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Bovo E, Jamrozik T, Kahn D, Karkut P, Robia SL, Zima AV. Phosphorylation of phospholamban promotes SERCA2a activation by dwarf open reading frame (DWORF). Cell Calcium 2024; 121:102910. [PMID: 38823350 DOI: 10.1016/j.ceca.2024.102910] [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: 03/22/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 06/03/2024]
Abstract
In cardiac myocytes, the type 2a sarco/endoplasmic reticulum Ca-ATPase (SERCA2a) plays a key role in intracellular Ca regulation. Due to its critical role in heart function, SERCA2a activity is tightly regulated by different mechanisms, including micropeptides. While phospholamban (PLB) is a well-known SERCA2a inhibitor, dwarf open reading frame (DWORF) is a recently identified SERCA2a activator. Since PLB phosphorylation is the most recognized mechanism of SERCA2a activation during adrenergic stress, we studied whether PLB phosphorylation also affects SERCA2a regulation by DWORF. By using confocal Ca imaging in a HEK293 expressing cell system, we analyzed the effect of the co-expression of PLB and DWORF using a bicistronic construct on SERCA2a-mediated Ca uptake. Under these conditions of matched expression of PLB and DWORF, we found that SERCA2a inhibition by non-phosphorylated PLB prevails over DWORF activating effect. However, when PLB is phosphorylated at PKA and CaMKII sites, not only PLB's inhibitory effect was relieved, but SERCA2a was effectively activated by DWORF. Förster resonance energy transfer (FRET) analysis between SERCA2a and DWORF showed that DWORF has a higher relative affinity for SERCA2a when PLB is phosphorylated. Thus, SERCA2a regulation by DWORF responds to the PLB phosphorylation status, suggesting that DWORF might contribute to SERCA2a activation during conditions of adrenergic stress.
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Affiliation(s)
- Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA.
| | - Thomas Jamrozik
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA
| | - Daniel Kahn
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA
| | - Patryk Karkut
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA
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Pluteanu F, Glaser D, Massing F, Schulte JS, Kirchhefer U. Loss of protein phosphatase 2A regulatory subunit PPP2R5A is associated with increased incidence of stress-induced proarrhythmia. Front Cardiovasc Med 2024; 11:1419597. [PMID: 38863902 PMCID: PMC11165201 DOI: 10.3389/fcvm.2024.1419597] [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: 04/18/2024] [Accepted: 05/16/2024] [Indexed: 06/13/2024] Open
Abstract
Background Protein phosphatase 2A (PP2A) is a serine/threonine-selective holoenzyme that controls Ca2+ homeostasis and contractility of the heart via dephosphorylation of regulatory proteins. In some genetically modified mouse models with increased arrhythmogenicity, a reduced expression of the regulatory subunit B56α of PP2A was found as a concomitant effect. Whether there is a general correlation between the abundance of B56α and the promotion of cardiac arrhythmogenesis remains unclear. Methods The aim of this study was therefore to investigate the role of PP2A-B56α in the propensity for arrhythmic activity in the heart. The experimental analysis of this question has been addressed by using a mouse model with deletion of the PP2A-B56α gene, PPP2R5A (KO), in comparison to wild-type animals (WT). Evidence for arrhythmogenicity was investigated in whole animal, isolated heart and cardiomyocytes by ECG, recording of monophasic action potential (MAP) induced by programmed electrical stimulation (PES), measurement of Ca2+ transients under increased pacing frequencies and determination of total K+ channel currents (I K). Results ECG measurements showed a prolongation of QT time in KO vs. WT. KO mice exhibited a higher rate of premature ventricular contractions in the ECG. MAP measurements in Langendorff-perfused KO hearts showed increased episodes of ventricular tachyarrhythmia induced by PES. However, the KO hearts showed values for MAP duration that were similar to those in WT hearts. In contrast, KO showed more myocardial cells with spontaneous arrhythmogenic Ca2+ transient events compared to WT. The whole-cell patch-clamp technique applied to ventricular cardiomyocytes revealed comparable peak potassium channel current densities between KO and WT. Conclusion These findings support the assumption that a decrease or even the loss of PP2A-B56α leads to an increased propensity of triggered arrhythmias. This could be based on the increased spontaneous Ca2+ tansients observed.
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Affiliation(s)
- Florentina Pluteanu
- Department of Anatomy, Animal Physiology and Biophysics, University of Bucharest, Bucharest, Romania
| | - Dennis Glaser
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Fabian Massing
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Universität Münster, Münster, Germany
| | - Jan S. Schulte
- 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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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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Asghari P, Scriven DR, Shahrasebi S, Valdivia HH, Alsina KM, Valdivia CR, Navarro-Garcia JA, Wehrens XH, Moore ED. Phosphorylation of RyR2 simultaneously expands the dyad and rearranges the tetramers. J Gen Physiol 2024; 156:e202213108. [PMID: 38385988 PMCID: PMC10883851 DOI: 10.1085/jgp.202213108] [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: 01/28/2022] [Revised: 01/23/2023] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
We have previously demonstrated that type II ryanodine receptors (RyR2) tetramers can be rapidly rearranged in response to a phosphorylation cocktail. The cocktail modified downstream targets indiscriminately, making it impossible to determine whether phosphorylation of RyR2 was an essential element of the response. Here, we used the β-agonist isoproterenol and mice homozygous for one of the following clinically relevant mutations: S2030A, S2808A, S2814A, or S2814D. We measured the length of the dyad using transmission electron microscopy (TEM) and directly visualized RyR2 distribution using dual-tilt electron tomography. We found that the S2814D mutation, by itself, significantly expanded the dyad and reorganized the tetramers, suggesting a direct link between the phosphorylation state of the tetramer and its microarchitecture. S2808A and S2814A mutant mice, as well as wild types, had significant expansions of their dyads in response to isoproterenol, while S2030A mutants did not. In agreement with functional data from these mutants, S2030 and S2808 were necessary for a complete β-adrenergic response, unlike S2814 mutants. Additionally, all mutants had unique effects on the organization of their tetramer arrays. Lastly, the correlation of structural with functional changes suggests that tetramer-tetramer contacts play an important functional role. We thus conclude that both the size of the dyad and the arrangement of the tetramers are linked to the state of the channel tetramer and can be dynamically altered by a β-adrenergic receptor agonist.
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Affiliation(s)
- Parisa Asghari
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - David R.L. Scriven
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Saba Shahrasebi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Hector H. Valdivia
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | - Carmen R. Valdivia
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - J. Alberto Navarro-Garcia
- Department of Integrative Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Xander H.T. Wehrens
- Department of Integrative Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Edwin D.W. Moore
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
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5
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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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Sharma B, Koren DT, Ghosh S. Nitric oxide modulates NMDA receptor through a negative feedback mechanism and regulates the dynamical behavior of neuronal postsynaptic components. Biophys Chem 2023; 303:107114. [PMID: 37832215 DOI: 10.1016/j.bpc.2023.107114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/22/2023] [Accepted: 09/24/2023] [Indexed: 10/15/2023]
Abstract
Nitric oxide (NO) is known to be an important regulator of neurological processes in the central nervous system which acts directly on the presynaptic neuron and enhances the release of neurotransmitters like glutamate into the synaptic cleft. Calcium influx activates a cascade of biochemical reactions to influence the production of nitric oxide in the postsynaptic neuron. This has been modeled in the present work as a system of ordinary differential equations, to explore the dynamics of the interacting components and predict the dynamical behavior of the postsynaptic neuron. It has been hypothesized that nitric oxide modulates the NMDA receptor via a feedback mechanism and regulates the dynamic behavior of postsynaptic components. Results obtained by numerical analyses indicate that the biochemical system is stimulus-dependent and shows oscillations of calcium and other components within a limited range of concentration. Some of the parameters such as stimulus strength, extracellular calcium concentration, and rate of nitric oxide feedback are crucial for the dynamics of the components in the postsynaptic neuron.
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Affiliation(s)
- Bhanu Sharma
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India
| | | | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India.
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7
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Barber KR, Vizcarra VS, Zilch A, Majuta L, Diezel CC, Culver OP, Hughes BW, Taniguchi M, Streicher JM, Vanderah TW, Riegel AC. The Role of Ryanodine Receptor 2 in Drug-Associated Learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560743. [PMID: 37873212 PMCID: PMC10592901 DOI: 10.1101/2023.10.03.560743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Type-2 ryanodine receptor (RyR2) ion channels facilitate the release of Ca 2+ from stores and serve an important function in neuroplasticity. The role for RyR2 in hippocampal-dependent learning and memory is well established and chronic hyperphosphorylation of RyR2 (RyR2P) is associated with pathological calcium leakage and cognitive disorders, including Alzheimer's disease. By comparison, little is known about the role of RyR2 in the ventral medial prefrontal cortex (vmPFC) circuitry important for working memory, decision making, and reward seeking. Here, we evaluated the basal expression and localization of RyR2 and RyR2P in the vmPFC. Next, we employed an operant model of sucrose, cocaine, or morphine self-administration (SA) followed by a (reward-free) recall test, to reengage vmPFC neurons and reactivate reward-seeking and re-evaluated the expression and localization of RyR2 and RyR2P in vmPFC. Under basal conditions, RyR2 was expressed in pyramidal cells but not regularly detected in PV/SST interneurons. On the contrary, RyR2P was rarely observed in PFC somata and was restricted to a different subcompartment of the same neuron - the apical dendrites of layer-5 pyramidal cells. Chronic SA of drug (cocaine or morphine) and nondrug (sucrose) rewards produced comparable increases in RyR2 protein expression. However, recalling either drug reward impaired the usual localization of RyR2P in dendrites and markedly increased its expression in somata immunoreactive for Fos, a marker of highly activated neurons. These effects could not be explained by chronic stress or drug withdrawal and instead appeared to require a recall experience associated with prior drug SA. In addition to showing the differential distribution of RyR2/RyR2P and affirming the general role of vmPFC in reward learning, this study provides information on the propensity of addictive drugs to redistribute RyR2P ion channels in a neuronal population engaged in drug-seeking. Hence, focusing on the early impact of addictive drugs on RyR2 function may serve as a promising approach to finding a treatment for substance use disorders.
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8
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Walweel K, Beard N, van Helden DF, Laver DR. Dantrolene inhibition of ryanodine channels (RyR2) in artificial lipid bilayers depends on FKBP12.6. J Gen Physiol 2023; 155:e202213277. [PMID: 37279522 PMCID: PMC10244881 DOI: 10.1085/jgp.202213277] [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: 10/10/2022] [Revised: 03/18/2023] [Accepted: 05/22/2023] [Indexed: 06/08/2023] Open
Abstract
Dantrolene is a neutral hydantoin that is clinically used as a skeletal muscle relaxant to prevent overactivation of the skeletal muscle calcium release channel (RyR1) in response to volatile anesthetics. Dantrolene has aroused considerable recent interest as a lead compound for stabilizing calcium release due to overactive cardiac calcium release channels (RyR2) in heart failure. Previously, we found that dantrolene produces up to a 45% inhibition RyR2 with an IC50 of 160 nM, and that this inhibition requires the physiological association between RyR2 and CaM. In this study, we tested the hypothesis that dantrolene inhibition of RyR2 in the presence of CaM is modulated by RyR2 phosphorylation at S2808 and S2814. Phosphorylation was altered by incubations with either exogenous phosphatase (PP1) or kinases; PKA to phosphorylate S2808 or endogenous CaMKII to phosphorylate S2814. We found that PKA caused selective dissociation of FKBP12.6 from the RyR2 complex and a loss of dantrolene inhibition. Rapamycin-induced FKBP12.6 dissociation from RyR2 also resulted in the loss of dantrolene inhibition. Subsequent incubations of RyR2 with exogenous FKBP12.6 reinstated dantrolene inhibition. These findings indicate that the inhibitory action of dantrolene on RyR2 depends on RyR2 association with FKBP12.6 in addition to CaM as previously found.
