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Dotti P, Fernandez-Tenorio M, Janicek R, Márquez-Neila P, Wullschleger M, Sznitman R, Egger M. A deep learning-based approach for efficient detection and classification of local Ca²⁺ release events in Full-Frame confocal imaging. Cell Calcium 2024; 121:102893. [PMID: 38701707 DOI: 10.1016/j.ceca.2024.102893] [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: 03/24/2024] [Accepted: 04/23/2024] [Indexed: 05/05/2024]
Abstract
The release of Ca2+ ions from intracellular stores plays a crucial role in many cellular processes, acting as a secondary messenger in various cell types, including cardiomyocytes, smooth muscle cells, hepatocytes, and many others. Detecting and classifying associated local Ca2+ release events is particularly important, as these events provide insight into the mechanisms, interplay, and interdependencies of local Ca2+release events underlying global intracellular Ca2+signaling. However, time-consuming and labor-intensive procedures often complicate analysis, especially with low signal-to-noise ratio imaging data. Here, we present an innovative deep learning-based approach for automatically detecting and classifying local Ca2+ release events. This approach is exemplified with rapid full-frame confocal imaging data recorded in isolated cardiomyocytes. To demonstrate the robustness and accuracy of our method, we first use conventional evaluation methods by comparing the intersection between manual annotations and the segmentation of Ca2+ release events provided by the deep learning method, as well as the annotated and recognized instances of individual events. In addition to these methods, we compare the performance of the proposed model with the annotation of six experts in the field. Our model can recognize more than 75 % of the annotated Ca2+ release events and correctly classify more than 75 %. A key result was that there were no significant differences between the annotations produced by human experts and the result of the proposed deep learning model. We conclude that the proposed approach is a robust and time-saving alternative to conventional full-frame confocal imaging analysis of local intracellular Ca2+ events.
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Affiliation(s)
- Prisca Dotti
- Department of Physiology, Universität Bern, Bern, Switzerland; ARTORG Center, Universität Bern, Bern, Switzerland
| | | | | | | | | | | | - Marcel Egger
- Department of Physiology, Universität Bern, Bern, Switzerland.
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2
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Bovo E, Seflova J, Robia SL, Zima AV. Protein carbonylation causes sarcoplasmic reticulum Ca 2+ overload by increasing intracellular Na + level in ventricular myocytes. Pflugers Arch 2024; 476:1077-1086. [PMID: 38769127 DOI: 10.1007/s00424-024-02972-7] [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: 02/26/2024] [Revised: 04/22/2024] [Accepted: 05/15/2024] [Indexed: 05/22/2024]
Abstract
Diabetes is commonly associated with an elevated level of reactive carbonyl species due to alteration of glucose and fatty acid metabolism. These metabolic changes cause an abnormality in cardiac Ca2+ regulation that can lead to cardiomyopathies. In this study, we explored how the reactive α-dicarbonyl methylglyoxal (MGO) affects Ca2+ regulation in mouse ventricular myocytes. Analysis of intracellular Ca2+ dynamics revealed that MGO (200 μM) increases action potential (AP)-induced Ca2+ transients and sarcoplasmic reticulum (SR) Ca2+ load, with a limited effect on L-type Ca2+ channel-mediated Ca2+ transients and SERCA-mediated Ca2+ uptake. At the same time, MGO significantly slowed down cytosolic Ca2+ extrusion by Na+/Ca2+ exchanger (NCX). MGO also increased the frequency of Ca2+ waves during rest and these Ca2+ release events were abolished by an external solution with zero [Na+] and [Ca2+]. Adrenergic receptor activation with isoproterenol (10 nM) increased Ca2+ transients and SR Ca2+ load, but it also triggered spontaneous Ca2+ waves in 27% of studied cells. Pretreatment of myocytes with MGO increased the fraction of cells with Ca2+ waves during adrenergic receptor stimulation by 163%. Measurements of intracellular [Na+] revealed that MGO increases cytosolic [Na+] by 57% from the maximal effect produced by the Na+-K+ ATPase inhibitor ouabain (20 μM). This increase in cytosolic [Na+] was a result of activation of a tetrodotoxin-sensitive Na+ influx, but not an inhibition of Na+-K+ ATPase. An increase in cytosolic [Na+] after treating cells with ouabain produced similar effects on Ca2+ regulation as MGO. These results suggest that protein carbonylation can affect cardiac Ca2+ regulation by increasing cytosolic [Na+] via a tetrodotoxin-sensitive pathway. This, in turn, reduces Ca2+ extrusion by NCX, causing SR Ca2+ overload and spontaneous Ca2+ waves.
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Affiliation(s)
- Elisa Bovo
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, IL, 60153, USA
| | - Jaroslava Seflova
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, IL, 60153, USA
| | - Seth L Robia
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, IL, 60153, USA
| | - Aleksey V Zima
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, IL, 60153, USA.
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Dewenter M, Seitz T, Steinbrecher JH, Westenbrink BD, Ling H, Lehnart SE, Wehrens XHT, Backs J, Brown JH, Maier LS, Neef S. Ca2+/calmodulin-dependent kinase IIδC-induced chronic heart failure does not depend on sarcoplasmic reticulum Ca2+ leak. ESC Heart Fail 2024. [PMID: 38616546 DOI: 10.1002/ehf2.14772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/07/2024] [Indexed: 04/16/2024] Open
Abstract
AIMS Hyperactivity of Ca2+/calmodulin-dependent protein kinase II (CaMKII) has emerged as a central cause of pathologic remodelling in heart failure. It has been suggested that CaMKII-induced hyperphosphorylation of the ryanodine receptor 2 (RyR2) and consequently increased diastolic Ca2+ leak from the sarcoplasmic reticulum (SR) is a crucial mechanism by which increased CaMKII activity leads to contractile dysfunction. We aim to evaluate the relevance of CaMKII-dependent RyR2 phosphorylation for CaMKII-induced heart failure development in vivo. METHODS AND RESULTS We crossbred CaMKIIδC overexpressing [transgenic (TG)] mice with RyR2-S2814A knock-in mice that are resistant to CaMKII-dependent RyR2 phosphorylation. Ca2+-spark measurements on isolated ventricular myocytes confirmed the severe diastolic SR Ca2+ leak previously reported in CaMKIIδC TG [4.65 ± 0.73 mF/F0 vs. 1.88 ± 0.30 mF/F0 in wild type (WT)]. Crossing in the S2814A mutation completely prevented SR Ca2+-leak induction in the CaMKIIδC TG, both regarding Ca2+-spark size and frequency, demonstrating that the CaMKIIδC-induced SR Ca2+ leak entirely depends on the CaMKII-specific RyR2-S2814 phosphorylation. Yet, the RyR2-S2814A mutation did not affect the massive contractile dysfunction (ejection fraction = 12.17 ± 2.05% vs. 45.15 ± 3.46% in WT), cardiac hypertrophy (heart weight/tibia length = 24.84 ± 3.00 vs. 9.81 ± 0.50 mg/mm in WT), or severe premature mortality (median survival of 12 weeks) associated with cardiac CaMKIIδC overexpression. In the face of a prevented SR Ca2+ leak, the phosphorylation status of other critical CaMKII downstream targets that can drive heart failure, including transcriptional regulator histone deacetylase 4, as well as markers of pathological gene expression including Xirp2, Il6, and Col1a1, was equally increased in hearts from CaMKIIδC TG on a RyR WT and S2814A background. CONCLUSIONS S2814 phosphoresistance of RyR2 prevents the CaMKII-dependent SR Ca2+ leak induction but does not prevent the cardiomyopathic phenotype caused by enhanced CaMKIIδC activity. Our data indicate that additional mechanisms-independent of SR Ca2+ leak-are critical for the maladaptive effects of chronically increased CaMKIIδC activity with respect to heart failure.
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Affiliation(s)
- Matthias Dewenter
- Medical Faculty Heidelberg, Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- Department of Internal Medicine 8, Heidelberg University Hospital, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Sites Heidelberg/Mannheim and Göttingen, Heidelberg/Mannheim and Göttingen, Germany
| | - Tilmann Seitz
- DZHK (German Centre for Cardiovascular Research), Partner Sites Heidelberg/Mannheim and Göttingen, Heidelberg/Mannheim and Göttingen, Germany
- Department of Cardiology and Pneumology, University Medical Center Göttingen (UMG), Georg August University of Göttingen, Göttingen, Germany
| | - Julia H Steinbrecher
- DZHK (German Centre for Cardiovascular Research), Partner Sites Heidelberg/Mannheim and Göttingen, Heidelberg/Mannheim and Göttingen, Germany
- Department of Cardiology and Pneumology, University Medical Center Göttingen (UMG), Georg August University of Göttingen, Göttingen, Germany
| | - B Daan Westenbrink
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Haiyun Ling
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
- Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Stephan E Lehnart
- DZHK (German Centre for Cardiovascular Research), Partner Sites Heidelberg/Mannheim and Göttingen, Heidelberg/Mannheim and Göttingen, Germany
- Department of Cardiology and Pneumology, University Medical Center Göttingen (UMG), Georg August University of Göttingen, Göttingen, Germany
| | - Xander H T Wehrens
- Cardiovascular Research Institute and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Johannes Backs
- Medical Faculty Heidelberg, Institute of Experimental Cardiology, Heidelberg University, Heidelberg, Germany
- Department of Internal Medicine 8, Heidelberg University Hospital, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Sites Heidelberg/Mannheim and Göttingen, Heidelberg/Mannheim and Göttingen, Germany
- Molecular Medicine Partnership Unit, Heidelberg University & EMBL, Heidelberg, Germany
- Helmholtz Institute for Translational AngioCardioScience (HI-TAC)-a branch of the MDC at Heidelberg University, Heidelberg, Germany
| | - Joan Heller Brown
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
| | - Lars S Maier
- Department of Internal Medicine II, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, Regensburg, Germany
| | - Stefan Neef
- Department of Internal Medicine II, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, Regensburg, Germany
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Pinckard KM, Félix-Soriano E, Hamilton S, Terentyeva R, Baer LA, Wright KR, Nassal D, Esteves JV, Abay E, Shettigar VK, Ziolo MT, Hund TJ, Wold LE, Terentyev D, Stanford KI. Maternal exercise preserves offspring cardiovascular health via oxidative regulation of the ryanodine receptor. Mol Metab 2024; 82:101914. [PMID: 38479548 PMCID: PMC10965826 DOI: 10.1016/j.molmet.2024.101914] [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: 01/04/2024] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024] Open
Abstract
OBJECTIVE The intrauterine environment during pregnancy is a critical factor in the development of obesity, diabetes, and cardiovascular disease in offspring. Maternal exercise prevents the detrimental effects of a maternal high fat diet on the metabolic health in adult offspring, but the effects of maternal exercise on offspring cardiovascular health have not been thoroughly investigated. METHODS To determine the effects of maternal exercise on offspring cardiovascular health, female mice were fed a chow (C; 21% kcal from fat) or high-fat (H; 60% kcal from fat) diet and further subdivided into sedentary (CS, HS) or wheel exercised (CW, HW) prior to pregnancy and throughout gestation. Offspring were maintained in a sedentary state and chow-fed throughout 52 weeks of age and subjected to serial echocardiography and cardiomyocyte isolation for functional and mechanistic studies. RESULTS High-fat fed sedentary dams (HS) produced female offspring with reduced ejection fraction (EF) compared to offspring from chow-fed dams (CS), but EF was preserved in offspring from high-fat fed exercised dams (HW) throughout 52 weeks of age. Cardiomyocytes from HW female offspring had increased kinetics, calcium cycling, and respiration compared to CS and HS offspring. HS offspring had increased oxidation of the RyR2 in cardiomyocytes coupled with increased baseline sarcomere length, resulting in RyR2 overactivity, which was negated in female HW offspring. CONCLUSIONS These data suggest a role for maternal exercise to protect against the detrimental effects of a maternal high-fat diet on female offspring cardiac health. Maternal exercise improved female offspring cardiomyocyte contraction, calcium cycling, respiration, RyR2 oxidation, and RyR2 activity. These data present an important, translatable role for maternal exercise to preserve cardiac health of female offspring and provide insight on mechanisms to prevent the transmission of cardiovascular diseases to subsequent generations.
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Affiliation(s)
- Kelsey M Pinckard
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Elisa Félix-Soriano
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Surgery, Division of General and Gastrointestinal Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Shanna Hamilton
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Radmila Terentyeva
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Lisa A Baer
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Surgery, Division of General and Gastrointestinal Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Katherine R Wright
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Drew Nassal
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, Cardiovascular Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Joao Victor Esteves
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Surgery, Division of General and Gastrointestinal Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Eaman Abay
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Vikram K Shettigar
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Mark T Ziolo
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Thomas J Hund
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, Cardiovascular Medicine, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus, OH, USA
| | - Loren E Wold
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Surgery, Division of Cardiac Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Dmitry Terentyev
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Kristin I Stanford
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA; Department of Surgery, Division of General and Gastrointestinal Surgery, The Ohio State University College of Medicine, Columbus, OH, USA.
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5
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Bovo E, Seflova J, Robia SL, Zima AV. Protein carbonylation causes sarcoplasmic reticulum Ca2+ overload by increasing intracellular Na+ level in ventricular myocytes. RESEARCH SQUARE 2024:rs.3.rs-3991887. [PMID: 38464201 PMCID: PMC10925417 DOI: 10.21203/rs.3.rs-3991887/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Diabetes is commonly associated with an elevated level of reactive carbonyl species due to alteration of glucose and fatty acid metabolism. These metabolic changes cause an abnormality in cardiac Ca2+ regulation that can lead to cardiomyopathies. In this study, we explored how the reactive α-dicarbonyl methylglyoxal (MGO) affects Ca2+ regulation in mouse ventricular myocytes. Analysis of intracellular Ca2+ dynamics revealed that MGO (200 μM) increases action potential (AP)-induced Ca2+ transients and sarcoplasmic reticulum (SR) Ca2+ load, with a limited effect on L-type Ca2+ channel-mediated Ca2+ transients and SERCA-mediated Ca2+ uptake. At the same time, MGO significantly slowed down cytosolic Ca2+ extrusion by Na+/Ca2+ exchanger (NCX). MGO also increased the frequency of Ca2+ waves during rest and these Ca2+ release events were abolished by an external solution with zero [Na+] and [Ca2+]. Adrenergic receptor activation with isoproterenol (10 nM) increased Ca2+ transients and SR Ca2+ load, but it also triggered spontaneous Ca2+ waves in 27% of studied cells. Pretreatment of myocytes with MGO increased the fraction of cells with Ca2+ waves during adrenergic receptor stimulation by 163%. Measurements of intracellular [Na+] revealed that MGO increases cytosolic [Na+] by 57% from the maximal effect produced by the Na+-K+ ATPase inhibitor ouabain (20 μM). This increase in cytosolic [Na+] was a result of activation of a tetrodotoxin-sensitive Na+ influx, but not an inhibition of Na+-K+ ATPase. An increase in cytosolic [Na+] after treating cells with ouabain produced similar effects on Ca2+ regulation as MGO. These results suggest that protein carbonylation can affect cardiac Ca2+ regulation by increasing cytosolic [Na+] via a tetrodotoxin-sensitive pathway. This, in turn, reduces Ca2+ extrusion by NCX, causing SR Ca2+ overload and spontaneous Ca2+ waves.
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Affiliation(s)
- Elisa Bovo
- Loyola University Chicago, Stritch School of Medicine
| | | | - Seth L Robia
- Loyola University Chicago, Stritch School of Medicine
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Wegener JW, Mitronova GY, ElShareif L, Quentin C, Belov V, Pochechueva T, Hasenfuss G, Ackermann L, Lehnart SE. A dual-targeted drug inhibits cardiac ryanodine receptor Ca 2+ leak but activates SERCA2a Ca 2+ uptake. Life Sci Alliance 2024; 7:e202302278. [PMID: 38012000 PMCID: PMC10681910 DOI: 10.26508/lsa.202302278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023] Open
Abstract
In the heart, genetic or acquired mishandling of diastolic [Ca2+] by ryanodine receptor type 2 (RyR2) overactivity correlates with risks of arrhythmia and sudden cardiac death. Strategies to avoid these risks include decrease of Ca2+ release by drugs modulating RyR2 activity or increase in Ca2+ uptake by drugs modulating SR Ca2+ ATPase (SERCA2a) activity. Here, we combine these strategies by developing experimental compounds that act simultaneously on both processes. Our screening efforts identified the new 1,4-benzothiazepine derivative GM1869 as a promising compound. Consequently, we comparatively studied the effects of the known RyR2 modulators Dantrolene and S36 together with GM1869 on RyR2 and SERCA2a activity in cardiomyocytes from wild type and arrhythmia-susceptible RyR2R2474S/+ mice by confocal live-cell imaging. All drugs reduced RyR2-mediated Ca2+ spark frequency but only GM1869 accelerated SERCA2a-mediated decay of Ca2+ transients in murine and human cardiomyocytes. Our data indicate that S36 and GM1869 are more suitable than dantrolene to directly modulate RyR2 activity, especially in RyR2R2474S/+ mice. Remarkably, GM1869 may represent a new dual-acting lead compound for maintenance of diastolic [Ca2+].
