1
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Caldwell JL, Clarke JD, Smith CER, Pinali C, Quinn CJ, Pearman CM, Adomaviciene A, Radcliffe EJ, Watkins A, Horn MA, Bode EF, Madders GWP, Eisner M, Eisner DA, Trafford AW, Dibb KM. Restoring Atrial T-Tubules Augments Systolic Ca Upon Recovery From Heart Failure. Circ Res 2024; 135:739-754. [PMID: 39140440 PMCID: PMC11392124 DOI: 10.1161/circresaha.124.324601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 07/24/2024] [Accepted: 08/06/2024] [Indexed: 08/15/2024]
Abstract
BACKGROUND Transverse (t)-tubules drive the rapid and synchronous Ca2+ rise in cardiac myocytes. The virtual complete atrial t-tubule loss in heart failure (HF) decreases Ca2+ release. It is unknown if or how atrial t-tubules can be restored and how this affects systolic Ca2+. METHODS HF was induced in sheep by rapid ventricular pacing and recovered following termination of rapid pacing. Serial block-face scanning electron microscopy and confocal imaging were used to study t-tubule ultrastructure. Function was assessed using patch clamp, Ca2+, and confocal imaging. Candidate proteins involved in atrial t-tubule recovery were identified by western blot and expressed in rat neonatal ventricular myocytes to determine if they altered t-tubule structure. RESULTS Atrial t-tubules were lost in HF but reappeared following recovery from HF. Recovered t-tubules were disordered, adopting distinct morphologies with increased t-tubule length and branching. T-tubule disorder was associated with mitochondrial disorder. Recovered t-tubules were functional, triggering Ca2+ release in the cell interior. Systolic Ca2+, ICa-L, sarcoplasmic reticulum Ca2+ content, and sarcoendoplasmic reticulum Ca2+ ATPase function were restored following recovery from HF. Confocal microscopy showed fragmentation of ryanodine receptor staining and movement away from the z-line in HF, which was reversed following recovery from HF. Acute detubulation, to remove recovered t-tubules, confirmed their key role in restoration of the systolic Ca2+ transient, the rate of Ca2+ removal, and the peak L-type Ca2+ current. The abundance of telethonin and myotubularin decreased during HF and increased during recovery. Transfection with these proteins altered the density and structure of tubules in neonatal myocytes. Myotubularin had a greater effect, increasing tubule length and branching, replicating that seen in the recovery atria. CONCLUSIONS We show that recovery from HF restores atrial t-tubules, and this promotes recovery of ICa-L, sarcoplasmic reticulum Ca2+ content, and systolic Ca2+. We demonstrate an important role for myotubularin in t-tubule restoration. Our findings reveal a new and viable therapeutic strategy.
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Affiliation(s)
- Jessica L Caldwell
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Jessica D Clarke
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Charlotte E R Smith
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Christian Pinali
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Callum J Quinn
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Charles M Pearman
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Aiste Adomaviciene
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Emma J Radcliffe
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Amy Watkins
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Margaux A Horn
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Elizabeth F Bode
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - George W P Madders
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Mark Eisner
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - David A Eisner
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Andrew W Trafford
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
| | - Katharine M Dibb
- Unit of Cardiac Physiology, Manchester Academic Health Science Centre, University of Manchester, United Kingdom
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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 2024; 602:4461-4486. [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] [MESH Headings] [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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Clancy CE, Santana LF. Advances in induced pluripotent stem cell-derived cardiac myocytes: technological breakthroughs, key discoveries and new applications. J Physiol 2024; 602:3871-3892. [PMID: 39032073 PMCID: PMC11326976 DOI: 10.1113/jp282562] [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: 02/21/2024] [Accepted: 07/02/2024] [Indexed: 07/22/2024] Open
Abstract
A transformation is underway in precision and patient-specific medicine. Rapid progress has been enabled by multiple new technologies including induced pluripotent stem cell-derived cardiac myocytes (iPSC-CMs). Here, we delve into these advancements and their future promise, focusing on the efficiency of reprogramming techniques, the fidelity of differentiation into the cardiac lineage, the functional characterization of the resulting cardiac myocytes, and the many applications of in silico models to understand general and patient-specific mechanisms controlling excitation-contraction coupling in health and disease. Furthermore, we explore the current and potential applications of iPSC-CMs in both research and clinical settings, underscoring the far-reaching implications of this rapidly evolving field.
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Affiliation(s)
- Colleen E Clancy
- Department of Physiology & Membrane Biology, School of Medicine, University of California Davis, Davis, CA, USA
- Center for Precision Medicine and Data Sciences, University of California Davis, School of Medicine, Sacramento, CA, USA
| | - L Fernando Santana
- Department of Physiology & Membrane Biology, School of Medicine, University of California Davis, Davis, CA, USA
- Center for Precision Medicine and Data Sciences, University of California Davis, School of Medicine, Sacramento, CA, USA
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4
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Giraud Q, Laporte J. Amphiphysin-2 (BIN1) functions and defects in cardiac and skeletal muscle. Trends Mol Med 2024; 30:579-591. [PMID: 38514365 DOI: 10.1016/j.molmed.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/11/2024] [Accepted: 02/14/2024] [Indexed: 03/23/2024]
Abstract
Amphiphysin-2 is a ubiquitously expressed protein also known as bridging integrator 1 (BIN1), playing a critical role in membrane remodeling, trafficking, and cytoskeleton dynamics in a wide range of tissues. Mutations in the gene encoding BIN1 cause centronuclear myopathies (CNM), and recent evidence has implicated BIN1 in heart failure, underlining its crucial role in both skeletal and cardiac muscle. Furthermore, altered expression of BIN1 is linked to an increased risk of late-onset Alzheimer's disease and several types of cancer, including breast, colon, prostate, and lung cancers. Recently, the first proof-of-concept for potential therapeutic strategies modulating BIN1 were obtained for muscle diseases. In this review article, we discuss the similarities and differences in BIN1's functions in cardiac and skeletal muscle, along with its associated diseases and potential therapies.
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Affiliation(s)
- Quentin Giraud
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC, INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch-Graffenstaden, 67400, France
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC, INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch-Graffenstaden, 67400, France.
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5
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Schwenzer N, Teiwes NK, Kohl T, Pohl C, Giller MJ, Lehnart SE, Steinem C. Ca V1.3 channel clusters characterized by live-cell and isolated plasma membrane nanoscopy. Commun Biol 2024; 7:620. [PMID: 38783117 PMCID: PMC11116533 DOI: 10.1038/s42003-024-06313-3] [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: 10/23/2023] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
A key player of excitable cells in the heart and brain is the L-type calcium channel CaV1.3. In the heart, it is required for voltage-dependent Ca2+-signaling, i.e., for controlling and modulating atrial cardiomyocyte excitation-contraction coupling. The clustering of CaV1.3 in functionally relevant channel multimers has not been addressed due to a lack of stoichiometric labeling combined with high-resolution imaging. Here, we developed a HaloTag-labeling strategy to visualize and quantify CaV1.3 clusters using STED nanoscopy to address the questions of cluster size and intra-cluster channel density. Channel clusters were identified in the plasma membrane of transfected live HEK293 cells as well as in giant plasma membrane vesicles derived from these cells that were spread on modified glass support to obtain supported plasma membrane bilayers (SPMBs). A small fraction of the channel clusters was colocalized with early and recycling endosomes at the membranes. STED nanoscopy in conjunction with live-cell and SPMB imaging enabled us to quantify CaV1.3 cluster sizes and their molecular density revealing significantly lower channel densities than expected for dense channel packing. CaV1.3 channel cluster size and molecular density were increased in SPMBs after treatment of the cells with the sympathomimetic compound isoprenaline, suggesting a regulated channel cluster condensation mechanism.
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Affiliation(s)
- Niko Schwenzer
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert‑Koch‑Str. 42a, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC 2067), University of Göttingen, 37073, Göttingen, Germany
| | - Nikolas K Teiwes
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC 2067), University of Göttingen, 37073, Göttingen, Germany
- Georg-August Universität, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077, Göttingen, Germany
| | - Tobias Kohl
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert‑Koch‑Str. 42a, 37075, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Celine Pohl
- Georg-August Universität, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077, Göttingen, Germany
| | - Michelle J Giller
- Georg-August Universität, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077, Göttingen, Germany
| | - Stephan E Lehnart
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert‑Koch‑Str. 42a, 37075, Göttingen, Germany.
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC 2067), University of Göttingen, 37073, Göttingen, Germany.
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
- Collaborative Research Center SFB 1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
| | - Claudia Steinem
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC 2067), University of Göttingen, 37073, Göttingen, Germany.
- Georg-August Universität, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077, Göttingen, Germany.
- Max-Planck-Institut für Dynamik und Selbstorganisation, Am Fassberg 17, 37077, Göttingen, Germany.