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Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Nicole Beard
- Faculty of Science and Technology, University of Canberra, Bruce, Australia
| | - Dirk F. van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Derek R. Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
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9
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Nikolaienko R, Bovo E, Kahn D, Gracia R, Jamrozik T, Zima AV. Cysteines 1078 and 2991 cross-linking plays a critical role in redox regulation of cardiac ryanodine receptor (RyR). Nat Commun 2023; 14:4498. [PMID: 37495581 PMCID: PMC10372021 DOI: 10.1038/s41467-023-40268-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 07/19/2023] [Indexed: 07/28/2023] Open
Abstract
The most common cardiac pathologies, such as myocardial infarction and heart failure, are associated with oxidative stress. Oxidation of the cardiac ryanodine receptor (RyR2) Ca2+ channel causes spontaneous oscillations of intracellular Ca2+, resulting in contractile dysfunction and arrhythmias. RyR2 oxidation promotes the formation of disulfide bonds between two cysteines on neighboring RyR2 subunits, known as intersubunit cross-linking. However, the large number of cysteines in RyR2 has been a major hurdle in identifying the specific cysteines involved in this pathology-linked post-translational modification of the channel. Through mutagenesis of human RyR2 and in-cell Ca2+ imaging, we identify that only two cysteines (out of 89) in each RyR2 subunit are responsible for half of the channel's functional response to oxidative stress. Our results identify cysteines 1078 and 2991 as a redox-sensitive pair that forms an intersubunit disulfide bond between neighboring RyR2 subunits during oxidative stress, resulting in a pathological "leaky" RyR2 Ca2+ channel.
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Affiliation(s)
- Roman Nikolaienko
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Daniel Kahn
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Ryan Gracia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Thomas Jamrozik
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, 60153, USA.
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10
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Terrar DA. Timing mechanisms to control heart rhythm and initiate arrhythmias: roles for intracellular organelles, signalling pathways and subsarcolemmal Ca 2. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220170. [PMID: 37122228 PMCID: PMC10150226 DOI: 10.1098/rstb.2022.0170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Rhythms of electrical activity in all regions of the heart can be influenced by a variety of intracellular membrane bound organelles. This is true both for normal pacemaker activity and for abnormal rhythms including those caused by early and delayed afterdepolarizations under pathological conditions. The influence of the sarcoplasmic reticulum (SR) on cardiac electrical activity is widely recognized, but other intracellular organelles including lysosomes and mitochondria also contribute. Intracellular organelles can provide a timing mechanism (such as an SR clock driven by cyclic uptake and release of Ca2+, with an important influence of intraluminal Ca2+), and/or can act as a Ca2+ store involved in signalling mechanisms. Ca2+ plays many diverse roles including carrying electric current, driving electrogenic sodium-calcium exchange (NCX) particularly when Ca2+ is extruded across the surface membrane causing depolarization, and activation of enzymes which target organelles and surface membrane proteins. Heart function is also influenced by Ca2+ mobilizing agents (cADP-ribose, nicotinic acid adenine dinucleotide phosphate and inositol trisphosphate) acting on intracellular organelles. Lysosomal Ca2+ release exerts its effects via calcium/calmodulin-dependent protein kinase II to promote SR Ca2+ uptake, and contributes to arrhythmias resulting from excessive beta-adrenoceptor stimulation. A separate arrhythmogenic mechanism involves lysosomes, mitochondria and SR. Interacting intracellular organelles, therefore, have profound effects on heart rhythms and NCX plays a central role. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Derek A Terrar
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
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11
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Jung E, Capel R, Jiang C, Venturi E, Neagu G, Pearcey S, Zhou Y, Zhang Y, Lei M. Cardiac deficiency of P21-activated kinase 1 promotes atrial arrhythmogenesis in mice following adrenergic challenge. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220168. [PMID: 37122217 PMCID: PMC10150202 DOI: 10.1098/rstb.2022.0168] [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: 09/16/2022] [Accepted: 11/24/2022] [Indexed: 05/02/2023] Open
Abstract
P21-activated kinase 1 (Pak1) signalling plays a vital and overall protective role in the heart. However, the phenotypes of Pak1 deficiency in the cardiac atria have not been well explored. In this study, Pak1 cardiac-conditional knock-out (cKO) mice were studied under baseline and adrenergic challenge conditions. Pak1 cKO mice show atrial arrhythmias including atrial fibrillation (AF) in vivo, detected during anaesthetized electrocardiography without evidence of interstitial fibrosis upon Masson's trichrome staining. Optical mapping of left atrial preparations from Pak1 cKO mice revealed a higher incidence of Ca2+ and action potential alternans under isoprenaline challenge and differences in baseline action potential and calcium transient characteristics. Type-2 ryanodine receptor (RyR2) channels from Pak1 cKO hearts had a higher open probability than those from wild-type. Reverse transcription-quantitative polymerase chain reaction and Western blotting indicated that pCamkIIδ and RyR2 are highly phosphorylated at baseline in the atria of Pak1 cKO mice, while the expression of Slc8a2 and Slc8a3 as a Na+-Ca2+ exchanger, controlling the influx of Ca2+ from outside of the cell and efflux of Na+ from the cytoplasm, are augmented. Chromatin immunoprecipitation study showed that pCreb1 interacts with Slc8a2 and Slc8a3. Our study thus demonstrates that deficiency of Pak1 promotes atrial arrhythmogenesis under adrenergic stress, probably through post-translational and transcriptional modifications of key molecules that are critical to Ca2+ homeostasis. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Eunjeong Jung
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Rebecca Capel
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Congshan Jiang
- National Regional Children's Medical Center (Northwest); Key Laboratory of Precision Medicine to Pediatric Diseases of Shaanxi Province; Xi'an Key Laboratory of Children's Health and Diseases, Shaanxi Institute for Pediatric Diseases; Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University. No. 69, Xijuyuan Lane, Xi'an 710003, People's Republic of China
| | - Elisa Venturi
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Georgiana Neagu
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Sarah Pearcey
- Paediatric Intensive Care, Addenbrooke's Hospital, Cambridge CB2 1QY, UK
| | - Yafei Zhou
- National Regional Children's Medical Center (Northwest); Key Laboratory of Precision Medicine to Pediatric Diseases of Shaanxi Province; Xi'an Key Laboratory of Children's Health and Diseases, Shaanxi Institute for Pediatric Diseases; Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University. No. 69, Xijuyuan Lane, Xi'an 710003, People's Republic of China
- Key Laboratory of Medical Electrophysiology of the Ministry of Education, Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, People's Republic of China
| | - Yanmin Zhang
- National Regional Children's Medical Center (Northwest); Key Laboratory of Precision Medicine to Pediatric Diseases of Shaanxi Province; Xi'an Key Laboratory of Children's Health and Diseases, Shaanxi Institute for Pediatric Diseases; Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University. No. 69, Xijuyuan Lane, Xi'an 710003, People's Republic of China
- Institute of Cardiovascular Sciences, Faculty of Medicine and Human Science, University of Manchester, Manchester, M13, 9GB UK
| | - Ming Lei
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
- Key Laboratory of Medical Electrophysiology of the Ministry of Education, Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, People's Republic of China
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12
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Asghari P, Scriven DRL, Shahrasebi S, Valdivia HH, Wehrens XHT, Moore EDW. PHOSPHORYLATION OF RyR2 SIMULTANEOUSLY EXPANDS THE DYAD AND REARRANGES THE TETRAMERS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541024. [PMID: 37292875 PMCID: PMC10245935 DOI: 10.1101/2023.05.23.541024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have previously demonstrated that type II ryanodine receptors (RyR2) tetramers can be rapidly rearranged in response to a phosphorylation cocktail. The cocktail modified downstream targets indiscriminately making it impossible to determine whether phosphorylation of RyR2 was an essential element of the response. We therefore used the β-agonist isoproterenol and mice with one of the homozygous mutations, S2030A +/+ , S2808A +/+ , S2814A +/+ , or S2814D +/+ , to address this question and to elucidate the role of these clinically relevant mutations. We measured the length of the dyad using transmission electron microscopy (TEM) and directly visualized RyR2 distribution using dual-tilt electron tomography. We found that: 1) The S2814D mutation, by itself, significantly expanded the dyad and reorganized the tetramers suggesting a direct link between the phosphorylation state of the tetramer and the microarchitecture. 2) All of the wild-type, as well as the S2808A and S2814A mice, had significant expansions of their dyads in response to ISO, while S2030A did not. 3) In agreement with functional data from the same mutants, S2030 and S2808 were necessary for a complete β-adrenergic response, whereas S2814 was not. 4) All the mutated residues had unique effects on the organization of their tetramer arrays. 5) The correlation of structure with function suggests that tetramer-tetramer contacts play an important functional role. We conclude that both the size of the dyad and the arrangement of the tetramers are linked to the state of the channel tetramer and can be dynamically altered by a β-adrenergic receptor agonist. Summary Analysis of RyR2 mutants suggests a direct link between the phosphorylation state of the channel tetramer and the microarchitecture of the dyad. All phosphorylation site mutations produced significant and unique effects on the structure of the dyad and its response to isoproterenol.
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13
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Reyes Gaido OE, Nkashama LJ, Schole KL, Wang Q, Umapathi P, Mesubi OO, Konstantinidis K, Luczak ED, Anderson ME. CaMKII as a Therapeutic Target in Cardiovascular Disease. Annu Rev Pharmacol Toxicol 2023; 63:249-272. [PMID: 35973713 PMCID: PMC11019858 DOI: 10.1146/annurev-pharmtox-051421-111814] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CaMKII (the multifunctional Ca2+ and calmodulin-dependent protein kinase II) is a highly validated signal for promoting a variety of common diseases, particularly in the cardiovascular system. Despite substantial amounts of convincing preclinical data, CaMKII inhibitors have yet to emerge in clinical practice. Therapeutic inhibition is challenged by the diversity of CaMKII isoforms and splice variants and by physiological CaMKII activity that contributes to learning and memory. Thus, uncoupling the harmful and beneficial aspects of CaMKII will be paramount to developing effective therapies. In the last decade, several targeting strategies have emerged, including small molecules, peptides, and nucleotides, which hold promise in discriminating pathological from physiological CaMKII activity. Here we review the cellular and molecular biology of CaMKII, discuss its role in physiological and pathological signaling, and consider new findings and approaches for developing CaMKII therapeutics.