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Affiliation(s)
- Jörg W Wegener
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center of Göttingen (UMG), Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Gyuzel Y Mitronova
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Lina ElShareif
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center of Göttingen (UMG), Göttingen, Germany
| | - Christine Quentin
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Vladimir Belov
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Tatiana Pochechueva
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center of Göttingen (UMG), Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Gerd Hasenfuss
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center of Göttingen (UMG), Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Lutz Ackermann
- Georg-August University of Göttingen, Institute of Organic and Biomolecular Chemistry, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Stephan E Lehnart
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center of Göttingen (UMG), Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
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7
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Power AS, Asamudo EU, Worthington LP, Alim CC, Parackal RE, Wallace RS, Ebenebe OV, Heller Brown J, Kohr MJ, Bers DM, Erickson JR. Nitric Oxide Modulates Ca 2+ Leak and Arrhythmias via S-Nitrosylation of CaMKII. Circ Res 2023; 133:1040-1055. [PMID: 37961889 PMCID: PMC10699507 DOI: 10.1161/circresaha.123.323571] [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: 08/23/2023] [Revised: 10/29/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND Nitric oxide (NO) has been identified as a signaling molecule generated during β-adrenergic receptor stimulation in the heart. Furthermore, a role for NO in triggering spontaneous Ca2+ release via S-nitrosylation of CaMKIIδ (Ca2+/calmodulin kinase II delta) is emerging. NO donors are routinely used clinically for their cardioprotective effects on the heart, but it is unknown how NO donors modulate the proarrhythmic CaMKII to alter cardiac arrhythmia incidence. We test the role of S-nitrosylation of CaMKIIδ at the Cysteine-273 inhibitory site and cysteine-290 activating site in cardiac Ca2+ handling and arrhythmogenesis before and during β-adrenergic receptor stimulation. METHODS We measured Ca2+-handling in isolated cardiomyocytes from C57BL/6J wild-type (WT) mice and mice lacking CaMKIIδ expression (CaMKIIδ-KO) or with deletion of the S-nitrosylation site on CaMKIIδ at cysteine-273 or cysteine-290 (CaMKIIδ-C273S and -C290A knock-in mice). Cardiomyocytes were exposed to NO donors, S-nitrosoglutathione (GSNO; 150 μM), sodium nitroprusside (200 μM), and β-adrenergic agonist isoproterenol (100 nmol/L). RESULTS Both WT and CaMKIIδ-KO cardiomyocytes responded to isoproterenol with a full inotropic and lusitropic Ca2+ transient response as well as increased Ca2+ spark frequency. However, the increase in Ca2+ spark frequency was significantly attenuated in CaMKIIδ-KO cardiomyocytes. The protection from isoproterenol-induced Ca2+ sparks and waves was mimicked by GSNO pretreatment in WT cardiomyocytes but lost in CaMKIIδ-C273S cardiomyocytes. When GSNO was applied after isoproterenol, this protection was not observed in WT or CaMKIIδ-C273S but was apparent in CaMKIIδ-C290A. In Langendorff-perfused isolated hearts, GSNO pretreatment limited isoproterenol-induced arrhythmias in WT but not CaMKIIδ-C273S hearts, while GSNO exposure after isoproterenol sustained or exacerbated arrhythmic events. CONCLUSIONS We conclude that prior S-nitrosylation of CaMKIIδ at cysteine-273 can limit subsequent β-adrenergic receptor-induced arrhythmias, but that S-nitrosylation at cysteine-290 might worsen or sustain β-adrenergic receptor-induced arrhythmias. This has important implications for the administration of NO donors in the clinical setting.
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Affiliation(s)
- Amelia S. Power
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
- Department of Physiology, University of Auckland, New Zealand (A.S.P.)
| | - Esther U. Asamudo
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
- Department of Pharmacology, University of California, Davis (E.U.A., C.C.A., D.M.B.)
| | - Luke P.I. Worthington
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
| | - Chidera C. Alim
- Department of Pharmacology, University of California, Davis (E.U.A., C.C.A., D.M.B.)
| | - Raquel E. Parackal
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
| | - Rachel S. Wallace
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
| | - Obialunanma V. Ebenebe
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (O.V.E., M.J.K.)
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, La Jolla (J.H.B.)
| | - Mark J. Kohr
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (O.V.E., M.J.K.)
| | - Donald M. Bers
- Department of Pharmacology, University of California, Davis (E.U.A., C.C.A., D.M.B.)
| | - Jeffrey R. Erickson
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand (A.S.P., E.U.A., L.P.I.W., R.E.P., R.S.W., J.R.E.)
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8
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Medvedev RY, Turner DGP, DeGuire FC, Leonov V, Lang D, Gorelik J, Alvarado FJ, Bondarenko VE, Glukhov AV. Caveolae-associated cAMP/Ca 2+-mediated mechano-chemical signal transduction in mouse atrial myocytes. J Mol Cell Cardiol 2023; 184:75-87. [PMID: 37805125 PMCID: PMC10842990 DOI: 10.1016/j.yjmcc.2023.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 09/11/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Caveolae are tiny invaginations in the sarcolemma that buffer extra membrane and contribute to mechanical regulation of cellular function. While the role of caveolae in membrane mechanosensation has been studied predominantly in non-cardiomyocyte cells, caveolae contribution to cardiac mechanotransduction remains elusive. Here, we studied the role of caveolae in the regulation of Ca2+ signaling in atrial cardiomyocytes. In Langendorff-perfused mouse hearts, atrial pressure/volume overload stretched atrial myocytes and decreased caveolae density. In isolated cells, caveolae were disrupted through hypotonic challenge that induced a temporal (<10 min) augmentation of Ca2+ transients and caused a rise in Ca2+ spark activity. Similar changes in Ca2+ signaling were observed after chemical (methyl-β-cyclodextrin) and genetic ablation of caveolae in cardiac-specific conditional caveolin-3 knock-out mice. Acute disruption of caveolae, both mechanical and chemical, led to the elevation of cAMP level in the cell interior, and cAMP-mediated augmentation of protein kinase A (PKA)-phosphorylated ryanodine receptors (at Ser2030 and Ser2808). Caveolae-mediated stimulatory effects on Ca2+ signaling were abolished via inhibition of cAMP production by adenyl cyclase antagonists MDL12330 and SQ22536, or reduction of PKA activity by H-89. A compartmentalized mathematical model of mouse atrial myocytes linked the observed changes to a microdomain-specific decrease in phosphodiesterase activity, which disrupted cAMP signaling and augmented PKA activity. Our findings add a new dimension to cardiac mechanobiology and highlight caveolae-associated cAMP/PKA-mediated phosphorylation of Ca2+ handling proteins as a novel component of mechano-chemical feedback in atrial myocytes.
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Affiliation(s)
- Roman Y Medvedev
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Daniel G P Turner
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Frank C DeGuire
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Vladislav Leonov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Di Lang
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Francisco J Alvarado
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
| | - Alexey V Glukhov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
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9
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Stopper G, Caudal LC, Rieder P, Gobbo D, Stopper L, Felix L, Everaerts K, Bai X, Rose CR, Scheller A, Kirchhoff F. Novel algorithms for improved detection and analysis of fluorescent signal fluctuations. Pflugers Arch 2023; 475:1283-1300. [PMID: 37700120 PMCID: PMC10567899 DOI: 10.1007/s00424-023-02855-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/02/2023] [Accepted: 08/26/2023] [Indexed: 09/14/2023]
Abstract
Fluorescent dyes and genetically encoded fluorescence indicators (GEFI) are common tools for visualizing concentration changes of specific ions and messenger molecules during intra- as well as intercellular communication. Using advanced imaging technologies, fluorescence indicators are a prerequisite for the analysis of physiological molecular signaling. Automated detection and analysis of fluorescence signals require to overcome several challenges, including correct estimation of fluorescence fluctuations at basal concentrations of messenger molecules, detection, and extraction of events themselves as well as proper segmentation of neighboring events. Moreover, event detection algorithms need to be sensitive enough to accurately capture localized and low amplitude events exhibiting a limited spatial extent. Here, we present two algorithms (PBasE and CoRoDe) for accurate baseline estimation and automated detection and segmentation of fluorescence fluctuations.
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Affiliation(s)
- Gebhard Stopper
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Laura C Caudal
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Phillip Rieder
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Davide Gobbo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Laura Stopper
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Lisa Felix
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Katharina Everaerts
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Xianshu Bai
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Anja Scheller
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany
| | - Frank Kirchhoff
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Building 48, 66421, Homburg, Germany.
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10
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Herting JR, König JH, Hadova K, Heinick A, Müller FU, Pauls P, Seidl MD, Soppa C, Kirchhefer U. Hypercontractile cardiac phenotype in mice overexpressing the regulatory subunit PR72 of protein phosphatase 2A. Front Cardiovasc Med 2023; 10:1239555. [PMID: 37868783 PMCID: PMC10590119 DOI: 10.3389/fcvm.2023.1239555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023] Open
Abstract
Background The activity, localization, and substrate specificity of the protein phosphatase 2A (PP2A) heterotrimer are controlled by various regulatory B subunits. PR72 belongs to the B'' gene family and has been shown to be upregulated in human heart failure. However, little is known about the functions of PR72 in the myocardium. Methods To address this issue, we generated a transgenic mouse model with heart-specific overexpression of PP2A-PR72. Biochemical and physiological methods were used to determine contractility, Ca2+ cycling parameters, and protein phosphorylation. Results A 2.5-fold increase in PR72 expression resulted in moderate cardiac hypertrophy. Maximal ventricular pressure was increased in catheterized transgenic mice (TG) compared to wild-type (WT) littermates. This was accompanied by an increased shortening of sarcomere length and faster relaxation at the single-cell level in TG. In parallel with these findings, the peak amplitude of Ca2+ transients was increased, and the decay in intracellular Ca2+ levels was shortened in TG compared to WT. The changes in Ca2+ cycling in TG were also evident from an increase in the full duration and width at half maximum of Ca2+ sparks. Consistent with the contractile data, phosphorylation of phospholamban at threonine-17 was higher in TG hearts. The lower expression of the Na+/Ca2+ exchanger may also contribute to the hypercontractile state in transgenic myocardium. Conclusion Our results suggest that PP2A-PR72 plays an important role in regulating cardiac contractile function and Ca2+ cycling, indicating that the upregulation of PR72 in heart failure is an attempt to compensate functionally.
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Affiliation(s)
- Julius R. Herting
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Jule H. König
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Katarina Hadova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovakia
| | - Alexander Heinick
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Frank U. Müller
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Paul Pauls
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Matthias D. Seidl
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Carolina Soppa
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
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11
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Gómez-Viquez NL, Balderas-Villalobos J, Bello-Sánchez MD, Mayorga-Luna M, Mailloux-Salinas P, García-Castañeda M, Ríos-Pérez EB, Mártinez-Ávila MA, Camacho-Castillo LDC, Bravo G, Ávila G, Altamirano J, Carvajal K. Oxidative stress in early metabolic syndrome impairs cardiac RyR2 and SERCA2a activity and modifies the interplay of these proteins during Ca 2+ waves. Arch Physiol Biochem 2023; 129:1058-1070. [PMID: 33689540 DOI: 10.1080/13813455.2021.1895224] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/19/2021] [Indexed: 10/21/2022]
Abstract
We investigated how oxidative stress (OS) alters Ca2+ handling in ventricular myocytes in early metabolic syndrome (MetS) in sucrose-fed rats. The effects of N-acetyl cysteine (NAC) or dl-Dithiothreitol (DTT) on systolic Ca2+ transients (SCaTs), diastolic Ca2+ sparks (CaS) and Ca2+ waves (CaW), recorded by confocal techniques, and L-type Ca2+ current (ICa), assessed by whole-cell patch clamp, were evaluated in MetS and Control cells. MetS myocytes exhibited decreased SCaTs and CaS frequency but unaffected CaW propagation. In Control cells, NAC/DTT reduced RyR2/SERCA2a activity blunting SCaTs, CaS frequency and CaW propagation, suggesting that basal ROS optimised Ca2+ signalling by maintaining RyR2/SERCA2a function and that these proteins facilitate CaW propagation. Conversely, NAC/DTT in MetS recovered RyR2/SERCA2a function, improving SCaTs and CaS frequency, but unexpectedly decreasing CaW propagation. We hypothesised that OS decreases RyR2/SERCA2a activity at early MetS, and while decreased SERCA2a favours CaW propagation, diminished RyR2 restrains it.
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Affiliation(s)
- Norma Leticia Gómez-Viquez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Jaime Balderas-Villalobos
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Ciudad de México, México
| | - Ma Dolores Bello-Sánchez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Maritza Mayorga-Luna
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Patrick Mailloux-Salinas
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Maricela García-Castañeda
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Erick Benjamín Ríos-Pérez
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | | | | | - Guadalupe Bravo
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Guillermo Ávila
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - Julio Altamirano
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, México
| | - Karla Carvajal
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Ciudad de México, México
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12
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Tomek J, Nieves-Cintron M, Navedo MF, Ko CY, Bers DM. SparkMaster 2: A New Software for Automatic Analysis of Calcium Spark Data. Circ Res 2023; 133:450-462. [PMID: 37555352 PMCID: PMC7615009 DOI: 10.1161/circresaha.123.322847] [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: 03/28/2023] [Revised: 07/22/2023] [Accepted: 07/26/2023] [Indexed: 08/10/2023]
Abstract
BACKGROUND Calcium (Ca) sparks are elementary units of subcellular Ca release in cardiomyocytes and other cells. Accordingly, Ca spark imaging is an essential tool for understanding the physiology and pathophysiology of Ca handling and is used to identify new drugs targeting Ca-related cellular dysfunction (eg, cardiac arrhythmias). The large volumes of imaging data produced during such experiments require accurate and high-throughput analysis. METHODS We developed a new software tool SparkMaster 2 (SM2) for the analysis of Ca sparks imaged by confocal line-scan microscopy, combining high accuracy, flexibility, and user-friendliness. SM2 is distributed as a stand-alone application requiring no installation. It can be controlled using a simple-to-use graphical user interface, or using Python scripting. RESULTS SM2 is shown to have the following strengths: (1) high accuracy at identifying Ca release events, clearly outperforming previous highly successful software SparkMaster; (2) multiple types of Ca release events can be identified using SM2: Ca sparks, waves, miniwaves, and long sparks; (3) SM2 can accurately split and analyze individual sparks within spark clusters, a capability not handled adequately by prior tools. We demonstrate the practical utility of SM2 in two case studies, investigating how Ca levels affect spontaneous Ca release, and how large-scale release events may promote release refractoriness. SM2 is also useful in atrial and smooth muscle myocytes, across different imaging conditions. CONCLUSIONS SparkMaster 2 is a new, much-improved user-friendly software for accurate high-throughput analysis of line-scan Ca spark imaging data. It is free, easy to use, and provides valuable built-in features to facilitate visualization, analysis, and interpretation of Ca spark data. It should enhance the quality and throughput of Ca spark and wave analysis across cell types, particularly in the study of arrhythmogenic Ca release events in cardiomyocytes.
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Affiliation(s)
- Jakub Tomek
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, California (J.T., M.N.-C., M.F.N., C.Y.K., D.M.B.)
- Department of Anatomy, Physiology, and Genetics, University of Oxford, Oxford, UK (J.T.)
| | - Madeline Nieves-Cintron
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, California (J.T., M.N.-C., M.F.N., C.Y.K., D.M.B.)
| | - Manuel F. Navedo
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, California (J.T., M.N.-C., M.F.N., C.Y.K., D.M.B.)
| | - Christopher Y. Ko
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, California (J.T., M.N.-C., M.F.N., C.Y.K., D.M.B.)
| | - Donald M. Bers
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, California (J.T., M.N.-C., M.F.N., C.Y.K., D.M.B.)