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6
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Westhoff M, Del Villar SG, Voelker TL, Thai PN, Spooner HC, Costa AD, Sirish P, Chiamvimonvat N, Dickson EJ, Dixon RE. BIN1 knockdown rescues systolic dysfunction in aging male mouse hearts. Nat Commun 2024; 15:3528. [PMID: 38664444 PMCID: PMC11045846 DOI: 10.1038/s41467-024-47847-8] [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: 05/02/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Cardiac dysfunction is a hallmark of aging in humans and mice. Here we report that a two-week treatment to restore youthful Bridging Integrator 1 (BIN1) levels in the hearts of 24-month-old mice rejuvenates cardiac function and substantially reverses the aging phenotype. Our data indicate that age-associated overexpression of BIN1 occurs alongside dysregulated endosomal recycling and disrupted trafficking of cardiac CaV1.2 and type 2 ryanodine receptors. These deficiencies affect channel function at rest and their upregulation during acute stress. In vivo echocardiography reveals reduced systolic function in old mice. BIN1 knockdown using an adeno-associated virus serotype 9 packaged shRNA-mBIN1 restores the nanoscale distribution and clustering plasticity of ryanodine receptors and recovers Ca2+ transient amplitudes and cardiac systolic function toward youthful levels. Enhanced systolic function correlates with increased phosphorylation of the myofilament protein cardiac myosin binding protein-C. These results reveal BIN1 knockdown as a novel therapeutic strategy to rejuvenate the aging myocardium.
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Affiliation(s)
- Maartje Westhoff
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Silvia G Del Villar
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Taylor L Voelker
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Phung N Thai
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
| | - Heather C Spooner
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Alexandre D Costa
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Padmini Sirish
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
| | - Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA, USA
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.
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7
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Chen Z, Pan Z, Huang C, Zhu X, Li N, Huynh H, Xu J, Huang L, Vaz FM, Liu J, Han Z, Ouyang K. Cardiac lipidomic profiles in mice undergo changes from fetus to adult. Life Sci 2024; 341:122484. [PMID: 38311219 DOI: 10.1016/j.lfs.2024.122484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/20/2024] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
AIMS Lipids are essential cellular components with many important biological functions. Disturbed lipid biosynthesis and metabolism has been shown to cause cardiac developmental abnormality and cardiovascular diseases. In this study, we aimed to investigate the composition and the molecular profiles of lipids in mammalian hearts between embryonic and adult stages and uncover the underlying links between lipid and cardiac development and maturation. MATERIALS AND METHODS We collected mouse hearts at the embryonic day 11.5 (E11.5), E15.5, and the age of 2 months, 4 months and 10 months, and performed lipidomic analysis to determine the changes of the composition, molecular species, and relative abundance of cardiac lipids between embryonic and adult stages. Additionally, we also performed the electronic microscopy and RNA sequencing in both embryonic and adult mouse hearts. KEY FINDINGS The relative abundances of certain phospholipids and sphingolipids including cardiolipin, phosphatidylglycerol, phosphatidylethanolamine, and ceramide, are different between embryonic and adult hearts. Such lipidomic changes are accompanied with increased densities of mitochondrial membranes and elevated expression of genes related to mitochondrial formation in adult mouse hearts. We also analyzed individual molecular species of phospholipids and sphingolipids, and revealed that the composition and distribution of lipid molecular species in hearts also change with development. SIGNIFICANCE Our study provides not only a lipidomic view of mammalian hearts when developing from the embryonic to the adult stage, but also a potential pool of lipid indicators for cardiac cell development and maturation.
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Affiliation(s)
- Ze'e Chen
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Zhixiang Pan
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Can Huang
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Xiangbin Zhu
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Na Li
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Helen Huynh
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA, United States of America
| | - Junjie Xu
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Lei Huang
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and Pediatrics, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands; Core Facility Metabolomics, Amsterdam UMC, the Netherlands
| | - Jie Liu
- Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, China
| | - Zhen Han
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China.
| | - Kunfu Ouyang
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong Province, China.
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8
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Moammer H, Bai J, Jones TLM, Ward M, Barrett C, Crossman DJ. Pirfenidone increases transverse tubule length in the infarcted rat myocardium. Interface Focus 2023; 13:20230047. [PMID: 38106917 PMCID: PMC10722216 DOI: 10.1098/rsfs.2023.0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/10/2023] [Indexed: 12/19/2023] Open
Abstract
Transverse (t)-tubule remodelling is a prominent feature of heart failure with reduced ejection fraction (HFrEF). In our previous research, we identified an increased amount of collagen within the t-tubules of HFrEF patients, suggesting fibrosis could contribute to the remodelling of t-tubules. In this research, we tested this hypothesis in a rodent model of myocardial infarction induced heart failure that was treated with the anti-fibrotic pirfenidone. Confocal microscopy demonstrated loss of t-tubules within the border zone region of the infarct. This was documented as a reduction in t-tubule frequency, area, length, and transverse elements. Eight weeks of pirfenidone treatment was able to significantly increase the area and length of the t-tubules within the border zone. Echocardiography showed no improvement with pirfenidone treatment. Surprisingly, pirfenidone significantly increased the thickness of the t-tubules in the remote left ventricle of heart failure animals. Dilation of t-tubules is a common feature in heart failure suggesting this may negatively impact function but there was no functional loss associated with pirfenidone treatment. However, due to the relatively short duration of treatment compared to that used clinically, the impact of long-term treatment on t-tubule structure should be investigated in future studies.
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Affiliation(s)
- Hussam Moammer
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
- Department of Clinical Physiology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jizhong Bai
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
| | - Timothy L. M. Jones
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Marie Ward
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
| | - Caroyln Barrett
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
| | - David J. Crossman
- Manaaki Manawa—The Centre for Heart Research, Department of Physiology, School of Medical and Health Sciences, Faculty of Medical and Health Sciences, Waipapa Taumata Rau / The University of Auckland, Park Road, Grafton, Auckland, New Zealand
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9
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Waddell HMM, Mereacre V, Alvarado FJ, Munro ML. Clustering properties of the cardiac ryanodine receptor in health and heart failure. J Mol Cell Cardiol 2023; 185:38-49. [PMID: 37890552 PMCID: PMC10717225 DOI: 10.1016/j.yjmcc.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 10/09/2023] [Accepted: 10/24/2023] [Indexed: 10/29/2023]
Abstract
The cardiac ryanodine receptor (RyR2) is an intracellular Ca2+ release channel vital for the function of the heart. Physiologically, RyR2 is triggered to release Ca2+ from the sarcoplasmic reticulum (SR) which enables cardiac contraction; however, spontaneous Ca2+ leak from RyR2 has been implicated in the pathophysiology of heart failure (HF). RyR2 channels have been well documented to assemble into clusters within the SR membrane, with the organisation of RyR2 clusters recently gaining interest as a mechanism by which the occurrence of pathological Ca2+ leak is regulated, including in HF. In this review, we explain the terminology relating to key nanoscale RyR2 clustering properties as both single clusters and functionally grouped Ca2+ release units, with a focus on the advancements in super-resolution imaging approaches which have enabled the detailed study of cluster organisation. Further, we discuss proposed mechanisms for modulating RyR2 channel organisation and the debate regarding the potential impact of cluster organisation on Ca2+ leak activity. Finally, recent experimental evidence investigating the nanoscale remodelling and functional alterations of RyR2 clusters in HF is discussed with consideration of the clinical implications.
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Affiliation(s)
- Helen M M Waddell
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Valeria Mereacre
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Francisco J Alvarado
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Michelle L Munro
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
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10
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Dries E, Gilbert G, Roderick HL, Sipido KR. The ryanodine receptor microdomain in cardiomyocytes. Cell Calcium 2023; 114:102769. [PMID: 37390591 DOI: 10.1016/j.ceca.2023.102769] [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: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023]
Abstract
The ryanodine receptor type 2 (RyR) is a key player in Ca2+ handling during excitation-contraction coupling. During each heartbeat, RyR channels are responsible for linking the action potential with the contractile machinery of the cardiomyocyte by releasing Ca2+ from the sarcoplasmic reticulum. RyR function is fine-tuned by associated signalling molecules, arrangement in clusters and subcellular localization. These parameters together define RyR function within microdomains and are subject to disease remodelling. This review describes the latest findings on RyR microdomain organization, the alterations with disease which result in increased subcellular heterogeneity and emergence of microdomains with enhanced arrhythmogenic potential, and presents novel technologies that guide future research to study and target RyR channels within specific microdomains.