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Affiliation(s)
- Oscar E Reyes Gaido
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | | | - Kate L Schole
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Qinchuan Wang
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Priya Umapathi
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Olurotimi O Mesubi
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Klitos Konstantinidis
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Elizabeth D Luczak
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
| | - Mark E Anderson
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;
- Departments of Physiology and Genetic Medicine and Program in Cellular and Molecular Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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14
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Keefe JA, Moore OM, Ho KS, Wehrens XHT. Role of Ca 2+ in healthy and pathologic cardiac function: from normal excitation-contraction coupling to mutations that cause inherited arrhythmia. Arch Toxicol 2023; 97:73-92. [PMID: 36214829 PMCID: PMC10122835 DOI: 10.1007/s00204-022-03385-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/15/2022] [Indexed: 01/19/2023]
Abstract
Calcium (Ca2+) ions are a key second messenger involved in the rhythmic excitation and contraction of cardiomyocytes throughout the heart. Proper function of Ca2+-handling proteins is required for healthy cardiac function, whereas disruption in any of these can cause cardiac arrhythmias. This comprehensive review provides a broad overview of the roles of Ca2+-handling proteins and their regulators in healthy cardiac function and the mechanisms by which mutations in these proteins contribute to inherited arrhythmias. Major Ca2+ channels and Ca2+-sensitive regulatory proteins involved in cardiac excitation-contraction coupling are discussed, with special emphasis on the function of the RyR2 macromolecular complex. Inherited arrhythmia disorders including catecholaminergic polymorphic ventricular tachycardia, long QT syndrome, Brugada syndrome, short QT syndrome, and arrhythmogenic right-ventricular cardiomyopathy are discussed with particular emphasis on subtypes caused by mutations in Ca2+-handling proteins.
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Affiliation(s)
- Joshua A Keefe
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Oliver M Moore
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kevin S Ho
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA.,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX, 77030, USA. .,Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Center for Space Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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15
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Calmodulin variant E140G associated with long QT syndrome impairs CaMKIIδ autophosphorylation and L-type calcium channel inactivation. J Biol Chem 2023; 299:102777. [PMID: 36496072 PMCID: PMC9830374 DOI: 10.1016/j.jbc.2022.102777] [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: 07/28/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Long QT syndrome (LQTS) is a human inherited heart condition that can cause life-threatening arrhythmia including sudden cardiac death. Mutations in the ubiquitous Ca2+-sensing protein calmodulin (CaM) are associated with LQTS, but the molecular mechanism by which these mutations lead to irregular heartbeats is not fully understood. Here, we use a multidisciplinary approach including protein biophysics, structural biology, confocal imaging, and patch-clamp electrophysiology to determine the effect of the disease-associated CaM mutation E140G on CaM structure and function. We present novel data showing that mutant-regulated CaMKIIδ kinase activity is impaired with a significant reduction in enzyme autophosphorylation rate. We report the first high-resolution crystal structure of a LQTS-associated CaM variant in complex with the CaMKIIδ peptide, which shows significant structural differences, compared to the WT complex. Furthermore, we demonstrate that the E140G mutation significantly disrupted Cav1.2 Ca2+/CaM-dependent inactivation, while cardiac ryanodine receptor (RyR2) activity remained unaffected. In addition, we show that the LQTS-associated mutation alters CaM's Ca2+-binding characteristics, secondary structure content, and interaction with key partners involved in excitation-contraction coupling (CaMKIIδ, Cav1.2, RyR2). In conclusion, LQTS-associated CaM mutation E140G severely impacts the structure-function relationship of CaM and its regulation of CaMKIIδ and Cav1.2. This provides a crucial insight into the molecular factors contributing to CaM-mediated arrhythmias with a central role for CaMKIIδ.
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16
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Sakanoue W, Yokoyama T, Hirakawa M, Maesawa S, Sato K, Saino T. 3-Iodothyronamine, a trace amine-associated receptor agonist, regulates intracellular Ca2+ increases via CaMK II through Epac2 in rat cerebral arterioles. Biomed Res 2023; 44:219-232. [PMID: 37779034 DOI: 10.2220/biomedres.44.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Trace amines (TAs) in the nervous system bind to TA-associated receptors (TAARs) and are involved in the regulation of monoaminergic functions. Among TAAR subtypes, TAAR1 has been implicated in the development of neurological disorders, such as schizophrenia. The present study investigated the effects of the TAAR1 agonist, 3-iodothyronamine (T1AM) on cerebral arterioles using fluctuations in the intracellular concentration of Ca2+ ([Ca2+]i) as an index of contractile responses. In cerebral arterioles, most of the TAAR agonists did not increase [Ca2+]i, while only T1AM elevated [Ca2+]i in vascular smooth muscle cells. This increase involved extracellular Ca2+ influx through T-type Ca2+ channels and inositol trisphosphate- and ryanodine-receptor-mediated Ca2+ release from intracellular stores. The inhibition of the cAMP sensor, exchange protein directly activated by cAMP (Epac) 2, and calmodulin kinase (CaMK) II strongly inhibited Ca2+ elevations. The present study revealed that T1AM acted not only on the TAAR1 receptor as previously suggested, but also on other G-protein coupled receptors and/or signal transduction systems to increase intracellular Ca2+ in cerebral arteriole smooth muscle cells. These results suggest that when using T1AM in clinical practice, attention should be paid to the early rise in blood pressure.
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Affiliation(s)
- Wakana Sakanoue
- Division of Dental Anesthesiology, Department of Reconstructive Oral and Maxillofacial Surgery, School of Dentistry, Iwate Medical University, Yahaba, Japan
| | - Takuya Yokoyama
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Masato Hirakawa
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba, Japan
| | - Satsuki Maesawa
- Division of Dental Anesthesiology, Department of Reconstructive Oral and Maxillofacial Surgery, School of Dentistry, Iwate Medical University, Yahaba, Japan
| | - Kenichi Sato
- Division of Dental Anesthesiology, Department of Reconstructive Oral and Maxillofacial Surgery, School of Dentistry, Iwate Medical University, Yahaba, Japan
| | - Tomoyuki Saino
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba, Japan
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17
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Recruitment of Muscle Genes as an Effect of Brown Adipose Tissue Ablation in Cold-Acclimated Brandt's Voles ( Lasiopodomys brandtii). Int J Mol Sci 2022; 24:ijms24010342. [PMID: 36613791 PMCID: PMC9820317 DOI: 10.3390/ijms24010342] [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: 11/10/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Skeletal muscle-based nonshivering thermogenesis (NST) plays an important role in the regulation and maintenance of body temperature in birds and large mammals, which do not contain brown adipose tissue (BAT). However, the relative contribution of muscle-based NST to thermoregulation is not clearly elucidated in wild small mammals, which have evolved an obligate thermogenic organ of BAT. In this study, we investigated whether muscle would become an important site of NST when BAT function is conditionally minimized in Brandt's voles (Lasiopodomys brandtii). We surgically removed interscapular BAT (iBAT, which constitutes 52%~56% of total BAT) and exposed the voles to prolonged cold (4 °C) for 28 days. The iBAT-ablated voles were able to maintain the same levels of NST and body temperature (~37.9 °C) during the entire period of cold acclimation as sham voles. The expression of uncoupling protein 1 (UCP1) and its transcriptional regulators at both protein and mRNA levels in the iBAT of cold-acclimated voles was higher than that in the warm group. However, no difference was observed in the protein or mRNA levels of these thermogenesis-related markers except for PGC-1α in other sites of BAT (including infrascapular region, neck, and axilla) between warm and cold groups either in sham or iBAT-ablated voles. The iBAT-ablated voles showed higher UCP1 expression in white adipose tissue (WAT) than sham voles during cold acclimation. The expression of sarcolipin (SLN) and sarcoplasmic endoplasmic reticulum Ca2+-dependent adenosine triphosphatase (SERCA) in skeletal muscles was higher in cold than in warm, but no alteration in phospholamban (PLB) and phosphorylated-PLB (P-PLB) was observed. Additionally, there was increased in iBAT-ablated voles compared to that in the sham group in cold. Moreover, these iBAT-ablated voles underwent extensive remodeling of mitochondria and genes of key components related with mitochondrial metabolism. These data collectively indicate that recruitment of skeletal muscle-based thermogenesis may compensate for BAT impairment and suggest a functional interaction between the two forms of thermogenic processes of iBAT and skeletal muscle in wild small mammals for coping cold stress.
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18
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Zheng M, Li RG, Song J, Zhao X, Tang L, Erhardt S, Chen W, Nguyen BH, Li X, Li M, Wang J, Evans SM, Christoffels VM, Li N, Wang J. Hippo-Yap Signaling Maintains Sinoatrial Node Homeostasis. Circulation 2022; 146:1694-1711. [PMID: 36317529 PMCID: PMC9897204 DOI: 10.1161/circulationaha.121.058777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 09/20/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND The sinoatrial node (SAN) functions as the pacemaker of the heart, initiating rhythmic heartbeats. Despite its importance, the SAN is one of the most poorly understood cardiac entities because of its small size and complex composition and function. The Hippo signaling pathway is a molecular signaling pathway fundamental to heart development and regeneration. Although abnormalities of the Hippo pathway are associated with cardiac arrhythmias in human patients, the role of this pathway in the SAN is unknown. METHODS We investigated key regulators of the Hippo pathway in SAN pacemaker cells by conditionally inactivating the Hippo signaling kinases Lats1 and Lats2 using the tamoxifen-inducible, cardiac conduction system-specific Cre driver Hcn4CreERT2 with Lats1 and Lats2 conditional knockout alleles. In addition, the Hippo-signaling effectors Yap and Taz were conditionally inactivated in the SAN. To determine the function of Hippo signaling in the SAN and other cardiac conduction system components, we conducted a series of physiological and molecular experiments, including telemetry ECG recording, echocardiography, Masson Trichrome staining, calcium imaging, immunostaining, RNAscope, cleavage under targets and tagmentation sequencing using antibodies against Yap1 or H3K4me3, quantitative real-time polymerase chain reaction, and Western blotting. We also performed comprehensive bioinformatics analyses of various datasets. RESULTS We found that Lats1/2 inactivation caused severe sinus node dysfunction. Compared with the controls, Lats1/2 conditional knockout mutants exhibited dysregulated calcium handling and increased fibrosis in the SAN, indicating that Lats1/2 function through both cell-autonomous and non-cell-autonomous mechanisms. It is notable that the Lats1/2 conditional knockout phenotype was rescued by genetic deletion of Yap and Taz in the cardiac conduction system. These rescued mice had normal sinus rhythm and reduced fibrosis of the SAN, indicating that Lats1/2 function through Yap and Taz. Cleavage Under Targets and Tagmentation sequencing data showed that Yap potentially regulates genes critical for calcium homeostasis such as Ryr2 and genes encoding paracrine factors important in intercellular communication and fibrosis induction such as Tgfb1 and Tgfb3. Consistent with this, Lats1/2 conditional knockout mutants had decreased Ryr2 expression and increased Tgfb1 and Tgfb3 expression compared with control mice. CONCLUSIONS We reveal, for the first time to our knowledge, that the canonical Hippo-Yap pathway plays a pivotal role in maintaining SAN homeostasis.
