin gene is functionally equivalent to its four mammalian counterparts and is a modifier of a Huntingtin poly-Q expansion and the Notch pathway. Dis Model Mech 2018; 11:dmm.029082. [PMID: 29208631 PMCID: PMC5818072 DOI: 10.1242/dmm.029082] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 11/08/2017] [Indexed: 12/13/2022] Open
Abstract
Members of the Junctophilin (JPH) protein family have emerged as key actors in all excitable cells, with crucial implications for human pathophysiology. In mammals, this family consists of four members (JPH1-JPH4) that are differentially expressed throughout excitable cells. The analysis of knockout mice lacking JPH subtypes has demonstrated their essential contribution to physiological functions in skeletal and cardiac muscles and in neurons. Moreover, mutations in the human JPH2 gene are associated with hypertrophic and dilated cardiomyopathies; mutations in JPH3 are responsible for the neurodegenerative Huntington's disease-like-2 (HDL2), whereas JPH1 acts as a genetic modifier in Charcot–Marie–Tooth 2K peripheral neuropathy. Drosophila melanogaster has a single junctophilin (jp) gene, as is the case in all invertebrates, which might retain equivalent functions of the four homologous JPH genes present in mammalian genomes. Therefore, owing to the lack of putatively redundant genes, a jpDrosophila model could provide an excellent platform to model the Junctophilin-related diseases, to discover the ancestral functions of the JPH proteins and to reveal new pathways. By up- and downregulation of Jp in a tissue-specific manner in Drosophila, we show that altering its levels of expression produces a phenotypic spectrum characterized by muscular deficits, dilated cardiomyopathy and neuronal alterations. Importantly, our study has demonstrated that Jp modifies the neuronal degeneration in a Drosophila model of Huntington's disease, and it has allowed us to uncover an unsuspected functional relationship with the Notch pathway. Therefore, this Drosophila model has revealed new aspects of Junctophilin function that can be relevant for the disease mechanisms of their human counterparts. Summary: This work reveals that the Drosophila Junctophilin protein has similar functions to its mammalian homologues and uncovers new interactions of potential biomedical interest with Huntingtin and Notch signalling.
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Affiliation(s)
- Eduardo Calpena
- Program in Molecular Mechanisms of Disease, Centro de Investigación Príncipe Felipe (CIPF), c/ Eduardo Primo Yúfera no. 3, 46012 Valencia, Spain
| | - Víctor López Del Amo
- Program in Molecular Mechanisms of Disease, Centro de Investigación Príncipe Felipe (CIPF), c/ Eduardo Primo Yúfera no. 3, 46012 Valencia, Spain
| | - Mouli Chakraborty
- Translational Genomics Group, Incliva Health Research Institute, Avda. Menendez Pelayo 4 acc 46010, Valencia, Spain.,Department of Genetics and Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED), Universitat de València, c/ Dr Moliner 50, 46100 Burjasot, Spain
| | - Beatriz Llamusí
- Translational Genomics Group, Incliva Health Research Institute, Avda. Menendez Pelayo 4 acc 46010, Valencia, Spain.,Department of Genetics and Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED), Universitat de València, c/ Dr Moliner 50, 46100 Burjasot, Spain
| | - Rubén Artero
- Translational Genomics Group, Incliva Health Research Institute, Avda. Menendez Pelayo 4 acc 46010, Valencia, Spain.,Department of Genetics and Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED), Universitat de València, c/ Dr Moliner 50, 46100 Burjasot, Spain
| | - Carmen Espinós
- Program in Molecular Mechanisms of Disease, Centro de Investigación Príncipe Felipe (CIPF), c/ Eduardo Primo Yúfera no. 3, 46012 Valencia, Spain.,UPV-CIPF Joint Unit Disease Mechanisms and Nanomedicine, 46012 Valencia, Spain
| | - Máximo I Galindo
- Program in Molecular Mechanisms of Disease, Centro de Investigación Príncipe Felipe (CIPF), c/ Eduardo Primo Yúfera no. 3, 46012 Valencia, Spain .,UPV-CIPF Joint Unit Disease Mechanisms and Nanomedicine, 46012 Valencia, Spain.,Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Universitat Politècnica de València, Universitat de València, 46022 Valencia, Spain