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Affiliation(s)
- Eef Dries
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Guillaume Gilbert
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Laboratoire ORPHY EA 4324, Université de Brest, Brest, France
| | - H Llewelyn Roderick
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Karin R Sipido
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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11
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Kermani F, Mosqueira M, Peters K, Lemma ED, Rapti K, Grimm D, Bastmeyer M, Laugsch M, Hecker M, Ullrich ND. Membrane remodelling triggers maturation of excitation-contraction coupling in 3D-shaped human-induced pluripotent stem cell-derived cardiomyocytes. Basic Res Cardiol 2023; 118:13. [PMID: 36988697 PMCID: PMC10060306 DOI: 10.1007/s00395-023-00984-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/14/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023]
Abstract
The prospective use of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) for cardiac regenerative medicine strongly depends on the electro-mechanical properties of these cells, especially regarding the Ca2+-dependent excitation-contraction (EC) coupling mechanism. Currently, the immature structural and functional features of hiPSC-CM limit the progression towards clinical applications. Here, we show that a specific microarchitecture is essential for functional maturation of hiPSC-CM. Structural remodelling towards a cuboid cell shape and induction of BIN1, a facilitator of membrane invaginations, lead to transverse (t)-tubule-like structures. This transformation brings two Ca2+ channels critical for EC coupling in close proximity, the L-type Ca2+ channel at the sarcolemma and the ryanodine receptor at the sarcoplasmic reticulum. Consequently, the Ca2+-dependent functional interaction of these channels becomes more efficient, leading to improved spatio-temporal synchronisation of Ca2+ transients and higher EC coupling gain. Thus, functional maturation of hiPSC-cardiomyocytes by optimised cell microarchitecture needs to be considered for future cardiac regenerative approaches.
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Affiliation(s)
- Fatemeh Kermani
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Matias Mosqueira
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Kyra Peters
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Enrico D Lemma
- Zoological Institute, Cell and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Kleopatra Rapti
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Heidelberg University, Heidelberg, Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Heidelberg University, Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- German Center for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Martin Bastmeyer
- Zoological Institute, Cell and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Biological and Chemical Systems-Biological information processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
- Research Bridge (Synthetic Biology), Heidelberg-Karlsruhe Research Partnership (HEiKA), Heidelberg University and Karlsruhe Institute of Technology, Heidelberg, Germany
| | - Magdalena Laugsch
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Markus Hecker
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Nina D Ullrich
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany.
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany.
- Research Bridge (Synthetic Biology), Heidelberg-Karlsruhe Research Partnership (HEiKA), Heidelberg University and Karlsruhe Institute of Technology, Heidelberg, Germany.
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12
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Dixon RE, Trimmer JS. Endoplasmic Reticulum-Plasma Membrane Junctions as Sites of Depolarization-Induced Ca 2+ Signaling in Excitable Cells. Annu Rev Physiol 2023; 85:217-243. [PMID: 36202100 PMCID: PMC9918718 DOI: 10.1146/annurev-physiol-032122-104610] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane contact sites between endoplasmic reticulum (ER) and plasma membrane (PM), or ER-PM junctions, are found in all eukaryotic cells. In excitable cells they play unique roles in organizing diverse forms of Ca2+ signaling as triggered by membrane depolarization. ER-PM junctions underlie crucial physiological processes such as excitation-contraction coupling, smooth muscle contraction and relaxation, and various forms of activity-dependent signaling and plasticity in neurons. In many cases the structure and molecular composition of ER-PM junctions in excitable cells comprise important regulatory feedback loops linking depolarization-induced Ca2+ signaling at these sites to the regulation of membrane potential. Here, we describe recent findings on physiological roles and molecular composition of native ER-PM junctions in excitable cells. We focus on recent studies that provide new insights into canonical forms of depolarization-induced Ca2+ signaling occurring at junctional triads and dyads of striated muscle, as well as the diversity of ER-PM junctions in these cells and in smooth muscle and neurons.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
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13
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Mackrill JJ. Evolution of the cardiac dyad. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210329. [PMID: 36189805 PMCID: PMC9527923 DOI: 10.1098/rstb.2021.0329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/22/2021] [Indexed: 12/30/2022] Open
Abstract
Cardiac dyads are the site of communication between the sarcoplasmic reticulum (SR) and infoldings of the sarcolemma called transverse-tubules (TT). During heart excitation-contraction coupling, Ca2+-influx through L-type Ca2+ channels in the TT is amplified by release of Ca2+-from the SR via type 2 ryanodine receptors, activating the contractile apparatus. Key proteins involved in cardiac dyad function are bridging integrator 1 (BIN1), junctophilin 2 and caveolin 3. The work presented here aims to reconstruct the evolutionary history of the cardiac dyad, by surveying the scientific literature for ultrastructural evidence of these junctions across all animal taxa; phylogenetically reconstructing the evolutionary history of BIN1; and by comparing peptide motifs involved in TT formation by this protein across metazoans. Key findings are that cardiac dyads have been identified in mammals, arthropods and molluscs, but not in other animals. Vertebrate BIN1 does not group with members of this protein family from other taxa, suggesting that invertebrate BINs are paralogues rather orthologues of this gene. Comparisons of BIN1 peptide sequences of mammals with those of other vertebrates reveals novel features that might contribute to TT and dyad formation. The analyses presented here suggest that the cardiac dyad evolved independently several times during metazoan evolution: an unexpected observation given the diversity of heart structure and function between different animal taxa. 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)
- John James Mackrill
- Department of Physiology, School of Medicine, University College Cork, Western Gateway Building, Western Road, Cork T12 XF62, Republic of Ireland
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14
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Guarina L, Moghbel AN, Pourhosseinzadeh MS, Cudmore RH, Sato D, Clancy CE, Santana LF. Biological noise is a key determinant of the reproducibility and adaptability of cardiac pacemaking and EC coupling. J Gen Physiol 2022; 154:e202012613. [PMID: 35482009 PMCID: PMC9059386 DOI: 10.1085/jgp.202012613] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/16/2022] [Accepted: 04/07/2022] [Indexed: 12/23/2022] Open
Abstract
Each heartbeat begins with the generation of an action potential in pacemaking cells in the sinoatrial node. This signal triggers contraction of cardiac muscle through a process termed excitation-contraction (EC) coupling. EC coupling is initiated in dyadic structures of cardiac myocytes, where ryanodine receptors in the junctional sarcoplasmic reticulum come into close apposition with clusters of CaV1.2 channels in invaginations of the sarcolemma. Cooperative activation of CaV1.2 channels within these clusters causes a local increase in intracellular Ca2+ that activates the juxtaposed ryanodine receptors. A salient feature of healthy cardiac function is the reliable and precise beat-to-beat pacemaking and amplitude of Ca2+ transients during EC coupling. In this review, we discuss recent discoveries suggesting that the exquisite reproducibility of this system emerges, paradoxically, from high variability at subcellular, cellular, and network levels. This variability is attributable to stochastic fluctuations in ion channel trafficking, clustering, and gating, as well as dyadic structure, which increase intracellular Ca2+ variance during EC coupling. Although the effects of these large, local fluctuations in function and organization are sometimes negligible at the macroscopic level owing to spatial-temporal summation within and across cells in the tissue, recent work suggests that the "noisiness" of these intracellular Ca2+ events may either enhance or counterintuitively reduce variability in a context-dependent manner. Indeed, these noisy events may represent distinct regulatory features in the tuning of cardiac contractility. Collectively, these observations support the importance of incorporating experimentally determined values of Ca2+ variance in all EC coupling models. The high reproducibility of cardiac contraction is a paradoxical outcome of high Ca2+ signaling variability at subcellular, cellular, and network levels caused by stochastic fluctuations in multiple processes in time and space. This underlying stochasticity, which counterintuitively manifests as reliable, consistent Ca2+ transients during EC coupling, also allows for rapid changes in cardiac rhythmicity and contractility in health and disease.
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Affiliation(s)
- Laura Guarina
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Ariana Neelufar Moghbel
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | | | - Robert H. Cudmore
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA
| | - Colleen E. Clancy
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Luis Fernando Santana
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
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15
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Tomatidine-stimulated maturation of human embryonic stem cell-derived cardiomyocytes for modeling mitochondrial dysfunction. Exp Mol Med 2022; 54:493-502. [PMID: 35379934 PMCID: PMC9076832 DOI: 10.1038/s12276-022-00746-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/22/2021] [Accepted: 10/19/2021] [Indexed: 11/08/2022] Open
Abstract
Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have been reported to exhibit immature embryonic or fetal cardiomyocyte-like phenotypes. To enhance the maturation of hESC-CMs, we identified a natural steroidal alkaloid, tomatidine, as a new substance that stimulates the maturation of hESC-CMs. Treatment of human embryonic stem cells with tomatidine during cardiomyocyte differentiation stimulated the expression of several cardiomyocyte-specific markers and increased the density of T-tubules. Furthermore, tomatidine treatment augmented the number and size of mitochondria and enhanced the formation of mitochondrial lamellar cristae. Tomatidine treatment stimulated mitochondrial functions, including mitochondrial membrane potential, oxidative phosphorylation, and ATP production, in hESC-CMs. Tomatidine-treated hESC-CMs were more sensitive to doxorubicin-induced cardiotoxicity than the control cells. In conclusion, the present study suggests that tomatidine promotes the differentiation of stem cells to adult cardiomyocytes by accelerating mitochondrial biogenesis and maturation and that tomatidine-treated mature hESC-CMs can be used for cardiotoxicity screening and cardiac disease modeling.