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Affiliation(s)
- Mingjie Zheng
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston (M.Z., X.Z., S.E., W.C., Jun Wang)
| | - Rich G Li
- Texas Heart Institute, Houston (R.G.L., X.L.)
| | - Jia Song
- Department of Medicine (Section of Cardiovascular Research), Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (J.S., N.L.)
| | - Xiaolei Zhao
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston (M.Z., X.Z., S.E., W.C., Jun Wang)
| | - Li Tang
- Hunan Provincial Key Lab on Bioinformatics, School of Computer Science and Engineering, Central South University, Changsha, Hunan, China (L.T., M.L., Jianxin Wang)
| | - Shannon Erhardt
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston (M.Z., X.Z., S.E., W.C., Jun Wang)
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, The University of Texas, Houston (S.E., Jun Wang)
| | - Wen Chen
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston (M.Z., X.Z., S.E., W.C., Jun Wang)
| | - Bao H Nguyen
- Department of Molecular Physiology and Biophysics (B.H.N.)
| | - Xiao Li
- Texas Heart Institute, Houston (R.G.L., X.L.)
| | - Min Li
- Hunan Provincial Key Lab on Bioinformatics, School of Computer Science and Engineering, Central South University, Changsha, Hunan, China (L.T., M.L., Jianxin Wang)
| | - Jianxin Wang
- Hunan Provincial Key Lab on Bioinformatics, School of Computer Science and Engineering, Central South University, Changsha, Hunan, China (L.T., M.L., Jianxin Wang)
| | - Sylvia M Evans
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Departments of Pharmacology and Medicine, University of California at San Diego, La Jolla (S.M.E.)
| | - Vincent M Christoffels
- Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, The Netherlands (V.M.C.)
| | - Na Li
- Department of Medicine (Section of Cardiovascular Research), Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (J.S., N.L.)
| | - Jun Wang
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston (M.Z., X.Z., S.E., W.C., Jun Wang)
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, The University of Texas, Houston (S.E., Jun Wang)
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19
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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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20
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Chai-Hu-San-Shen Capsule Ameliorates Ventricular Arrhythmia Through Inhibition of the CaMKII/FKBP12.6/RyR2/Ca 2+ Signaling Pathway in Rats with Myocardial Ischemia. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:2670473. [PMID: 36225189 PMCID: PMC9550443 DOI: 10.1155/2022/2670473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022]
Abstract
Ventricular arrhythmia is one of the main causes of sudden cardiac death, especially after myocardial ischemia. Previous studies have shown that Chai-Hu-San-Shen capsule (CHSSC) can reduce the incidence of ventricular arrhythmias following myocardial ischemia, however, the mechanisms of it are unclear. In present study, we explored the mechanism of CHSSC ameliorates ventricular arrhythmia following myocardial ischemia via inhibiting the CaMKII/FKBP12.6/RyR2/Ca2+ signaling pathway. In vivo, a myocardial ischemia rat model was established and treated with CHSSC to evaluate the therapeutic effect of CHSSC. In vitro, we established an ischemia model in H9C2 cells and treated with CHSSC, KN-93, or H-89. Then, intracellular Ca2+ content, the expression of RyR2, and the interaction between FKBP12.6 and RyR2 were detected. The results showed that CHSSC could delay the occurrence of ventricular arrhythmias and shorten the duration of ventricular arrhythmias. After myocardial ischemia, the intracellular Ca2+ content was increased, and CHSSC treatment mitigated this increase, down-regulated the levels of p-CaMKII, CaMKII, p-RyR2, and RyR2, and up-regulated the levels of p-RyR2 (Ser2808) and p-RyR2 (Ser2814). Co-immunoprecipitation showed an interaction between FKBP12.6 and RyR2, and CHSSC up-regulated the content of the FKBP12.6-RyR2 complex in ischemic cells. In conclusion, our study showed that CaMKII activation led to hyperphosphorylation of RyR2 (Ser2814) and RyR2 (Ser2808) during cardiomyocyte ischemia, which resulted in dissociation of the FKBP12.6-RyR2 complex, and increased intracellular Ca2+ content, which may contribute to the development of ventricular arrhythmias. CHSSC may reduce the incidence of ventricular arrhythmias following myocardial ischemia through inhibition of the CaMKII/RyR2/FKBP12.6/Ca2+ signaling pathway.
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21
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Hagiwara H, Watanabe M, Fujioka Y, Kadosaka T, Koizumi T, Koya T, Nakao M, Kamada R, Temma T, Okada K, Moreno JA, Kwon O, Sabe H, Ohba Y, Anzai T. Stimulation of the mitochondrial calcium uniporter mitigates chronic heart failure-associated ventricular arrhythmia in mice. Heart Rhythm 2022; 19:1725-1735. [PMID: 35660475 PMCID: PMC10746330 DOI: 10.1016/j.hrthm.2022.05.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/02/2022] [Accepted: 05/24/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND An aberrant increase in the diastolic calcium concentration ([Ca2+]i) level is a hallmark of heart failure (HF) and the cause of delayed afterdepolarization and ventricular arrhythmia (VA). Although mitochondria play a role in regulating [Ca2+]i, whether they can compensate for the [Ca2+]i abnormality in ventricular myocytes is unknown. OBJECTIVE The purpose of this study was to investigate whether enhanced Ca2+ uptake of mitochondria may compensate for an abnormal increase in the [Ca2+]i of ventricular myocytes in HF to effectively mitigate VA. METHODS We used a HF mouse model in which myocardial infarction was induced by permanent left anterior descending coronary artery ligation. The mitochondrial Ca2+ uniporter was stimulated by kaempferol. Ca2+ dynamics and membrane potential were measured using an epifluorescence microscope, a confocal microscope, and the perforated patch-clamp technique. VA was induced in Langendorff-perfused hearts, and hemodynamic parameters were measured using a microtip transducer catheter. RESULTS Protein expression of the mitochondrial Ca2+ uniporter, as assessed by its subunit expression, did not change between HF and sham mice. Treatment of cardiomyocytes with kaempferol, isolated from HF mice 28 days after coronary ligation, reduced the appearance of aberrant diastolic [Ca2+]i waves and sparks and spontaneous action potentials. Kaempferol effectively reduced VA occurring in Langendorff-perfused hearts. Intravenous administration of kaempferol did not markedly affect left ventricular hemodynamic parameters. CONCLUSION The effects of kaempferol in HF of mice implied that mitochondria may have the potential to compensate for abnormal [Ca2+]i. Mechanisms involved in mitochondrial Ca2+ uptake may provide novel targets for treatment of HF-associated VA.
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Affiliation(s)
- Hikaru Hagiwara
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Masaya Watanabe
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
| | - Yoichiro Fujioka
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takahide Kadosaka
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takuya Koizumi
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Taro Koya
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Motoki Nakao
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Rui Kamada
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Taro Temma
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Kazufumi Okada
- Data Science Center, Promotion Unit, Institute of Health Science Innovation for Medical Care, Hokkaido University Hospital, Sapporo, Japan
| | - Jose Antonio Moreno
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California
| | - Hisakata Sabe
- Department of Molecular Biology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yusuke Ohba
- Department of Cell Physiology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Toshihisa Anzai
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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22
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Bossuyt J, Borst JM, Verberckmoes M, Bailey LRJ, Bers DM, Hegyi B. Protein Kinase D1 Regulates Cardiac Hypertrophy, Potassium Channel Remodeling, and Arrhythmias in Heart Failure. J Am Heart Assoc 2022; 11:e027573. [PMID: 36172952 DOI: 10.1161/jaha.122.027573] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Structural and electrophysiological remodeling characterize heart failure (HF) enhancing arrhythmias. PKD1 (protein kinase D1) is upregulated in HF and mediates pathological hypertrophic signaling, but its role in K+ channel remodeling and arrhythmogenesis in HF is unknown. Methods and Results We performed echocardiography, electrophysiology, and expression analysis in wild-type and PKD1 cardiomyocyte-specific knockout (cKO) mice following transverse aortic constriction (TAC). PKD1-cKO mice exhibited significantly less cardiac hypertrophy post-TAC and were protected from early decline in cardiac contractile function (3 weeks post-TAC) but not the progression to HF at 7 weeks post-TAC. Wild-type mice exhibited ventricular action potential duration prolongation at 8 weeks post-TAC, which was attenuated in PKD1-cKO, consistent with larger K+ currents via the transient outward current, sustained current, inward rectifier K+ current, and rapid delayed rectifier K+ current and increased expression of corresponding K+ channels. Conversely, reduction of slowly inactivating K+ current was independent of PKD1 in HF. Acute PKD inhibition slightly increased transient outward current in TAC and sham wild-type myocytes but did not alter other K+ currents. Sham PKD1-cKO versus wild-type also exhibited larger transient outward current and faster early action potential repolarization. Tachypacing-induced action potential duration alternans in TAC animals was increased and independent of PKD1, but diastolic arrhythmogenic activities were reduced in PKD1-cKO. Conclusions Our data indicate an important role for PKD1 in the HF-related hypertrophic response and K+ channel downregulation. Therefore, PKD1 inhibition may represent a therapeutic strategy to reduce hypertrophy and arrhythmias; however, PKD1 inhibition may not prevent disease progression and reduced contractility in HF.
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Affiliation(s)
- Julie Bossuyt
- Department of Pharmacology University of California Davis CA
| | - Johanna M Borst
- Department of Pharmacology University of California Davis CA
| | | | | | - Donald M Bers
- Department of Pharmacology University of California Davis CA
| | - Bence Hegyi
- Department of Pharmacology University of California Davis CA
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23
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Rupee S, Rupee K, Singh RB, Hanoman C, Ismail AMA, Smail M, Singh J. Diabetes-induced chronic heart failure is due to defects in calcium transporting and regulatory contractile proteins: cellular and molecular evidence. Heart Fail Rev 2022; 28:627-644. [PMID: 36107271 DOI: 10.1007/s10741-022-10271-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Heart failure (HF) is a major deteriorating disease of the myocardium due to weak myocardial muscles. As such, the heart is unable to pump blood efficiently around the body to meet its constant demand. HF is a major global health problem with more than 7 million deaths annually worldwide, with some patients dying suddenly due to sudden cardiac death (SCD). There are several risk factors which are associated with HF and SCD which can negatively affect the heart synergistically. One major risk factor is diabetes mellitus (DM) which can cause an elevation in blood glucose level or hyperglycaemia (HG) which, in turn, has an insulting effect on the myocardium. This review attempted to explain the subcellular, cellular and molecular mechanisms and to a lesser extent, the genetic factors associated with the development of diabetes- induced cardiomyopathy due to the HG which can subsequently lead to chronic heart failure (CHF) and SCD. The study first explained the structure and function of the myocardium and then focussed mainly on the excitation-contraction coupling (ECC) processes highlighting the defects of calcium transporting (SERCA, NCX, RyR and connexin) and contractile regulatory (myosin, actin, titin and troponin) proteins. The study also highlighted new therapies and those under development, as well as preventative strategies to either treat or prevent diabetic cardiomyopathy (DCM). It is postulated that prevention is better than cure.