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13
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Lin R, Peng X, Li Y, Wang X, Liu X, Jia X, Zhang C, Liu N, Dong J. Empagliflozin attenuates doxorubicin-impaired cardiac contractility by suppressing reactive oxygen species in isolated myocytes. Mol Cell Biochem 2023:10.1007/s11010-023-04830-z. [PMID: 37648958 DOI: 10.1007/s11010-023-04830-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 08/14/2023] [Indexed: 09/01/2023]
Abstract
In animal studies, sodium-glucose co-transporter-2 inhibitors-such as empagliflozin-have been shown to improve heart failure and impaired cardiac contractility induced by anthracyclines-including doxorubicin-although the therapeutic mechanism remains unclear. Moreover, abnormalities in Ca2+ handling within ventricular myocytes are the predominant feature of heart failure. Accordingly, this study aimed to investigate whether empagliflozin can alleviate Ca2+ handling disorders induced by acute doxorubicin exposure and elucidate the underlying mechanisms. To this end, ventricular myocytes were isolated from C57BL/6 mice. Contraction function, Ca2+ handling, and mitochondrial reactive oxygen species (ROS) generation were then evaluated using IonOptix or confocal microscopy. Ca2+ handling proteins were detected by western blotting. Results show that incubation with 1 μmol/L of doxorubicin for 120-min impaired cardiac contractility in isolated myocytes, which was significantly alleviated by pretreatment with 1 μmol/L of empagliflozin. Doxorubicin also markedly induced Ca2+ handling disorders, including decreased Ca2+ transients, prolonged Ca2+ transient decay time, enhanced frequency of Ca2+ sparks, and decreased Ca2+ content in the sarcoplasmic reticulum. These dysregulations were improved by pretreatment with empagliflozin. Moreover, empagliflozin effectively inhibited doxorubicin-induced mitochondrial ROS production in isolated myocytes and rescued doxorubicin-induced oxidation of Ca2+/calmodulin-dependent protein kinase II (ox-CaMKII) and CaMKII-dependent phosphorylation of RyR2. Similarly, preincubation with 10 μmol/L Mito-TEMPO mimicked the protective effects of empagliflozin. Collectively, Empagliflozin ameliorated the doxorubicin-induced contraction malfunction and Ca2+-handling disorders. These findings suggest that empagliflozin alleviates Ca2+-handling disorders by improving ROS production in the mitochondria and alleviating the enhanced oxidative CaMKII signaling pathway induced by doxorubicin.
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Affiliation(s)
- Rong Lin
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China
- North China Medical & Health Group XingTai General Hospital, Xingtai, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Xiaodong Peng
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Yukun Li
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Xuesi Wang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Xinmeng Liu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Xingze Jia
- North China Medical & Health Group XingTai General Hospital, Xingtai, China
| | - Chengjun Zhang
- North China Medical & Health Group XingTai General Hospital, Xingtai, China
| | - Nian Liu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China.
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China.
| | - Jianzeng Dong
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, No 2. Anzhen Road, Chaoyang, 100029, Beijing, China.
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China.
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14
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Power AS, Asamudo E, Worthington LPI, Alim CC, Parackal R, Wallace RS, Ebenebe OV, Brown JH, Kohr MJ, Bers DM, Erickson JR. Nitric Oxide modulates spontaneous Ca 2+ release and ventricular arrhythmias during β-adrenergic signalling through S-nitrosylation of Calcium/Calmodulin dependent kinase II. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.23.554546. [PMID: 37662205 PMCID: PMC10473710 DOI: 10.1101/2023.08.23.554546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Rationale Nitric oxide (NO) has been identified as a signalling molecule generated during β-adrenergic receptor (AR) stimulation in the heart. Furthermore, a role for NO in triggering spontaneous Ca2+ release via S-nitrosylation of Ca2+/calmodulin kinase II delta (CaMKIIδ) is emerging. NO donors are routinely used clinically for their cardioprotective effects in the heart, but it is unknown how NO donors modulate the pro-arrhythmic CaMKII to alter cardiac arrhythmia incidence. Objective We test the role of S-nitrosylation of CaMKIIδ at the Cys-273 inhibitory site and Cys-290 activating site in cardiac Ca2+ handling and arrhythmogenesis before and during β-AR stimulation. Methods and Results We measured Ca2+-handling in isolated cardiomyocytes from C57BL/6J wild-type (WT) mice and mice lacking CaMKIIδ expression (CaMKIIδ-KO) or with deletion of the S-nitrosylation site on CaMKIIδ at Cys-273 or Cys-290 (CaMKIIδ-C273S and -C290A knock-in mice). Cardiomyocytes were exposed to NO donors, S-nitrosoglutathione (GSNO; 150 μM), sodium nitroprusside (SNP; 200 μM) and/or β-adrenergic agonist isoproterenol (ISO; 100 nM). WT and CaMKIIδ-KO cardiomyocytes treated with GSNO showed no change in Ca2+ transient or spark properties under baseline conditions (0.5 Hz stimulation frequency). Both WT and CaMKIIδ-KO cardiomyocytes responded to ISO with a full inotropic and lusitropic Ca2+ transient response as well as increased Ca2+ spark frequency. However, the increase in Ca2+ spark frequency was significantly attenuated in CaMKIIδ-KO cardiomyocytes. The protection from ISO-induced Ca2+ sparks and waves was mimicked by GSNO pre-treatment in WT cardiomyocytes, but lost in CaMKIIδ-C273S cardiomyocytes that displayed a robust increase in Ca2+ waves. This observation is consistent with CaMKIIδ-C273 S-nitrosylation being critical in limiting ISO-induced arrhythmogenic sarcoplasmic reticulum Ca2+ leak. When GSNO was applied after ISO this protection was not observed in WT or CaMKIIδ-C273S but was apparent in CaMKIIδ-C290A. In Langendorff-perfused isolated hearts, GSNO pre-treatment limited ISO-induced arrhythmias in WT but not CaMKIIδ-C273S hearts, while GSNO exposure after ISO sustained or exacerbated arrhythmic events. Conclusions We conclude that prior S-nitrosylation of CaMKIIδ at Cys-273 can limit subsequent β-AR induced arrhythmias, but that S-nitrosylation at Cys-290 might worsen or sustain β-AR-induced arrhythmias. This has important implications for the administration of NO donors in the clinical setting.
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Affiliation(s)
- Amelia S. Power
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Esther Asamudo
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
- Department of Pharmacology, University of California, Davis
| | | | | | - Raquel Parackal
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Rachel S. Wallace
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Obialunanma V. Ebenebe
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, La Jolla
| | - Mark J. Kohr
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Donald M. Bers
- Department of Pharmacology, University of California, Davis
| | - Jeffrey R. Erickson
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
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15
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Nawata J, Yamamoto T, Tanaka S, Yano Y, Uchida T, Fujii S, Nakamura Y, Suetomi T, Uchinoumi H, Oda T, Kobayashi S, Yano M. Dantrolene improves left ventricular diastolic property in mineralcorticoid-salt-induced hypertensive rats. Biochem Biophys Rep 2023; 34:101449. [PMID: 36926278 PMCID: PMC10011190 DOI: 10.1016/j.bbrep.2023.101449] [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: 12/22/2022] [Revised: 02/13/2023] [Accepted: 02/26/2023] [Indexed: 03/04/2023] Open
Abstract
Left ventricular (LV) diastolic dysfunction is increasingly common in heart failure with preserved ejection fraction (HFpEF), and new drug therapy is desired. We recently reported that dantrolene (DAN) attenuates pressure-overload induced hypertrophic signaling through stabilization of tetrameric structure of cardiac ryanodine receptor (RyR2). Because cardiac hypertrophy substantially affects LV diastolic properties, we investigated the effect of DAN on LV diastolic properties in mineralocorticoid-salt-induced hypertensive rat model exhibiting the HFpEF phenotype. Male Sprague-Dawley (SD) rats (8 weeks old) received an uninephrectomy (UNX), subcutaneous implantation of a 200 mg pellet of deoxycorticosterone acetate (DOCA), and 0.9% NaCl water (UNX + DOCA-salt). UNX, a control pellet, and water without NaCl served as controls (UNX control). The effect of oral administration of 100 mg/kg/d DAN was examined in UNX control and UNX + DOCA-salt groups (UNX + DAN and UNX + DOCA-salt + DAN). UNX + DOCA-salt treatment resulted in mild hypertension. Chronic administration of DAN to UNX + DOCA-salt rats (UNX + DOCA-salt + DAN) did not affect blood pressure. DAN treatment increased the mitral annular early relaxation velocity in the UNX + DOCA-salt group. The size of cardiomyocytes increased in the UNX + DOCA-salt group, whereas the increase was suppressed by DAN treatment. LV fibrotic area was significantly smaller in the UNX + DOCA-salt + DAN group than in the UNX + DOCA-salt group (2.0 ± 0.2% vs 4.0 ± 0.4%). The LV chamber stiffness significantly increased in the UNX + DOCA-salt group, whereas the increase was suppressed by DAN treatment. DAN treatment normalized the CaM-RyR2 interaction and inhibited aberrant Ca2+ release. DAN improved left ventricular diastolic properties with respect to both myocardial relaxation and chamber stiffness. DAN may be a new treatment option for HFpEF.
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Affiliation(s)
- Junya Nawata
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Yamamoto
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shinji Tanaka
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yasutake Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Tomoyuki Uchida
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shohei Fujii
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yoshihide Nakamura
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Suetomi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Hitoshi Uchinoumi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shigeki Kobayashi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
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16
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Hohendanner F, Prabhu A, Wilck N, Stangl V, Pieske B, Stangl K, Althoff TF. G q-Mediated Arrhythmogenic Signaling Promotes Atrial Fibrillation. Biomedicines 2023; 11:biomedicines11020526. [PMID: 36831062 PMCID: PMC9953645 DOI: 10.3390/biomedicines11020526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is promoted by various stimuli like angiotensin II, endothelin-1, epinephrine/norepinephrine, vagal activation, or mechanical stress, all of which activate receptors coupled to G-proteins of the Gαq/Gα11-family (Gq). Besides pro-fibrotic and pro-inflammatory effects, Gq-mediated signaling induces inositol trisphosphate receptor (IP3R)-mediated intracellular Ca2+ mobilization related to delayed after-depolarisations and AF. However, direct evidence of arrhythmogenic Gq-mediated signaling is absent. METHODS AND RESULTS To define the role of Gq in AF, transgenic mice with tamoxifen-inducible, cardiomyocyte-specific Gαq/Gα11-deficiency (Gq-KO) were created and exposed to intracardiac electrophysiological studies. Baseline electrophysiological properties, including heart rate, sinus node recovery time, and atrial as well as AV nodal effective refractory periods, were comparable in Gq-KO and control mice. However, inducibility and mean duration of AF episodes were significantly reduced in Gq-KO mice-both before and after vagal stimulation. To explore underlying mechanisms, left atrial cardiomyocytes were isolated from Gq-KO and control mice and electrically stimulated to study Ca2+-mobilization during excitation-contraction coupling using confocal microscopy. Spontaneous arrhythmogenic Ca2+ waves and sarcoplasmic reticulum content-corrected Ca2+ sparks were less frequent in Gq-KO mice. Interestingly, nuclear but not cytosolic Ca2+ transient amplitudes were significantly decreased in Gq-KO mice. CONCLUSION Gq-signaling promotes arrhythmogenic atrial Ca2+-release and AF in mice. Targeting this pathway, ideally using Gq-selective, biased receptor ligands, may be a promising approach for the treatment and prevention of AF. Importantly, the atrial-specific expression of the Gq-effector IP3R confers atrial selectivity mitigating the risk of life-threatening ventricular pro-arrhythmic effects.
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Affiliation(s)
- Felix Hohendanner
- Department of Cardiology and German Heart Center, Campus Virchow-Klinikum, Charité–University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Ashok Prabhu
- Department of Cardiology and German Heart Center, Campus Virchow-Klinikum, Charité–University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Nicola Wilck
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
- Experimental and Clinical Research Center (ECRC), a Cooperation of Charité–Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine (MDC), 13125 Berlin, Germany
- Department of Nephrology and Medical Intensive Care Medicine, Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Verena Stangl
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
- Department of Cardiology and Angiology, Charité Campus Mitte, Charité–University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Burkert Pieske
- Department of Cardiology and German Heart Center, Campus Virchow-Klinikum, Charité–University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Karl Stangl
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
- Department of Cardiology and Angiology, Charité Campus Mitte, Charité–University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Till F. Althoff
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, 13316 Berlin, Germany
- Berlin Institute of Health at Charité–Universitätsmedizin Berlin, 10117 Berlin, Germany
- Department of Cardiology and Angiology, Charité Campus Mitte, Charité–University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany
- Arrhythmia Section, Cardiovascular Institute (ICCV), Hospital Clínic, Universitat de Barcelona, C/Villarroel N° 170, 08036 Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
- Correspondence: ; Tel.: +34-93-2275551; Fax: +34-93-4513045
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Baglaeva I, Iaparov B, Zahradník I, Zahradníková A. Analysis of noisy transient signals based on Gaussian process regression. Biophys J 2023; 122:451-459. [PMID: 36609141 PMCID: PMC9941716 DOI: 10.1016/j.bpj.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/26/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023] Open
Abstract
Dynamic systems such as cells or tissues generate, either spontaneously or in response to stimuli, transient signals that carry information about the system. Characterization of recorded transients is often hampered by a low signal-to-noise ratio (SNR). Reduction of the noise by filtering has limited use due to partial signal distortion. Occasionally, transients can be approximated by a mathematical function, but such a function may not hold correctly if recording conditions change. We introduce here the model-independent approximation method for general noisy transient signals based on the Gaussian process regression. The method was implemented in the software TransientAnalyzer, which detects transients in a record, finds their best approximation by the Gaussian process, constructs a surrogate spline function, and estimates specified signal parameters. The method and software were tested on a cellular model of the calcium concentration transient corrupted by various SNR levels and recorded at a low sampling frequency. Statistical analysis of the model data sets provided the error of estimation <7.5% and the coefficient of variation of estimates <17% for peak SNR = 5. The performance of Gaussian process regression on signals of diverse experimental origin was even better than fitting by a function. The software and its description are available on GitHub.
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Affiliation(s)
- Iuliia Baglaeva
- Department of Cellular Cardiology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Bogdan Iaparov
- Department of Cellular Cardiology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ivan Zahradník
- Department of Cellular Cardiology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Alexandra Zahradníková
- Department of Cellular Cardiology, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia.
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18
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Landstrom AP, Yang Q, Sun B, Perelli RM, Bidzimou MT, Zhang Z, Aguilar-Sanchez Y, Alsina KM, Cao S, Reynolds JO, Word TA, van der Sangen NM, Wells Q, Kannankeril PJ, Ludwig A, Kim JJ, Wehrens XH. Reduction in Junctophilin 2 Expression in Cardiac Nodal Tissue Results in Intracellular Calcium-Driven Increase in Nodal Cell Automaticity. Circ Arrhythm Electrophysiol 2023; 16:e010858. [PMID: 36706317 PMCID: PMC9974897 DOI: 10.1161/circep.122.010858] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/06/2023] [Indexed: 01/29/2023]
Abstract
BACKGROUND Spontaneously depolarizing nodal cells comprise the pacemaker of the heart. Intracellular calcium (Ca2+) plays a critical role in mediating nodal cell automaticity and understanding this so-called Ca2+ clock is critical to understanding nodal arrhythmias. We previously demonstrated a role for Jph2 (junctophilin 2) in regulating Ca2+-signaling through inhibition of RyR2 (ryanodine receptor 2) Ca2+ leak in cardiac myocytes; however, its role in pacemaker function and nodal arrhythmias remains unknown. We sought to determine whether nodal Jph2 expression silencing causes increased sinoatrial and atrioventricular nodal cell automaticity due to aberrant RyR2 Ca2+ leak. METHODS A tamoxifen-inducible, nodal tissue-specific, knockdown mouse of Jph2 was achieved using a Cre-recombinase-triggered short RNA hairpin directed against Jph2 (Hcn4:shJph2). In vivo cardiac rhythm was monitored by surface ECG, implantable cardiac telemetry, and intracardiac electrophysiology studies. Intracellular Ca2+ imaging was performed using confocal-based line scans of isolated nodal cells loaded with fluorescent Ca2+ reporter Cal-520. Whole cell patch clamp was conducted on isolated nodal cells to determine action potential kinetics and sodium-calcium exchanger function. RESULTS Hcn4:shJph2 mice demonstrated a 40% reduction in nodal Jph2 expression, resting sinus tachycardia, and impaired heart rate response to pharmacologic stress. In vivo intracardiac electrophysiology studies and ex vivo optical mapping demonstrated accelerated junctional rhythm originating from the atrioventricular node. Hcn4:shJph2 nodal cells demonstrated increased and irregular Ca2+ transient generation with increased Ca2+ spark frequency and Ca2+ leak from the sarcoplasmic reticulum. This was associated with increased nodal cell AP firing rate, faster diastolic repolarization rate, and reduced sodium-calcium exchanger activity during repolarized states compared to control. Phenome-wide association studies of the JPH2 locus identified an association with sinoatrial nodal disease and atrioventricular nodal block. CONCLUSIONS Nodal-specific Jph2 knockdown causes increased nodal automaticity through increased Ca2+ leak from intracellular stores. Dysregulated intracellular Ca2+ underlies nodal arrhythmogenesis in this mouse model.