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16
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Abstract
In mammalian cardiac myocytes, the plasma membrane includes the surface sarcolemma but also a network of membrane invaginations called transverse (t-) tubules. These structures carry the action potential deep into the cell interior, allowing efficient triggering of Ca2+ release and initiation of contraction. Once thought to serve as rather static enablers of excitation-contraction coupling, recent work has provided a newfound appreciation of the plasticity of the t-tubule network's structure and function. Indeed, t-tubules are now understood to support dynamic regulation of the heartbeat across a range of timescales, during all stages of life, in both health and disease. This review article aims to summarize these concepts, with consideration given to emerging t-tubule regulators and their targeting in future therapies.
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Affiliation(s)
- Katharine M Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom;
| | - 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
| | - Andrew W Trafford
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom;
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17
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Nusier M, Shah AK, Dhalla NS. Structure-Function Relationships and Modifications of Cardiac Sarcoplasmic Reticulum Ca2+-Transport. Physiol Res 2022; 70:S443-S470. [DOI: 10.33549/physiolres.934805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sarcoplasmic reticulum (SR) is a specialized tubular network, which not only maintains the intracellular concentration of Ca2+ at a low level but is also known to release and accumulate Ca2+ for the occurrence of cardiac contraction and relaxation, respectively. This subcellular organelle is composed of several phospholipids and different Ca2+-cycling, Ca2+-binding and regulatory proteins, which work in a coordinated manner to determine its function in cardiomyocytes. Some of the major proteins in the cardiac SR membrane include Ca2+-pump ATPase (SERCA2), Ca2+-release protein (ryanodine receptor), calsequestrin (Ca2+-binding protein) and phospholamban (regulatory protein). The phosphorylation of SR Ca2+-cycling proteins by protein kinase A or Ca2+-calmodulin kinase (directly or indirectly) has been demonstrated to augment SR Ca2+-release and Ca2+-uptake activities and promote cardiac contraction and relaxation functions. The activation of phospholipases and proteases as well as changes in different gene expressions under different pathological conditions have been shown to alter the SR composition and produce Ca2+-handling abnormalities in cardiomyocytes for the development of cardiac dysfunction. The post-translational modifications of SR Ca2+ cycling proteins by processes such as oxidation, nitrosylation, glycosylation, lipidation, acetylation, sumoylation, and O GlcNacylation have also been reported to affect the SR Ca2+ release and uptake activities as well as cardiac contractile activity. The SR function in the heart is also influenced in association with changes in cardiac performance by several hormones including thyroid hormones and adiponectin as well as by exercise-training. On the basis of such observations, it is suggested that both Ca2+-cycling and regulatory proteins in the SR membranes are intimately involved in determining the status of cardiac function and are thus excellent targets for drug development for the treatment of heart disease.
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Affiliation(s)
| | | | - NS Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen, Research Centre, 351 Tache Avenue, Winnipeg, MB, R2H 2A6 Canada.
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18
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Dixon RE. Nanoscale Organization, Regulation, and Dynamic Reorganization of Cardiac Calcium Channels. Front Physiol 2022; 12:810408. [PMID: 35069264 PMCID: PMC8769284 DOI: 10.3389/fphys.2021.810408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 11/30/2021] [Indexed: 12/19/2022] Open
Abstract
The architectural specializations and targeted delivery pathways of cardiomyocytes ensure that L-type Ca2+ channels (CaV1.2) are concentrated on the t-tubule sarcolemma within nanometers of their intracellular partners the type 2 ryanodine receptors (RyR2) which cluster on the junctional sarcoplasmic reticulum (jSR). The organization and distribution of these two groups of cardiac calcium channel clusters critically underlies the uniform contraction of the myocardium. Ca2+ signaling between these two sets of adjacent clusters produces Ca2+ sparks that in health, cannot escalate into Ca2+ waves because there is sufficient separation of adjacent clusters so that the release of Ca2+ from one RyR2 cluster or supercluster, cannot activate and sustain the release of Ca2+ from neighboring clusters. Instead, thousands of these Ca2+ release units (CRUs) generate near simultaneous Ca2+ sparks across every cardiomyocyte during the action potential when calcium induced calcium release from RyR2 is stimulated by depolarization induced Ca2+ influx through voltage dependent CaV1.2 channel clusters. These sparks summate to generate a global Ca2+ transient that activates the myofilaments and thus the electrical signal of the action potential is transduced into a functional output, myocardial contraction. To generate more, or less contractile force to match the hemodynamic and metabolic demands of the body, the heart responds to β-adrenergic signaling by altering activity of calcium channels to tune excitation-contraction coupling accordingly. Recent accumulating evidence suggests that this tuning process also involves altered expression, and dynamic reorganization of CaV1.2 and RyR2 channels on their respective membranes to control the amplitude of Ca2+ entry, SR Ca2+ release and myocardial function. In heart failure and aging, altered distribution and reorganization of these key Ca2+ signaling proteins occurs alongside architectural remodeling and is thought to contribute to impaired contractile function. In the present review we discuss these latest developments, their implications, and future questions to be addressed.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, United States
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19
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Dixon RE, Navedo MF, Binder MD, Santana LF. Mechanisms and Physiological Implications of Cooperative Gating of Ion Channels Clusters. Physiol Rev 2021; 102:1159-1210. [PMID: 34927454 DOI: 10.1152/physrev.00022.2021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ion channels play a central role in the regulation of nearly every cellular process. Dating back to the classic 1952 Hodgkin-Huxley model of the generation of the action potential, ion channels have always been thought of as independent agents. A myriad of recent experimental findings exploiting advances in electrophysiology, structural biology, and imaging techniques, however, have posed a serious challenge to this long-held axiom as several classes of ion channels appear to open and close in a coordinated, cooperative manner. Ion channel cooperativity ranges from variable-sized oligomeric cooperative gating in voltage-gated, dihydropyridine-sensitive Cav1.2 and Cav1.3 channels to obligatory dimeric assembly and gating of voltage-gated Nav1.5 channels. Potassium channels, transient receptor potential channels, hyperpolarization cyclic nucleotide-activated channels, ryanodine receptors (RyRs), and inositol trisphosphate receptors (IP3Rs) have also been shown to gate cooperatively. The implications of cooperative gating of these ion channels range from fine tuning excitation-contraction coupling in muscle cells to regulating cardiac function and vascular tone, to modulation of action potential and conduction velocity in neurons and cardiac cells, and to control of pace-making activity in the heart. In this review, we discuss the mechanisms leading to cooperative gating of ion channels, their physiological consequences and how alterations in cooperative gating of ion channels may induce a range of clinically significant pathologies.
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Affiliation(s)
- Rose Ellen Dixon
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, United States
| | - Marc D Binder
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
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20
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Chen L, He Y, Wang X, Ge J, Li H. Ventricular voltage-gated ion channels: Detection, characteristics, mechanisms, and drug safety evaluation. Clin Transl Med 2021; 11:e530. [PMID: 34709746 PMCID: PMC8516344 DOI: 10.1002/ctm2.530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac voltage-gated ion channels (VGICs) play critical roles in mediating cardiac electrophysiological signals, such as action potentials, to maintain normal heart excitability and contraction. Inherited or acquired alterations in the structure, expression, or function of VGICs, as well as VGIC-related side effects of pharmaceutical drug delivery can result in abnormal cellular electrophysiological processes that induce life-threatening cardiac arrhythmias or even sudden cardiac death. Hence, to reduce possible heart-related risks, VGICs must be acknowledged as important targets in drug discovery and safety studies related to cardiac disease. In this review, we first summarize the development and application of electrophysiological techniques that are employed in cardiac VGIC studies alone or in combination with other techniques such as cryoelectron microscopy, optical imaging and optogenetics. Subsequently, we describe the characteristics, structure, mechanisms, and functions of various well-studied VGICs in ventricular myocytes and analyze their roles in and contributions to both physiological cardiac excitability and inherited cardiac diseases. Finally, we address the implications of the structure and function of ventricular VGICs for drug safety evaluation. In summary, multidisciplinary studies on VGICs help researchers discover potential targets of VGICs and novel VGICs in heart, enrich their knowledge of the properties and functions, determine the operation mechanisms of pathological VGICs, and introduce groundbreaking trends in drug therapy strategies, and drug safety evaluation.
