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Hord JM, Anderson ME, Prouty SJ, Melton S, Gastel Z, Zimmerman K, Weiss RM, Campbell KP. Matriglycan maintains t-tubule structural integrity in cardiac muscle. Proc Natl Acad Sci U S A 2024; 121:e2402890121. [PMID: 38771868 PMCID: PMC11145246 DOI: 10.1073/pnas.2402890121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/08/2024] [Indexed: 05/23/2024] Open
Abstract
Maintaining the structure of cardiac membranes and membrane organelles is essential for heart function. A critical cardiac membrane organelle is the transverse tubule system (called the t-tubule system) which is an invagination of the surface membrane. A unique structural characteristic of the cardiac muscle t-tubule system is the extension of the extracellular matrix (ECM) from the surface membrane into the t-tubule lumen. However, the importance of the ECM extending into the cardiac t-tubule lumen is not well understood. Dystroglycan (DG) is an ECM receptor in the surface membrane of many cells, and it is also expressed in t-tubules in cardiac muscle. Extensive posttranslational processing and O-glycosylation are required for DG to bind ECM proteins and the binding is mediated by a glycan structure known as matriglycan. Genetic disruption resulting in defective O-glycosylation of DG results in muscular dystrophy with cardiorespiratory pathophysiology. Here, we show that DG is essential for maintaining cardiac t-tubule structural integrity. Mice with defects in O-glycosylation of DG developed normal t-tubules but were susceptible to stress-induced t-tubule loss or severing that contributed to cardiac dysfunction and disease progression. Finally, we observed similar stress-induced cardiac t-tubule disruption in a cohort of mice that solely lacked matriglycan. Collectively, our data indicate that DG in t-tubules anchors the luminal ECM to the t-tubule membrane via the polysaccharide matriglycan, which is critical to transmitting structural strength of the ECM to the t-tubules and provides resistance to mechanical stress, ultimately preventing disruptions in cardiac t-tubule integrity.
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Affiliation(s)
- Jeffrey M. Hord
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Mary E. Anderson
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Sally J. Prouty
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Shelly Melton
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Zeita Gastel
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Kathy Zimmerman
- Division of Cardiology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Robert M. Weiss
- Division of Cardiology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Abboud Cardiovascular Research Center, Carver College of Medicine, Department of Internal Medicine-Cardiovascular Medicine, University of Iowa, Iowa City, IA52242
- Iowa City Veterans Affairs Health Care System, University of Iowa, Iowa City, IA52242
| | - Kevin P. Campbell
- HHMI, University of Iowa, Iowa City, IA52242
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Iowa, Iowa City, IA52242
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA52242
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2
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Manfra O, Louey S, Jonker SS, Perdreau-Dahl H, Frisk M, Giraud GD, Thornburg KL, Louch WE. Augmenting workload drives T-tubule assembly in developing cardiomyocytes. J Physiol 2023:10.1113/JP284538. [PMID: 37128962 PMCID: PMC10854476 DOI: 10.1113/jp284538] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023] Open
Abstract
Contraction of cardiomyocytes is initiated at subcellular elements called dyads, where L-type Ca2+ channels in t-tubules are located within close proximity to ryanodine receptors in the sarcoplasmic reticulum. While evidence from small rodents indicates that dyads are assembled gradually in the developing heart, it is unclear how this process occurs in large mammals. We presently examined dyadic formation in fetal and newborn sheep (Ovis aries), and the regulation of this process by fetal cardiac workload. By employing advanced imaging methods, we demonstrated that t-tubule growth and dyadic assembly proceed gradually during fetal sheep development, from 93 days of gestational age until birth (147 days). This process parallels progressive increases in fetal systolic blood pressure, and includes step-wise colocalization of L-type Ca2+ channels and the Na+ /Ca2+ exchanger with ryanodine receptors. These proteins are upregulated together with the dyadic anchor junctophilin-2 during development, alongside changes in the expression of amphiphysin-2 (BIN1) and its partner proteins myotubularin and dynamin-2. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth. Conversely, reducing fetal systolic load with infusion of enalaprilat, an angiotensin converting enzyme inhibitor, blunted t-tubule formation. Interestingly, altered t-tubule densities did not relate to changes in dyadic junctions, or marked changes in the expression of dyadic regulatory proteins, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum. In conclusion, augmenting blood pressure and workload during normal fetal development critically promotes t-tubule growth, while additional signals contribute to dyadic assembly. KEY POINTS: T-tubule growth and dyadic assembly proceed gradually in cardiomyocytes during fetal sheep development, from 93 days of gestational age until the post-natal stage. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth and hypertrophy. In contrast, reducing fetal systolic load by enalaprilat infusion slowed t-tubule development and decreased cardiomyocyte size. Load-dependent modulation of t-tubule maturation was linked to altered expression patterns of the t-tubule regulatory proteins junctophilin-2 and amphiphysin-2 (BIN1) and its protein partners. Altered t-tubule densities did not influence dyadic formation, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum.
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Affiliation(s)
- Ornella Manfra
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Sonnet S Jonker
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Harmonie Perdreau-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - George D Giraud
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
- VA Portland Health Care System Portland, OR, USA
| | - Kent L Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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3
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Frisk M, Norseng PA, Stenersen Espe EK, Louch WE. Tubulator: an automated approach to analysis of t-tubule and dyadic organization in cardiomyocytes. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210468. [PMID: 36189810 PMCID: PMC9527907 DOI: 10.1098/rstb.2021.0468] [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] [Indexed: 11/12/2022] Open
Abstract
During cardiac disease, t-tubules and dyads are remodelled and disrupted within cardiomyocytes, thereby reducing cardiac performance. Given the pathological implications of such dyadic remodelling, robust and versatile tools for characterizing these sub-cellular structures are needed. While analysis programs for continuous and regular structures such as rodent ventricular t-tubules are available, at least in two dimensions, these approaches are less appropriate for assessment of more irregular structures, such as dyadic proteins and non-rodent t-tubules. Here, we demonstrate versatile, easy-to-use software that performs such analyses. This software, called Tubulator, enables automated analysis of t-tubules and dyadic proteins alike, in both tissue sections and isolated myocytes. The program measures densities of subcellular structures and proteins in individual cells, quantifies their distribution into transversely and longitudinally oriented elements, and supports detailed co-localization analyses. Importantly, Tubulator provides tools for three-dimensional assessment and rendering of image stacks, extending examinations from the single plane to the whole-myocyte level. To provide insight into the consequences of dyadic organization for synchrony of Ca2+ handling, Tubulator also creates 'distance maps', by calculating the distance from all cytosolic positions to the nearest t-tubule and/or dyad. In conclusion, this freely accessible program provides detailed automated analysis of the three-dimensional nature of dyadic and t-tubular structures. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.