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Affiliation(s)
- Andrew P. Landstrom
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
- Dept of Cell Biology, Duke Univ School of Medicine, Durham, NC
| | - Qixin Yang
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
- Dept of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang Univ, Hangzhou, China
| | - Bo Sun
- Dept of Pediatrics, Division of Cardiology, Duke Univ School of Medicine, Durham, NC
| | | | | | - Zhushan Zhang
- Dept of Cell Biology, Duke Univ School of Medicine, Durham, NC
| | - Yuriana Aguilar-Sanchez
- Integrative Molecular & Biomedical Sciences Program, Baylor College of Medicine, Houston, TX
| | - Katherina M. Alsina
- Integrative Molecular & Biomedical Sciences Program, Baylor College of Medicine, Houston, TX
| | - Shuyi Cao
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | - Julia O. Reynolds
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | - Tarah A. Word
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
| | | | - Quinn Wells
- Depts of Medicine, Pharmacology, and Biomedical Informatics, Vanderbilt Univ School of Medicine, Nashville, TN
| | - Prince J. Kannankeril
- Center for Pediatric Precision Medicine, Dept of Pediatrics, Vanderbilt Univ School of Medicine, Nashville, TN
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jeffrey J. Kim
- Dept of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, TX
| | - Xander H.T. Wehrens
- Dept of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX
- Dept of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, TX
- Depts of Neuroscience & Center for Space Medicine and the Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
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19
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Haugsten Hansen M, Sadredini M, Hasic A, Anderson ME, Sjaastad I, Korseberg Stokke M. CaMKII and reactive oxygen species contribute to early reperfusion arrhythmias, but oxidation of CaMKIIδ at methionines 281/282 is not a determining factor. J Mol Cell Cardiol 2023; 175:49-61. [PMID: 36528076 DOI: 10.1016/j.yjmcc.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/16/2022]
Abstract
BACKGROUND Available evidence suggest that Ca2+/calmodulin-dependent protein kinase type IIδ (CaMKIIδ) and reactive oxygen species (ROS) are important in early ischemia-reperfusion arrhythmias (IRA). Since ROS can activate CaMKIIδ by oxidation of two methionines at positions 281/282, oxidized-CaMKIIδ (Ox-CaMKIIδ) has been proposed to be important for IRA. However, direct evidence for this is missing. METHODS We exposed Langendorff-perfused hearts and ventricular cardiomyocytes from C57BL/6 mice to global and simulated ischemia, respectively, and recorded arrhythmic events during early reperfusion. Hearts were collected for immunoblotting of key phosphoproteins. We evaluated the effects of beta-adrenoceptor stimulation, inhibition of CaMKII, and reduced ROS levels with isoprenaline, KN93/AIP and N-acetylcysteine (NAC), respectively. We further tested the importance of Ox-CaMKIIδ by using hearts and cardiomyocytes from mice with CaMKIIδ resistant to oxidation of methionines 281 and 282 (MMVV). RESULTS Hearts treated with KN93, AIP or NAC had lower incidence of early IRA, and NAC-treated cardiomyocytes had lower incidence of arrhythmogenic events. However, hearts from MMVV mice had a similar incidence of early IRA to wild type mice (WT), and MMVV and WT cardiomyocytes had a similar frequency of Ca2+ waves and Ca2+ sparks. Immunoblotting confirmed high levels of oxidation in early reperfusion, but revealed no significant differences in the phosphorylation levels of Ca2+-handling proteins in MMVV and WT hearts. CONCLUSIONS Although CaMKII and ROS both contribute to early IRA, hearts from mice with CaMKII resistant to oxidation at methionines 281/282 were not protected from such arrhythmias, suggesting that oxidation at these sites is not a determining factor.
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Affiliation(s)
- Marie Haugsten Hansen
- 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
| | - Mani Sadredini
- 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
| | - Almira Hasic
- 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
| | - Mark E Anderson
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ivar Sjaastad
- 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
| | - Mathis Korseberg Stokke
- 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; Department of Cardiology, Oslo University Hospital Rikshospitalet, Oslo, Norway.
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20
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Nikolaienko R, Bovo E, Yuen SL, Treinen LM, Berg K, Aldrich CC, Thomas DD, Cornea RL, Zima AV. New N-aryl-N-alkyl-thiophene-2-carboxamide compound enhances intracellular Ca 2+ dynamics by increasing SERCA2a Ca 2+ pumping. Biophys J 2023; 122:386-396. [PMID: 36463408 PMCID: PMC9892616 DOI: 10.1016/j.bpj.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/31/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
The type 2a sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) plays a central role in the intracellular Ca2+ homeostasis of cardiac myocytes, pumping Ca2+ from the cytoplasm into the sarcoplasmic reticulum (SR) lumen to maintain relaxation (diastole) and prepare for contraction (systole). Diminished SERCA2a function has been reported in several pathological conditions, including heart failure. Therefore, development of new drugs that improve SERCA2a Ca2+ transport is of great clinical significance. In this study, we characterized the effect of a recently identified N-aryl-N-alkyl-thiophene-2-carboxamide (or compound 1) on SERCA2a Ca2+-ATPase and Ca2+ transport activities in cardiac SR vesicles, and on Ca2+ regulation in a HEK293 cell expression system and in mouse ventricular myocytes. We found that compound 1 enhances SERCA2a Ca2+-ATPase and Ca2+ transport in SR vesicles. Fluorescence lifetime measurements of fluorescence resonance energy transfer between SERCA2a and phospholamban indicated that compound 1 interacts with the SERCA-phospholamban complex. Measurement of endoplasmic reticulum Ca2+ dynamics in HEK293 cells expressing human SERCA2a showed that compound 1 increases endoplasmic reticulum Ca2+ load by enhancing SERCA2a-mediated Ca2+ transport. Analysis of cytosolic Ca2+ dynamics in mouse ventricular myocytes revealed that compound 1 increases the action potential-induced Ca2+ transients and SR Ca2+ load, with negligible effects on L-type Ca2+ channels and Na+/Ca2+ exchanger. However, during adrenergic receptor activation, compound 1 did not further increase Ca2+ transients and SR Ca2+ load, but it decreased the propensity toward Ca2+ waves. Suggestive of concurrent desirable effects of compound 1 on RyR2, [3H]-ryanodine binding to cardiac SR vesicles shows a small decrease in nM Ca2+ and a small increase in μM Ca2+. Accordingly, compound 1 slightly decreased Ca2+ sparks in permeabilized myocytes. Thus, this novel compound shows promising characteristics to improve intracellular Ca2+ dynamics in cardiomyocytes that exhibit reduced SERCA2a Ca2+ uptake, as found in failing hearts.
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Affiliation(s)
- Roman Nikolaienko
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois
| | - Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois
| | - Samantha L Yuen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Levy M Treinen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Kaja Berg
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
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21
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Knighten JM, Aziz T, Pleshinger DJ, Annamdevula N, Rich TC, Taylor MS, Andrews JF, Macarilla CT, Francis CM. Algorithm for biological second messenger analysis with dynamic regions of interest. PLoS One 2023; 18:e0284394. [PMID: 37167308 PMCID: PMC10174521 DOI: 10.1371/journal.pone.0284394] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 03/29/2023] [Indexed: 05/13/2023] Open
Abstract
Physiological function is regulated through cellular communication that is facilitated by multiple signaling molecules such as second messengers. Analysis of signal dynamics obtained from cell and tissue imaging is difficult because of intricate spatially and temporally distinct signals. Signal analysis tools based on static region of interest analysis may under- or overestimate signals in relation to region of interest size and location. Therefore, we developed an algorithm for biological signal detection and analysis based on dynamic regions of interest, where time-dependent polygonal regions of interest are automatically assigned to the changing perimeter of detected and segmented signals. This approach allows signal profiles to be rigorously and precisely tracked over time, eliminating the signal distortion observed with static methods. Integration of our approach with state-of-the-art image processing and particle tracking pipelines enabled the isolation of dynamic cellular signaling events and characterization of biological signaling patterns with distinct combinations of parameters including amplitude, duration, and spatial spread. Our algorithm was validated using synthetically generated datasets and compared with other available methods. Application of the algorithm to volumetric time-lapse hyperspectral images of cyclic adenosine monophosphate measurements in rat microvascular endothelial cells revealed distinct signal heterogeneity with respect to cell depth, confirming the utility of our approach for analysis of 5-dimensional data. In human tibial arteries, our approach allowed the identification of distinct calcium signal patterns associated with atherosclerosis. Our algorithm for automated detection and analysis of second messenger signals enables the decoding of signaling patterns in diverse tissues and identification of pathologic cellular responses.
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Affiliation(s)
- Jennifer M Knighten
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Takreem Aziz
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Donald J Pleshinger
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Naga Annamdevula
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Thomas C Rich
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Mark S Taylor
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Joel F Andrews
- Bioimaging Core Facility, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - Christian T Macarilla
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
| | - C Michael Francis
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, United States of America
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22
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Steer EJ, Yang Z, Al-Owais MM, Kirton HM, White E, Steele DS. Flecainide induces a sustained countercurrent dependent effect on RyR2 in permeabilized WT ventricular myocytes but not in intact cells. Front Pharmacol 2023; 14:1155601. [PMID: 37124209 PMCID: PMC10130871 DOI: 10.3389/fphar.2023.1155601] [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: 01/31/2023] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
Background and purpose: While flecainide is now an accepted treatment for arrhythmias associated with catecholaminergic polymorphic ventricular tachycardia (CPVT), its mechanism of action remains controversial. In studies on myocytes from CPVT mice, inhibition of proarrhythmic Ca2+ waves was initially attributed to a novel action on the type-2 ryanodine receptor (RyR2). However, subsequent work on wild type (WT) myocytes questioned the conclusion that flecainide has a direct action on RyR2. In the present study, the effects of flecainide were compared in intact and permeabilized WT myocytes. Experimental approach: Intracellular Ca2+ was measured using confocal microscopy in intact or saponin permeabilized adult rat ventricular myocytes (ARVM). In some experiments on permeabilized cells, flecainide was studied following partial inhibition of the sarcoplasmic reticulum (SR) counter-current. Key results: Flecainide induced sustained changes Ca2+ sparks and waves in permeabilized ARVM, which were comparable to those reported in intact or permeabilized myocytes from CPVT mice. However, a relatively high level of flecainide (25 μM) was required to induce these effects. Inhibition of the SR counter-current potentiated the effects of flecainide on SR Ca2+ waves. In intact field stimulated ARVM, prolonged exposure to 15 μM flecainide decreased wave frequency but RyR2 dependent effects on Ca2+ sparks were absent; higher drug concentrations blocked field stimulation, consistent with inhibition of Nav1.5. Conclusions and implications: In intact ARVM, the absence of effects on Ca2+ sparks suggests that the intracellular flecainide concentration was insufficient to influence RyR2. Wave inhibition in intact ARVM may reflect secondary effects of Nav1.5 inhibition. Potentiation of flecainide's action by counter-current inhibition can be explained if transient polarization of the SR membrane during SR Ca2+ release facilitates its action on RyR2.
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23
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Alim CC, Ko CY, Mira Hernandez J, Shen EY, Baidar S, Chen‐Izu Y, Bers DM, Bossuyt J. Nitrosylation of cardiac CaMKII at Cys290 mediates mechanical afterload-induced increases in Ca 2+ transient and Ca 2+ sparks. J Physiol 2022; 600:4865-4879. [PMID: 36227145 PMCID: PMC9827875 DOI: 10.1113/jp283427] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/30/2022] [Indexed: 01/12/2023] Open
Abstract
Cardiac mechanical afterload induces an intrinsic autoregulatory increase in myocyte Ca2+ dynamics and contractility to enhance contraction (known as the Anrep effect or slow force response). Our prior work has implicated both nitric oxide (NO) produced by NO synthase 1 (NOS1) and calcium/calmodulin-dependent protein kinase II (CaMKII) activity as required mediators of this form of mechano-chemo-transduction. To test whether a single S-nitrosylation site on CaMKIIδ (Cys290) mediates enhanced sarcoplasmic reticulum Ca2+ leak and afterload-induced increases in sarcoplasmic reticulum (SR) Ca2+ uptake and release, we created a novel CRISPR-based CaMKIIδ knock-in (KI) mouse with a Cys to Ala mutation at C290. These CaMKIIδ-C290A-KI mice exhibited normal cardiac morphometry and function, as well as basal myocyte Ca2+ transients (CaTs) and β-adrenergic responses. However, the NO donor S-nitrosoglutathione caused an acute increased Ca2+ spark frequency in wild-type (WT) myocytes that was absent in the CaMKIIδ-C290A-KI myocytes. Using our cell-in-gel system to exert multiaxial three-dimensional mechanical afterload on myocytes during contraction, we found that WT myocytes exhibited an afterload-induced increase in Ca2+ sparks and Ca2+ transient amplitude and rate of decline. These afterload-induced effects were prevented in both cardiac-specific CaMKIIδ knockout and point mutant CaMKIIδ-C290A-KI myocytes. We conclude that CaMKIIδ activation by S-nitrosylation at the C290 site is essential in mediating the intrinsic afterload-induced enhancement of myocyte SR Ca2+ uptake, release and Ca2+ transient amplitude (the Anrep effect). The data also indicate that NOS1 activation is upstream of S-nitrosylation at C290 of CaMKII, and that this molecular mechano-chemo-transduction pathway is beneficial in allowing the heart to increase contractility to limit the reduction in stroke volume when aortic pressure (afterload) is elevated. KEY POINTS: A novel CRISPR-based CaMKIIδ knock-in mouse was created in which kinase activation by S-nitrosylation at Cys290 (C290A) is prevented. How afterload affects Ca2+ signalling was measured in cardiac myocytes that were embedded in a hydrogel that imposes a three-dimensional afterload. This mechanical afterload induced an increase in Ca2+ transient amplitude and decay in wild-type myocytes, but not in cardiac-specific CaMKIIδ knockout or C290A knock-in myocytes. The CaMKIIδ-C290 S-nitrosylation site is essential for the afterload-induced enhancement of Ca2+ transient amplitude and Ca2+ sparks.
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Affiliation(s)
- Chidera C. Alim
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | | | - Juliana Mira Hernandez
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA,Research Group in Veterinary MedicineSchool of Veterinary MedicineUniversity Corporation LasallistaCaldasAntioquiaColombia
| | - Erin Y. Shen
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Sonya Baidar
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Ye Chen‐Izu
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA,Department of Biomedical EngineeringUniversity of CaliforniaDavisCAUSA,Department of Internal Medicine/CardiologyUniversity of CaliforniaDavisCAUSA
| | - Donald M. Bers
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Julie Bossuyt
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
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24
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Wleklinski MJ, Kryshtal DO, Kim K, Parikh SS, Blackwell DJ, Marty I, Iyer VR, Knollmann BC. Impaired Dynamic Sarcoplasmic Reticulum Ca Buffering in Autosomal Dominant CPVT2. Circ Res 2022; 131:673-686. [PMID: 36102198 PMCID: PMC9529867 DOI: 10.1161/circresaha.121.320661] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal cardiac arrhythmia syndrome triggered by catecholamines released during exercise, stress, or sudden emotion. Variants in the calsequestrin-2 gene (CASQ2), encoding the major calcium (Ca) binding protein in the sarcoplasmic reticulum (SR), are the second most common cause of CPVT. Recently, several CASQ2 gene variants, such as CASQ2-K180R, have been linked to an autosomal dominant form of Casq2-linked CPVT (CPVT2), but the underlying mechanism is not known. METHODS A K180R mouse model was generated using CRIPSR/Cas9. Heterozygous and homozygous K180R mice were studied using telemetry ECG recordings in vivo. Ventricular cardiomyocytes were isolated and studied using fluorescent Ca indicators and patch clamp. Expression levels and localization of SR Ca-handling proteins were evaluated using Western blotting and immunostaining. Intra-SR Ca kinetics were quantified using low-affinity Ca indicators. RESULTS K180R mice exhibit an autosomal dominant CPVT phenotype following exercise or catecholamine stress. Upon catecholamine stress, K180R ventricular cardiomyocytes exhibit increased spontaneous SR Ca release events, triggering delayed afterdepolarizations and spontaneous beats. K180R had no effect on levels of Casq2, Casq2 polymers, or other SR Ca-handling proteins. Intra-SR Ca measurements revealed that K180R impaired dynamic intra-SR Ca buffering, resulting in a more rapid rise of free Ca in the SR during diastole. Steady-state SR Ca buffering and total SR Ca content were not changed. Consistent with the reduced dynamic intra-SR buffering, K180R causes reduced SR Ca release refractoriness. CONCLUSIONS CASQ2-K180R causes CPVT2 via a heretofore unknown mechanism that differs from CASQ2 variants associated with autosomal recessive CPVT2. Unlike autosomal recessive CASQ2 variants, K180R impairs the dynamic buffering of Ca within the SR without affecting total SR Ca content or Casq2 protein levels. Our data provide insight into the molecular mechanism underlying autosomal dominant CPVT2.