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Affiliation(s)
- Lulan Chen
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Yue He
- Department of CardiologyShanghai Xuhui District Central Hospital & Zhongshan‐xuhui HospitalShanghaiChina
| | - Xiangdong Wang
- Institute of Clinical Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Hua Li
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
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21
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Approaches to Optimize Stem Cell-Derived Cardiomyocyte Maturation and Function. CURRENT STEM CELL REPORTS 2021. [DOI: 10.1007/s40778-021-00197-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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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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23
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Guo J, Tian Q, Barth M, Xian W, Ruppenthal S, Schaefers HJ, Chen Z, Moretti A, Laugwitz KL, Lipp P. Human BIN1 isoforms grow, maintain and regenerate excitation-contraction couplons in adult rat and human stem cell-derived cardiomyocytes. Cardiovasc Res 2021; 118:1479-1491. [PMID: 34152414 DOI: 10.1093/cvr/cvab195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Indexed: 12/31/2022] Open
Abstract
AIMS In ventricular myocytes, Transverse-tubules (T-tubules) are instrumental for excitation-contraction (EC) coupling and their disarray is a hallmark of cardiac diseases. BIN1 is a key contributor to their biogenesis. Our study set out to investigate the role of human BIN1 splice variants in the maintenance and regeneration of EC-coupling in rat adult ventricular myocytes and human induced pluripotent stem cell-derived cardiac myocytes (hiPS-CMs). METHODS AND RESULTS In heart samples from healthy human donors expression patterns of 5 BIN1 splice variants were identified. Following viral transduction of human BIN1 splice variants in cellular models of T-tubular disarray we employed high-speed confocal calcium imaging and Ca-CLEAN analysis to identify functional EC-coupling sites and T-tubular architecture. Adult rat ventricular myocytes were used to investigate the regeneration after loss and maintenance of EC-coupling while we studied the enhancement of EC-coupling in hiPS-CMs. All five human BIN1 splice variants induced de novo generation of T-tubules in both cell types. Isoforms with the phosphoinositide binding motif (PI) were most potent in maintenance and regeneration of T-tubules and functional EC-coupling in adult rat myocytes. In hiPSC-CMs, BIN1 variants with PI motiv induced de-novo generation of T-tubules, functional EC-coupling sites and enhanced calcium handling. CONCLUSION(S) BIN1 is essential for the maintenance, regeneration, and de-novo generation of functional T-tubules, especially isoforms with PI motifs. These T-tubules trigger the development of functional EC couplons resulting in enhanced calcium handling. TRANSLATIONAL PERSPECTIVE Cardiomyopathy and heart failure are among the most frequent causes of death in modern societies. Gene therapies and hiPSC technology are becoming increasingly promising, both for treatment and therapy development. On the cellular level, one of the common denominators of cardiac diseases is the concurrent loss of T-tubules essential for efficient EC-coupling. While initial approaches in animal models employing gene therapy with BIN1 have depicted encouraging improvements the expression pattern of BIN1 isoforms in the human heart is still elusive. The present study identifies a unique set of five distinct BIN1 isoforms in healthy human hearts and demonstrates their potency in both, T-tubule maintenance and re-generation after loss resulting in efficient EC-coupling. Noteworthy, PI-motif containing isoforms were potent trigger of de-novo generation of T-tubules and establishment of efficient EC-coupling in hiPSC-CMs. Therefore, the expression of BIN1 might be novel and promising for pharmaceutical treatment and gene therapy.
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Affiliation(s)
- Jia Guo
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Qinghai Tian
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Monika Barth
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Wenying Xian
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Sandra Ruppenthal
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Hans-Joachim Schaefers
- Department of Thoracic and Cardiovascular Surgery, Saarland University Medical Center, Homburg/Saar, Germany
| | - Zhifen Chen
- I. Department of Medicine, Klinikum rechts der Isar, Technische Universität München, 81675, München, Germany.,DZHK (German Centre for Cardiovascular Research) - partner site Munich Heart Alliance, Munich, Germany
| | - Alessandra Moretti
- I. Department of Medicine, Klinikum rechts der Isar, Technische Universität München, 81675, München, Germany.,DZHK (German Centre for Cardiovascular Research) - partner site Munich Heart Alliance, Munich, Germany
| | - Karl-Ludwig Laugwitz
- I. Department of Medicine, Klinikum rechts der Isar, Technische Universität München, 81675, München, Germany.,DZHK (German Centre for Cardiovascular Research) - partner site Munich Heart Alliance, Munich, Germany
| | - Peter Lipp
- Molecular Cell Biology, Centre for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
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24
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Mechanisms and Regulation of Cardiac Ca V1.2 Trafficking. Int J Mol Sci 2021; 22:ijms22115927. [PMID: 34072954 PMCID: PMC8197997 DOI: 10.3390/ijms22115927] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 01/05/2023] Open
Abstract
During cardiac excitation contraction coupling, the arrival of an action potential at the ventricular myocardium triggers voltage-dependent L-type Ca2+ (CaV1.2) channels in individual myocytes to open briefly. The level of this Ca2+ influx tunes the amplitude of Ca2+-induced Ca2+ release from ryanodine receptors (RyR2) on the junctional sarcoplasmic reticulum and thus the magnitude of the elevation in intracellular Ca2+ concentration and ultimately the downstream contraction. The number and activity of functional CaV1.2 channels at the t-tubule dyads dictates the amplitude of the Ca2+ influx. Trafficking of these channels and their auxiliary subunits to the cell surface is thus tightly controlled and regulated to ensure adequate sarcolemmal expression to sustain this critical process. To that end, recent discoveries have revealed the existence of internal reservoirs of preformed CaV1.2 channels that can be rapidly mobilized to enhance sarcolemmal expression in times of acute stress when hemodynamic and metabolic demand increases. In this review, we provide an overview of the current thinking on CaV1.2 channel trafficking dynamics in the heart. We highlight the numerous points of control including the biosynthetic pathway, the endosomal recycling pathway, ubiquitination, and lysosomal and proteasomal degradation pathways, and discuss the effects of β-adrenergic and angiotensin receptor signaling cascades on this process.
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25
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Lee MB, Bitto A, Kaeberlein M. Proceedings from the annual University of Washington Geroscience Symposium, October 23, 2020. GeroScience 2021; 43:1585-1589. [PMID: 33791939 PMCID: PMC8012076 DOI: 10.1007/s11357-021-00346-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 01/02/2023] Open
Abstract
The University of Washington Nathan Shock Center of Excellence in the Biology of Aging in conjunction with the Healthy Aging and Longevity Research Institute held its annual geroscience symposium virtually on October 23, 2020. The symposium was divided into three sessions: (I) organ aging and growth signaling, (II) neurodegeneration and metabolism, and (III) innovative approaches in geroscience and aging research. Nine speakers affiliated with the University of Washington and three invited guest speakers, predominantly trainee, and junior faculty presented their research. Here, we summarize research presented during the symposium. A geroscience special issue, of which this is a part, collects submissions from symposium presenters as well as trainees supported by the Biological Mechanisms of Healthy Aging training program.
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Affiliation(s)
- Mitchell B Lee
- Department of Laboratory Medicine and Pathology, University of Washington, Box 357470, Seattle, WA, 98195-7470, USA
| | - Alessandro Bitto
- Department of Laboratory Medicine and Pathology, University of Washington, Box 357470, Seattle, WA, 98195-7470, USA
| | - Matt Kaeberlein
- Department of Laboratory Medicine and Pathology, University of Washington, Box 357470, Seattle, WA, 98195-7470, USA.
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26
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Romer SH, Metzger S, Peraza K, Wright MC, Jobe DS, Song LS, Rich MM, Foy BD, Talmadge RJ, Voss AA. A mouse model of Huntington's disease shows altered ultrastructure of transverse tubules in skeletal muscle fibers. J Gen Physiol 2021; 153:211860. [PMID: 33683318 PMCID: PMC7931643 DOI: 10.1085/jgp.202012637] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/05/2020] [Accepted: 01/26/2021] [Indexed: 12/12/2022] Open
Abstract
Huntington’s disease (HD) is a fatal and progressive condition with severe debilitating motor defects and muscle weakness. Although classically recognized as a neurodegenerative disorder, there is increasing evidence of cell autonomous toxicity in skeletal muscle. We recently demonstrated that skeletal muscle fibers from the R6/2 model mouse of HD have a decrease in specific membrane capacitance, suggesting a loss of transverse tubule (t-tubule) membrane in R6/2 muscle. A previous report also indicated that Cav1.1 current was reduced in R6/2 skeletal muscle, suggesting defects in excitation–contraction (EC) coupling. Thus, we hypothesized that a loss and/or disruption of the skeletal muscle t-tubule system contributes to changes in EC coupling in R6/2 skeletal muscle. We used live-cell imaging with multiphoton confocal microscopy and transmission electron microscopy to assess the t-tubule architecture in late-stage R6/2 muscle and found no significant differences in the t-tubule system density, regularity, or integrity. However, electron microscopy images revealed that the cross-sectional area of t-tubules at the triad were 25% smaller in R6/2 compared with age-matched control skeletal muscle. Computer simulation revealed that the resulting decrease in the R6/2 t-tubule luminal conductance contributed to, but did not fully explain, the reduced R6/2 membrane capacitance. Analyses of bridging integrator-1 (Bin1), which plays a primary role in t-tubule formation, revealed decreased Bin1 protein levels and aberrant splicing of Bin1 mRNA in R6/2 muscle. Additionally, the distance between the t-tubule and sarcoplasmic reticulum was wider in R6/2 compared with control muscle, which was associated with a decrease in junctophilin 1 and 2 mRNA levels. Altogether, these findings can help explain dysregulated EC coupling and motor impairment in Huntington’s disease.