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24
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Sultan A, Adeghate E, Emerald BS, Qureshi MA, Minhas ST, Howarth FC. Effects of Obesity and Diabesity on Ventricular Muscle Structure and Function in the Zucker Rat. Life (Basel) 2022; 12:1221. [PMID: 36013400 PMCID: PMC9410105 DOI: 10.3390/life12081221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023] Open
Abstract
(1) Background: Cardiovascular complications are a leading cause of morbidity and mortality in diabetic patients. The effects of obesity and diabesity on the function and structure of ventricular myocytes in the Zucker fatty (ZF) rat and the Zucker diabetic fatty (ZDF) rat compared to Zucker lean (ZL) control rats have been investigated. (2) Methods: Shortening and intracellular Ca2+ were simultaneously measured with cell imaging and fluorescence photometry, respectively. Ventricular muscle protein expression and structure were investigated with Western blot and electron microscopy, respectively. (3) Results: The amplitude of shortening was increased in ZF compared to ZL but not compared to ZDF myocytes. Resting Ca2+ was increased in ZDF compared to ZL myocytes. Time to half decay of the Ca2+ transient was prolonged in ZDF compared to ZL and was reduced in ZF compared to ZL myocytes. Changes in expression of proteins associated with cardiac muscle contraction are presented. Structurally, there were reductions in sarcomere length in ZDF and ZF compared to ZL and reductions in mitochondria count in ZF compared to ZDF and ZL myocytes. (4) Conclusions: Alterations in ventricular muscle proteins and structure may partly underlie the defects observed in Ca2+ signaling in ZDF and ZF compared to ZL rat hearts.
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Affiliation(s)
- Ahmed Sultan
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Ernest Adeghate
- Department of Anatomy, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Muhammad A. Qureshi
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Saeed Tariq Minhas
- Department of Anatomy, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates
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25
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Miotto MC, Weninger G, Dridi H, Yuan Q, Liu Y, Wronska A, Melville Z, Sittenfeld L, Reiken S, Marks AR. Structural analyses of human ryanodine receptor type 2 channels reveal the mechanisms for sudden cardiac death and treatment. SCIENCE ADVANCES 2022; 8:eabo1272. [PMID: 35857850 PMCID: PMC9299551 DOI: 10.1126/sciadv.abo1272] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/03/2022] [Indexed: 05/29/2023]
Abstract
Ryanodine receptor type 2 (RyR2) mutations have been linked to an inherited form of exercise-induced sudden cardiac death called catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT results from stress-induced sarcoplasmic reticular Ca2+ leak via the mutant RyR2 channels during diastole. We present atomic models of human wild-type (WT) RyR2 and the CPVT mutant RyR2-R2474S determined by cryo-electron microscopy with overall resolutions in the range of 2.6 to 3.6 Å, and reaching local resolutions of 2.25 Å, unprecedented for RyR2 channels. Under nonactivating conditions, the RyR2-R2474S channel is in a "primed" state between the closed and open states of WT RyR2, rendering it more sensitive to activation that results in stress-induced Ca2+ leak. The Rycal drug ARM210 binds to RyR2-R2474S, reverting the primed state toward the closed state. Together, these studies provide a mechanism for CPVT and for the therapeutic actions of ARM210.
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Affiliation(s)
- Marco C. Miotto
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Gunnar Weninger
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Haikel Dridi
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Qi Yuan
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Yang Liu
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Anetta Wronska
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Zephan Melville
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Leah Sittenfeld
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
| | - Andrew R. Marks
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University, New York, NY, USA
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26
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Scott SS, Greenlee AN, Matzko A, Stein M, Naughton MT, Zaramo TZ, Schwendeman EJ, Mohammad SJ, Diallo M, Revan R, Shimmin G, Tarun S, Ferrall J, Ho TH, Smith SA. Intracellular Signaling Pathways Mediating Tyrosine Kinase Inhibitor Cardiotoxicity. Heart Fail Clin 2022; 18:425-442. [PMID: 35718417 PMCID: PMC10391230 DOI: 10.1016/j.hfc.2022.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Tyrosine kinase inhibitors (TKIs) are used to treat several cancers; however, a myriad of adverse cardiotoxic effects remain a primary concern. Although hypertension (HTN) is the most common adverse effect reported with TKI therapy, incidents of arrhythmias (eg, QT prolongation, atrial fibrillation) and heart failure are also prevalent. These complications warrant further research toward understanding the mechanisms of TKI-induced cardiotoxicity. Recent literature has given some insight into the intracellular signaling pathways that may mediate TKI-induced cardiac dysfunction. In this article, we discuss the cardiotoxic effects of TKIs on cardiomyocyte function, signaling, and possible treatments.
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27
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Lu Y, Ji J, Chu S, Shen F, Yang W, Lei W, Jiang M, Bai G. CaMKII, that binds with ligustilide, as a potential drug target of Suxiao jiuxin pill, a traditional Chinese medicine to dilate thoracic aorta. Clin Transl Med 2022; 12:e907. [PMID: 35678102 PMCID: PMC9178388 DOI: 10.1002/ctm2.907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/11/2022] [Accepted: 05/16/2022] [Indexed: 12/01/2022] Open
Affiliation(s)
- Yujie Lu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Jie Ji
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China.,National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Simeng Chu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Fukui Shen
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Wen Yang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Wei Lei
- Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Min Jiang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Gang Bai
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
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28
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Hadiatullah H, He Z, Yuchi Z. Structural Insight Into Ryanodine Receptor Channelopathies. Front Pharmacol 2022; 13:897494. [PMID: 35677449 PMCID: PMC9168041 DOI: 10.3389/fphar.2022.897494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/09/2022] [Indexed: 11/28/2022] Open
Abstract
The ryanodine receptors (RyRs) are large cation-selective ligand-gated channels that are expressed in the sarcoplasmic reticulum (SR) membrane. They mediate the controlled release of Ca2+ from SR and play an important role in many cellular processes. The mutations in RyRs are associated with several skeletal muscle and cardiac conditions, including malignant hyperthermia (MH), central core disease (CCD), catecholaminergic polymorphic ventricular tachycardia (CPVT), and arrhythmogenic right ventricular dysplasia (ARVD). Recent breakthroughs in structural biology including cryo-electron microscopy (EM) and X-ray crystallography allowed the determination of a number of near-atomic structures of RyRs, including wildtype and mutant structures as well as the structures in complex with different modulating molecules. This allows us to comprehend the physiological gating and regulatory mechanisms of RyRs and the underlying pathological mechanisms of the disease-causing mutations. In this review, based on the insights gained from the available high-resolution structures of RyRs, we address several questions: 1) what are the gating mechanisms of different RyR isoforms; 2) how RyRs are regulated by multiple channel modulators, including ions, small molecules, and regulatory proteins; 3) how do disease-causing mutations affect the structure and function of RyRs; 4) how can these structural information aid in the diagnosis of the related diseases and the development of pharmacological therapies.
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Affiliation(s)
- Hadiatullah Hadiatullah
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Zhao He
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
- *Correspondence: Zhiguang Yuchi,
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29
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Hu Q, Chen H, Shen C, Zhang B, Weng X, Sun X, Liu J, Dong Z, Hu K, Ge J, Sun A. Impact and potential mechanism of effects of chronic moderate alcohol consumption on cardiac function in aldehyde dehydrogenase 2 gene heterozygous mice. Alcohol Clin Exp Res 2022; 46:707-723. [PMID: 35315077 PMCID: PMC9321750 DOI: 10.1111/acer.14811] [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: 10/23/2021] [Revised: 03/12/2022] [Accepted: 03/16/2022] [Indexed: 12/01/2022]
Abstract
Background Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism. The ALDH2*2 mutations are found in approximately 45% of East Asians, with 40% being heterozygous (HE) ALDH2*1/*2 and 5% homozygous (HO) ALDH2*2/*2. Studies have shown that HO mice lack cardioprotective effects induced by moderate alcohol consumption. However, the impact of moderate alcohol consumption on cardiac function in HE mice is unknown. Methods In this study, HO, HE, and wild‐type (WT) mice were subjected to a 6‐week moderate alcohol drinking protocol, following which myocardial tissue and cardiomyocytes of the mice were extracted. Results We found that moderate alcohol exposure did not increase mortality, myocardial fibrosis, apoptosis, or inflammation in HE mice, which differs from the effects observed in HO mice. After exposure to the 6‐week alcohol drinking protocol, there was impaired cardiac function, cardiomyocyte contractility, and intracellular Ca2+ homeostasis and mitochondrial function in both HE and HO mice as compared to WT mice. Moreover, these animals showed overt oxidative stress production and increased levels of the activated forms of calmodulin‐dependent protein kinase II (CaMKII) and ryanodine receptor type 2 (RYR2) phosphorylation protein. Conclusion We found that moderate alcohol exposure impaired cardiac function in HE mice, possibly by increasing reactive oxygen species (ROS)/CaMKII/RYR2‐mediated Ca2+ handling abnormalities. Hence, we advocate that people with ALDH2*1/*2 genotypes rigorously avoid alcohol consumption to prevent potential cardiovascular harm induced by moderate alcohol consumption.
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Affiliation(s)
- Qinfeng Hu
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hang Chen
- Heart Center of Fujian Province, Union Hospital, Fujian Medical University, Fuzhou, China.,Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Cheng Shen
- Department of Cardiology, Affiliated Hospital of Jining Medical University, Jining, China
| | - Beijian Zhang
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xinyu Weng
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xiaolei Sun
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jin Liu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Zhen Dong
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Kai Hu
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Junbo Ge
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Aijun Sun
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China.,Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Viral Heart Diseases, Shanghai, China.,Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China
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30
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Lopez R, Janicek R, Fernandez-Tenorio M, Courtehoux M, Matas L, Gerbaud P, Gomez AM, Egger M, Niggli E. Uptake-leak balance of SR Ca2+ determines arrhythmogenic potential of RyR2R420Q+/− cardiomyocytes. J Mol Cell Cardiol 2022; 170:1-14. [DOI: 10.1016/j.yjmcc.2022.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 04/01/2022] [Accepted: 05/22/2022] [Indexed: 11/25/2022]
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Ziprasidone Induces Rabbit Atrium Arrhythmogenesis via Modification of Oxidative Stress and Sodium/Calcium Homeostasis. Biomedicines 2022; 10:biomedicines10050976. [PMID: 35625713 PMCID: PMC9138982 DOI: 10.3390/biomedicines10050976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/13/2022] [Accepted: 04/21/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Atypical antipsychotics increase the risk of atrial arrhythmias and sudden cardiac death. This study investigated whether ziprasidone, a second-generation antipsychotic, affected intracellular Ca2+ and Na+ regulation and oxidative stress, providing proarrhythmogenic substrates in atriums. Methods: Electromechanical analyses of rabbit atrial tissues were conducted. Intracellular Ca2+ monitoring using Fluo-3, the patch-clamp method for ionic current recordings, and a fluorescence study for the detection of reactive oxygen species and intracellular Na+ levels were conducted in enzymatically dissociated atrial myocytes. Results: Ziprasidone-treated atriums showed sustained triggered activities after rapid pacing, which were inhibited by KN-93 and ranolazine. A reduced peak L-type Ca2+ channel current and enhanced late Na+ current were observed in ziprasidone-treated atrial myocytes, together with an increased cytosolic Na+ level. KN-93 suppressed the enhanced late Na+ current in ziprasidone-treated atrial myocytes. Atrial myocytes treated with ziprasidone showed reduced Ca2+ transient amplitudes and sarcoplasmic reticulum (SR) Ca2+ stores, and increased SR Ca2+ leakage. Cytosolic and mitochondrial reactive oxygen species production was increased in atrial myocytes treated with ziprasidone. TNF-α and NLRP3 were upregulated in ziprasidone-treated myocytes, and the level of phosphorylated calcium/calmodulin-dependent protein kinase II protein was increased. Conclusions: Our results suggest that ziprasidone increases the occurrence of atrial triggered activity and causes intracellular Ca2+ and Na+ dysregulation, which may result from enhanced oxidative stress and activation of the TNF-α/NLRP3 inflammasome pathway in ziprasidone-treated myocytes.