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Affiliation(s)
- Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway.,K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Per Andreas Norseng
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway.,K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Emil Knut Stenersen Espe
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway.,K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway.,K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
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4
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Lin J, Chen Z, Yang L, Liu L, Yue P, Sun Y, Zhao M, Guo X, Hu X, Zhang Y, Zhang H, Li Y, Guo Y, Dong E. Cas9/AAV9-Mediated Somatic Mutagenesis Uncovered the Cell-Autonomous Role of Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 2 in Murine Cardiomyocyte Maturation. Front Cell Dev Biol 2022; 10:864516. [PMID: 35433671 PMCID: PMC9012521 DOI: 10.3389/fcell.2022.864516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/03/2022] [Indexed: 11/24/2022] Open
Abstract
Sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) is a key player in cardiomyocyte calcium handling and also a classic target in the gene therapy for heart failure. SERCA2 expression dramatically increases during cardiomyocyte maturation in the postnatal phase of heart development, which is essential for the heart to acquire its full function in adults. However, whether and how SERCA2 regulates cardiomyocyte maturation remains unclear. Here, we performed Cas9/AAV9-mediated somatic mutagenesis (CASAAV) in mice and achieved cardiomyocyte-specific knockout of Atp2a2, the gene coding SERCA2. Through a cardiac genetic mosaic analysis, we demonstrated the cell-autonomous role of SERCA2 in building key ultrastructures of mature ventricular cardiomyocytes, including transverse-tubules and sarcomeres. SERCA2 also exerts a profound impact on oxidative respiration gene expression and sarcomere isoform switching from Myh7/Tnni1 to Myh6/Tnni3, which are transcriptional hallmarks of cardiomyocyte maturation. Together, this study uncovered a pivotal role of SERCA2 in heart development and provided new insights about SERCA2-based cardiac gene therapy.
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Affiliation(s)
- Junsen Lin
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Zhan Chen
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Luzi Yang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Lei Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Peng Yue
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yueshen Sun
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
- Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Mingming Zhao
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, National Health Commission of China (NHC) Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research. Beijing, China
| | - Xiaoling Guo
- Basic Medical Research Center, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaomin Hu
- State Key Laboratory of Complex Severe and Rare Diseases, Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
- Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Yan Zhang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Hong Zhang
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yuxuan Guo
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
- *Correspondence: Yuxuan Guo,
| | - Erdan Dong
- Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
- Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, National Health Commission of China (NHC) Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research. Beijing, China
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5
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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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Uchida K, Nikouee A, Moench I, Tamkus G, Elghoul Y, Lopatin AN. The mechanism of osmotically induced sealing of cardiac t tubules. Am J Physiol Heart Circ Physiol 2020; 319:H410-H421. [PMID: 32648820 DOI: 10.1152/ajpheart.00573.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac t tubules undergo significant remodeling in various pathological and experimental conditions, which can be associated with mechanical or osmotic stress. In particular, it has been shown that removal of hyposmotic stress can lead to sealing of t tubules. However, the mechanisms underlying the sealing process remain essentially unknown. In this study we used dextran trapping assay to demonstrate that in adult mouse cardiomyocytes, t-tubular sealing can also be induced by hyperosmotic challenge and that both hypo- and hyperosmotic sealing display a clear threshold behavior requiring ≈100 mosmol/L minimal stress. Importantly, during both hypo- and hyperosmotic challenges, the sealing of t tubules occurs only during the shrinking phase. Analysis of the time course of t-tubular remodeling following removal of hyposmotic stress shows that t tubules become sealed essentially instantly, well before any significant reduction in cell size can be observed. Overall, the data support the hypothesis that the critical event in the process of t-tubular sealing during osmotic challenges is detachment (peeling) of the membrane from the underlying cytoskeleton due to suprathreshold stress.NEW & NOTEWORTHY This study provides new insights into how t-tubular membranes respond to osmotic forces. In particular, the data show that osmotically induced sealing of cardiac t tubules is a threshold phenomenon initiated by detachment of t-tubular membrane from the underlying cytoskeleton. The findings are consistent with the hypothesis that final sealing of t tubules is driven by negative hydrostatic intracellular pressure coincident with cell shrinking.
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Affiliation(s)
- Keita Uchida
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Azadeh Nikouee
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Ian Moench
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Greta Tamkus
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Yasmine Elghoul
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Anatoli N Lopatin
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
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7
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Pitoulis FG, Watson SA, Perbellini F, Terracciano CM. Myocardial slices come to age: an intermediate complexity in vitro cardiac model for translational research. Cardiovasc Res 2020; 116:1275-1287. [PMID: 31868875 PMCID: PMC7243278 DOI: 10.1093/cvr/cvz341] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/31/2019] [Accepted: 12/19/2019] [Indexed: 12/17/2022] Open
Abstract
Although past decades have witnessed significant reductions in mortality of heart failure together with advances in our understanding of its cellular, molecular, and whole-heart features, a lot of basic cardiac research still fails to translate into clinical practice. In this review we examine myocardial slices, a novel model in the translational arena. Myocardial slices are living ultra-thin sections of heart tissue. Slices maintain the myocardium's native function (contractility, electrophysiology) and structure (multicellularity, extracellular matrix) and can be prepared from animal and human tissue. The discussion begins with the history and current advances in the model, the different interlaboratory methods of preparation and their potential impact on results. We then contextualize slices' advantages and limitations by comparing it with other cardiac models. Recently, sophisticated methods have enabled slices to be cultured chronically in vitro while preserving the functional and structural phenotype. This is more timely now than ever where chronic physiologically relevant in vitro platforms for assessment of therapeutic strategies are urgently needed. We interrogate the technological developments that have permitted this, their limitations, and future directions. Finally, we look into the general obstacles faced by the translational field, and how implementation of research systems utilizing slices could help in resolving these.