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Hypertension Susceptibility Loci are Associated with Anthracycline-related Cardiotoxicity in Long-term Childhood Cancer Survivors. Sci Rep 2017; 7:9698. [PMID: 28851949 PMCID: PMC5575079 DOI: 10.1038/s41598-017-09517-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/21/2017] [Indexed: 01/25/2023] Open
Abstract
Anthracycline-based chemotherapy is associated with dose-dependent, irreversible damage to the heart. Childhood cancer survivors with hypertension after anthracycline exposure are at increased risk of cardiotoxicity, leading to the hypothesis that genetic susceptibility loci for hypertension may serve as predictors for development of late cardiotoxicity. Therefore, we determined the association between 12 GWAS-identified hypertension-susceptibility loci and cardiotoxicity in a cohort of long-term childhood cancer survivors (N = 108) who received anthracyclines and were screened for cardiac function via echocardiograms. Hypertension-susceptibility alleles of PLCE1:rs9327264 and ATP2B1:rs17249754 were significantly associated with cardiotoxicity risk conferring a protective effect with a 64% (95% CI: 0.18–0.76, P = 0.0068) and 74% (95% CI: 0.07–0.96, P = 0.040) reduction in risk, respectively. In RNAseq experiments of human induced pluripotent stem cell (iPSC) derived cardiomyocytes treated with doxorubicin, both PLCE1 and ATP2B1 displayed anthracycline-dependent gene expression profiles. In silico functional assessment further supported this relationship - rs9327264 in PLCE1 (P = 0.0080) and ATP2B1 expression (P = 0.0079) were both significantly associated with daunorubicin IC50 values in a panel of lymphoblastoid cell lines. Our findings demonstrate that the hypertension-susceptibility variants in PLCE1 and ATP2B1 confer a protective effect on risk of developing anthracycline-related cardiotoxicity, and functional analyses suggest that these genes are influenced by exposure to anthracyclines.
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Seidel T, Sankarankutty AC, Sachse FB. Remodeling of the transverse tubular system after myocardial infarction in rabbit correlates with local fibrosis: A potential role of biomechanics. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:302-314. [PMID: 28709857 DOI: 10.1016/j.pbiomolbio.2017.07.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 02/03/2023]
Abstract
The transverse tubular system (t-system) of ventricular cardiomyocytes is essential for efficient excitation-contraction coupling. In cardiac diseases, such as heart failure, remodeling of the t-system contributes to reduced cardiac contractility. However, mechanisms of t-system remodeling are incompletely understood. Prior studies suggested an association with altered cardiac biomechanics and gene expression in disease. Since fibrosis may alter tissue biomechanics, we investigated the local microscopic association of t-system remodeling with fibrosis in a rabbit model of myocardial infarction (MI). Biopsies were taken from the MI border zone of 6 infarcted hearts and from 6 control hearts. Using confocal microscopy and automated image analysis, we quantified t-system integrity (ITT) and the local fraction of extracellular matrix (fECM). In control, fECM was 18 ± 0.3%. ITT was high and homogeneous (0.07 ± 0.006), and did not correlate with fECM (R2 = 0.05 ± 0.02). The MI border zone exhibited increased fECM within 3 mm from the infarct scar (30 ± 3.5%, p < 0.01 vs control), indicating fibrosis. Myocytes in the MI border zone exhibited significant t-system remodeling, with dilated, sheet-like components, resulting in low ITT (0.03 ± 0.008, p < 0.001 vs control). While both fECM and t-system remodeling decreased with infarct distance, ITT correlated better with decreasing fECM (R2 = 0.44) than with infarct distance (R2 = 0.24, p < 0.05). Our results show that t-system remodeling in the rabbit MI border zone resembles a phenotype previously described in human heart failure. T-system remodeling correlated with the amount of local fibrosis, which is known to stiffen cardiac tissue, but was not found in regions without fibrosis. Thus, locally altered tissue mechanics may contribute to t-system remodeling.