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Therapeutic Approaches of Ryanodine Receptor-Associated Heart Diseases. Int J Mol Sci 2022; 23:ijms23084435. [PMID: 35457253 PMCID: PMC9031589 DOI: 10.3390/ijms23084435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 01/08/2023] Open
Abstract
Cardiac diseases are the leading causes of death, with a growing number of cases worldwide, posing a challenge for both healthcare and research. Therefore, the most relevant aim of cardiac research is to unravel the molecular pathomechanisms and identify new therapeutic targets. Cardiac ryanodine receptor (RyR2), the Ca2+ release channel of the sarcoplasmic reticulum, is believed to be a good therapeutic target in a group of certain heart diseases, collectively called cardiac ryanopathies. Ryanopathies are associated with the impaired function of the RyR, leading to heart diseases such as congestive heart failure (CHF), catecholaminergic polymorphic ventricular tachycardia (CPVT), arrhythmogenic right ventricular dysplasia type 2 (ARVD2), and calcium release deficiency syndrome (CRDS). The aim of the current review is to provide a short insight into the pathological mechanisms of ryanopathies and discuss the pharmacological approaches targeting RyR2.
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Hulsurkar MM, Lahiri SK, Karch J, Wang MC, Wehrens XH. Targeting calcium-mediated inter-organellar crosstalk in cardiac diseases. Expert Opin Ther Targets 2022; 26:303-317. [PMID: 35426759 PMCID: PMC9081256 DOI: 10.1080/14728222.2022.2067479] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Abnormal calcium signaling between organelles such as the sarcoplasmic reticulum (SR), mitochondria and lysosomes is a key feature of heart diseases. Calcium serves as a secondary messenger mediating inter-organellar crosstalk, essential for maintaining the cardiomyocyte function. AREAS COVERED This article examines the available literature related to calcium channels and transporters involved in inter-organellar calcium signaling. The SR calcium-release channels ryanodine receptor type-2 (RyR2) and inositol 1,4,5-trisphosphate receptor (IP3R), and calcium-transporter SR/ER-ATPase 2a (SERCA2a) are illuminated. The roles of mitochondrial voltage-dependent anion channels (VDAC), the mitochondria Ca2+ uniporter complex (MCUC), and the lysosomal H+/Ca2+ exchanger, two pore channels (TPC), and transient receptor potential mucolipin (TRPML) are discussed. Furthermore, recent studies showing calcium-mediated crosstalk between the SR, mitochondria, and lysosomes as well as how this crosstalk is dysregulated in cardiac diseases are placed under the spotlight. EXPERT OPINION Enhanced SR calcium release via RyR2 and reduced SR reuptake via SERCA2a, increased VDAC and MCUC-mediated calcium uptake into mitochondria, and enhanced lysosomal calcium-release via lysosomal TPC and TRPML may all contribute to aberrant calcium homeostasis causing heart disease. While mechanisms of this crosstalk need to be studied further, interventions targeting these calcium channels or combinations thereof might represent a promising therapeutic strategy.
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Affiliation(s)
- Mohit M. Hulsurkar
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Satadru K. Lahiri
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Jason Karch
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Meng C. Wang
- Cardiovascular Research Institute
- Huffington Center on Aging
- Department of Molecular and Human Genetics
- Howard Hughes Medical Institute
| | - Xander H.T. Wehrens
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
- Dept. of Medicine (Cardiology)
- Dept. of Neuroscience
- Dept. of Pediatrics (Cardiology)
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Regulation of cardiac ryanodine receptor function by the cyclic-GMP dependent protein kinase G. Curr Res Physiol 2022; 5:171-178. [PMID: 35356048 PMCID: PMC8958330 DOI: 10.1016/j.crphys.2022.03.004] [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: 11/08/2021] [Revised: 02/20/2022] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Background The cGMP-dependent protein kinase G (PKG) phosphorylates the cardiac ryanodine receptor (RyR2) in vitro. We aimed to determine whether modulation of endogenous PKG alters RyR2-mediated spontaneous Ca2+ release and whether this effect is linked to a change in RyR2 phosphorylation. Methods & Results: Human embryonic kidney (HEK293) cells with inducible RyR2 expression were treated with the cGMP analogue 8-Br-cGMP (100 μM) to activate endogenous PKG. In cells transfected with luminal Ca2+ sensor, D1ER, PKG activation significantly reduced the threshold for RyR2-mediated spontaneous Ca2+ release (93.9 ± 0.4% of store size with vehicle vs. 91.7 ± 0.8% with 8-Br-cGMP, P = 0.04). Mutation of the proposed PKG phosphorylation sites, S2808 and S2030, either individually or as a combination, prevented the decrease in Ca2+ release threshold induced by endogenous PKG activation. Interestingly, despite a functional dependence on expression of RyR2 phosphorylation sites, 8-Br-cGMP activation of PKG did not promote a detectable change in S2808 phosphorylation (P = 0.9). Paradoxically, pharmacological inhibition of PKG with KT 5823 (1 μM) also reduced the threshold for spontaneous Ca2+ release through RyR2 without affecting S2808 phosphorylation. Silencing RNA knockdown of endogenous PKG expression also had no quantifiable effect on RyR2 S2808 phosphorylation (P = 0.9). However, unlike PKG inhibition with KT 5823, PKG knockdown did not alter spontaneous Ca2+ release propensity or luminal Ca2+ handling. Conclusion In an intact cell model, activation of endogenous PKG reduces the threshold for RyR2-mediated spontaneous Ca2+ release in a manner dependent on the RyR2 phosphorylation sites S2808 and S2030. This study clarifies the regulation of RyR2 Ca2+ release by endogenous PKG and functionally implicates the role of RyR2 phosphorylation. PKG regulation of RyR2 has been under-researched relative to other kinases. Endogenous PKG activation reduced the threshold for spontaneous RyR2 Ca2+ release. Regulation of RyR2 by PKG required expression of serine residues 2808 and 2030. Knockdown of PKG found minimal basal regulation of RyR2 by PKG.
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Pabel S, Knierim M, Stehle T, Alebrand F, Paulus M, Sieme M, Herwig M, Barsch F, Körtl T, Pöppl A, Wenner B, Ljubojevic-Holzer S, Molina CE, Dybkova N, Camboni D, Fischer TH, Sedej S, Scherr D, Schmid C, Brochhausen C, Hasenfuß G, Maier LS, Hamdani N, Streckfuss-Bömeke K, Sossalla S. Effects of Atrial Fibrillation on the Human Ventricle. Circ Res 2022; 130:994-1010. [PMID: 35193397 PMCID: PMC8963444 DOI: 10.1161/circresaha.121.319718] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 11/16/2022]
Abstract
RATIONALE Atrial fibrillation (AF) and heart failure often coexist, but their interaction is poorly understood. Clinical data indicate that the arrhythmic component of AF may contribute to left ventricular (LV) dysfunction. OBJECTIVE This study investigates the effects and molecular mechanisms of AF on the human LV. METHODS AND RESULTS Ventricular myocardium from patients with aortic stenosis and preserved LV function with sinus rhythm or rate-controlled AF was studied. LV myocardium from patients with sinus rhythm and patients with AF showed no differences in fibrosis. In functional studies, systolic Ca2+ transient amplitude of LV cardiomyocytes was reduced in patients with AF, while diastolic Ca2+ levels and Ca2+ transient kinetics were not statistically different. These results were confirmed in LV cardiomyocytes from nonfailing donors with sinus rhythm or AF. Moreover, normofrequent AF was simulated in vitro using arrhythmic or rhythmic pacing (both at 60 bpm). After 24 hours of AF-simulation, human LV cardiomyocytes from nonfailing donors showed an impaired Ca2+ transient amplitude. For a standardized investigation of AF-simulation, human iPSC-cardiomyocytes were tested. Seven days of AF-simulation caused reduced systolic Ca2+ transient amplitude and sarcoplasmic reticulum Ca2+ load likely because of an increased diastolic sarcoplasmic reticulum Ca2+ leak. Moreover, cytosolic Na+ concentration was elevated and action potential duration was prolonged after AF-simulation. We detected an increased late Na+ current as a potential trigger for the detrimentally altered Ca2+/Na+-interplay. Mechanistically, reactive oxygen species were higher in the LV of patients with AF. CaMKII (Ca2+/calmodulin-dependent protein kinase IIδc) was found to be more oxidized at Met281/282 in the LV of patients with AF leading to an increased CaMKII activity and consequent increased RyR2 phosphorylation. CaMKII inhibition and ROS scavenging ameliorated impaired systolic Ca2+ handling after AF-simulation. CONCLUSIONS AF causes distinct functional and molecular remodeling of the human LV. This translational study provides the first mechanistic characterization and the potential negative impact of AF in the absence of tachycardia on the human ventricle.
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Affiliation(s)
- Steffen Pabel
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Maria Knierim
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Thea Stehle
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Felix Alebrand
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Michael Paulus
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Marcel Sieme
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Melissa Herwig
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Friedrich Barsch
- Institute of Pathology, University Hospital Regensburg, Germany (F.B., C.B.)
| | - Thomas Körtl
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Arnold Pöppl
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Brisca Wenner
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | | | - Cristina E. Molina
- Institute of Experimental Cardiovascular Research, University Medical Centre Hamburg-Eppendorf, Germany (C.E.M.)
| | - Nataliya Dybkova
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Daniele Camboni
- Department of Cardiothoracic Surgery, University Hospital Regensburg, Germany (D.C., C.S.)
| | - Thomas H. Fischer
- Department of Internal Medicine I, University of Würzburg, Germany (T.H.F.)
| | - Simon Sedej
- Department of Cardiology, Medical University of Graz, Austria (S.L.-H., S. Sedej, D.S.)
- Faculty of Medicine, University of Maribor, Maribor, Slovenia (S. Sedej)
- BioTechMed Graz, Graz, Austria (S. Sedej)
| | - Daniel Scherr
- Department of Cardiology, Medical University of Graz, Austria (S.L.-H., S. Sedej, D.S.)
| | - Christof Schmid
- Department of Cardiothoracic Surgery, University Hospital Regensburg, Germany (D.C., C.S.)
| | | | - Gerd Hasenfuß
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
| | - Lars S. Maier
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Department of Molecular and Experimental Cardiology and Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Germany (M.S., M.H., N.H.)