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Affiliation(s)
- Fotios G Pitoulis
- Laboratory of Cell Electrophysiology, Department of Myocardial Function, Imperial College London, National Heart and Lung Institute, 4th Floor ICTEM Building Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Samuel A Watson
- Laboratory of Cell Electrophysiology, Department of Myocardial Function, Imperial College London, National Heart and Lung Institute, 4th Floor ICTEM Building Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - Filippo Perbellini
- Laboratory of Cell Electrophysiology, Department of Myocardial Function, Imperial College London, National Heart and Lung Institute, 4th Floor ICTEM Building Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- Hannover Medical School, Institute of Molecular and Translational Therapeutic Strategies, Hannover, Germany
| | - Cesare M Terracciano
- Laboratory of Cell Electrophysiology, Department of Myocardial Function, Imperial College London, National Heart and Lung Institute, 4th Floor ICTEM Building Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
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8
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Pitoulis FG, Terracciano CM. Heart Plasticity in Response to Pressure- and Volume-Overload: A Review of Findings in Compensated and Decompensated Phenotypes. Front Physiol 2020; 11:92. [PMID: 32116796 PMCID: PMC7031419 DOI: 10.3389/fphys.2020.00092] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/27/2020] [Indexed: 12/20/2022] Open
Abstract
The adult human heart has an exceptional ability to alter its phenotype to adapt to changes in environmental demand. This response involves metabolic, mechanical, electrical, and structural alterations, and is known as cardiac plasticity. Understanding the drivers of cardiac plasticity is essential for development of therapeutic agents. This is particularly important in contemporary cardiology, which uses treatments with peripheral effects (e.g., on kidneys, adrenal glands). This review focuses on the effects of different hemodynamic loads on myocardial phenotype. We examine mechanical scenarios of pressure- and volume overload, from the initial insult, to compensated, and ultimately decompensated stage. We discuss how different hemodynamic conditions occur and are underlined by distinct phenotypic and molecular changes. We complete the review by exploring how current basic cardiac research should leverage available cardiac models to study mechanical load in its different presentations.
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9
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Shahinian JH, Rog-Zielinska EA, Schlimpert M, Mayer B, Tholen S, Kammerer B, Biniossek ML, Beyersdorf F, Schilling O, Siepe M. Impact of left ventricular assist device therapy on the cardiac proteome and metabolome composition in ischemic cardiomyopathy. Artif Organs 2019; 44:257-267. [PMID: 31494943 DOI: 10.1111/aor.13566] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 07/26/2019] [Accepted: 08/28/2019] [Indexed: 12/14/2022]
Abstract
The changes in the myocardial proteome and metabolome associated with left ventricular assist device (LVAD) therapy in patients with ischemic cardiomyopathy (ICM) are poorly characterized. We investigated the impact of mechanical unloading following LVAD therapy on the myocardial proteome and metabolome. Matched samples of 5 patients' myocardial tissue, harvested at the time of LVAD implant ("pre-LVAD") or heart transplant ("post-LVAD"), were studied by quantitative proteomics and metabolomics as well as being probed for T-tubule structure and connexin-43 distribution. Moreover, pre-LVAD proteome profiles of ICM context were bioinformatically compared to pre-LVAD proteome profiles of dilated cardiac myopathy (DCM). More than 2120 proteins were reliably identified and quantified in paired patient samples. LVAD therapy led to proteomic remodeling, including reduced levels of α-1-antichymotrypsin together with an overall decrease of immune response proteins and an increase of proteins involved in membrane biology. Metabolomics highlighted increased glucose and glucose-6-phosphate levels in the left ventricle upon LVAD therapy. Wheat germ agglutinin staining demonstrated improved T-tubule structure. Connexin-43 displayed a trend for more pronounced intercalated disc localization. In comparing pre-LVAD proteome profiles of ICM context with pre-LVAD proteome profiles of dilated cardiac myopathy (DCM), we noticed an overrepresentation in ICM of proteins associated with humoral immune response. Our findings underline an impact of LVAD therapy on left ventricular biology in ICM. The proteomic, metabolomic, and structural alterations described here are typically associated with cardiac recovery. On the molecular level, our findings indicate the possibility of cardiac remodeling under LVAD therapy in ICM.
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Affiliation(s)
- Jasmin Hasmik Shahinian
- Department of Cardiovascular Surgery, University Heart Center Freiburg • Bad Krozingen, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Eva A Rog-Zielinska
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg • Bad Krozingen, Freiburg, Germany
| | - Manuel Schlimpert
- Center for Biological Systems Analysis, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Bettina Mayer
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Stefan Tholen
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Bernd Kammerer
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany.,Center for Biological Systems Analysis ZBSA, Albert-Ludwigs-University, Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Martin L Biniossek
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Friedhelm Beyersdorf
- Department of Cardiovascular Surgery, University Heart Center Freiburg • Bad Krozingen, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Schilling
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany.,Institute of Surgical Pathology, Medical Center, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Matthias Siepe
- Department of Cardiovascular Surgery, University Heart Center Freiburg • Bad Krozingen, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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10
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Watson SA, Perbellini F, Terracciano CM. Cardiac t-tubules: where structural plasticity meets functional adaptation. Cardiovasc Res 2019; 112:423-5. [PMID: 27659500 DOI: 10.1093/cvr/cvw198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Samuel A Watson
- National Heart & Lung Institute, Imperial College London, Hammersmith Campus, DuCane Road, W120NN, London, UK
| | - Filippo Perbellini
- National Heart & Lung Institute, Imperial College London, Hammersmith Campus, DuCane Road, W120NN, London, UK
| | - Cesare M Terracciano
- National Heart & Lung Institute, Imperial College London, Hammersmith Campus, DuCane Road, W120NN, London, UK
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11
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Antoniou CK, Manolakou P, Magkas N, Konstantinou K, Chrysohoou C, Dilaveris P, Gatzoulis KA, Tousoulis D. Cardiac Resynchronisation Therapy and Cellular Bioenergetics: Effects Beyond Chamber Mechanics. Eur Cardiol 2019; 14:33-44. [PMID: 31131035 PMCID: PMC6523053 DOI: 10.15420/ecr.2019.2.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cardiac resynchronisation therapy is a cornerstone in the treatment of advanced dyssynchronous heart failure. However, despite its widespread clinical application, precise mechanisms through which it exerts its beneficial effects remain elusive. Several studies have pointed to a metabolic component suggesting that, both in concert with alterations in chamber mechanics and independently of them, resynchronisation reverses detrimental changes to cellular metabolism, increasing energy efficiency and metabolic reserve. These actions could partially account for the existence of responders that improve functionally but not echocardiographically. This article will attempt to summarise key components of cardiomyocyte metabolism in health and heart failure, with a focus on the dyssynchronous variant. Both chamber mechanics-related and -unrelated pathways of resynchronisation effects on bioenergetics – stemming from the ultramicroscopic level – and a possible common underlying mechanism relating mechanosensing to metabolism through the cytoskeleton will be presented. Improved insights regarding the cellular and molecular effects of resynchronisation on bioenergetics will promote our understanding of non-response, optimal device programming and lead to better patient care.