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Affiliation(s)
- T Seidel
- Institute for Cellular and Molecular Physiology, University of Erlangen-Nuremberg, Erlangen, Germany; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, USA.
| | - A C Sankarankutty
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, USA; Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - F B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, USA; Department of Bioengineering, University of Utah, Salt Lake City, USA.
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Abstract
There has been a significant progress in our understanding of the molecular mechanisms by which calcium (Ca2+) ions mediate various types of cardiac arrhythmias. A growing list of inherited gene defects can cause potentially lethal cardiac arrhythmia syndromes, including catecholaminergic polymorphic ventricular tachycardia, congenital long QT syndrome, and hypertrophic cardiomyopathy. In addition, acquired deficits of multiple Ca2+-handling proteins can contribute to the pathogenesis of arrhythmias in patients with various types of heart disease. In this review article, we will first review the key role of Ca2+ in normal cardiac function-in particular, excitation-contraction coupling and normal electric rhythms. The functional involvement of Ca2+ in distinct arrhythmia mechanisms will be discussed, followed by various inherited arrhythmia syndromes caused by mutations in Ca2+-handling proteins. Finally, we will discuss how changes in the expression of regulation of Ca2+ channels and transporters can cause acquired arrhythmias, and how these mechanisms might be targeted for therapeutic purposes.
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Affiliation(s)
- Andrew P Landstrom
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Dobromir Dobrev
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Xander H T Wehrens
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.).
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Differential gene expression profile of Buyanghuanwu decoction in rats with ventricular remodeling post-myocardial infarction. J TRADIT CHIN MED 2017. [DOI: 10.1016/s0254-6272(17)30070-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Prins KW, Tian L, Wu D, Thenappan T, Metzger JM, Archer SL. Colchicine Depolymerizes Microtubules, Increases Junctophilin-2, and Improves Right Ventricular Function in Experimental Pulmonary Arterial Hypertension. J Am Heart Assoc 2017; 6:JAHA.117.006195. [PMID: 28566298 PMCID: PMC5669202 DOI: 10.1161/jaha.117.006195] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a lethal disease characterized by obstructive pulmonary vascular remodeling and right ventricular (RV) dysfunction. Although RV function predicts outcomes in PAH, mechanisms of RV dysfunction are poorly understood, and RV-targeted therapies are lacking. We hypothesized that in PAH, abnormal microtubular structure in RV cardiomyocytes impairs RV function by reducing junctophilin-2 (JPH2) expression, resulting in t-tubule derangements. Conversely, we assessed whether colchicine, a microtubule-depolymerizing agent, could increase JPH2 expression and enhance RV function in monocrotaline-induced PAH. METHODS AND RESULTS Immunoblots, confocal microscopy, echocardiography, cardiac catheterization, and treadmill testing were used to examine colchicine's (0.5 mg/kg 3 times/week) effects on pulmonary hemodynamics, RV function, and functional capacity. Rats were treated with saline (n=28) or colchicine (n=24) for 3 weeks, beginning 1 week after monocrotaline (60 mg/kg, subcutaneous). In the monocrotaline RV, but not the left ventricle, microtubule density is increased, and JPH2 expression is reduced, with loss of t-tubule localization and t-tubule disarray. Colchicine reduces microtubule density, increases JPH2 expression, and improves t-tubule morphology in RV cardiomyocytes. Colchicine therapy diminishes RV hypertrophy, improves RV function, and enhances RV-pulmonary artery coupling. Colchicine reduces small pulmonary arteriolar thickness and improves pulmonary hemodynamics. Finally, colchicine increases exercise capacity. CONCLUSIONS Monocrotaline-induced PAH causes RV-specific derangement of microtubules marked by reduction in JPH2 and t-tubule disarray. Colchicine reduces microtubule density, increases JPH2 expression, and improves both t-tubule architecture and RV function. Colchicine also reduces adverse pulmonary vascular remodeling. These results provide biological plausibility for a clinical trial to repurpose colchicine as a RV-directed therapy for PAH.