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Affiliation(s)
- Matthew J Wleklinski
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
| | - Dmytro O Kryshtal
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
| | - Kyungsoo Kim
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
| | - Shan S Parikh
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
| | - Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
| | - Isabelle Marty
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France (I.M.)
| | - V Ramesh Iyer
- Division of Cardiology, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania (V.R.I.)
| | - Bjӧrn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (M.J.W., D.O.K., K.K., S.S.P., D.J.B., B.C.K.)
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25
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Singh AV, Chandrasekar V, Laux P, Luch A, Dakua SP, Zamboni P, Shelar A, Yang Y, Pandit V, Tisato V, Gemmati D. Micropatterned Neurovascular Interface to Mimic the Blood–Brain Barrier’s Neurophysiology and Micromechanical Function: A BBB-on-CHIP Model. Cells 2022; 11:cells11182801. [PMID: 36139383 PMCID: PMC9497163 DOI: 10.3390/cells11182801] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/24/2022] [Accepted: 09/01/2022] [Indexed: 12/25/2022] Open
Abstract
A hybrid blood–brain barrier (BBB)-on-chip cell culture device is proposed in this study by integrating microcontact printing and perfusion co-culture to facilitate the study of BBB function under high biological fidelity. This is achieved by crosslinking brain extracellular matrix (ECM) proteins to the transwell membrane at the luminal surface and adapting inlet–outlet perfusion on the porous transwell wall. While investigating the anatomical hallmarks of the BBB, tight junction proteins revealed tortuous zonula occludens (ZO-1), and claudin expressions with increased interdigitation in the presence of astrocytes were recorded. Enhanced adherent junctions were also observed. This junctional phenotype reflects in-vivo-like features related to the jamming of cell borders to prevent paracellular transport. Biochemical regulation of BBB function by astrocytes was noted by the transient intracellular calcium effluxes induced into endothelial cells. Geometry-force control of astrocyte–endothelial cell interactions was studied utilizing traction force microscopy (TFM) with fluorescent beads incorporated into a micropatterned polyacrylamide gel (PAG). We observed the directionality and enhanced magnitude in the traction forces in the presence of astrocytes. In the future, we envisage studying transendothelial electrical resistance (TEER) and the effect of chemomechanical stimulations on drug/ligand permeability and transport. The BBB-on-chip model presented in this proposal should serve as an in vitro surrogate to recapitulate the complexities of the native BBB cellular milieus.
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Affiliation(s)
- Ajay Vikram Singh
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), 10589 Berlin, Germany
- Correspondence: (A.V.S.); (S.P.D.)
| | | | - Peter Laux
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), 10589 Berlin, Germany
| | - Andreas Luch
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), 10589 Berlin, Germany
| | - Sarada Prasad Dakua
- Department of Surgery, Hamad Medical Corporation (HMC), Doha 3050, Qatar
- Correspondence: (A.V.S.); (S.P.D.)
| | - Paolo Zamboni
- Department of Vascular Surgery, University of Ferrara, 44121 Ferrara, Italy
| | - Amruta Shelar
- Department of Technology, Savitribai Phule Pune University, Pune 411007, India
| | - Yin Yang
- College of Science and Engineering, Hamad Bin Khalifa University (HBKU), Doha 24404, Qatar
| | - Vaibhav Pandit
- Dynex Technologies, 14340 Sullyfield Circle, Chantilly, VA 20151, USA
| | - Veronica Tisato
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
- Centre Hemostasis & Thrombosis, University of Ferrara, 44121 Ferrara, Italy
| | - Donato Gemmati
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
- Centre Hemostasis & Thrombosis, University of Ferrara, 44121 Ferrara, Italy
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26
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Qiliqiangxin Capsule Modulates Calcium Transients and Calcium Sparks in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:9361077. [PMID: 36082183 PMCID: PMC9448542 DOI: 10.1155/2022/9361077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/19/2022] [Accepted: 08/06/2022] [Indexed: 12/03/2022]
Abstract
Background The therapeutic effects of Qiliqiangxin capsule (QLQX), a Chinese patent medicine, in patients with chronic heart failure are well established. However, whether QLQX modulates cardiac calcium (Ca2+) signals, which are crucial for the heart function, remains unclear. Aim of the Study. This study aimed to evaluate the role of QLQX in modulating Ca2+ signals in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Materials and Methods Fluorescence imaging was used to monitor Ca2+ signals in the cytosol and nuclei of hiPSC-CMs. For Ca2+ spark measurements, the line-scan mode of a confocal microscope was used. Results The QLQX treatment substantially decreased the frequency of spontaneous Ca2+ transients, whereas the amplitude of Ca2+ transients elicited by electrical stimulation did not change. QLQX increased the Ca2+ spark frequency in both the cytosol and nuclei without changing the sarcoplasmic reticulum Ca2+ content. Interestingly, QLQX ameliorated abnormal Ca2+ transients in CMs differentiated from hiPSCs derived from patients with long-QT syndrome. Conclusions Our findings provide the first line of evidence that QLQX directly modulates cardiac Ca2+ signals in a human cardiomyocyte model.
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27
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Glaser D, Heinick A, Herting JR, Massing F, Müller FU, Pauls P, Rozhdestvensky TS, Schulte JS, Seidl MD, Skryabin BV, Stümpel F, Kirchhefer U. Impaired myocellular Ca 2+ cycling in protein phosphatase PP2A-B56α knockout mice is normalized by β-adrenergic stimulation. J Biol Chem 2022; 298:102362. [PMID: 35963431 PMCID: PMC9478386 DOI: 10.1016/j.jbc.2022.102362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/24/2022] Open
Abstract
The activity of protein phosphatase 2A (PP2A) is determined by the expression and localization of the regulatory B-subunits. PP2A-B56α is the dominant isoform of the B′-family in the heart. Its role in regulating the cardiac response to β-adrenergic stimulation is not yet fully understood. We therefore generated mice deficient in B56α to test the functional cardiac effects in response to catecholamine administration versus corresponding WT mice. We found the decrease in basal PP2A activity in hearts of KO mice was accompanied by a counter-regulatory increase in the expression of B′ subunits (β and γ) and higher phosphorylation of sarcoplasmic reticulum Ca2+ regulatory and myofilament proteins. The higher phosphorylation levels were associated with enhanced intraventricular pressure and relaxation in catheterized KO mice. In contrast, at the cellular level, we detected depressed Ca2+ transient and sarcomere shortening parameters in KO mice at basal conditions. Consistently, the peak amplitude of the L-type Ca2+ current was reduced and the inactivation kinetics of ICaL were prolonged in KO cardiomyocytes. However, we show β-adrenergic stimulation resulted in a comparable peak amplitude of Ca2+ transients and myocellular contraction between KO and WT cardiomyocytes. Therefore, we propose higher isoprenaline-induced Ca2+ spark frequencies might facilitate the normalized Ca2+ signaling in KO cardiomyocytes. In addition, the application of isoprenaline was associated with unchanged L-type Ca2+ current parameters between both groups. Our data suggest an important influence of PP2A-B56α on the regulation of Ca2+ signaling and contractility in response to β-adrenergic stimulation in the myocardium.
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Affiliation(s)
- Dennis Glaser
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Alexander Heinick
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Julius R Herting
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Fabian Massing
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Paul Pauls
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Timofey S Rozhdestvensky
- Department of Medicine, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Münster, Münster, Germany
| | - Jan S Schulte
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Matthias D Seidl
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Boris V Skryabin
- Department of Medicine, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Münster, Münster, Germany
| | - Frank Stümpel
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Uwe Kirchhefer
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany.
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28
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Lazzarini E, Lodrini AM, Arici M, Bolis S, Vagni S, Panella S, Rendon-Angel A, Saibene M, Metallo A, Torre T, Vassalli G, Ameri P, Altomare C, Rocchetti M, Barile L. Stress-induced premature senescence is associated with a prolonged QT interval and recapitulates features of cardiac aging. Theranostics 2022; 12:5237-5257. [PMID: 35836799 PMCID: PMC9274748 DOI: 10.7150/thno.70884] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 06/11/2022] [Indexed: 01/12/2023] Open
Abstract
Rationale: Aging in the heart is a gradual process, involving continuous changes in cardiovascular cells, including cardiomyocytes (CMs), namely cellular senescence. These changes finally lead to adverse organ remodeling and resulting in heart failure. This study exploits CMs from human induced pluripotent stem cells (iCMs) as a tool to model and characterize mechanisms involved in aging. Methods and Results: Human somatic cells were reprogrammed into human induced pluripotent stem cells and subsequently differentiated in iCMs. A senescent-like phenotype (SenCMs) was induced by short exposure (3 hours) to doxorubicin (Dox) at the sub-lethal concentration of 0.2 µM. Dox treatment induced expression of cyclin-dependent kinase inhibitors p21 and p16, and increased positivity to senescence-associated beta-galactosidase when compared to untreated iCMs. SenCMs showed increased oxidative stress, alteration in mitochondrial morphology and depolarized mitochondrial membrane potential, which resulted in decreased ATP production. Functionally, when compared to iCMs, SenCMs showed, prolonged multicellular QTc and single cell APD, with increased APD variability and delayed afterdepolarizations (DADs) incidence, two well-known arrhythmogenic indexes. These effects were largely ascribable to augmented late sodium current (INaL) and reduced delayed rectifier potassium current (Ikr). Moreover sarcoplasmic reticulum (SR) Ca2+ content was reduced because of downregulated SERCA2 and increased RyR2-mediated Ca2+ leak. Electrical and intracellular Ca2+ alterations were mostly justified by increased CaMKII activity in SenCMs. Finally, SenCMs phenotype was furtherly confirmed by analyzing physiological aging in CMs isolated from old mice in comparison to young ones. Conclusions: Overall, we showed that SenCMs recapitulate the phenotype of aged primary CMs in terms of senescence markers, electrical and Ca2+ handling properties and metabolic features. Thus, Dox-induced SenCMs can be considered a novel in vitro platform to study aging mechanisms and to envision cardiac specific anti-aging approach in humans.
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Affiliation(s)
- Edoardo Lazzarini
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
| | - Alessandra Maria Lodrini
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milano, Italy.,Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Martina Arici
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Sara Bolis
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.,Cellular and Molecular Cardiology, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
| | - Sara Vagni
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Stefano Panella
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
| | - Azucena Rendon-Angel
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.,Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Melissa Saibene
- Department of Earth and Environmental Sciences, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Alessia Metallo
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Tiziano Torre
- Department of Cardiac Surgery Istituto Cardiocentro Ticino, Ente Ospedaliero Cantonale, Lugano, Switzerland
| | - Giuseppe Vassalli
- Cellular and Molecular Cardiology, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.,Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Pietro Ameri
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico, Genova, Italy.,Department of Internal Medicine, University of Genova, Genova, Italy
| | - Claudia Altomare
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
| | - Marcella Rocchetti
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milano, Italy.,✉ Corresponding authors: Lucio Barile, PhD. Istituto Cardiocentro Ticino, Laboratories for Translational Research, EOC Via Chiesa 5, 6500 Bellinzona, Switzerland. +41 586667104 ; Marcella Rocchetti, PhD. University of Milano-Bicocca, Dept. of Biotechnology and Biosciences, P.za della Scienza 2, 20126 Milano, Italy. +39 0264483313
| | - Lucio Barile
- Cardiovascular Theranostics, Istituto Cardiocentro Ticino, Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.,Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland.,Institute of Life Science, Scuola Superiore Sant'Anna, Pisa, Italy.,✉ Corresponding authors: Lucio Barile, PhD. Istituto Cardiocentro Ticino, Laboratories for Translational Research, EOC Via Chiesa 5, 6500 Bellinzona, Switzerland. +41 586667104 ; Marcella Rocchetti, PhD. University of Milano-Bicocca, Dept. of Biotechnology and Biosciences, P.za della Scienza 2, 20126 Milano, Italy. +39 0264483313
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29
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Grune J, Lewis AJM, Yamazoe M, Hulsmans M, Rohde D, Xiao L, Zhang S, Ott C, Calcagno DM, Zhou Y, Timm K, Shanmuganathan M, Pulous FE, Schloss MJ, Foy BH, Capen D, Vinegoni C, Wojtkiewicz GR, Iwamoto Y, Grune T, Brown D, Higgins J, Ferreira VM, Herring N, Channon KM, Neubauer S, Sosnovik DE, Milan DJ, Swirski FK, King KR, Aguirre AD, Ellinor PT, Nahrendorf M. Neutrophils incite and macrophages avert electrical storm after myocardial infarction. NATURE CARDIOVASCULAR RESEARCH 2022; 1:649-664. [PMID: 36034743 PMCID: PMC9410341 DOI: 10.1038/s44161-022-00094-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 06/06/2022] [Indexed: 12/24/2022]
Abstract
Sudden cardiac death, arising from abnormal electrical conduction, occurs frequently in patients with coronary heart disease. Myocardial ischemia simultaneously induces arrhythmia and massive myocardial leukocyte changes. In this study, we optimized a mouse model in which hypokalemia combined with myocardial infarction triggered spontaneous ventricular tachycardia in ambulatory mice, and we showed that major leukocyte subsets have opposing effects on cardiac conduction. Neutrophils increased ventricular tachycardia via lipocalin-2 in mice, whereas neutrophilia associated with ventricular tachycardia in patients. In contrast, macrophages protected against arrhythmia. Depleting recruited macrophages in Ccr2 -/- mice or all macrophage subsets with Csf1 receptor inhibition increased both ventricular tachycardia and fibrillation. Higher arrhythmia burden and mortality in Cd36 -/- and Mertk -/- mice, viewed together with reduced mitochondrial integrity and accelerated cardiomyocyte death in the absence of macrophages, indicated that receptor-mediated phagocytosis protects against lethal electrical storm. Thus, modulation of leukocyte function provides a potential therapeutic pathway for reducing the risk of sudden cardiac death.
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Affiliation(s)
- Jana Grune
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew J. M. Lewis
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- These authors contributed equally and are listed in alphabetical order: Andrew J. M. Lewis, Masahiro Yamazoe
| | - Masahiro Yamazoe
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- These authors contributed equally and are listed in alphabetical order: Andrew J. M. Lewis, Masahiro Yamazoe
| | - Maarten Hulsmans
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Rohde
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Ling Xiao
- Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Shuang Zhang
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Christiane Ott
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - David M. Calcagno
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Yirong Zhou
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kerstin Timm
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Mayooran Shanmuganathan
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- National Institute for Health (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
| | - Fadi E. Pulous
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Maximilian J. Schloss
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Brody H. Foy
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Diane Capen
- Program in Membrane Biology, Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Claudio Vinegoni
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Gregory R. Wojtkiewicz
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Yoshiko Iwamoto
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Tilman Grune
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Dennis Brown
- Program in Membrane Biology, Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - John Higgins
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | | | - Neil Herring
- National Institute for Health (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Keith M. Channon
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- National Institute for Health (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
| | - Stefan Neubauer
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- National Institute for Health (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
| | | | - David E. Sosnovik
- Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Filip K. Swirski
- Cardiovascular Research Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kevin R. King
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, University of California, San Diego La Jolla, CA, USA
| | - Aaron D. Aguirre
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Patrick T. Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Matthias Nahrendorf
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Department of Internal Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
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Rebbeck R, Ginsburg KS, Ko CY, Fasoli A, Rusch K, Cai GF, Dong X, Thomas DD, Bers DM, Cornea RL. Synergistic FRET assays for drug discovery targeting RyR2 channels. J Mol Cell Cardiol 2022; 168:13-23. [PMID: 35405106 PMCID: PMC10088286 DOI: 10.1016/j.yjmcc.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/09/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
A key therapeutic target for heart failure and arrhythmia is the deleterious leak through sarcoplasmic reticulum (SR) ryanodine receptor 2 (RyR2) calcium release channels. We have previously developed methods to detect the pathologically leaky state of RyR2 in adult cardiomyocytes by monitoring RyR2 binding to either calmodulin (CaM) or a biosensor peptide (DPc10). Here, we test whether these complementary binding measurements are effective as high-throughput screening (HTS) assays to discover small molecules that target leaky RyR2. Using FRET, we developed and validated HTS procedures under conditions that mimic a pathological state, to screen the library of 1280 pharmaceutically active compounds (LOPAC) for modulators of RyR2 in cardiac SR membrane preparations. Complementary FRET assays with acceptor-labeled CaM and DPc10 were used for Hit prioritization based on the opposing binding properties of CaM vs. DPc10. This approach narrowed the Hit list to one compound, Ro 90-7501, which altered FRET to suggest increased RyR2-CaM binding and decreased DPc10 binding. Follow-up studies revealed that Ro 90-7501 does not detrimentally affect myocyte Ca2+ transients. Moreover, Ro 90-7501 partially inhibits overall Ca2+ leak, as assessed by Ca2+ sparks in permeabilized rat cardiomyocytes. Together, these results demonstrate (1) the effectiveness of our HTS approach where two complementary assays synergize for Hit ranking and (2) a drug discovery process that combines high-throughput, high-precision in vitro structural assays with in situ myocyte assays of the pathologic RyR2 leak. These provide a drug discovery platform compatible with large-scale HTS campaigns, to identify agents that inhibit RyR2 for therapeutic development.