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Affiliation(s)
- Shannon H Romer
- Department of Biological Sciences, Wright State University, Dayton, OH.,Odyssey Systems, Environmental Health Effects Laboratory, Navy Medical Research Unit, Dayton, Wright-Patterson Air Force Base, Dayton, OH
| | - Sabrina Metzger
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University, Dayton, OH
| | - Kristiana Peraza
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - Matthew C Wright
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - D Scott Jobe
- Department of Biological Sciences, Wright State University, Dayton, OH
| | - 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
| | - Mark M Rich
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University, Dayton, OH
| | - Brent D Foy
- Department of Physics, Wright State University, Dayton, OH
| | - Robert J Talmadge
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - Andrew A Voss
- Department of Biological Sciences, Wright State University, Dayton, OH
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27
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Li J, Richmond B, Hong T. Cardiac T-Tubule cBIN1-Microdomain, a Diagnostic Marker and Therapeutic Target of Heart Failure. Int J Mol Sci 2021; 22:ijms22052299. [PMID: 33669042 PMCID: PMC7956774 DOI: 10.3390/ijms22052299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/19/2021] [Accepted: 02/22/2021] [Indexed: 12/23/2022] Open
Abstract
Since its first identification as a cardiac transverse tubule (t-tubule) protein, followed by the cloning of the cardiac isoform responsible for t-tubule membrane microdomain formation, cardiac bridging integrator 1 (cBIN1) and its organized microdomains have emerged as a key mechanism in maintaining normal beat-to-beat heart contraction and relaxation. The abnormal remodeling of cBIN1-microdomains occurs in stressed and diseased cardiomyocytes, contributing to the pathophysiology of heart failure. Due to the homeostatic turnover of t-tubule cBIN1-microdomains via microvesicle release into the peripheral circulation, plasma cBIN1 can be assayed as a liquid biopsy of cardiomyocyte health. A new blood test cBIN1 score (CS) has been developed as a dimensionless inverse index derived from plasma cBIN1 concentration with a diagnostic and prognostic power for clinical outcomes in stable ambulatory patients with heart failure with reduced or preserved ejection fraction (HFrEF or HFpEF). Recent evidence further indicates that exogenous cBIN1 introduced by adeno-associated virus 9-based gene therapy can rescue cardiac contraction and relaxation in failing hearts. The therapeutic potential of cBIN1 gene therapy is enormous given its ability to rescue cardiac inotropy and provide lusitropic protection in the meantime. These unprecedented capabilities of cBIN1 gene therapy are shifting the current paradigm of therapy development for heart failure, particularly HFpEF.
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Affiliation(s)
- Jing Li
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (B.R.)
| | - Bradley Richmond
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (B.R.)
| | - TingTing Hong
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (B.R.)
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT 84112, USA
- Correspondence: ; Tel.: +1-801-581-3090
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28
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Li LL, Guo QJ, Lou HY, Liang JH, Yang Y, Xing X, Li HT, Han J, Shen S, Li H, Ye H, Di Wu H, Cui B, Wang SQ. Nanobar Array Assay Revealed Complementary Roles of BIN1 Splice Isoforms in Cardiac T-Tubule Morphogenesis. NANO LETTERS 2020; 20:6387-6395. [PMID: 32787151 PMCID: PMC8486496 DOI: 10.1021/acs.nanolett.0c01957] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Bridging integrator-1 (BIN1) is a family of banana-shaped molecules implicated in cell membrane tubulation. To understand the curvature sensitivity and functional roles of BIN1 splicing isoforms, we engineered vertical nanobars on a cell culture substrate to create high and low curvatures. When expressed individually, BIN1 isoforms with phosphoinositide-binding motifs (pBIN1) appeared preferentially at high-curvature nanobar ends, agreeing well with their membrane tubulation in cardiomyocytes. In contrast, the ubiquitous BIN1 isoform without phosphoinositide-binding motif (uBIN1) exhibited no affinity to membranes around nanobars but accumulated along Z-lines in cardiomyocytes. Importantly, in pBIN1-uBIN1 coexpression, pBIN1 recruited uBIN1 to high-curvature membranes at nanobar ends, and uBIN1 attached the otherwise messy pBIN1 tubules to Z-lines. The complementary cooperation of BIN1 isoforms (comboBIN1) represents a novel mechanism of T-tubule formation along Z-lines in cardiomyocytes. Dysregulation of BIN1 splicing, e.g., during myocardial infarction, underlied T-tubule disorganization, and correction of uBIN1/pBIN1 stoichiometry rescued T-tubule morphology in heart disease.
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Affiliation(s)
- Lin-Lin Li
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
- National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Qian-Jin Guo
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking University, Beijing 100871, China
| | - Hsin-Ya Lou
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jing-Hui Liang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yang Yang
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Xin Xing
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Hong-Tao Li
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Jing Han
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Shan Shen
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Hui Li
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Haihong Ye
- Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing 100069, China
| | - Hao Di Wu
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Shi-Qiang Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
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29
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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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30
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Abstract
Maturation is the last phase of heart development that prepares the organ for strong, efficient, and persistent pumping throughout the mammal's lifespan. This process is characterized by structural, gene expression, metabolic, and functional specializations in cardiomyocytes as the heart transits from fetal to adult states. Cardiomyocyte maturation gained increased attention recently due to the maturation defects in pluripotent stem cell-derived cardiomyocyte, its antagonistic effect on myocardial regeneration, and its potential contribution to cardiac disease. Here, we review the major hallmarks of ventricular cardiomyocyte maturation and summarize key regulatory mechanisms that promote and coordinate these cellular events. With advances in the technical platforms used for cardiomyocyte maturation research, we expect significant progress in the future that will deepen our understanding of this process and lead to better maturation of pluripotent stem cell-derived cardiomyocyte and novel therapeutic strategies for heart disease.
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Affiliation(s)
- Yuxuan Guo
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - William Pu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard Stem Cell Institute, Cambridge, MA 02138, USA
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31
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Jiang X, Zhu Y, Liu H, Chen S, Zhang D. Effect of BIN1 on cardiac dysfunction and malignant arrhythmias. Acta Physiol (Oxf) 2020; 228:e13429. [PMID: 31837094 DOI: 10.1111/apha.13429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 11/24/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023]
Abstract
Heart failure (HF) is the end-stage syndrome for most cardiac diseases, and the 5-year morbidity and mortality of HF remain high. Malignant arrhythmia is the main cause of sudden death in the progression of HF. Recently, bridging integrator 1 (BIN1) was discovered as a regulator of transverse tubule function and calcium signalling in cardiomyocytes. BIN1 downregulation is linked to abnormal cardiac contraction, and it increases the possibility of malignant arrhythmias preceding HF. Because of the detectability of cardiac BIN1 in peripheral blood, BIN1 may serve as a predictor of HF and may be useful in therapy development. However, the mechanism of BIN1 downregulation in HF and how BIN1 regulates normal cardiac function under physiological conditions remain unclear. In this review, recent progress in the biological studies of BIN1-related cardiomyocytes and the effect of cardiac dysfunction and malignant arrhythmia will be discussed.
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Affiliation(s)
- Xiao‐Xin Jiang
- Department of Cardiology Nanjing First Hospital Nanjing Medical University Nanjing Jiangsu P. R. China
| | - Yan‐Rong Zhu
- Department of Cardiology Nanjing First Hospital Nanjing Medical University Nanjing Jiangsu P. R. China
| | - Hong‐Ming Liu
- Department of Geriatric Cardiology The First Affiliated Hospital of Kunming Medical University Kunming Yunnan P. R. China
| | - Shao‐Liang Chen
- Department of Cardiology Nanjing First Hospital Nanjing Medical University Nanjing Jiangsu P. R. China
| | - Dai‐Min Zhang
- Department of Cardiology Nanjing First Hospital Nanjing Medical University Nanjing Jiangsu P. R. China
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32
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Drum BM, Yuan C, de la Mata A, Grainger N, Santana LF. Junctional sarcoplasmic reticulum motility in adult mouse ventricular myocytes. Am J Physiol Cell Physiol 2020; 318:C598-C604. [PMID: 31967858 DOI: 10.1152/ajpcell.00573.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Excitation-contraction (EC) coupling is the coordinated process by which an action potential triggers cardiac myocyte contraction. EC coupling is initiated in dyads where the junctional sarcoplasmic reticulum (jSR) is in tight proximity to the sarcolemma of cardiac myocytes. Existing models of EC coupling critically depend on dyad stability to ensure the fidelity and strength of EC coupling, where even small variations in ryanodine receptor channel and voltage-gated calcium channel-α 1.2 subunit separation dramatically alter EC coupling. However, dyadic motility has never been studied. Here, we developed a novel strategy to track specific jSR units in dissociated adult ventricular myocytes using photoactivatable fluorescent proteins. We found that the jSR is not static. Instead, we observed dynamic formation and dissolution of multiple dyadic junctions regulated by the microtubule-associated molecular motors kinesin-1 and dynein. Our data support a model where reproducibility of EC coupling results from the activation of a temporally averaged number of SR Ca2+ release units forming and dissolving SR-sarcolemmal junctions. These findings challenge the long-held view that the jSR is an immobile structure and provide insights into the mechanisms underlying its motility.