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Affiliation(s)
| | - Panagiota Manolakou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Nikolaos Magkas
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos Konstantinou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Christina Chrysohoou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Polychronis Dilaveris
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos A Gatzoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Dimitrios Tousoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
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12
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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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13
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Bryant SM, Kong CHT, Watson JJ, Gadeberg HC, Roth DM, Patel HH, Cannell MB, James AF, Orchard CH. Caveolin-3 KO disrupts t-tubule structure and decreases t-tubular I Ca density in mouse ventricular myocytes. Am J Physiol Heart Circ Physiol 2018; 315:H1101-H1111. [PMID: 30028203 PMCID: PMC6415741 DOI: 10.1152/ajpheart.00209.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/25/2018] [Accepted: 07/11/2018] [Indexed: 02/06/2023]
Abstract
Caveolin-3 (Cav-3) is a protein that has been implicated in t-tubule formation and function in cardiac ventricular myocytes. In cardiac hypertrophy and failure, Cav-3 expression decreases, t-tubule structure is disrupted, and excitation-contraction coupling is impaired. However, the extent to which the decrease in Cav-3 expression underlies these changes is unclear. We therefore investigated the structure and function of myocytes isolated from the hearts of Cav-3 knockout (KO) mice. These mice showed cardiac dilatation and decreased ejection fraction in vivo compared with wild-type control mice. Isolated KO myocytes showed cellular hypertrophy, altered t-tubule structure, and decreased L-type Ca2+ channel current ( ICa) density. This decrease in density occurred predominantly in the t-tubules, with no change in total ICa, and was therefore a consequence of the increase in membrane area. Cav-3 KO had no effect on L-type Ca2+ channel expression, and C3SD peptide, which mimics the scaffolding domain of Cav-3, had no effect on ICa in KO myocytes. However, inhibition of PKA using H-89 decreased ICa at the surface and t-tubule membranes in both KO and wild-type myocytes. Cav-3 KO had no significant effect on Na+/Ca2+ exchanger current or Ca2+ release. These data suggest that Cav-3 KO causes cellular hypertrophy, thereby decreasing t-tubular ICa density. NEW & NOTEWORTHY Caveolin-3 (Cav-3) is a protein that inhibits hypertrophic pathways, has been implicated in the formation and function of cardiac t-tubules, and shows decreased expression in heart failure. This study demonstrates that Cav-3 knockout mice show cardiac dysfunction in vivo, while isolated ventricular myocytes show cellular hypertrophy, changes in t-tubule structure, and decreased t-tubular L-type Ca2+ current density, suggesting that decreased Cav-3 expression contributes to these changes in cardiac hypertrophy and failure.
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MESH Headings
- Action Potentials
- Animals
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Caveolin 3/deficiency
- Caveolin 3/genetics
- Down-Regulation
- Genetic Predisposition to Disease
- Heart Ventricles/metabolism
- Heart Ventricles/pathology
- Hypertrophy, Left Ventricular/genetics
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phenotype
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/pathology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
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Affiliation(s)
- Simon M Bryant
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - Cherrie H T Kong
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - Judy J Watson
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - Hanne C Gadeberg
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - David M Roth
- Veterans Affairs San Diego Healthcare System and Department of Anesthesiology, University of California-San Diego , La Jolla, California
| | - Hemal H Patel
- Veterans Affairs San Diego Healthcare System and Department of Anesthesiology, University of California-San Diego , La Jolla, California
| | - Mark B Cannell
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - Andrew F James
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
| | - Clive H Orchard
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol , Bristol , United Kingdom
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14
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Crossman DJ, Shen X, Jüllig M, Munro M, Hou Y, Middleditch M, Shrestha D, Li A, Lal S, Dos Remedios CG, Baddeley D, Ruygrok PN, Soeller C. Increased collagen within the transverse tubules in human heart failure. Cardiovasc Res 2018; 113:879-891. [PMID: 28444133 DOI: 10.1093/cvr/cvx055] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 03/20/2017] [Indexed: 12/22/2022] Open
Abstract
Aims In heart failure transverse-tubule (t-tubule) remodelling disrupts calcium release, and contraction. T-tubules in human failing hearts exhibit increased labelling by wheat germ agglutinin (WGA), a lectin that binds to the dystrophin-associated glycoprotein complex. We hypothesized changes in this complex may explain the increased WGA labelling and contribute to t-tubule remodelling in the failing human heart. In this study we sought to identify the molecules responsible for this increased WGA labelling. Methods and results Confocal and super-resolution fluorescence microscopy and proteomic analyses were used to quantify left ventricle samples from healthy donors and patients with idiopathic dilated cardiomyopathy (IDCM). Confocal microscopy demonstrated both WGA and dystrophin were located at t-tubules. Super-resolution microscopy revealed that WGA labelling of t-tubules is largely located within the lumen while dystrophin was restricted to near the sarcolemma. Western blots probed with WGA reveal a 5.7-fold increase in a 140 kDa band in IDCM. Mass spectrometry identified this band as type VI collagen (Col-VI) comprised of α1(VI), α2(VI), and α3(VI) chains. Pertinently, mutations in Col-VI cause muscular dystrophy. Western blotting identified a 2.4-fold increased expression and 3.2-fold increased WGA binding of Col-VI in IDCM. Confocal images showed that Col-VI is located in the t-tubules and that their diameter increased in the IDCM samples. Super-resolution imaging revealed Col-VI was restricted to the t-tubule lumen where increases were associated with displacement in the sarcolemma as identified from dystrophin labelling. Samples were also labelled for type I, III, and IV collagen. Both confocal and super-resolution imaging identified that these collagens were also present within t-tubule lumen. Conclusion Increased expression and labelling of collagen in IDCM samples indicates fibrosis may contribute to t-tubule remodelling in human heart failure.