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Affiliation(s)
- RobynT Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | | | - Christopher Y Ko
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Katherine Rusch
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | - George F Cai
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | - Xiaoqiong Dong
- Department of Pharmacology, University of California, Davis, CA, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA; Photonic Pharma LLC, Minneapolis, MN, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA; Photonic Pharma LLC, Minneapolis, MN, USA.
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Balasubramanian PS, Lal A. GHz Ultrasound and Electrode Chip-Scale Arrays Stimulate and Influence Morphology of Human Neural Cells. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1898-1909. [PMID: 35180080 DOI: 10.1109/tuffc.2022.3152427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study describes the effects of chip-scale gigahertz (GHz) ultrasound (US) and electrical stimulus on the morphology, functionality, and viability of neural cells in vitro. The GHz frequency stimulation is achieved using aluminum nitride piezoelectric transducers fabricated on a silicon wafer, operating at 1.47 GHz, corresponding to the film's thickness mode resonance. These devices are used to stimulate SH-SY5Y neural cells in vitro and observe effects on the morphology and viability of the stimulated cells. It is possible to use these devices to deliver either ultrasonic stimulus alone or US stimulus in conjunction with electrical stimulus. Viability tests demonstrated that the neurons retained structural integrity and viability across a wide range of GHz US stimulus intensities (0-1.2 W/cm2), validating that measurements occur at nontoxic doses of US. Neural stimulation is validated with these devices following the outputs of a previous study, with the normalized fluorescence intensity of activated cells between 1.9 and 2.4. The 300-s ultrasonic stimulation at 1.47 GHz and 0.05 W/cm2 peak intensity led to a decrease in nuclear elongation by 17.5% and a cross-sectional area decrease by 17.8% across three independent trials of over 150 cells per category ( ). The F-actin governed cellular elongation increased in length by up to 16.3% in cells exposed to an ultrasonic stimulus or costimulus ( ). Neurite length increased following ultrasonic stimulation compared with control by 75.8% ( ). This article demonstrates new GHz US and electrical chip-scale arrays with apparent effects in both neural excitation and cell morphology.
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van Opbergen CJM, Bagwan N, Maurya SR, Kim JC, Smith AN, Blackwell DJ, Johnston JN, Knollmann BC, Cerrone M, Lundby A, Delmar M. Exercise Causes Arrhythmogenic Remodeling of Intracellular Calcium Dynamics in Plakophilin-2-Deficient Hearts. Circulation 2022; 145:1480-1496. [PMID: 35491884 PMCID: PMC9086182 DOI: 10.1161/circulationaha.121.057757] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Exercise training, and catecholaminergic stimulation, increase the incidence of arrhythmic events in patients affected with arrhythmogenic right ventricular cardiomyopathy correlated with plakophilin-2 (PKP2) mutations. Separate data show that reduced abundance of PKP2 leads to dysregulation of intracellular Ca2+ (Ca2+i) homeostasis. Here, we study the relation between excercise, catecholaminergic stimulation, Ca2+i homeostasis, and arrhythmogenesis in PKP2-deficient murine hearts. METHODS Experiments were performed in myocytes from a cardiomyocyte-specific, tamoxifen-activated, PKP2 knockout murine line (PKP2cKO). For training, mice underwent 75 minutes of treadmill running once per day, 5 days each week for 6 weeks. We used multiple approaches including imaging, high-resolution mass spectrometry, electrocardiography, and pharmacological challenges to study the functional properties of cells/hearts in vitro and in vivo. RESULTS In myocytes from PKP2cKO animals, training increased sarcoplasmic reticulum Ca2+ load, increased the frequency and amplitude of spontaneous ryanodine receptor (ryanodine receptor 2)-mediated Ca2+ release events (sparks), and changed the time course of sarcomeric shortening. Phosphoproteomics analysis revealed that training led to hyperphosphorylation of phospholamban in residues 16 and 17, suggesting a catecholaminergic component. Isoproterenol-induced increase in Ca2+i transient amplitude showed a differential response to β-adrenergic blockade that depended on the purported ability of the blockers to reach intracellular receptors. Additional experiments showed significant reduction of isoproterenol-induced Ca2+i sparks and ventricular arrhythmias in PKP2cKO hearts exposed to an experimental blocker of ryanodine receptor 2 channels. CONCLUSIONS Exercise disproportionately affects Ca2+i homeostasis in PKP2-deficient hearts in a manner facilitated by stimulation of intracellular β-adrenergic receptors and hyperphosphorylation of phospholamban. These cellular changes create a proarrhythmogenic state that can be mitigated by ryanodine receptor 2 blockade. Our data unveil an arrhythmogenic mechanism for exercise-induced or catecholaminergic life-threatening arrhythmias in the setting of PKP2 deficit. We suggest that membrane-permeable β-blockers are potentially more efficient for patients with arrhythmogenic right ventricular cardiomyopathy, highlight the potential for ryanodine receptor 2 channel blockers as treatment for the control of heart rhythm in the population at risk, and propose that PKP2-dependent and phospholamban-dependent arrhythmogenic right ventricular cardiomyopathy-related arrhythmias have a common mechanism.
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Affiliation(s)
- Chantal JM van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Navratan Bagwan
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Svetlana R Maurya
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joon-Chul Kim
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Abigail N Smith
- Department of Chemistry & Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey N Johnston
- Department of Chemistry & Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Björn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Marina Cerrone
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Alicia Lundby
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
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Prasad V, Makkaoui N, Rajan R, Patel A, Mainali B, Bagchi P, Kumar R, Rogers J, Diamond J, Maxwell JT. Loss of cardiac myosin light chain kinase contributes to contractile dysfunction in right ventricular pressure overload. Physiol Rep 2022; 10:e15238. [PMID: 35384363 PMCID: PMC8981447 DOI: 10.14814/phy2.15238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/03/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023] Open
Abstract
Nearly 1 in every 100 children born have a congenital heart defect. Many of these defects primarily affect the right heart causing pressure overload of the right ventricle (RV). The RV maintains function by adapting to the increased pressure; however, many of these adaptations eventually lead to RV hypertrophy and failure. In this study, we aim to identify the cellular and molecular mechanisms of these adaptions. We utilized a surgical animal model of pulmonary artery banding (PAB) in juvenile rats that has been shown to accurately recapitulate the physiology of right ventricular pressure overload in young hearts. Using this model, we examined changes in cardiac myocyte protein expression as a result of pressure overload with mass spectrometry 4 weeks post-banding. We found pressure overload of the RV induced significant downregulation of cardiac myosin light chain kinase (cMLCK). Single myocyte calcium and contractility recordings showed impaired contraction and relaxation in PAB RV myocytes, consistent with the loss of cMLCK. In the PAB myocytes, calcium transients were of smaller amplitude and decayed at a slower rate compared to controls. We also identified miR-200c, which has been shown to regulate cMLCK expression, as upregulated in the RV in response to pressure overload. These results indicate the loss of cMLCK is a critical maladaptation of the RV to pressure overload and represents a novel target for therapeutic approaches to treat RV hypertrophy and failure associated with congenital heart defects.
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Affiliation(s)
- Vidhya Prasad
- Division of Pediatric CardiologyDepartment of PediatricsEmory University School of MedicineAtlantaGeorgiaUSA
- Children’s Heart Research & Outcomes (HeRO) CenterChildren’s Healthcare of Atlanta & Emory UniversityAtlantaGeorgiaUSA
| | - Nour Makkaoui
- Division of Pediatric CardiologyDepartment of PediatricsEmory University School of MedicineAtlantaGeorgiaUSA
- Children’s Heart Research & Outcomes (HeRO) CenterChildren’s Healthcare of Atlanta & Emory UniversityAtlantaGeorgiaUSA
| | - Rohan Rajan
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Alisha Patel
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Bipul Mainali
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Pritha Bagchi
- Department of BiochemistryEmory University School of MedicineAtlantaGeorgiaUSA
| | - Rhea Kumar
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Julia Rogers
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Jake Diamond
- Emory University College of Arts and SciencesAtlantaGeorgiaUSA
| | - Joshua T. Maxwell
- Division of Pediatric CardiologyDepartment of PediatricsEmory University School of MedicineAtlantaGeorgiaUSA
- Children’s Heart Research & Outcomes (HeRO) CenterChildren’s Healthcare of Atlanta & Emory UniversityAtlantaGeorgiaUSA
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Varma D, Almeida JFQ, DeSantiago J, Blatter LA, Banach K. Inositol 1,4,5-trisphosphate receptor - reactive oxygen signaling domain regulates excitation-contraction coupling in atrial myocytes. J Mol Cell Cardiol 2022; 163:147-155. [PMID: 34755642 PMCID: PMC8826595 DOI: 10.1016/j.yjmcc.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/03/2021] [Accepted: 10/13/2021] [Indexed: 02/03/2023]
Abstract
The inositol 1,4,5-trisphosphate receptor (InsP3R) is up-regulated in patients with atrial fibrillation (AF) and InsP3-induced Ca2+ release (IICR) is linked to pro-arrhythmic spontaneous Ca2+ release events. Nevertheless, knowledge of the physiological relevance and regulation of InsP3Rs in atrial muscle is still limited. We hypothesize that InsP3R and NADPH oxidase 2 (NOX2) form a functional signaling domain where NOX2 derived reactive oxygen species (ROS) regulate InsP3R agonist affinity and thereby Ca2+ release. To quantitate the contribution of IICR to atrial excitation-contraction coupling (ECC) atrial myocytes (AMs) were isolated from wild type and NOX2 deficient (Nox2-/-) mice and changes in the cytoplasmic Ca2+ concentration ([Ca2+]i; fluo-4/AM, indo-1) or ROS (2',7'-dichlorofluorescein, DCF) were monitored by fluorescence microscopy. Superfusion of AMs with Angiotensin II (AngII: 1 μmol/L) significantly increased diastolic [Ca2+]i (F/F0, Ctrl: 1.00 ± 0.01, AngII: 1.20 ± 0.03; n = 7; p < 0.05), the field stimulation induced Ca2+ transient (CaT) amplitude (ΔF/F0, Ctrl: 2.00 ± 0.17, AngII: 2.39 ± 0.22, n = 7; p < 0.05), and let to the occurrence of spontaneous increases in [Ca2+]i. These changes in [Ca2+]i were suppressed by the InsP3R blocker 2-aminoethoxydiphenyl-borate (2-APB; 1 μmol/L). Concomitantly, AngII induced an increase in ROS production that was sensitive to the NOX2 specific inhibitor gp91ds-tat (1 μmol/L). In NOX2-/- AMs, AngII failed to increase diastolic [Ca2+]i, CaT amplitude, and the frequency of spontaneous Ca2+ increases. Furthermore, the enhancement of CaTs by exposure to membrane permeant InsP3 was abolished by NOX inhibition with apocynin (1 μM). AngII induced IICR in Nox2-/- AMs could be restored by addition of exogenous ROS (tert-butyl hydroperoxide, tBHP: 5 μmol/L). In saponin permeabilized AMs InsP3 (5 μmol/L) induced Ca2+ sparks that increased in frequency in the presence of ROS (InsP3: 9.65 ± 1.44 sparks*s-1*(100μm)-1; InsP3 + tBHP: 10.77 ± 1.5 sparks*s-1*(100μm)-1; n = 5; p < 0.05). The combined effect of InsP3 + tBHP was entirely suppressed by 2-APB and Xestospongine C (XeC). Changes in IICR due to InsP3R glutathionylation induced by diamide could be reversed by the reducing agent dithiothreitol (DTT: 1 mmol/L) and prevented by pretreatment with 2-APB, supporting that the ROS-dependent post-translational modification of the InsP3R plays a role in the regulation of ECC. Our data demonstrate that in AMs the InsP3R is under dual control of agonist induced InsP3 and ROS formation and suggest that InsP3 and NOX2-derived ROS co-regulate atrial IICR and ECC in a defined InsP3R/NOX2 signaling domain.
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Affiliation(s)
- Disha Varma
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jonathas F Q Almeida
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jaime DeSantiago
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Lothar A Blatter
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Kathrin Banach
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
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Tanaka S, Yamamoto T, Mikawa M, Nawata J, Fujii S, Nakamura Y, Kato T, Fukuda M, Suetomi T, Uchinoumi H, Oda T, Okuda S, Okamura T, Kobayashi S, Yano. M. Stabilization of RyR2 maintains right ventricular function, reduces the development of ventricular arrhythmias, and improves prognosis in pulmonary hypertension. Heart Rhythm 2022; 19:986-997. [DOI: 10.1016/j.hrthm.2022.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/18/2022] [Accepted: 02/01/2022] [Indexed: 02/01/2023]
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Yang S, Li R, Chen J, Li Z, Huang Z, Xie W. Calcium Spark Detection and Event-Based Classification of Single Cardiomyocyte Using Deep Learning. Front Physiol 2021; 12:770051. [PMID: 34819876 PMCID: PMC8607692 DOI: 10.3389/fphys.2021.770051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/15/2021] [Indexed: 11/13/2022] Open
Abstract
Ca2+ sparks are the elementary Ca2+ release events in cardiomyocytes, altered properties of which lead to impaired Ca2+ handling and finally contribute to cardiac pathology under various diseases. Despite increasing use of machine-learning algorithms in deciphering the content of biological and medical data, Ca2+ spark images and data are yet to be deeply learnt and analyzed. In the present study, we developed a deep residual convolutional neural network method to detect Ca2+ sparks. Compared to traditional detection methods with arbitrarily defined thresholds to distinguish signals from noises, our new method detected more Ca2+ sparks with lower amplitudes but similar spatiotemporal distributions, thereby indicating that our new algorithm detected many very weak events that are usually omitted when using traditional detection methods. Furthermore, we proposed an event-based logistic regression and binary classification model to classify single cardiomyocytes using Ca2+ spark characteristics, which to date have generally been used only for simple statistical analyses and comparison between normal and diseased groups. Using this new detection algorithm and classification model, we succeeded in distinguishing wild type (WT) vs RyR2-R2474S± cardiomyocytes with 100% accuracy, and vehicle vs isoprenaline-insulted WT cardiomyocytes with 95.6% accuracy. The model can be extended to judge whether a small number of cardiomyocytes (and so the whole heart) are under a specific cardiac disease. Thus, this study provides a novel and powerful approach for the research and application of calcium signaling in cardiac diseases.
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Affiliation(s)
- Shengqi Yang
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Ran Li
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Jiliang Chen
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Zhen Li
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Zhangqin Huang
- Beijing Engineering Research Center for IoT Software and Systems, Beijing University of Technology, Beijing, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Health and Rehabilitation Science, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
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Cardiac ryanodine receptor N-terminal region biosensors identify novel inhibitors via FRET-based high-throughput screening. J Biol Chem 2021; 298:101412. [PMID: 34793835 PMCID: PMC8689225 DOI: 10.1016/j.jbc.2021.101412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 12/15/2022] Open
Abstract
The N-terminal region (NTR) of ryanodine receptor (RyR) channels is critical for the regulation of Ca2+ release during excitation–contraction (EC) coupling in muscle. The NTR hosts numerous mutations linked to skeletal (RyR1) and cardiac (RyR2) myopathies, highlighting its potential as a therapeutic target. Here, we constructed two biosensors by labeling the mouse RyR2 NTR at domains A, B, and C with FRET pairs. Using fluorescence lifetime (FLT) detection of intramolecular FRET signal, we developed high-throughput screening (HTS) assays with these biosensors to identify small-molecule RyR modulators. We then screened a small validation library and identified several hits. Hits with saturable FRET dose–response profiles and previously unreported effects on RyR were further tested using [3H]ryanodine binding to isolated sarcoplasmic reticulum vesicles to determine effects on intact RyR opening in its natural membrane. We identified three novel inhibitors of both RyR1 and RyR2 and two RyR1-selective inhibitors effective at nanomolar Ca2+. Two of these hits activated RyR1 only at micromolar Ca2+, highlighting them as potential enhancers of excitation–contraction coupling. To determine whether such hits can inhibit RyR leak in muscle, we further focused on one, an FDA-approved natural antibiotic, fusidic acid (FA). In skinned skeletal myofibers and permeabilized cardiomyocytes, FA inhibited RyR leak with no detrimental effect on skeletal myofiber excitation–contraction coupling. However, in intact cardiomyocytes, FA induced arrhythmogenic Ca2+ transients, a cautionary observation for a compound with an otherwise solid safety record. These results indicate that HTS campaigns using the NTR biosensor can identify compounds with therapeutic potential.