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Affiliation(s)
- Benjamin M Drum
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Can Yuan
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Ana de la Mata
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - Nathan Grainger
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, California
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33
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Asghari P, Scriven DR, Ng M, Panwar P, Chou KC, van Petegem F, Moore ED. Cardiac ryanodine receptor distribution is dynamic and changed by auxiliary proteins and post-translational modification. eLife 2020; 9:51602. [PMID: 31916935 PMCID: PMC6994221 DOI: 10.7554/elife.51602] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/09/2020] [Indexed: 12/14/2022] Open
Abstract
The effects of the immunophilins, FKBP12 and FKBP12.6, and phosphorylation on type II ryanodine receptor (RyR2) arrangement and function were examined using correlation microscopy (line scan confocal imaging of Ca2+ sparks and dual-tilt electron tomography) and dSTORM imaging of permeabilized Wistar rat ventricular myocytes. Saturating concentrations (10 µmol/L) of either FKBP12 or 12.6 significantly reduced the frequency, spread, amplitude and Ca2+ spark mass relative to control, while the tomograms revealed both proteins shifted the tetramers into a largely side-by-side configuration. Phosphorylation of immunophilin-saturated RyR2 resulted in structural and functional changes largely comparable to phosphorylation alone. dSTORM images of myocyte surfaces demonstrated that both FKBP12 and 12.6 significantly reduced RyR2 cluster sizes, while phosphorylation, even of immunophilin-saturated RyR2, increased them. We conclude that both RyR2 cluster size and the arrangement of tetramers within clusters is dynamic and respond to changes in the cellular environment. Further, these changes affect Ca2+ spark formation.
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Affiliation(s)
- Parisa Asghari
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - David Rl Scriven
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Myles Ng
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Pankaj Panwar
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Keng C Chou
- Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Filip van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Edwin Dw Moore
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
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34
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Silbernagel N, Körner A, Balitzki J, Jaggy M, Bertels S, Richter B, Hippler M, Hellwig A, Hecker M, Bastmeyer M, Ullrich ND. Shaping the heart: Structural and functional maturation of iPSC-cardiomyocytes in 3D-micro-scaffolds. Biomaterials 2020; 227:119551. [DOI: 10.1016/j.biomaterials.2019.119551] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 10/06/2019] [Accepted: 10/14/2019] [Indexed: 02/05/2023]
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35
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Gowrisankaran S, Wang Z, Morgan DG, Milosevic I, Mim C. Cells Control BIN1-Mediated Membrane Tubulation by Altering the Membrane Charge. J Mol Biol 2019; 432:1235-1250. [PMID: 31857086 DOI: 10.1016/j.jmb.2019.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/18/2019] [Accepted: 12/07/2019] [Indexed: 11/15/2022]
Abstract
The Bridging integrator 1 (BIN1)/Amphiphysin/Rvs (BAR) protein family is an essential part of the cell's machinery to bend membranes. BIN1 is a muscle-enriched BAR protein with an established role in muscle development and skeletal myopathies. Here, we demonstrate that BIN1, on its own, is able to form complex interconnected tubular systems in vitro, reminiscent of t-tubule system in muscle cells. We further describe how BIN1's electrostatic interactions regulate membrane bending: the ratio of negatively charged lipids in the bilayer altered membrane bending and binding properties of BIN1 and so did the manipulation of BIN1's surface charge. We show that the electrostatically mediated BIN1 membrane binding depended on the membrane curvature-it was less affected in liposomes with high curvature. Curiously, BIN1 membrane binding and bending was diminished in cells where the membrane's charge was experimentally reduced. Membrane bending was also reduced in BIN1 mutants where negative or positive charges in the BAR domain have been eliminated. This phenotype, characteristic of BIN1 mutants linked to myopathies, was rescued when the membrane charge was made more negative. The latter findings also show that cells can control tubulation at their membranes by simply altering the membrane charge and through it, the recruitment of BAR proteins and their interaction partners (e.g. dynamin).
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Affiliation(s)
- Sindhuja Gowrisankaran
- European Neuroscience Institute (ENI), A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Synaptic Vesicle Dynamics Group, Göttingen, Germany
| | - Zuoneng Wang
- Royal Technical Institute (KTH), Dept. for Biomedical Engineering and Health Systems, Stockholm, Sweden; Karolinska Institute, Department of Nutrition and Biosciences, Huddinge, Sweden
| | - David G Morgan
- Indiana University, Electron Microscopy Center, Bloomington, IN USA
| | - Ira Milosevic
- European Neuroscience Institute (ENI), A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Synaptic Vesicle Dynamics Group, Göttingen, Germany
| | - Carsten Mim
- Royal Technical Institute (KTH), Dept. for Biomedical Engineering and Health Systems, Stockholm, Sweden; Karolinska Institute, Department of Nutrition and Biosciences, Huddinge, Sweden.
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36
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Glucocorticoids preserve the t-tubular system in ventricular cardiomyocytes by upregulation of autophagic flux. Basic Res Cardiol 2019; 114:47. [PMID: 31673803 DOI: 10.1007/s00395-019-0758-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
Abstract
A major contributor to contractile dysfunction in heart failure is remodelling and loss of the cardiomyocyte transverse tubular system (t-system), but underlying mechanisms and signalling pathways remain elusive. It has been shown that dexamethasone promotes t-tubule development in stem cell-derived cardiomyocytes and that cardiomyocyte-specific glucocorticoid receptor (GR) knockout (GRKO) leads to heart failure. Here, we studied if the t-system is altered in GRKO hearts and if GR signalling is required for t-system preservation in adult cardiomyocytes. Confocal and 3D STED microscopy of myocardium from cardiomyocyte-specific GRKO mice revealed decreased t-system density and increased distances between ryanodine receptors (RyR) and L-type Ca2+ channels (LTCC). Because t-system remodelling and heart failure are intertwined, we investigated the underlying mechanisms in vitro. Ventricular cardiomyocytes from failing human and healthy adult rat hearts cultured in the absence of glucocorticoids (CTRL) showed distinctively lower t-system density than cells treated with dexamethasone (EC50 1.1 nM) or corticosterone. The GR antagonist mifepristone abrogated the effect of dexamethasone. Dexamethasone improved RyR-LTCC coupling and synchrony of intracellular Ca2+ release, but did not alter expression levels of t-system-associated proteins junctophilin-2 (JPH2), bridging integrator-1 (BIN1) or caveolin-3 (CAV3). Rather, dexamethasone upregulated LC3B and increased autophagic flux. The broad-spectrum protein kinase inhibitor staurosporine prevented dexamethasone-induced upregulation of autophagy and t-system preservation, and autophagy inhibitors bafilomycin A and chloroquine accelerated t-system loss. Conversely, induction of autophagy by rapamycin or amino acid starvation preserved the t-system. These findings suggest that GR signalling and autophagy are critically involved in t-system preservation and remodelling in the heart.
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Sato D, Hernández-Hernández G, Matsumoto C, Tajada S, Moreno CM, Dixon RE, O'Dwyer S, Navedo MF, Trimmer JS, Clancy CE, Binder MD, Santana LF. A stochastic model of ion channel cluster formation in the plasma membrane. J Gen Physiol 2019; 151:1116-1134. [PMID: 31371391 PMCID: PMC6719406 DOI: 10.1085/jgp.201912327] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 07/05/2019] [Accepted: 07/08/2019] [Indexed: 12/24/2022] Open
Abstract
Ion channels are often found arranged into dense clusters in the plasma membranes of excitable cells, but the mechanisms underlying the formation and maintenance of these functional aggregates are unknown. Here, we tested the hypothesis that channel clustering is the consequence of a stochastic self-assembly process and propose a model by which channel clusters are formed and regulated in size. Our hypothesis is based on statistical analyses of the size distributions of the channel clusters we measured in neurons, ventricular myocytes, arterial smooth muscle, and heterologous cells, which in all cases were described by exponential functions, indicative of a Poisson process (i.e., clusters form in a continuous, independent, and memory-less fashion). We were able to reproduce the observed cluster distributions of five different types of channels in the membrane of excitable and tsA-201 cells in simulations using a computer model in which channels are "delivered" to the membrane at randomly assigned locations. The model's three parameters represent channel cluster nucleation, growth, and removal probabilities, the values of which were estimated based on our experimental measurements. We also determined the time course of cluster formation and membrane dwell time for CaV1.2 and TRPV4 channels expressed in tsA-201 cells to constrain our model. In addition, we elaborated a more complex version of our model that incorporated a self-regulating feedback mechanism to shape channel cluster formation. The strong inference we make from our results is that CaV1.2, CaV1.3, BK, and TRPV4 proteins are all randomly inserted into the plasma membranes of excitable cells and that they form homogeneous clusters that increase in size until they reach a steady state. Further, it appears likely that cluster size for a diverse set of membrane-bound proteins and a wide range of cell types is regulated by a common feedback mechanism.