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Affiliation(s)
- Kurt W Prins
- Cardiovascular Division, University of Minnesota Medical School, Minneapolis, MN
| | - Lian Tian
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Danchen Wu
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Thenappan Thenappan
- Cardiovascular Division, University of Minnesota Medical School, Minneapolis, MN
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, Ontario, Canada
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Seidel T, Navankasattusas S, Ahmad A, Diakos NA, Xu WD, Tristani-Firouzi M, Bonios MJ, Taleb I, Li DY, Selzman CH, Drakos SG, Sachse FB. Sheet-Like Remodeling of the Transverse Tubular System in Human Heart Failure Impairs Excitation-Contraction Coupling and Functional Recovery by Mechanical Unloading. Circulation 2017; 135:1632-1645. [PMID: 28073805 PMCID: PMC5404964 DOI: 10.1161/circulationaha.116.024470] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/14/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Cardiac recovery in response to mechanical unloading by left ventricular assist devices (LVADs) has been demonstrated in subgroups of patients with chronic heart failure (HF). Hallmarks of HF are depletion and disorganization of the transverse tubular system (t-system) in cardiomyocytes. Here, we investigated remodeling of the t-system in human end-stage HF and its role in cardiac recovery. METHODS Left ventricular biopsies were obtained from 5 donors and 26 patients with chronic HF undergoing implantation of LVADs. Three-dimensional confocal microscopy and computational image analysis were applied to assess t-system structure, density, and distance of ryanodine receptor clusters to the sarcolemma, including the t-system. Recovery of cardiac function in response to mechanical unloading was assessed by echocardiography during turndown of the LVAD. RESULTS The majority of HF myocytes showed remarkable t-system remodeling, particularly sheet-like invaginations of the sarcolemma. Circularity of t-system components was decreased in HF versus controls (0.37±0.01 versus 0.46±0.02; P<0.01), and the volume/length ratio was increased in HF (0.36±0.01 versus 0.25±0.02 µm2; P<0.0001). T-system density was reduced in HF, leading to increased ryanodine receptor-sarcolemma distances (0.96±0.05 versus 0.64±0.1 µm; P<0.01). Low ryanodine receptor-sarcolemma distances at the time of LVAD implantation predicted high post-LVAD left ventricular ejection fractions (P<0.01) and ejection fraction increases during unloading (P<0.01). Ejection fraction in patients with pre-LVAD ryanodine receptor-sarcolemma distances >1 µm did not improve after mechanical unloading. In addition, calcium transients were recorded in field-stimulated isolated human cardiomyocytes and analyzed with respect to local t-system density. Calcium release in HF myocytes was restricted to regions proximal to the sarcolemma. Local calcium upstroke was delayed (23.9±4.9 versus 10.3±1.7 milliseconds; P<0.05) and more asynchronous (18.1±1.5 versus 8.9±2.2 milliseconds; P<0.01) in HF cells with low t-system density versus cells with high t-system density. CONCLUSIONS The t-system in end-stage human HF presents a characteristic novel phenotype consisting of sheet-like invaginations of the sarcolemma. Our results suggest that the remodeled t-system impairs excitation-contraction coupling and functional recovery during chronic LVAD unloading. An intact t-system at the time of LVAD implantation may constitute a precondition and predictor for functional cardiac recovery after mechanical unloading.