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Affiliation(s)
- David J Crossman
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Xin Shen
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Mia Jüllig
- School of Biological Sciences, University of Auckland, 3a Symonds Street, Auckland 1010, New Zealand
| | - Michelle Munro
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Yufeng Hou
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Martin Middleditch
- School of Biological Sciences, University of Auckland, 3a Symonds Street, Auckland 1010, New Zealand
| | - Darshan Shrestha
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Amy Li
- Bosch Institute, University of Sydney, Fisher Road Sydney, NSW 2006, Australia
| | - Sean Lal
- Bosch Institute, University of Sydney, Fisher Road Sydney, NSW 2006, Australia
| | | | - David Baddeley
- Department of Cell Biology, Yale University, West Campus, 300 Heffernan Drive, Haven, CT 06515, USA
| | - Peter N Ruygrok
- Department of Cardiology, Auckland City Hospital, Auckland 1042, New Zealand
| | - Christian Soeller
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand.,Living Systems Institute and Biomedical Physics, University of Exeter, Stocker Road, Exeter EX4QL, UK
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15
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Guo A, Chen R, Wang Y, Huang CK, Chen B, Kutschke W, Hong J, Song LS. Transient activation of PKC results in long-lasting detrimental effects on systolic [Ca 2+] i in cardiomyocytes by altering actin cytoskeletal dynamics and T-tubule integrity. J Mol Cell Cardiol 2018; 115:104-114. [PMID: 29307535 DOI: 10.1016/j.yjmcc.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/18/2017] [Accepted: 01/03/2018] [Indexed: 11/25/2022]
Abstract
AIMS Protein kinase C (PKC) isozymes contribute to the development of heart failure through dysregulation of Ca2+ handling properties and disruption of contractile function in cardiomyocytes. However, the mechanisms by which PKC activation leads to Ca2+ dysfunction are incompletely understood. METHODS AND RESULTS Shortly upon ventricular pressure overload in mice, we detected transient PKC activation that was associated with pulsed actin cytoskeletal rearrangement. In cultured cardiomyocytes, transient activation of PKC promoted long-term deleterious effects on the integrity of the transverse (T)- tubule system, resulting in a significant decrease in the amplitude and increase in the rising kinetics of Ca2+ transients. Treatment with a PKCα/β inhibitor restored the synchronization of Ca2+ transients and maintained T-tubule integrity in cultured cardiomyocytes. Supporting these data, PKCα/β inhibition protected against T-tubule remodeling and cardiac dysfunction in a mouse model of pressure overload-induced heart failure. Mechanistically, transient activation of PKC resulted in biphasic actin cytoskeletal rearrangement, consistent with in vivo observations in the pressure overloaded mouse model. Transient inhibition of actin polymerization or depolymerization resulted in severe T-tubule damage, recapitulating the T-tubule damage induced by PKC activation. Moreover, inhibition of stretch activated channels (SAC) protected against T-tubule remodeling and E-C coupling dysfunction induced by transient PKC activation and actin cytoskeletal rearrangement. CONCLUSIONS These data identify a key mechanistic link between transient PKC activation and long-term Ca2+ handling defects through PKC-induced actin cytoskeletal rearrangement and resultant T-tubule damage.
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Affiliation(s)
- Ang Guo
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China
| | - Rong Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Yihui Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Chun-Kai Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - William Kutschke
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jiang Hong
- Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200080, China
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine & Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Veterans Affairs Medical Center, Iowa City, IA 52242, USA.
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16
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Abstract
PURPOSE OF REVIEW Membrane invaginations called t-tubules play an integral role in triggering cardiomyocyte contraction, and their disruption during diseases such as heart failure critically impairs cardiac performance. In this review, we outline the growing understanding of the malleability of t-tubule structure and function, and highlight emerging t-tubule regulators which may be exploited for novel therapies. RECENT FINDINGS New technologies are revealing the nanometer scale organization of t-tubules, and their functional junctions with the sarcoplasmic reticulum called dyads, which generate Ca2+ sparks. Recent data have indicated that the dyadic anchoring protein junctophilin-2, and the membrane-bending protein BIN1 are key regulators of dyadic formation and maintenance. While the underlying signals which control expression and localization of these proteins remain unclear, accumulating data support an important role of myocardial workload. Although t-tubule alterations are believed to be a key cause of heart failure, the plasticity of these structures also creates an opportunity for therapy. Promising recent data suggest that such therapies may specifically target junctophilin-2, BIN1, and/or mechanotransduction.
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17
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Crossman DJ, Jayasinghe ID, Soeller C. Transverse tubule remodelling: a cellular pathology driven by both sides of the plasmalemma? Biophys Rev 2017; 9:919-929. [PMID: 28695473 DOI: 10.1007/s12551-017-0273-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/06/2017] [Indexed: 01/10/2023] Open
Abstract
Transverse (t)-tubules are invaginations of the plasma membrane that form a complex network of ducts, 200-400 nm in diameter depending on the animal species, that penetrates deep within the cardiac myocyte, where they facilitate a fast and synchronous contraction across the entire cell volume. There is now a large body of evidence in animal models and humans demonstrating that pathological distortion of the t-tubule structure has a causative role in the loss of myocyte contractility that underpins many forms of heart failure. Investigations into the molecular mechanisms of pathological t-tubule remodelling to date have focused on proteins residing in the intracellular aspect of t-tubule membrane that form linkages between the membrane and myocyte cytoskeleton. In this review, we shed light on the mechanisms of t-tubule remodelling which are not limited to the intracellular side. Our recent data have demonstrated that collagen is an integral part of the t-tubule network and that it increases within the tubules in heart failure, suggesting that a fibrotic mechanism could drive cardiac junctional remodelling. We examine the evidence that the linkages between the extracellular matrix, t-tubule membrane and cellular cytoskeleton should be considered as a whole when investigating the mechanisms of t-tubule pathology in the failing heart.