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Affiliation(s)
- Daisuke Sato
- Department of Pharmacology, University of California School of Medicine, Davis, CA
| | | | - Collin Matsumoto
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Sendoa Tajada
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Claudia M Moreno
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Samantha O'Dwyer
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Manuel F Navedo
- Department of Pharmacology, University of California School of Medicine, Davis, CA
| | - James S Trimmer
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Colleen E Clancy
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
| | - Marc D Binder
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California School of Medicine, Davis, CA
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Caporizzo MA, Chen CY, Prosser BL. Cardiac microtubules in health and heart disease. Exp Biol Med (Maywood) 2019; 244:1255-1272. [PMID: 31398994 DOI: 10.1177/1535370219868960] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cardiomyocytes are large (∼40,000 µm3), rod-shaped muscle cells that provide the working force behind each heartbeat. These highly structured cells are packed with dense cytoskeletal networks that can be divided into two groups—the contractile (i.e. sarcomeric) cytoskeleton that consists of filamentous actin-myosin arrays organized into myofibrils, and the non-sarcomeric cytoskeleton, which is composed of β- and γ-actin, microtubules, and intermediate filaments. Together, microtubules and intermediate filaments form a cross-linked scaffold, and these networks are responsible for the delivery of intracellular cargo, the transmission of mechanical signals, the shaping of membrane systems, and the organization of myofibrils and organelles. Microtubules are extensively altered as part of both adaptive and pathological cardiac remodeling, which has diverse ramifications for the structure and function of the cardiomyocyte. In heart failure, the proliferation and post-translational modification of the microtubule network is linked to a number of maladaptive processes, including the mechanical impediment of cardiomyocyte contraction and relaxation. This raises the possibility that reversing microtubule alterations could improve cardiac performance, yet therapeutic efforts will strongly benefit from a deeper understanding of basic microtubule biology in the heart. The aim of this review is to summarize the known physiological roles of the cardiomyocyte microtubule network, the consequences of its pathological remodeling, and to highlight the open and intriguing questions regarding cardiac microtubules. Impact statement Advancements in cell biological and biophysical approaches and super-resolution imaging have greatly broadened our view of tubulin biology over the last decade. In the heart, microtubules and microtubule-based transport help to organize and maintain key structures within the cardiomyocyte, including the sarcomere, intercalated disc, protein clearance machinery and transverse-tubule and sarcoplasmic reticulum membranes. It has become increasingly clear that post translational regulation of microtubules is a key determinant of their sub-cellular functionality. Alterations in microtubule network density, stability, and post-translational modifications are hallmarks of pathological cardiac remodeling, and modified microtubules can directly impede cardiomyocyte contractile function in various forms of heart disease. This review summarizes the functional roles and multi-leveled regulation of the cardiac microtubule cytoskeleton and highlights how refined experimental techniques are shedding mechanistic clarity on the regionally specified roles of microtubules in cardiac physiology and pathophysiology.
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Affiliation(s)
- Matthew A Caporizzo
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Christina Yingxian Chen
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Penn Cardiovascular Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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Lawless M, Caldwell JL, Radcliffe EJ, Smith CER, Madders GWP, Hutchings DC, Woods LS, Church SJ, Unwin RD, Kirkwood GJ, Becker LK, Pearman CM, Taylor RF, Eisner DA, Dibb KM, Trafford AW. Phosphodiesterase 5 inhibition improves contractile function and restores transverse tubule loss and catecholamine responsiveness in heart failure. Sci Rep 2019; 9:6801. [PMID: 31043634 PMCID: PMC6494852 DOI: 10.1038/s41598-019-42592-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/26/2019] [Indexed: 12/13/2022] Open
Abstract
Heart failure (HF) is characterized by poor survival, a loss of catecholamine reserve and cellular structural remodeling in the form of disorganization and loss of the transverse tubule network. Indeed, survival rates for HF are worse than many common cancers and have not improved over time. Tadalafil is a clinically relevant drug that blocks phosphodiesterase 5 with high specificity and is used to treat erectile dysfunction. Using a sheep model of advanced HF, we show that tadalafil treatment improves contractile function, reverses transverse tubule loss, restores calcium transient amplitude and the heart's response to catecholamines. Accompanying these effects, tadalafil treatment normalized BNP mRNA and prevented development of subjective signs of HF. These effects were independent of changes in myocardial cGMP content and were associated with upregulation of both monomeric and dimerized forms of protein kinase G and of the cGMP hydrolyzing phosphodiesterases 2 and 3. We propose that the molecular switch for the loss of transverse tubules in HF and their restoration following tadalafil treatment involves the BAR domain protein Amphiphysin II (BIN1) and the restoration of catecholamine sensitivity is through reductions in G-protein receptor kinase 2, protein phosphatase 1 and protein phosphatase 2 A abundance following phosphodiesterase 5 inhibition.
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Affiliation(s)
- Michael Lawless
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Jessica L Caldwell
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Emma J Radcliffe
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Charlotte E R Smith
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - George W P Madders
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - David C Hutchings
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Lori S Woods
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Stephanie J Church
- Division of Cardiovascular Sciences, Centre for Advanced Discovery and Experimental Therapeutics, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Richard D Unwin
- Division of Cardiovascular Sciences, Centre for Advanced Discovery and Experimental Therapeutics, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Graeme J Kirkwood
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Lorenz K Becker
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Charles M Pearman
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Rebecca F Taylor
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - David A Eisner
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Katharine M Dibb
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom
| | - Andrew W Trafford
- Division of Cardiovascular Sciences, Unit of Cardiac Physiology, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, 3.24 Core Technology Facility, 46 Grafton Street, Manchester, M13 9NT, United Kingdom.
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40
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Biendarra-Tiegs SM, Li X, Ye D, Brandt EB, Ackerman MJ, Nelson TJ. Single-Cell RNA-Sequencing and Optical Electrophysiology of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Reveal Discordance Between Cardiac Subtype-Associated Gene Expression Patterns and Electrophysiological Phenotypes. Stem Cells Dev 2019; 28:659-673. [PMID: 30892143 PMCID: PMC6534093 DOI: 10.1089/scd.2019.0030] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The ability to accurately phenotype cells differentiated from human induced pluripotent stem cells (hiPSCs) is essential for their application in modeling developmental and disease processes, yet also poses a particular challenge without the context of anatomical location. Our specific objective was to determine if single-cell gene expression was sufficient to predict the electrophysiology of iPSC-derived cardiac lineages, to evaluate the concordance between molecular and functional surrogate markers. To this end, we used the genetically encoded voltage indicator ArcLight to profile hundreds of hiPSC-derived cardiomyocytes (hiPSC-CMs), thus identifying patterns of electrophysiological maturation and increased prevalence of cells with atrial-like action potentials (APs) between days 11 and 42 of differentiation. To profile expression patterns of cardiomyocyte subtype-associated genes, single-cell RNA-seq was performed at days 12 and 40 after the populations were fully characterized with the high-throughput ArcLight platform. Although we could detect global gene expression changes supporting progressive differentiation, individual cellular expression patterns alone were not able to delineate the individual cardiomyocytes into atrial, ventricular, or nodal subtypes as functionally documented by electrophysiology measurements. Furthermore, our efforts to understand the distinct electrophysiological properties associated with day 12 versus day 40 hiPSC-CMs revealed that ion channel regulators SLMAP, FGF12, and FHL1 were the most significantly increased genes at day 40, categorized by electrophysiology-related gene functions. Notably, FHL1 knockdown during differentiation was sufficient to significantly modulate APs toward ventricular-like electrophysiology. Thus, our results establish the inability of subtype-associated gene expression patterns to specifically categorize hiPSC-derived cells according to their functional electrophysiology, and yet, altered FHL1 expression is able to redirect electrophysiological maturation of these developing cells. Therefore, noncanonical gene expression patterns of cardiac maturation may be sufficient to direct functional maturation of cardiomyocytes, with canonical gene expression patterns being insufficient to temporally define cardiac subtypes of in vitro differentiation.
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Affiliation(s)
- Sherri M Biendarra-Tiegs
- 1 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,2 Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Xing Li
- 2 Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,3 Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | - Dan Ye
- 4 Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Emma B Brandt
- 1 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,2 Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Michael J Ackerman
- 4 Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,5 Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,6 Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Timothy J Nelson
- 1 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,2 Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,5 Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,6 Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota.,7 Division of General Internal Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
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