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Affiliation(s)
- Thomas Seidel
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany.
| | - Sutip Navankasattusas
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Azmi Ahmad
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Nikolaos A Diakos
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Weining David Xu
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Martin Tristani-Firouzi
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Michael J Bonios
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Iosif Taleb
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Dean Y Li
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Craig H Selzman
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany
| | - Stavros G Drakos
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany.
| | - Frank B Sachse
- From Nora Eccles Harrison Cardiovascular Research and Training Institute (T.S., A.A., M.T.-F., S.G.D., F.B.S.), Molecular Medicine Program (S.N., N.A.D., D.Y.L., C.H.S.), Department of Bioengineering (A.A., F.B.S.), Division of Cardiovascular Medicine (W.D.X., M.J.B., I.T., D.Y.L., S.G.D.), and Division of Cardiothoracic Surgery (C.H.S.), University of Utah, Salt Lake City. Dr Seidel is currently at the Institute for Cellular and Molecular Physiology, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Germany.
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Quick AP, Landstrom AP, Wang Q, Beavers DL, Reynolds JO, Barreto-Torres G, Tran V, Showell J, Philippen LE, Morris SA, Skapura D, Bos JM, Pedersen SE, Pautler RG, Ackerman MJ, Wehrens XHT. Novel junctophilin-2 mutation A405S is associated with basal septal hypertrophy and diastolic dysfunction. ACTA ACUST UNITED AC 2017; 2:56-67. [PMID: 28393127 PMCID: PMC5384575 DOI: 10.1016/j.jacbts.2016.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A JPH2 A405S mutation was found in a human HCM patient. A novel echocardiographic imaging plane revealed septal hypertrophy in a mouse model bearing the human JPH2 mutation, thereby causally linking it to HCM pathogenesis. This alpha helical JPH2 mutation resulted in decreased transverse tubule regularity and aberrant calcium handling in septal cardiomyocytes.
Junctophilin-2 (JPH2) is a structural calcium (Ca2+) handling protein, which approximates the cardiomyocyte transverse tubules (TTs) to the sarcoplasmic reticulum. This facilitates communication of the voltage-gated Ca2+ channel and the ryanodine receptor RyR2. A human patient with hypertrophic cardiomyopathy was positive for a JPH2 mutation substituting alanine-405—located within the alpha helix domain—with a serine (A405S). Using a novel mouse echocardiography plane, we found that mice bearing this JPH2 mutation developed increased subvalvular septal thickness. Cardiomyocytes from the septa of these mice displayed irregular TTs and abnormal Ca2+ handling including increased SERCA activity.
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Affiliation(s)
- Ann P Quick
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Andrew P Landstrom
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Qiongling Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - David L Beavers
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Julia O Reynolds
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Giselle Barreto-Torres
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Viet Tran
- Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Jordan Showell
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Leonne E Philippen
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Shaine A Morris
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Darlene Skapura
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - J Martijn Bos
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Steen E Pedersen
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Robia G Pautler
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Michael J Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
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47
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Tan T, Ko YG, Ma J. Dual function of MG53 in membrane repair and insulin signaling. BMB Rep 2017; 49:414-23. [PMID: 27174502 PMCID: PMC5070728 DOI: 10.5483/bmbrep.2016.49.8.079] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Indexed: 12/20/2022] Open
Abstract
MG53 is a member of the TRIM-family protein that acts as a key component of the cell membrane repair machinery. MG53 is also an E3-ligase that ubiquinates insulin receptor substrate-1 and controls insulin signaling in skeletal muscle cells. Since its discovery in 2009, research efforts have been devoted to translate this basic discovery into clinical applications in human degenerative and metabolic diseases. This review article highlights the dual function of MG53 in cell membrane repair and insulin signaling, the mechanism that underlies the control of MG53 function, and the therapeutic value of targeting MG53 function in regenerative medicine. [BMB Reports 2016; 49(8): 414-423]