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany (K.S.-B.)
| | - Samuel Sossalla
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.P., M.K., T.S., M.P., T.K., A.P., L.S.M., S. Sossalla)
- Clinic for Cardiology and Pneumology, Georg-August University Göttingen, and DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany (M.K., F.A., B.W., N.D., G.H., K.S.-B., S. Sossalla)
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Haupt LP, Rebs S, Maurer W, Hübscher D, Tiburcy M, Pabel S, Maus A, Köhne S, Tappu R, Haas J, Li Y, Sasse A, Santos CCX, Dressel R, Wojnowski L, Bunt G, Möbius W, Shah AM, Meder B, Wollnik B, Sossalla S, Hasenfuss G, Streckfuss-Bömeke K. Doxorubicin induces cardiotoxicity in a pluripotent stem cell model of aggressive B cell lymphoma cancer patients. Basic Res Cardiol 2022; 117:13. [PMID: 35260914 PMCID: PMC8904375 DOI: 10.1007/s00395-022-00918-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 01/22/2022] [Accepted: 02/07/2022] [Indexed: 01/31/2023]
Abstract
Cancer therapies with anthracyclines have been shown to induce cardiovascular complications. The aims of this study were to establish an in vitro induced pluripotent stem cell model (iPSC) of anthracycline-induced cardiotoxicity (ACT) from patients with an aggressive form of B-cell lymphoma and to examine whether doxorubicin (DOX)-treated ACT-iPSC cardiomyocytes (CM) can recapitulate the clinical features exhibited by patients, and thus help uncover a DOX-dependent pathomechanism. ACT-iPSC CM generated from individuals with CD20+ B-cell lymphoma who had received high doses of DOX and suffered cardiac dysfunction were studied and compared to control-iPSC CM from cancer survivors without cardiac symptoms. In cellular studies, ACT-iPSC CM were persistently more susceptible to DOX toxicity including augmented disorganized myofilament structure, changed mitochondrial shape, and increased apoptotic events. Consistently, ACT-iPSC CM and cardiac fibroblasts isolated from fibrotic human ACT myocardium exhibited higher DOX-dependent reactive oxygen species. In functional studies, Ca2+ transient amplitude of ACT-iPSC CM was reduced compared to control cells, and diastolic sarcoplasmic reticulum Ca2+ leak was DOX-dependently increased. This could be explained by overactive CaMKIIδ in ACT CM. Together with DOX-dependent augmented proarrhythmic cellular triggers and prolonged action potentials in ACT CM, this suggests a cellular link to arrhythmogenic events and contractile dysfunction especially found in ACT engineered human myocardium. CamKIIδ inhibition prevented proarrhythmic triggers in ACT. In contrast, control CM upregulated SERCA2a expression in a DOX-dependent manner, possibly to avoid heart failure conditions. In conclusion, we developed the first human patient-specific stem cell model of DOX-induced cardiac dysfunction from patients with B-cell lymphoma. Our results suggest that DOX-induced stress resulted in arrhythmogenic events associated with contractile dysfunction and finally in heart failure after persistent stress activation in ACT patients.
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Affiliation(s)
- Luis Peter Haupt
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Sabine Rebs
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,Institute of Pharmacology and Toxicology, Würzburg University, Würzburg, Germany
| | - Wiebke Maurer
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Daniela Hübscher
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Malte Tiburcy
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Centre Göttingen, Göttingen, Germany
| | - Steffen Pabel
- Department of Internal Medicine 2, Cardiology, University Medical Centre Regensburg, Regensburg, Germany
| | - Andreas Maus
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,King's College London, British Heart Foundation Centre of Excellence, London, UK
| | - Steffen Köhne
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Rewati Tappu
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centrefor Cardiovascular Research), partner site Heidelberg, Heidelberg, Germany
| | - Jan Haas
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centrefor Cardiovascular Research), partner site Heidelberg, Heidelberg, Germany
| | - Yun Li
- Institute of Human Genetics, University Hospital Centre Göttingen, Göttingen, Germany
| | - Andre Sasse
- Institute of Cellular and Molecular Immunology, University Medical Centre Göttingen, Göttingen, Germany
| | - Celio C X Santos
- King's College London, British Heart Foundation Centre of Excellence, London, UK
| | - Ralf Dressel
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,Institute of Cellular and Molecular Immunology, University Medical Centre Göttingen, Göttingen, Germany
| | - Leszek Wojnowski
- Department of Pharmacology, University Medical Centre Mainz, Mainz, Germany
| | - Gertrude Bunt
- Clinical Optical Microscopy, University Medical Centre Göttingen, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Electron Microscopy Core Unit, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Ajay M Shah
- King's College London, British Heart Foundation Centre of Excellence, London, UK
| | - Benjamin Meder
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centrefor Cardiovascular Research), partner site Heidelberg, Heidelberg, Germany
| | - Bernd Wollnik
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,Institute of Human Genetics, University Hospital Centre Göttingen, Göttingen, Germany
| | - Samuel Sossalla
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.,Department of Internal Medicine 2, Cardiology, University Medical Centre Regensburg, Regensburg, Germany
| | - Gerd Hasenfuss
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, University Medical Centre Göttingen, Göttingen, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Göttingen, Germany. .,Institute of Pharmacology and Toxicology, Würzburg University, Würzburg, Germany.
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Enhanced Cardiac CaMKII Oxidation and CaMKII-Dependent SR Ca Leak in Patients with Sleep-Disordered Breathing. Antioxidants (Basel) 2022; 11:antiox11020331. [PMID: 35204213 PMCID: PMC8868143 DOI: 10.3390/antiox11020331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/26/2022] [Accepted: 02/07/2022] [Indexed: 02/04/2023] Open
Abstract
Background: Sleep-disordered breathing (SDB) is associated with increased oxidant generation. Oxidized Ca/calmodulin kinase II (CaMKII) can contribute to atrial arrhythmias by the stimulation of sarcoplasmic reticulum Ca release events, i.e., Ca sparks. Methods: We prospectively enrolled 39 patients undergoing cardiac surgery to screen for SDB and collected right atrial appendage biopsies. Results: SDB was diagnosed in 14 patients (36%). SDB patients had significantly increased levels of oxidized and activated CaMKII (assessed by Western blotting/specific pulldown). Moreover, SDB patients showed a significant increase in Ca spark frequency (CaSpF measured by confocal microscopy) compared with control subjects. CaSpF was 3.58 ± 0.75 (SDB) vs. 2.49 ± 0.84 (no SDB) 1/100 µm−1s−1 (p < 0.05). In linear multivariable regression models, SDB severity was independently associated with increased CaSpF (B [95%CI]: 0.05 [0.03; 0.07], p < 0.001) after adjusting for important comorbidities. Interestingly, 30 min exposure to the CaMKII inhibitor autocamtide-2 related autoinhibitory peptide normalized the increased CaSpF and eliminated the association between SDB and CaSpF (B [95%CI]: 0.01 [−0.1; 0.03], p = 0.387). Conclusions: Patients with SDB have increased CaMKII oxidation/activation and increased CaMKII-dependent CaSpF in the atrial myocardium, independent of major clinical confounders, which may be a novel target for treatment of atrial arrhythmias in SDB.
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Role of ranolazine in heart failure: From cellular to clinic perspective. Eur J Pharmacol 2022; 919:174787. [PMID: 35114190 DOI: 10.1016/j.ejphar.2022.174787] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/25/2021] [Accepted: 01/25/2022] [Indexed: 12/17/2022]
Abstract
Ranolazine was approved by the US Food and Drug Administration as an antianginal drug in 2006, and has been used since in certain groups of patients with stable angina. The therapeutic action of ranolazine was initially attributed to inhibitory effects on fatty acids metabolism. As investigations went on, however, it developed that the main beneficial effects of ranolazine arise from its action on the late sodium current in the heart. Since late sodium currents were discovered to be involved in various heart pathologies such as ischemia, arrhythmias, systolic and diastolic dysfunctions, and all these conditions are associated with heart failure, ranolazine has in some way been tested either directly or indirectly on heart failure in numerous experimental and clinical studies. As the heart continuously remodels following any sort of severe injury, the inhibition by ranolazine of the underlying mechanisms of cardiac remodeling including ion disturbances, oxidative stress, inflammation, apoptosis, fibrosis, metabolic dysregulation, and neurohormonal impairment are discussed, along with unresolved issues. A projection of pathologies targeted by ranolazine from cellular level to clinical is provided in this review.
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Prakash O, Held M, McCormick LF, Gupta N, Lian LY, Antonyuk S, Haynes LP, Thomas NL, Helassa N. CPVT-associated calmodulin variants N53I and A102V dysregulate Ca2+ signalling via different mechanisms. J Cell Sci 2022; 135:274029. [PMID: 34888671 PMCID: PMC8917356 DOI: 10.1242/jcs.258796] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 11/29/2021] [Indexed: 12/26/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited condition that can cause fatal cardiac arrhythmia. Human mutations in the Ca2+ sensor calmodulin (CaM) have been associated with CPVT susceptibility, suggesting that CaM dysfunction is a key driver of the disease. However, the detailed molecular mechanism remains unclear. Focusing on the interaction with the cardiac ryanodine receptor (RyR2), we determined the effect of CPVT-associated variants N53I and A102V on the structural characteristics of CaM and on Ca2+ fluxes in live cells. We provide novel data showing that interaction of both Ca2+/CaM-N53I and Ca2+/CaM-A102V with the RyR2 binding domain is decreased. Ca2+/CaM-RyR23583-3603 high-resolution crystal structures highlight subtle conformational changes for the N53I variant, with A102V being similar to wild type (WT). We show that co-expression of CaM-N53I or CaM-A102V with RyR2 in HEK293 cells significantly increased the duration of Ca2+ events; CaM-A102V exhibited a lower frequency of Ca2+ oscillations. In addition, we show that CaMKIIδ (also known as CAMK2D) phosphorylation activity is increased for A102V, compared to CaM-WT. This paper provides novel insight into the molecular mechanisms of CPVT-associated CaM variants and will facilitate the development of strategies for future therapies.
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Affiliation(s)
- Ohm Prakash
- Liverpool Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Marie Held
- Liverpool Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Liam F. McCormick
- Liverpool Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Nitika Gupta
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Lu-Yun Lian
- Nuclear Magnetic Resonance Centre for Structural Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, UK
| | - Svetlana Antonyuk
- Molecular Biophysics Group, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, UK
| | - Lee P. Haynes
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - N. Lowri Thomas
- School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff, Redwood Building, CF10 3NB, UK
| | - Nordine Helassa
- Liverpool Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK,Author for correspondence ()
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The function and regulation of calsequestrin-2: implications in calcium-mediated arrhythmias. Biophys Rev 2022; 14:329-352. [PMID: 35340602 PMCID: PMC8921388 DOI: 10.1007/s12551-021-00914-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/14/2021] [Indexed: 01/09/2023] Open
Abstract
Cardiac arrhythmias are life-threatening events in which the heart develops an irregular rhythm. Mishandling of Ca2+ within the myocytes of the heart has been widely demonstrated to be an underlying mechanism of arrhythmogenesis. This includes altered function of the ryanodine receptor (RyR2)-the primary Ca2+ release channel located to the sarcoplasmic reticulum (SR). The spontaneous leak of SR Ca2+ via RyR2 is a well-established contributor in the development of arrhythmic contractions. This leak is associated with increased channel activity in response to changes in SR Ca2+ load. RyR2 activity can be regulated through several avenues, including interactions with numerous accessory proteins. One such protein is calsequestrin-2 (CSQ2), which is the primary Ca2+-buffering protein within the SR. The capacity of CSQ2 to buffer Ca2+ is tightly associated with the ability of the protein to polymerise in response to changing Ca2+ levels. CSQ2 can itself be regulated through phosphorylation and glycosylation modifications, which impact protein polymerisation and trafficking. Changes in CSQ2 modifications are implicated in cardiac pathologies, while mutations in CSQ2 have been identified in arrhythmic patients. Here, we review the role of CSQ2 in arrhythmogenesis including evidence for the indirect and direct regulation of RyR2 by CSQ2, and the consequences of a loss of functional CSQ2 in Ca2+ homeostasis and Ca2+-mediated arrhythmias. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-021-00914-6.