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Islam MMT, Tarnowski D, Zhang M, Trum M, Lebek S, Mustroph J, Daniel H, Moellencamp J, Pabel S, Sossalla S, El‐Armouche A, Nikolaev VO, Shah AM, Eaton P, Maier LS, Sag CM, Wagner S. Enhanced Heart Failure in Redox-Dead Cys17Ser PKARIα Knock-In Mice. J Am Heart Assoc 2021; 10:e021985. [PMID: 34583520 PMCID: PMC8649132 DOI: 10.1161/jaha.121.021985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background PKARIα (protein kinase A type I-α regulatory subunit) is redox-active independent of its physiologic agonist cAMP. However, it is unknown whether this alternative mechanism of PKARIα activation may be of relevance to cardiac excitation-contraction coupling. Methods and Results We used a redox-dead transgenic mouse model with homozygous knock-in replacement of redox-sensitive cysteine 17 with serine within the regulatory subunits of PKARIα (KI). Reactive oxygen species were acutely evoked by exposure of isolated cardiac myocytes to AngII (angiotensin II, 1 µmol/L). The long-term relevance of oxidized PKARIα was investigated in KI mice and their wild-type (WT) littermates following transverse aortic constriction (TAC). AngII increased reactive oxygen species in both groups but with RIα dimer formation in WT only. AngII induced translocation of PKARI to the cell membrane and resulted in protein kinase A-dependent stimulation of ICa (L-type Ca current) in WT with no effect in KI myocytes. Consequently, Ca transients were reduced in KI myocytes as compared with WT cells following acute AngII exposure. Transverse aortic constriction-related reactive oxygen species formation resulted in RIα oxidation in WT but not in KI mice. Within 6 weeks after TAC, KI mice showed an enhanced deterioration of contractile function and impaired survival compared with WT. In accordance, compared with WT, ventricular myocytes from failing KI mice displayed significantly reduced Ca transient amplitudes and lack of ICa stimulation. Conversely, direct pharmacological stimulation of ICa using Bay K8644 rescued Ca transients in AngII-treated KI myocytes and contractile function in failing KI mice in vivo. Conclusions Oxidative activation of PKARIα with subsequent stimulation of ICa preserves cardiac function in the setting of acute and chronic oxidative stress.
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Affiliation(s)
- M. M. Towhidul Islam
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
- Department of Biochemistry and Molecular BiologyUniversity of DhakaBangladesh
| | - Daniel Tarnowski
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Min Zhang
- School of Cardiovascular Medicine & SciencesKings College London British Heart Foundation Centre of ExcellenceLondonUnited Kingdom
| | - Maximilian Trum
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Simon Lebek
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Julian Mustroph
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Henriette Daniel
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Johanna Moellencamp
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Steffen Pabel
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Samuel Sossalla
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Ali El‐Armouche
- Department of Pharmacology and ToxicologyTechnical University DresdenDresdenGermany
| | - Viacheslav O. Nikolaev
- Institute of Experimental Cardiovascular ResearchUniversity Medical Center Hamburg‐EppendorfEppendorfGermany
| | - Ajay M. Shah
- School of Cardiovascular Medicine & SciencesKings College London British Heart Foundation Centre of ExcellenceLondonUnited Kingdom
| | - Philip Eaton
- The William Harvey Research InstituteBarts and the London School of Medicine and DentistryQueen Mary University of LondonLondonUnited Kingdom
| | - Lars S. Maier
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Can Martin Sag
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Stefan Wagner
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
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Filomena MC, Yamamoto DL, Carullo P, Medvedev R, Ghisleni A, Piroddi N, Scellini B, Crispino R, D'Autilia F, Zhang J, Felicetta A, Nemska S, Serio S, Tesi C, Catalucci D, Linke WA, Polishchuk R, Poggesi C, Gautel M, Bang ML. Myopalladin knockout mice develop cardiac dilation and show a maladaptive response to mechanical pressure overload. eLife 2021; 10:e58313. [PMID: 34558411 PMCID: PMC8547954 DOI: 10.7554/elife.58313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/23/2021] [Indexed: 12/13/2022] Open
Abstract
Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice.
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Affiliation(s)
- Maria Carmela Filomena
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Daniel L Yamamoto
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
| | - Pierluigi Carullo
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Roman Medvedev
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Cardiac Surgery, University of VeronaVeronaItaly
| | - Andrea Ghisleni
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Nicoletta Piroddi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Beatrice Scellini
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Roberta Crispino
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | | | - Jianlin Zhang
- Department of Medicine, University of California, San DiegoLa JollaUnited States
| | - Arianna Felicetta
- IRCCS Humanitas Research HospitalMilanItaly
- Humanitas UniversityPieve EmanueleItaly
| | | | | | - Chiara Tesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | | | - Wolfgang A Linke
- Institute of Physiology II, University of MuensterMuensterGermany
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
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EphA2 signaling within integrin adhesions regulates fibrillar adhesion elongation and fibronectin deposition. Matrix Biol 2021; 103-104:1-21. [PMID: 34537369 DOI: 10.1016/j.matbio.2021.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 12/28/2022]
Abstract
The multifunctional glycoprotein fibronectin influences several crucial cellular processes and contributes to multiple pathologies. While a link exists between fibronectin-associated pathologies and the receptor tyrosine kinase EphA2, the mechanism by which EphA2 promotes fibronectin matrix remodeling remains unknown. We previously demonstrated that EphA2 deletion reduces smooth muscle fibronectin deposition and blunts fibronectin deposition in atherosclerosis without influencing fibronectin expression. We now show that EphA2 expression is required for contractility-dependent elongation of tensin- and α5β1 integrin-rich fibrillar adhesions that drive fibronectin fibrillogenesis. Mechanistically, EphA2 localizes to integrin adhesions where focal adhesion kinase mediates ligand-independent Y772 phosphorylation, and mutation of this site significantly blunts fibrillar adhesion length. EphA2 deficiency decreases smooth muscle cell contractility by enhancing p190RhoGAP activation and reducing RhoA activity, whereas stimulating RhoA signaling in EphA2 deficient cells rescues fibrillar adhesion elongation. Together, these data identify EphA2 as a novel regulator of fibrillar adhesion elongation and provide the first data identifying a role for EphA2 signaling in integrin adhesions.
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Sadredini M, Haugsten Hansen M, Frisk M, Louch WE, Lehnart SE, Sjaastad I, Stokke MK. CaMKII inhibition has dual effects on spontaneous Ca 2+ release and Ca 2+ alternans in ventricular cardiomyocytes from mice with a gain-of-function RyR2 mutation. Am J Physiol Heart Circ Physiol 2021; 321:H446-H460. [PMID: 34270372 DOI: 10.1152/ajpheart.00011.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In conditions with abnormally increased activity of the cardiac ryanodine receptor (RyR2), Ca2+/calmodulin-dependent protein kinase II (CaMKII) can contribute to a further destabilization of RyR2 that results in triggered arrhythmias. Therefore, inhibition of CaMKII in such conditions has been suggested as a strategy to suppress RyR2 activity and arrhythmias. However, suppression of RyR2 activity can lead to the development of arrhythmogenic Ca2+ alternans. The aim of this study was to test whether the suppression of RyR2 activity caused by inhibition of CaMKII increases propensity for Ca2+ alternans. We studied spontaneous Ca2+ release events and Ca2+ alternans in isolated left ventricular cardiomyocytes from mice carrying the gain-of-function RyR2 mutation RyR2-R2474S and from wild-type mice. CaMKII inhibition by KN-93 effectively decreased the frequency of spontaneous Ca2+ release events in RyR2-R2474S cardiomyocytes exposed to the β-adrenoceptor agonist isoprenaline. However, KN-93-treated RyR2-R2474S cardiomyocytes also showed increased propensity for Ca2+ alternans and increased Ca2+ alternans ratio compared with both an inactive analog of KN-93 and with vehicle-treated controls. This increased propensity for Ca2+ alternans was explained by prolongation of Ca2+ release refractoriness. Importantly, the increased propensity for Ca2+ alternans in KN-93-treated RyR2-R2474S cardiomyocytes did not surpass that of wild type. In conclusion, inhibition of CaMKII efficiently reduces spontaneous Ca2+ release but promotes Ca2+ alternans in RyR2-R2474S cardiomyocytes with a gain-of-function RyR2 mutation. The dominant effect in RyR2-R2474S is to reduce spontaneous Ca2+ release, which supports this intervention as a therapeutic strategy in this specific condition. However, future studies on CaMKII inhibition in conditions with increased propensity for Ca2+ alternans should include investigation of both phenomena.NEW & NOTEWORTHY Genetically increased RyR2 activity promotes arrhythmogenic Ca2+ release. Inhibition of CaMKII suppresses RyR2 activity and arrhythmogenic Ca2+ release. Suppression of RyR2 activity prolongs refractoriness of Ca2+ release. Prolonged refractoriness of Ca2+ release leads to arrhythmogenic Ca2+ alternans. CaMKII inhibition promotes Ca2+ alternans by prolonging Ca2+ release refractoriness.
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Affiliation(s)
- Mani Sadredini
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Marie Haugsten Hansen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Stephan E Lehnart
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Göttingen, Germany
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Mathis Korseberg Stokke
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway.,Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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Racioppi MF, Burgos JI, Morell M, Gonano LA, Vila Petroff M. Cellular Mechanisms Underlying the Low Cardiotoxicity of Istaroxime. J Am Heart Assoc 2021; 10:e018833. [PMID: 34219467 PMCID: PMC8483492 DOI: 10.1161/jaha.120.018833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Istaroxime is an inhibitor of Na+/K+ ATPase with proven efficacy to increase cardiac contractility and to accelerate relaxation attributable to a relief in phospholamban‐dependent inhibition of the sarcoplasmic reticulum Ca2+ ATPase. We have previously shown that pharmacologic Na+/K+ ATPase inhibition promotes calcium/calmodulin‐dependent kinase II activation, which mediates both cardiomyocyte death and arrhythmias. Here, we aim to compare the cardiotoxic effects promoted by classic pharmacologic Na+/K+ ATPase inhibition versus istaroxime. Methods and Results Ventricular cardiomyocytes were treated with ouabain or istaroxime at previously tested equi‐inotropic concentrations to compare their impact on cell viability, apoptosis, and calcium/calmodulin‐dependent kinase II activation. In contrast to ouabain, istaroxime neither promoted calcium/calmodulin‐dependent kinase II activation nor cardiomyocyte death. In addition, we explored the differential behavior promoted by ouabain and istaroxime on spontaneous diastolic Ca2+ release. In rat cardiomyocytes, istaroxime did not significantly increase Ca2+ spark and wave frequency but increased the proportion of aborted Ca2+ waves. Further insight was provided by studying cardiomyocytes from mice that do not express phospholamban. In this model, the lower Ca2+ wave incidence observed with istaroxime remains present, suggesting that istaroxime‐dependent relief on phospholamban‐dependent sarcoplasmic reticulum Ca2+ ATPase 2A inhibition is not the unique mechanism underlying the low arrhythmogenic profile of this drug. Conclusions Our results indicate that, different from ouabain, istaroxime can reach a significant inotropic effect without leading to calcium/calmodulin‐dependent kinase II–dependent cardiomyocyte death. Additionally, we provide novel insights regarding the low arrhythmogenic impact of istaroxime on cardiac Ca2+ handling.
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Affiliation(s)
- María Florencia Racioppi
- Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina
| | - Juan Ignacio Burgos
- Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina
| | - Malena Morell
- Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina
| | - Luis Alberto Gonano
- Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina
| | - Martín Vila Petroff
- Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina
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Resveratrol Prevents Right Ventricle Dysfunction, Calcium Mishandling, and Energetic Failure via SIRT3 Stimulation in Pulmonary Arterial Hypertension. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:9912434. [PMID: 34239697 PMCID: PMC8238598 DOI: 10.1155/2021/9912434] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 12/17/2022]
Abstract
Pulmonary arterial hypertension (PAH) is characterized by pulmonary vessel remodeling; however, its severity and impact on survival depend on right ventricular (RV) failure. Resveratrol (RES), a polyphenol found in red wine, exhibits cardioprotective effects on RV dysfunction in PAH. However, most literature has focused on RES protective effect on lung vasculature; recent finding indicates that RES has a cardioprotective effect independent of pulmonary arterial pressure on RV dysfunction, although the underlying mechanism in RV has not been determined. Therefore, this study is aimed at evaluating sirtuin-3 (SIRT3) modulation by RES in RV using a monocrotaline- (MC-) induced PAH rat model. Myocyte function was evaluated by confocal microscopy as cell contractility, calcium signaling, and mitochondrial membrane potential (ΔΨm); cell energetics was assessed by high-resolution respirometry, and western blot and immunoprecipitation evaluated posttranslational modifications. PAH significantly affects mitochondrial function in RV; PAH is prone to mitochondrial permeability transition pore (mPTP) opening, thus decreasing the mitochondrial membrane potential. The compromised cellular energetics affects cardiomyocyte function by decreasing sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity and delaying myofilament unbinding, disrupting cell relaxation. RES partially protects mitochondrial integrity by deacetylating cyclophilin-D, a critical component of the mPTP, increasing SIRT3 expression and activity and preventing mPTP opening. The preserved energetic capability rescues cell relaxation by maintaining SERCA activity. Avoiding Ca2+ transient and cell contractility mismatch by preserving mitochondrial function describes, for the first time, impairment in excitation-contraction-energetics coupling in RV failure. These results highlight the importance of mitochondrial energetics and mPTP in PAH.
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Scott Jr L, Fender AC, Saljic A, Li L, Chen X, Wang X, Linz D, Lang J, Hohl M, Twomey D, Pham TT, Diaz-Lankenau R, Chelu MG, Kamler M, Entman ML, Taffet GE, Sanders P, Dobrev D, Li N. NLRP3 inflammasome is a key driver of obesity-induced atrial arrhythmias. Cardiovasc Res 2021; 117:1746-1759. [PMID: 33523143 PMCID: PMC8208743 DOI: 10.1093/cvr/cvab024] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/17/2020] [Accepted: 01/18/2021] [Indexed: 12/27/2022] Open
Abstract
AIMS Obesity, an established risk factor of atrial fibrillation (AF), is frequently associated with enhanced inflammatory response. However, whether inflammatory signaling is causally linked to AF pathogenesis in obesity remains elusive. We recently demonstrated that the constitutive activation of the 'NACHT, LRR, and PYD Domains-containing Protein 3' (NLRP3) inflammasome promotes AF susceptibility. In this study, we hypothesized that the NLRP3 inflammasome is a key driver of obesity-induced AF. METHODS AND RESULTS Western blotting was performed to determine the level of NLRP3 inflammasome activation in atrial tissues of obese patients, sheep, and diet-induced obese (DIO) mice. The increased body weight in patients, sheep, and mice was associated with enhanced NLRP3-inflammasome activation. To determine whether NLRP3 contributes to the obesity-induced atrial arrhythmogenesis, wild-type (WT) and NLRP3 homozygous knockout (NLRP3-/-) mice were subjected to high-fat-diet (HFD) or normal chow (NC) for 10 weeks. Relative to NC-fed WT mice, HFD-fed WT mice were more susceptible to pacing-induced AF with longer AF duration. In contrast, HFD-fed NLRP3-/- mice were resistant to pacing-induced AF. Optical mapping in DIO mice revealed an arrhythmogenic substrate characterized by abbreviated refractoriness and action potential duration (APD), two key determinants of reentry-promoting electrical remodeling. Upregulation of ultra-rapid delayed-rectifier K+-channel (Kv1.5) contributed to the shortening of atrial refractoriness. Increased profibrotic signaling and fibrosis along with abnormal Ca2+ release from sarcoplasmic reticulum (SR) accompanied atrial arrhythmogenesis in DIO mice. Conversely, genetic ablation of Nlrp3 (NLRP3-/-) in HFD-fed mice prevented the increases in Kv1.5 and the evolution of electrical remodeling, the upregulation of profibrotic genes, and abnormal SR Ca2+ release in DIO mice. CONCLUSION These results demonstrate that the atrial NLRP3 inflammasome is a key driver of obesity-induced atrial arrhythmogenesis and establishes a mechanistic link between obesity-induced AF and NLRP3-inflammasome activation.