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Affiliation(s)
- Tao Tan
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Young-Gyu Ko
- Division of Life Sciences, Korea University, Seoul 02841, Korea
| | - Jianjie Ma
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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48
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Munro ML, Jayasinghe I, Wang Q, Quick A, Wang W, Baddeley D, Wehrens XHT, Soeller C. Junctophilin-2 in the nanoscale organisation and functional signalling of ryanodine receptor clusters in cardiomyocytes. J Cell Sci 2016; 129:4388-4398. [PMID: 27802169 PMCID: PMC5201013 DOI: 10.1242/jcs.196873] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/14/2016] [Indexed: 11/20/2022] Open
Abstract
Signalling nanodomains requiring close contact between the plasma membrane and internal compartments, known as 'junctions', are fast communication hubs within excitable cells such as neurones and muscle. Here, we have examined two transgenic murine models probing the role of junctophilin-2, a membrane-tethering protein crucial for the formation and molecular organisation of sub-microscopic junctions in ventricular muscle cells of the heart. Quantitative single-molecule localisation microscopy showed that junctions in animals producing above-normal levels of junctophilin-2 were enlarged, allowing the re-organisation of the primary functional protein within it, the ryanodine receptor (RyR; in this paper, we use RyR to refer to the myocardial isoform RyR2). Although this change was associated with much enlarged RyR clusters that, due to their size, should be more excitable, functionally it caused a mild inhibition in the Ca2+ signalling output of the junctions (Ca2+ sparks). Analysis of the single-molecule densities of both RyR and junctophilin-2 revealed an ∼3-fold increase in the junctophilin-2 to RyR ratio. This molecular rearrangement is compatible with direct inhibition of RyR opening by junctophilin-2 to intrinsically stabilise the Ca2+ signalling properties of the junction and thus the contractile function of the cell.
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Affiliation(s)
- Michelle L Munro
- Department of Physiology, School of Medical Sciences, University of Auckland, 1023, New Zealand
| | - Izzy Jayasinghe
- School of Physics, University of Exeter, Exeter EX4 4QL, UK
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Qiongling Wang
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Ann Quick
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Wei Wang
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - David Baddeley
- Department of Cell Biology, Yale University, New Haven, CT 06520, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Christian Soeller
- Department of Physiology, School of Medical Sciences, University of Auckland, 1023, New Zealand
- School of Physics, University of Exeter, Exeter EX4 4QL, UK
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49
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Reynolds JO, Quick AP, Wang Q, Beavers DL, Philippen LE, Showell J, Barreto-Torres G, Thuerauf DJ, Doroudgar S, Glembotski CC, Wehrens XHT. Junctophilin-2 gene therapy rescues heart failure by normalizing RyR2-mediated Ca 2+ release. Int J Cardiol 2016; 225:371-380. [PMID: 27760414 DOI: 10.1016/j.ijcard.2016.10.021] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/05/2016] [Accepted: 10/07/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND Junctophilin-2 (JPH2) is the primary structural protein for the coupling of transverse (T)-tubule associated cardiac L-type Ca channels and type-2 ryanodine receptors on the sarcoplasmic reticulum within junctional membrane complexes (JMCs) in cardiomyocytes. Effective signaling between these channels ensures adequate Ca-induced Ca release required for normal cardiac contractility. Disruption of JMC subcellular domains, a common feature of failing hearts, has been attributed to JPH2 downregulation. Here, we tested the hypothesis that adeno-associated virus type 9 (AAV9) mediated overexpression of JPH2 could halt the development of heart failure in a mouse model of transverse aortic constriction (TAC). METHODS AND RESULTS Following TAC, a progressive decrease in ejection fraction was paralleled by a progressive decrease of cardiac JPH2 levels. AAV9-mediated expression of JPH2 rescued cardiac contractility in mice subjected to TAC. AAV9-JPH2 also preserved T-tubule structure. Moreover, the Ca2+ spark frequency was reduced and the Ca2+ transient amplitude was increased in AAV9-JPH2 mice following TAC, consistent with JPH2-mediated normalization of SR Ca2+ handling. CONCLUSIONS This study demonstrates that AAV9-mediated JPH2 gene therapy maintained cardiac function in mice with early stage heart failure. Moreover, restoration of JPH2 levels prevented loss of T-tubules and suppressed abnormal SR Ca2+ leak associated with contractile failure following TAC. These findings suggest that targeting JPH2 might be an attractive therapeutic approach for treating pathological cardiac remodeling during heart failure.