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Affiliation(s)
- David J Crossman
- Department of Physiology, University of Auckland, Auckland, New Zealand.
| | | | - Christian Soeller
- Department of Physiology, University of Auckland, Auckland, New Zealand
- Biomedical Physics, University of Exeter, Exeter, UK
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18
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Louch WE, Nattel S. T-tubular collagen: a new player in mechanosensing and disease? Cardiovasc Res 2017; 113:839-840. [PMID: 28481973 DOI: 10.1093/cvr/cvx091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, 4.etg. Bygg 7, 0407 Oslo, Norway
| | - Stanley Nattel
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
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19
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Heterotopic Abdominal Rat Heart Transplantation as a Model to Investigate Volume Dependency of Myocardial Remodeling. Transplantation 2017; 101:498-505. [PMID: 27906830 DOI: 10.1097/tp.0000000000001585] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Heterotopic abdominal rat heart transplantation has been extensively used to investigate ischemic-reperfusion injury, immunological consequences during heart transplantations and also to study remodeling of the myocardium due to volume unloading. We provide a unique review on the latter and present a summary of the experimental studies on rat heart transplantation to illustrate changes that occur to the myocardium due to volume unloading. We divided the literature based on whether normal or failing rat heart models were used. This analysis may provide a basis to understand the physiological effects of mechanical circulatory support therapy.
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20
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Rame JE, Lavandero S. Subcellular Remodeling of the T-Tubule Membrane System: The Limits of Myocardial Recovery Revealed? Circulation 2017; 135:1646-1650. [PMID: 28438805 DOI: 10.1161/circulationaha.117.025319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- J Eduardo Rame
- From Division of Cardiovascular Medicine (J.E.R.) and Cardiovascular Institute (J.E.R.), University of Pennsylvania, Philadelphia; Advanced Center for Chronic Diseases, Faculty Chemical and Pharmaceutical Sciences and Faculty of Medicine, University of Chile, Santiago (S.L.); and Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas (S.L.).
| | - Sergio Lavandero
- From Division of Cardiovascular Medicine (J.E.R.) and Cardiovascular Institute (J.E.R.), University of Pennsylvania, Philadelphia; Advanced Center for Chronic Diseases, Faculty Chemical and Pharmaceutical Sciences and Faculty of Medicine, University of Chile, Santiago (S.L.); and Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas (S.L.).
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21
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Peana D, Domeier TL. Cardiomyocyte Ca 2+ homeostasis as a therapeutic target in heart failure with reduced and preserved ejection fraction. Curr Opin Pharmacol 2017; 33:17-26. [PMID: 28437711 DOI: 10.1016/j.coph.2017.03.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/22/2017] [Indexed: 12/28/2022]
Abstract
Heart failure is a highly prevalent syndrome of multiple etiologies and associated comorbidities, and aberrant intracellular Ca2+ homeostasis is a hallmark finding in heart failure patients. The cyclical changes in Ca2+ concentration within cardiomyocytes control cycles of cardiac contraction and relaxation, and dysregulation of Ca2+ handling processes leads to systolic dysfunction, diastolic dysfunction, and adverse remodeling. For this reason, greater understanding of Ca2+ handling mechanisms in heart failure is critical for selection of appropriate treatment strategies. In this review, we summarize the mechanisms of altered Ca2+ handling in two subsets of heart failure, heart failure with reduced ejection fraction and heart failure with preserved ejection fraction, and outline current and experimental treatments that target cardiomyocyte Ca2+ handling processes.
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Affiliation(s)
- Deborah Peana
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Timothy L Domeier
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
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22
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Abstract
Unique to striated muscle cells, transverse tubules (t-tubules) are membrane organelles that consist of sarcolemma penetrating into the myocyte interior, forming a highly branched and interconnected network. Mature t-tubule networks are found in mammalian ventricular cardiomyocytes, with the transverse components of t-tubules occurring near sarcomeric z-discs. Cardiac t-tubules contain membrane microdomains enriched with ion channels and signaling molecules. The microdomains serve as key signaling hubs in regulation of cardiomyocyte function. Dyad microdomains formed at the junctional contact between t-tubule membrane and neighboring sarcoplasmic reticulum are critical in calcium signaling and excitation-contraction coupling necessary for beat-to-beat heart contraction. In this review, we provide an overview of the current knowledge in gross morphology and structure, membrane and protein composition, and function of the cardiac t-tubule network. We also review in detail current knowledge on the formation of functional membrane subdomains within t-tubules, with a particular focus on the cardiac dyad microdomain. Lastly, we discuss the dynamic nature of t-tubules including membrane turnover, trafficking of transmembrane proteins, and the life cycles of membrane subdomains such as the cardiac BIN1-microdomain, as well as t-tubule remodeling and alteration in diseased hearts. Understanding cardiac t-tubule biology in normal and failing hearts is providing novel diagnostic and therapeutic opportunities to better treat patients with failing hearts.
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Affiliation(s)
- TingTing Hong
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
| | - Robin M Shaw
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
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23
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Zhou K, Hong T. Cardiac BIN1 (cBIN1) is a regulator of cardiac contractile function and an emerging biomarker of heart muscle health. SCIENCE CHINA-LIFE SCIENCES 2016; 60:257-263. [DOI: 10.1007/s11427-016-0249-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/06/2016] [Indexed: 12/01/2022]
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Frisk M, Ruud M, Espe EKS, Aronsen JM, Røe ÅT, Zhang L, Norseng PA, Sejersted OM, Christensen GA, Sjaastad I, Louch WE. Elevated ventricular wall stress disrupts cardiomyocyte t-tubule structure and calcium homeostasis. Cardiovasc Res 2016; 112:443-51. [PMID: 27226008 PMCID: PMC5031949 DOI: 10.1093/cvr/cvw111] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 05/16/2016] [Indexed: 11/13/2022] Open
Abstract
AIMS Invaginations of the cellular membrane called t-tubules are essential for maintaining efficient excitation-contraction coupling in ventricular cardiomyocytes. Disruption of t-tubule structure during heart failure has been linked to dyssynchronous, slowed Ca(2+) release and reduced power of the heartbeat. The underlying mechanism is, however, unknown. We presently investigated whether elevated ventricular wall stress triggers remodelling of t-tubule structure and function. METHODS AND RESULTS MRI and blood pressure measurements were employed to examine regional wall stress across the left ventricle of sham-operated and failing, post-infarction rat hearts. In failing hearts, elevated left ventricular diastolic pressure and ventricular dilation resulted in markedly increased wall stress, particularly in the thin-walled region proximal to the infarct. High wall stress in this proximal zone was associated with reduced expression of the dyadic anchor junctophilin-2 and disrupted cardiomyocyte t-tubular structure. Indeed, local wall stress measurements predicted t-tubule density across sham and failing hearts. Elevated wall stress and disrupted cardiomyocyte structure in the proximal zone were also associated with desynchronized Ca(2+) release in cardiomyocytes and markedly reduced local contractility in vivo. A causative role of wall stress in promoting t-tubule remodelling was established by applying stretch to papillary muscles ex vivo under culture conditions. Loads comparable to wall stress levels observed in vivo in the proximal zone reduced expression of junctophilin-2 and promoted t-tubule loss. CONCLUSION Elevated wall stress reduces junctophilin-2 expression and disrupts t-tubule integrity, Ca(2+) release, and contractile function. These findings provide new insight into the role of wall stress in promoting heart failure progression.