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Affiliation(s)
- Larry Scott Jr
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Anke C Fender
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | - Arnela Saljic
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Luge Li
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Xiaohui Chen
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Xiaolei Wang
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Dominik Linz
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre, Maastricht, The Netherlands
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, Royal Adelaide Hospital, University of Adelaide, Adelaide, Australia
| | - Jilu Lang
- Department of Cardiac Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Mathias Hohl
- Department of Cardiology/Angiology, University-Clinic of Saarland, Internal Medicine III, Homburg/Saar, Germany
| | | | - Thuy T Pham
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Rodrigo Diaz-Lankenau
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Mihail G Chelu
- Division of Cardiology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Markus Kamler
- Department of Thoracic and Cardiovascular Surgery, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | - Mark L Entman
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - George E Taffet
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, Royal Adelaide Hospital, University of Adelaide, Adelaide, Australia
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | - Na Li
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
- Section of Cardiovascular Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
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Grainger N, Guarina L, Cudmore RH, Santana LF. The Organization of the Sinoatrial Node Microvasculature Varies Regionally to Match Local Myocyte Excitability. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab031. [PMID: 34250490 PMCID: PMC8259512 DOI: 10.1093/function/zqab031] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/28/2021] [Accepted: 06/10/2021] [Indexed: 01/06/2023]
Abstract
The cardiac cycle starts when an action potential is produced by pacemaking cells in the sinoatrial node. This cycle is repeated approximately 100 000 times in humans and 1 million times in mice per day, imposing a monumental metabolic demand on the heart, requiring efficient blood supply via the coronary vasculature to maintain cardiac function. Although the ventricular coronary circulation has been extensively studied, the relationship between vascularization and cellular pacemaking modalities in the sinoatrial node is poorly understood. Here, we tested the hypothesis that the organization of the sinoatrial node microvasculature varies regionally, reflecting local myocyte firing properties. We show that vessel densities are higher in the superior versus inferior sinoatrial node. Accordingly, sinoatrial node myocytes are closer to vessels in the superior versus inferior regions. Superior and inferior sinoatrial node myocytes produce stochastic subthreshold voltage fluctuations and action potentials. However, the intrinsic action potential firing rate of sinoatrial node myocytes is higher in the superior versus inferior node. Our data support a model in which the microvascular densities vary regionally within the sinoatrial node to match the electrical and Ca2+ dynamics of nearby myocytes, effectively determining the dominant pacemaking site within the node. In this model, the high vascular density in the superior sinoatrial node places myocytes with metabolically demanding, high-frequency action potentials near vessels. The lower vascularization and electrical activity of inferior sinoatrial node myocytes could limit these cells to function to support sinoatrial node periodicity with sporadic voltage fluctuations via a stochastic resonance mechanism.
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Liu X, Zhao R, Ding Q, Yao X, Tsang SY. TRPC7 regulates the electrophysiological functions of embryonic stem cell-derived cardiomyocytes. Stem Cell Res Ther 2021; 12:262. [PMID: 33941260 PMCID: PMC8091699 DOI: 10.1186/s13287-021-02308-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022] Open
Abstract
Background Biological pacemakers consisting of pluripotent stem cell-derived cardiomyocytes are potentially useful for treating bradycardia. However, tachyarrhythmia caused by derived cardiomyocytes themselves is one of main barriers hampering their clinical translation. An in-depth understanding of the mechanisms underlying the spontaneous action potential (a.k.a. automaticity) might provide potential approaches to solve this problem. The aim of this project is to study the role of canonical transient receptor potential isoform 7 (TRPC7) channels in regulating the automaticity of embryonic stem cell-derived cardiomyocytes (ESC-CMs). Methods and results By Western blotting, the expression of TRPC7 was found to be increased during the differentiation of mouse ESC-CMs (mESC-CMs). Adenovirus-mediated TRPC7 knockdown decreased while overexpression increased the frequency of Ca2+ transients (CaTs), local Ca2+ releases (LCRs), and action potentials (APs) as detected by confocal microscopy and whole-cell patch-clamping. TRPC7 was found to be positively associated with the activity of ryanodine receptor 2 (RyR2), sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), and sodium-calcium exchanger (NCX) but not hyperpolarization-activated, cyclic nucleotide-gated channel (HCN), and inositol trisphosphate receptor (IP3R). Knockdown or overexpression of TRPC7 did not alter the expression of HCN4, Cav1.3, Cav3.1, Cav3.2, IP3R1, RyR2, and SERCA but positively regulated the phosphorylation of RyR2 at S2814 and phospholamban (PLN) at T17. Moreover, the positive regulation of APs by TRPC7 was Ca2+-dependent, as overexpression of N-terminus of TRPC7 (dominant negative of TRPC7) which diminished the Ca2+ permeability of TRPC7 decreased the AP frequency. Conclusions TRPC7 regulates the automaticity of mESC-CMs through two mechanisms. On the one hand, TRPC7 positively regulates the intracellular Ca2+ clock through the regulation of activities of both RyR2 and SERCA; on the other hand, TRPC7 also positively regulates the membrane clock via its influence on NCX activity. Altogether, our study reveals that TRPC7 is a potential drug target to manipulate the action potential firing rate of pluripotent stem cell-derived cardiomyocyte-based biological pacemakers to prevent tachyarrhythmia, a condition that might be encountered after transplantation.
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Affiliation(s)
- Xianji Liu
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Rui Zhao
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Qianqian Ding
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiaoqiang Yao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Suk Ying Tsang
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China. .,State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR, China. .,Key Laboratory for Regenerative Medicine, Ministry of Education, The Chinese University of Hong Kong, Hong Kong SAR, China. .,Institute for Tissue Engineering and Regenerative Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Altomare C, Lodrini AM, Milano G, Biemmi V, Lazzarini E, Bolis S, Pernigoni N, Torre E, Arici M, Ferrandi M, Barile L, Rocchetti M, Vassalli G. Structural and Electrophysiological Changes in a Model of Cardiotoxicity Induced by Anthracycline Combined With Trastuzumab. Front Physiol 2021; 12:658790. [PMID: 33897465 PMCID: PMC8058443 DOI: 10.3389/fphys.2021.658790] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/16/2021] [Indexed: 11/29/2022] Open
Abstract
Background Combined treatment with anthracyclines (e.g., doxorubicin; Dox) and trastuzumab (Trz), a humanized anti-human epidermal growth factor receptor 2 (HER2; ErbB2) antibody, in patients with HER2-positive cancer is limited by cardiotoxicity, as manifested by contractile dysfunction and arrhythmia. The respective roles of the two agents in the cardiotoxicity of the combined therapy are incompletely understood. Objective To assess cardiac performance, T-tubule organization, electrophysiological changes and intracellular Ca2+ handling in cardiac myocytes (CMs) using an in vivo rat model of Dox/Trz-related cardiotoxicity. Methods and Results Adult rats received 6 doses of either Dox or Trz, or the two agents sequentially. Dox-mediated left ventricular (LV) dysfunction was aggravated by Trz administration. Dox treatment, but not Trz, induced T-tubule disarray. Moreover, Dox, but not Trz monotherapy, induced prolonged action potential duration (APD), increased incidence of delayed afterdepolarizations (DADs) and beat-to-beat variability of repolarization (BVR), and slower Ca2+ transient decay. Although APD, DADs, BVR and Ca2+ transient decay recovered over time after the cessation of Dox treatment, subsequent Trz administration exacerbated these abnormalities. Trz, but not Dox, reduced Ca2+ transient amplitude and SR Ca2+ content, although only Dox treatment was associated with SERCA downregulation. Finally, Dox treatment increased Ca2+ spark frequency, resting Ca2+ waves, sarcoplasmic reticulum (SR) Ca2+ leak, and long-lasting Ca2+ release events (so-called Ca2+ “embers”), partially reproduced by Trz treatment. Conclusion These results suggest that in vivo Dox but not Trz administration causes T-tubule disarray and pronounced changes in electrical activity of CMs. While adaptive changes may account for normal AP shape and reduced DADs late after Dox administration, subsequent Trz administration interferes with such adaptive changes. Intracellular Ca2+ handling was differently affected by Dox and Trz treatment, leading to SR instability in both cases. These findings illustrate the specific roles of Dox and Trz, and their interactions in cardiotoxicity and arrhythmogenicity.
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Affiliation(s)
- Claudia Altomare
- Laboratory of Cellular and Molecular Cardiology, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Alessandra Maria Lodrini
- Department of Biotechnology and Biosciences, Università degli Studi di Milano - Bicocca, Milan, Italy.,Laboratory for Cardiovascular Theranostics, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Giuseppina Milano
- Laboratory of Cellular and Molecular Cardiology, Cardiocentro Ticino Foundation, Lugano, Switzerland.,Laboratory of Cardiovascular Research, Lausanne University Hospital, Lausanne, Switzerland
| | - Vanessa Biemmi
- Laboratory for Cardiovascular Theranostics, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Edoardo Lazzarini
- Laboratory for Cardiovascular Theranostics, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Sara Bolis
- Laboratory of Cellular and Molecular Cardiology, Cardiocentro Ticino Foundation, Lugano, Switzerland.,Laboratory for Cardiovascular Theranostics, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Nicolò Pernigoni
- Laboratory of Cellular and Molecular Cardiology, Cardiocentro Ticino Foundation, Lugano, Switzerland
| | - Eleonora Torre
- Department of Biotechnology and Biosciences, Università degli Studi di Milano - Bicocca, Milan, Italy
| | - Martina Arici
- Department of Biotechnology and Biosciences, Università degli Studi di Milano - Bicocca, Milan, Italy
| | - Mara Ferrandi
- Windtree Therapeutics Inc., Warrington, PA, United States
| | - Lucio Barile
- Laboratory for Cardiovascular Theranostics, Cardiocentro Ticino Foundation, Lugano, Switzerland.,Faculty of Biomedical Sciences, Università della Svizzera italiana, Lugano, Switzerland.,Institute of Life Science, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Marcella Rocchetti
- Department of Biotechnology and Biosciences, Università degli Studi di Milano - Bicocca, Milan, Italy
| | - Giuseppe Vassalli
- Laboratory of Cellular and Molecular Cardiology, Cardiocentro Ticino Foundation, Lugano, Switzerland.,Faculty of Biomedical Sciences, Università della Svizzera italiana, Lugano, Switzerland.,Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
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48
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Berisha F, Götz KR, Wegener JW, Brandenburg S, Subramanian H, Molina CE, Rüffer A, Petersen J, Bernhardt A, Girdauskas E, Jungen C, Pape U, Kraft AE, Warnke S, Lindner D, Westermann D, Blankenberg S, Meyer C, Hasenfuß G, Lehnart SE, Nikolaev VO. cAMP Imaging at Ryanodine Receptors Reveals β 2-Adrenoceptor Driven Arrhythmias. Circ Res 2021; 129:81-94. [PMID: 33902292 DOI: 10.1161/circresaha.120.318234] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Filip Berisha
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (F.B., H.S., C.E.M., A.E.K., V.O.N.).,Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Konrad R Götz
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, Georg August University Medical Center, Germany (K.R.G., J.W.W., S. Brandenburg, G.H., S.E.L.)
| | - Jörg W Wegener
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, Georg August University Medical Center, Germany (K.R.G., J.W.W., S. Brandenburg, G.H., S.E.L.).,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Germany (J.W.W., S. Brandenburg, G.H., S.E.L.)
| | - Sören Brandenburg
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, Georg August University Medical Center, Germany (K.R.G., J.W.W., S. Brandenburg, G.H., S.E.L.).,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Germany (J.W.W., S. Brandenburg, G.H., S.E.L.)
| | - Hariharan Subramanian
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (F.B., H.S., C.E.M., A.E.K., V.O.N.).,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Cristina E Molina
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (F.B., H.S., C.E.M., A.E.K., V.O.N.).,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - André Rüffer
- Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg, Germany (A.R., J.P., A.B., E.G.)
| | - Johannes Petersen
- Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg, Germany (A.R., J.P., A.B., E.G.)
| | - Alexander Bernhardt
- Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg, Germany (A.R., J.P., A.B., E.G.)
| | - Evaldas Girdauskas
- Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg, Germany (A.R., J.P., A.B., E.G.)
| | - Christiane Jungen
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Cardiology-Electrophysiology, cNEP (Cardiac Neuro- and Electrophysiology Research Group) (C.J., U.P., C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrike Pape
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Cardiology-Electrophysiology, cNEP (Cardiac Neuro- and Electrophysiology Research Group) (C.J., U.P., C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Axel E Kraft
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (F.B., H.S., C.E.M., A.E.K., V.O.N.).,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Svenja Warnke
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Diana Lindner
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Dirk Westermann
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Stefan Blankenberg
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
| | - Christian Meyer
- Department of Cardiology (F.B., C.J., U.P., S.W., D.L., D.W., S. Blankenberg, C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Cardiology-Electrophysiology, cNEP (Cardiac Neuro- and Electrophysiology Research Group) (C.J., U.P., C.M.), University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gerd Hasenfuß
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, Georg August University Medical Center, Germany (K.R.G., J.W.W., S. Brandenburg, G.H., S.E.L.).,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Germany (J.W.W., S. Brandenburg, G.H., S.E.L.)
| | - Stephan E Lehnart
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, Germany (J.W.W., S. Brandenburg, G.H., S.E.L.)
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (F.B., H.S., C.E.M., A.E.K., V.O.N.).,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany (F.B., H.S., C.E.M., A.E., S.W., D.L., D.W., S. Blankenberg, V.O.N.)
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49
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Raaijmakers EAL, Wanders N, Mestrom RMC, Luttge R. Analyzing Developing Brain-On-Chip Cultures with the CALIMA Calcium Imaging Tool. MICROMACHINES 2021; 12:mi12040412. [PMID: 33917720 PMCID: PMC8068150 DOI: 10.3390/mi12040412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/30/2021] [Accepted: 04/03/2021] [Indexed: 01/04/2023]
Abstract
Brain-on-chip (BoC) models are tools for reproducing the native microenvironment of neurons, in order to study the (patho)physiology and drug-response of the brain. Recent developments in BoC techniques focus on steering neurons in their activity via microfabrication and via computer-steered feedback mechanisms. These cultures are often studied through calcium imaging (CI), a method for visualizing the cellular activity through infusing cells with a fluorescent dye. CAlciumImagingAnalyser 2.0 (CALIMA 2.0) is an updated version of a software tool that detects and analyzes fluorescent signals and correlates cellular activity to identify possible network formation in BoC cultures. Using three previous published data sets, it was demonstrated that CALIMA 2.0 can analyze large data sets of CI-data and interpret cell activity to help study the activity and maturity of BoC cultures. Last, an analysis of the processing speed shows that CALIMA 2.0 is sufficiently fast to process data sets with an acquisition rate up to 5 Hz in real-time on a medium-performance computer.
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Affiliation(s)
- Elles A. L. Raaijmakers
- Electromagnetics Group, Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.A.L.R.); (R.M.C.M.)
| | - Nikki Wanders
- Neuro-Nanoscale Engineering Group, Department of Mechanical Engineering and Institute of Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
| | - Rob M. C. Mestrom
- Electromagnetics Group, Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.A.L.R.); (R.M.C.M.)
| | - Regina Luttge
- Neuro-Nanoscale Engineering Group, Department of Mechanical Engineering and Institute of Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Correspondence:
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50
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Zhao R, Liu X, Qi Z, Yao X, Tsang SY. TRPV1 channels regulate the automaticity of embryonic stem cell-derived cardiomyocytes through stimulating the Na + /Ca 2+ exchanger current. J Cell Physiol 2021; 236:6806-6823. [PMID: 33782967 DOI: 10.1002/jcp.30369] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 02/25/2021] [Accepted: 03/09/2021] [Indexed: 12/16/2022]
Abstract
Calcium controls the excitation-contraction coupling in cardiomyocytes. Embryonic stem cell-derived cardiomyocytes (ESC-CMs) are an important cardiomyocyte source for regenerative medicine and drug screening. Transient receptor potential vanilloid 1 (TRPV1) channels are nonselective cation channels that permeate sodium and calcium. This study aimed to investigate whether TRPV1 channels regulate the electrophysiological characteristics of ESC-CMs. If yes, what is the mechanism behind? By immunostaining and subcellular fractionation, followed by western blotting, TRPV1 was found to locate intracellularly. The staining pattern of TRPV1 was found to largely overlap with that of the sarco/endoplasmic reticulum Ca2+ -ATPase, the sarcoplasmic reticulum (SR) marker. By electrophysiology and calcium imaging, pharmacological blocker of TRPV1 and the molecular tool TRPV1β (which could functionally knockdown TRPV1) were found to decrease the rate and diastolic depolarization slope of spontaneous action potentials, and the amplitude and frequency of global calcium transients. By calcium imaging, in the absence of external calcium, TRPV1-specific opener increased intracellular calcium; this increase was abolished by preincubation with caffeine, which could deplete SR calcium store. The results suggest that TRPV1 controls calcium release from the SR. By electrophysiology, TRPV1 blockade and functional knockdown of TRPV1 decreased the Na+ /Ca2+ exchanger (NCX) currents from both the forward and reverse modes, suggesting that sodium and calcium through TRPV1 stimulate the NCX activity. Our novel findings suggest that TRPV1 activity is important for regulating the spontaneous activity of ESC-CMs and reveal a novel interplay between TRPV1 and NCX in regulating the physiological functions of ESC-CMs.
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Affiliation(s)
- Rui Zhao
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xianji Liu
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Zenghua Qi
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xiaoqiang Yao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Suk Ying Tsang
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.,State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.,Key Laboratory for Regenerative Medicine, Ministry of Education, The Chinese University of Hong Kong, Hong Kong, China
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