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Affiliation(s)
- Julia O Reynolds
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ann P Quick
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qiongling Wang
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David L Beavers
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Translational Biology and Molecular Medicine Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Leonne E Philippen
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jordan Showell
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Giselle Barreto-Torres
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Donna J Thuerauf
- San Diego State University Heart Institute and Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Shirin Doroudgar
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Innere Medizin III, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Christopher C Glembotski
- San Diego State University Heart Institute and Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Medicine/Cardiology, Baylor College of Medicine, Houston, TX 77030, USA; Dept. of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
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50
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Li L, Pan ZF, Huang X, Wu BW, Li T, Kang MX, Ge RS, Hu XY, Zhang YH, Ge LJ, Zhu DY, Wu YL, Lou YJ. Junctophilin 3 expresses in pancreatic beta cells and is required for glucose-stimulated insulin secretion. Cell Death Dis 2016; 7:e2275. [PMID: 27336719 PMCID: PMC5143404 DOI: 10.1038/cddis.2016.179] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/26/2016] [Accepted: 05/30/2016] [Indexed: 12/15/2022]
Abstract
It is well accepted that junctophilin (JPHs) isoforms act as a physical bridge linking plasma membrane and endoplasmic reticulum (ER) for channel crosstalk in excitable cells. Our purpose is to investigate whether JPHs are involved in the proper communication between Ca(2+) influx and subsequent Ca(2+) amplification in pancreatic beta cells, thereby participating in regulating insulin secretion. The expression of JPH isoforms was examined in human and mouse pancreatic tissues, and JPH3 expression was found in both the beta cells. In mice, knockdown of Jph3 (si-Jph3) in islets decreased glucose-stimulated insulin secretion (GSIS) accompanied by mitochondrial function impairment. Si-Jph3 lowered the insulin secretory response to Ca(2+) signaling in the presence of glucose, and reduced [Ca(2+)]c transient amplitude triggered by caffeine. Si-Jph3 also attenuated mitofusin 2 expression, thereby disturbing the spatial organization of ER-mitochondria contact in islets. These results suggest that the regulation of GSIS by the KATP channel-independent pathways is partly impaired due to decrease of JPH3 expression in mouse islets. JPH3 also binds to type 2 ryanodine receptors (RyR2) in mouse and human pancreatic tissues, which might contribute to Ca(2+) release amplification in GSIS. This study demonstrates some previously unrecognized findings in pancreatic tissues: (1) JPH3 expresses in mouse and human beta cells; (2) si-Jph3 in mouse primary islets impairs GSIS in vitro; (3) impairment in GSIS in si-Jph3 islets is due to changes in RyR2-[Ca(2+)]c transient amplitude and ER-mitochondria contact.
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Affiliation(s)
- L Li
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Department of Pharmacy, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China
| | - Z-F Pan
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - X Huang
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Cardiovascular Key Laboratory of Zhejiang Province, The 2nd Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China
| | - B-W Wu
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - T Li
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - M-X Kang
- Department of General Surgery, The 2nd Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China
| | - R-S Ge
- The Population Council at the Rockefeller University, New York 10021, NY, USA
- Institute of Reproductive Biomedicine, the 2nd Affiliated Hospital, Wenzhou Medical University, Wenzhou 325027, China
| | - X-Y Hu
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Cardiovascular Key Laboratory of Zhejiang Province, The 2nd Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Y-H Zhang
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - L-J Ge
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - D-Y Zhu
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Y-L Wu
- Department of General Surgery, The 2nd Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Y-J Lou
- Insititute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
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