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Affiliation(s)
- Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Marianne Ruud
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Emil K S Espe
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | | | - Åsmund T Røe
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Lili Zhang
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Per Andreas Norseng
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ole M Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Geir A Christensen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, 0424 Oslo, Norway K.G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
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BIN1 regulates dynamic t-tubule membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1839-47. [PMID: 26578114 DOI: 10.1016/j.bbamcr.2015.11.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/31/2015] [Accepted: 11/09/2015] [Indexed: 11/23/2022]
Abstract
Cardiac transverse tubules (t-tubules) are specific membrane organelles critical in calcium signaling and excitation-contraction coupling required for beat-to-beat heart contraction. T-tubules are highly branched and form an interconnected network that penetrates the myocyte interior to form junctions with the sarcoplasmic reticulum. T-tubules are selectively enriched with specific ion channels and proteins crucial in calcium transient development necessary in excitation-contraction coupling, thus t-tubules are a key component of cardiac myocyte function. In this review, we focus primarily on two proteins concentrated within the t-tubular network, the L-type calcium channel (LTCC) and associated membrane anchor protein, bridging integrator 1 (BIN1). Here, we provide an overview of current knowledge in t-tubule morphology, composition, microdomains, as well as the dynamics of the t-tubule network. Secondly, we highlight multiple aspects of BIN1-dependent t-tubule function, which includes forward trafficking of LTCCs to t-tubules, LTCC clustering at t-tubule surface, microdomain organization and regulation at t-tubule membrane, and the formation of a slow diffusion barrier within t-tubules. Lastly, we describe progress in characterizing how acquired human heart failure can be attributed to abnormal BIN1 transcription and associated t-tubule remodeling. Understanding BIN1-regulated cardiac t-tubule biology in human heart failure management has the dual benefit of promoting progress in both biomarker development and therapeutic target identification. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Sitsapesan R. A new look at structures and mechanisms regulating endoplasmic/sarcoplasmic reticulum Ca(2+) release in health and disease. J Physiol 2015; 593:3239-40. [PMID: 26228552 DOI: 10.1113/jphysiol.2014.281907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/03/2014] [Accepted: 10/05/2014] [Indexed: 11/08/2022] Open
Affiliation(s)
- Rebecca Sitsapesan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
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Ibrahim M, Nader A, Yacoub MH, Terracciano C. Manipulation of sarcoplasmic reticulum Ca(2+) release in heart failure through mechanical intervention. J Physiol 2015; 593:3253-9. [PMID: 25922157 DOI: 10.1113/jp270446] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/26/2015] [Indexed: 12/24/2022] Open
Abstract
Left ventricular assist devices (LVADs) were developed as a means of temporary circulatory support, but the mechanical unloading they offer also results in significant reverse remodelling. In selected patients, these improvements are sufficient to allow ultimate device explantation without requiring transplantation; this represents a fundamental shift in our understanding of heart failure. Like heart failure itself, LVADs influence multiple biological systems. The transverse tubules are a system of membrane invaginations in ventricular cardiomyocytes which allow rapid propagation of the action potential throughout the cell. Through their dense concentration of L-type Ca(2+) channels in close proximity to intracellular ryanodine receptors, the t-tubules enable synchronous Ca(2+) release throughout the cell. The t-tubules' structure appears to be specifically regulated by mechanical load, such that either the overload of heart failure (or the spontaneously hypertensive rat model) or the profound unloading in a chronically unloaded heart result in impaired t-tubule structure, with ineffective Ca(2+) release. While there are multiple molecular pathways which underpin t-tubule regulation, Telethonin (Tcap) appears to be important in regulating the effect of altered loading on the t-tubule system.
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Affiliation(s)
- Michael Ibrahim
- Integrated Resident in Cardiac Surgery, Division of Cardiovascular Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, 19104, USA
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Terracciano CM, Navaratnarajah M, Bello SOZ, Ibrahim M. Does size matter? In search of a physiological definition of myocardial atrophy. J Am Coll Cardiol 2015; 65:2154-6. [PMID: 25975487 DOI: 10.1016/j.jacc.2014.12.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 12/18/2014] [Indexed: 10/23/2022]
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Louch WE, Koivumäki JT, Tavi P. Calcium signalling in developing cardiomyocytes: implications for model systems and disease. J Physiol 2015; 593:1047-63. [PMID: 25641733 PMCID: PMC4358669 DOI: 10.1113/jphysiol.2014.274712] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 12/28/2014] [Indexed: 12/15/2022] Open
Abstract
Adult cardiomyocytes exhibit complex Ca(2+) homeostasis, enabling tight control of contraction and relaxation. This intricate regulatory system develops gradually, with progressive maturation of specialized structures and increasing capacity of Ca(2+) sources and sinks. In this review, we outline current understanding of these developmental processes, and draw parallels to pathophysiological conditions where cardiomyocytes exhibit a striking regression to an immature state of Ca(2+) homeostasis. We further highlight the importance of understanding developmental physiology when employing immature cardiomyocyte models such as cultured neonatal cells and stem cells.
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Affiliation(s)
- William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo0424, Oslo, Norway
- K. G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo0316, Oslo, Norway
| | - Jussi T Koivumäki
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical ComputingOslo, Norway
| | - Pasi Tavi
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
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Lavorato M, Huang TQ, Iyer VR, Perni S, Meissner G, Franzini-Armstrong C. Dyad content is reduced in cardiac myocytes of mice with impaired calmodulin regulation of RyR2. J Muscle Res Cell Motil 2015; 36:205-14. [DOI: 10.1007/s10974-015-9405-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/24/2015] [Indexed: 11/27/2022]
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Jackman CP, Shadrin IY, Carlson AL, Bursac N. Human Cardiac Tissue Engineering: From Pluripotent Stem Cells to Heart Repair. Curr Opin Chem Eng 2015; 7:57-64. [PMID: 25599018 PMCID: PMC4293542 DOI: 10.1016/j.coche.2014.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Engineered cardiac tissues hold great promise for use in drug and toxicology screening, in vitro studies of human physiology and disease, and as transplantable tissue grafts for myocardial repair. In this review, we discuss recent progress in cell-based therapy and functional tissue engineering using pluripotent stem cell-derived cardiomyocytes and we describe methods for delivery of cells into the injured heart. While significant hurdles remain, notable advances have been made in the methods to derive large numbers of pure human cardiomyocytes, mature their phenotype, and produce and implant functional cardiac tissues, bringing the field a step closer to widespread in vitro and in vivo applications.
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Affiliation(s)
| | - Ilya Y. Shadrin
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Aaron L. Carlson
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Nenad Bursac
- Department of Biomedical Engineering, Duke University, Durham, NC
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Wu CYC, Chen B, Jiang YP, Jia Z, Martin DW, Liu S, Entcheva E, Song LS, Lin RZ. Calpain-dependent cleavage of junctophilin-2 and T-tubule remodeling in a mouse model of reversible heart failure. J Am Heart Assoc 2014; 3:e000527. [PMID: 24958777 PMCID: PMC4309042 DOI: 10.1161/jaha.113.000527] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background A highly organized transverse tubule (T‐tubule) network is necessary for efficient Ca2+‐induced Ca2+ release and synchronized contraction of ventricular myocytes. Increasing evidence suggests that T‐tubule remodeling due to junctophilin‐2 (JP‐2) downregulation plays a critical role in the progression of heart failure. However, the mechanisms underlying JP‐2 dysregulation remain incompletely understood. Methods and Results A mouse model of reversible heart failure that is driven by conditional activation of the heterotrimeric G protein Gαq in cardiac myocytes was used in this study. Mice with activated Gαq exhibited disruption of the T‐tubule network and defects in Ca2+ handling that culminated in heart failure compared with wild‐type mice. Activation of Gαq/phospholipase Cβ signaling increased the activity of the Ca2+‐dependent protease calpain, leading to the proteolytic cleavage of JP‐2. A novel calpain cleavage fragment of JP‐2 is detected only in hearts with constitutive Gαq signaling to phospholipase Cβ. Termination of the Gαq signal was followed by normalization of the JP‐2 protein level, repair of the T‐tubule network, improvements in Ca2+ handling, and reversal of heart failure. Treatment of mice with a calpain inhibitor prevented Gαq‐dependent JP‐2 cleavage, T‐tubule disruption, and the development of heart failure. Conclusions Disruption of the T‐tubule network in heart failure is a reversible process. Gαq‐dependent activation of calpain and subsequent proteolysis of JP‐2 appear to be the molecular mechanism that leads to T‐tubule remodeling, Ca2+ handling dysfunction, and progression to heart failure in this mouse model.
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Affiliation(s)
- Chia-Yen C Wu
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (B.C., L.S.S.)
| | - Ya-Ping Jiang
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Zhiheng Jia
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY (Z.J., E.E.)
| | - Dwight W Martin
- Department of Medicine and Proteomics Center, Stony Brook University, Stony Brook, NY (D.W.M.)
| | - Shengnan Liu
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Emilia Entcheva
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.) Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY (Z.J., E.E.)
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (B.C., L.S.S.)
| | - Richard Z Lin
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.) Department of Veterans Affairs Medical Center, Northport, NY (R.Z.L.)
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Moench I, Lopatin AN. Ca(2+) homeostasis in sealed t-tubules of mouse ventricular myocytes. J Mol Cell Cardiol 2014; 72:374-83. [PMID: 24787472 DOI: 10.1016/j.yjmcc.2014.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 04/15/2014] [Accepted: 04/18/2014] [Indexed: 10/25/2022]
Abstract
We have recently shown that in mouse ventricular myocytes, t-tubules can be quickly and tightly sealed during the resolution of hyposmotic shock of physiologically relevant magnitude. Sealing of t-tubules is associated with trapping extracellular solution inside the myocytes but the ionic homeostasis of sealed t-tubules and the consequences of potential transtubular ion fluxes remain unknown. In this study we investigated the dynamics of Ca(2+) movements associated with sealing of t-tubules. The data show that under normal conditions sealed t-tubules contain Ca(2+) at concentrations below 100μM. However, blockade of voltage-dependent Ca(2+) channels with 10μM nicardipine, or increasing extracellular concentration of K(+) from 5.4mM to 20mM led to several fold increase in concentration of t-tubular Ca(2+). Alternatively, the release of Ca(2+) from sarcoplasmic reticulum using 10mM caffeine led to the restoration of t-tubular Ca(2+) towards extracellular levels within few seconds. Sealing of t-tubules in the presence of extracellular 1.5mM Ca(2+) and 5.4mM extracellular K(+) led to occasional and sporadic intracellular Ca(2+) transients. In contrast, sealing of t-tubules in the presence of 10mM caffeine was characterized by a significant long lasting increase in intracellular Ca(2+). The effect was completely abolished in the absence of extracellular Ca(2+) and significantly reduced in pre-detubulated myocytes but was essentially preserved in the presence of mitochondrial decoupler dinitrophenol. This study shows that sealed t-tubules are capable of highly regulated transport of Ca(2+) and present a major route for Ca(2+) influx into the cytosol during sealing process.
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Affiliation(s)
- I Moench
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - A N Lopatin
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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