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Carlson CR, Aronsen JM, Bergan-Dahl A, Moutty MC, Lunde M, Lunde PK, Jarstadmarken H, Wanichawan P, Pereira L, Kolstad TRS, Dalhus B, Subramanian H, Hille S, Christensen G, Müller OJ, Nikolaev V, Bers DM, Sjaastad I, Shen X, Louch WE, Klussmann E, Sejersted OM. AKAP18δ Anchors and Regulates CaMKII Activity at Phospholamban-SERCA2 and RYR. Circ Res 2022; 130:27-44. [PMID: 34814703 PMCID: PMC9500498 DOI: 10.1161/circresaha.120.317976] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The sarcoplasmic reticulum (SR) Ca2+-ATPase 2 (SERCA2) mediates Ca2+ reuptake into SR and thereby promotes cardiomyocyte relaxation, whereas the ryanodine receptor (RYR) mediates Ca2+ release from SR and triggers contraction. Ca2+/CaMKII (CaM [calmodulin]-dependent protein kinase II) regulates activities of SERCA2 through phosphorylation of PLN (phospholamban) and RYR through direct phosphorylation. However, the mechanisms for CaMKIIδ anchoring to SERCA2-PLN and RYR and its regulation by local Ca2+ signals remain elusive. The objective of this study was to investigate CaMKIIδ anchoring and regulation at SERCA2-PLN and RYR. METHODS A role for AKAP18δ (A-kinase anchoring protein 18δ) in CaMKIIδ anchoring and regulation was analyzed by bioinformatics, peptide arrays, cell-permeant peptide technology, immunoprecipitations, pull downs, transfections, immunoblotting, proximity ligation, FRET-based CaMKII activity and ELISA-based assays, whole cell and SR vesicle fluorescence imaging, high-resolution microscopy, adenovirus transduction, adenoassociated virus injection, structural modeling, surface plasmon resonance, and alpha screen technology. RESULTS Our results show that AKAP18δ anchors and directly regulates CaMKIIδ activity at SERCA2-PLN and RYR, via 2 distinct AKAP18δ regions. An N-terminal region (AKAP18δ-N) inhibited CaMKIIδ through binding of a region homologous to the natural CaMKII inhibitor peptide and the Thr17-PLN region. AKAP18δ-N also bound CaM, introducing a second level of control. Conversely, AKAP18δ-C, which shares homology to neuronal CaMKIIα activator peptide (N2B-s), activated CaMKIIδ by lowering the apparent Ca2+ threshold for kinase activation and inducing CaM trapping. While AKAP18δ-C facilitated faster Ca2+ reuptake by SERCA2 and Ca2+ release through RYR, AKAP18δ-N had opposite effects. We propose a model where the 2 unique AKAP18δ regions fine-tune Ca2+-frequency-dependent activation of CaMKIIδ at SERCA2-PLN and RYR. CONCLUSIONS AKAP18δ anchors and functionally regulates CaMKII activity at PLN-SERCA2 and RYR, indicating a crucial role of AKAP18δ in regulation of the heartbeat. To our knowledge, this is the first protein shown to enhance CaMKII activity in heart and also the first AKAP (A-kinase anchoring protein) reported to anchor a CaMKII isoform, defining AKAP18δ also as a CaM-KAP.
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Affiliation(s)
- Cathrine R. Carlson
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo Norway,Department of Pharmacology, Oslo University Hospital, Norway
| | - Anna Bergan-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Marie Christine Moutty
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Marianne Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Per Kristian Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Hilde Jarstadmarken
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Pimthanya Wanichawan
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Laetitia Pereira
- Department of Pharmacology, University of California at Davis, Davis, CA, USA
| | - Terje RS Kolstad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Bjørn Dalhus
- Department of Microbiology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway,Department of Medical Biochemistry, Institute for Clinical Medicine, University of Oslo, 0424 Oslo, Norway
| | - Hariharan Subramanian
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Susanne Hille
- German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany,Department of Internal Medicine III, University of Kiel, Kiel, Germany
| | - Geir Christensen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Oliver J. Müller
- German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany,Department of Internal Medicine III, University of Kiel, Kiel, Germany
| | - Viacheslav Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Donald M. Bers
- Department of Pharmacology, University of California at Davis, Davis, CA, USA
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Xin Shen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - William E. Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Enno Klussmann
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany,German Centre for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Ole M. Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway,The KG Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
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Ca 2+ mishandling and mitochondrial dysfunction: a converging road to prediabetic and diabetic cardiomyopathy. Pflugers Arch 2022; 474:33-61. [PMID: 34978597 PMCID: PMC8721633 DOI: 10.1007/s00424-021-02650-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/17/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022]
Abstract
Diabetic cardiomyopathy is defined as the myocardial dysfunction that suffers patients with diabetes mellitus (DM) in the absence of hypertension and structural heart diseases such as valvular or coronary artery dysfunctions. Since the impact of DM on cardiac function is rather silent and slow, early stages of diabetic cardiomyopathy, known as prediabetes, are poorly recognized, and, on many occasions, cardiac illness is diagnosed only after a severe degree of dysfunction was reached. Therefore, exploration and recognition of the initial pathophysiological mechanisms that lead to cardiac dysfunction in diabetic cardiomyopathy are of vital importance for an on-time diagnosis and treatment of the malady. Among the complex and intricate mechanisms involved in diabetic cardiomyopathy, Ca2+ mishandling and mitochondrial dysfunction have been described as pivotal early processes. In the present review, we will focus on these two processes and the molecular pathway that relates these two alterations to the earlier stages and the development of diabetic cardiomyopathy.
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43
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Bremner SB, Mandrycky CJ, Leonard A, Padgett RM, Levinson AR, Rehn ES, Pioner JM, Sniadecki NJ, Mack DL. Full-length dystrophin deficiency leads to contractile and calcium transient defects in human engineered heart tissues. J Tissue Eng 2022; 13:20417314221119628. [PMID: 36003954 PMCID: PMC9393922 DOI: 10.1177/20417314221119628] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/28/2022] [Indexed: 12/13/2022] Open
Abstract
Cardiomyopathy is currently the leading cause of death for patients with Duchenne muscular dystrophy (DMD), a severe neuromuscular disorder affecting young boys. Animal models have provided insight into the mechanisms by which dystrophin protein deficiency causes cardiomyopathy, but there remains a need to develop human models of DMD to validate pathogenic mechanisms and identify therapeutic targets. Here, we have developed human engineered heart tissues (EHTs) from CRISPR-edited, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) expressing a truncated dystrophin protein lacking part of the actin-binding domain. The 3D EHT platform enables direct measurement of contractile force, simultaneous monitoring of Ca2+ transients, and assessment of myofibril structure. Dystrophin-mutant EHTs produced less contractile force as well as delayed kinetics of force generation and relaxation, as compared to isogenic controls. Contractile dysfunction was accompanied by reduced sarcomere length, increased resting cytosolic Ca2+ levels, delayed Ca2+ release and reuptake, and increased beat rate irregularity. Transcriptomic analysis revealed clear differences between dystrophin-deficient and control EHTs, including downregulation of genes related to Ca2+ homeostasis and extracellular matrix organization, and upregulation of genes related to regulation of membrane potential, cardiac muscle development, and heart contraction. These findings indicate that the EHT platform provides the cues necessary to expose the clinically-relevant, functional phenotype of force production as well as mechanistic insights into the role of Ca2+ handling and transcriptomic dysregulation in dystrophic cardiac function, ultimately providing a powerful platform for further studies in disease modeling and drug discovery.
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Affiliation(s)
- Samantha B Bremner
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Christian J Mandrycky
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Andrea Leonard
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
| | - Ruby M Padgett
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
| | - Alan R Levinson
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ethan S Rehn
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - J Manuel Pioner
- Department of Biology, University of Florence, Florence, Italy
| | - Nathan J Sniadecki
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
- Center for Cardiovascular Biology, University of Washington, Seattle, WA, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - David L Mack
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
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Hegyi B, Ko CY, Bossuyt J, Bers DM. Two-hit mechanism of cardiac arrhythmias in diabetic hyperglycaemia: reduced repolarization reserve, neurohormonal stimulation, and heart failure exacerbate susceptibility. Cardiovasc Res 2021; 117:2781-2793. [PMID: 33483728 PMCID: PMC8683706 DOI: 10.1093/cvr/cvab006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 01/10/2021] [Indexed: 12/11/2022] Open
Abstract
AIMS Diabetic hyperglycaemia is associated with increased arrhythmia risk. We aimed to investigate whether hyperglycaemia alone can be accountable for arrhythmias or whether it requires the presence of additional pathological factors. METHODS AND RESULTS Action potentials (APs) and arrhythmogenic spontaneous diastolic activities were measured in isolated murine ventricular, rabbit atrial, and ventricular myocytes acutely exposed to high glucose. Acute hyperglycaemia increased the short-term variability (STV) of action potential duration (APD), enhanced delayed afterdepolarizations, and the inducibility of APD alternans during tachypacing in both murine and rabbit atrial and ventricular myocytes. Hyperglycaemia also prolonged APD in mice and rabbit atrial cells but not in rabbit ventricular myocytes. However, rabbit ventricular APD was more strongly depressed by block of late Na+ current (INaL) during hyperglycaemia, consistent with elevated INaL in hyperglycaemia. All the above proarrhythmic glucose effects were Ca2+-dependent and abolished by CaMKII inhibition. Importantly, when the repolarization reserve was reduced by pharmacological inhibition of K+ channels (either Ito, IKr, IKs, or IK1) or hypokalaemia, acute hyperglycaemia further prolonged APD and further increased STV and alternans in rabbit ventricular myocytes. Likewise, when rabbit ventricular myocytes were pretreated with isoproterenol or angiotensin II, hyperglycaemia significantly prolonged APD, increased STV and promoted alternans. Moreover, acute hyperglycaemia markedly prolonged APD and further enhanced STV in failing rabbit ventricular myocytes. CONCLUSION We conclude that even though hyperglycaemia alone can enhance cellular proarrhythmic mechanisms, a second hit which reduces the repolarization reserve or stimulates G protein-coupled receptor signalling greatly exacerbates cardiac arrhythmogenesis in diabetic hyperglycaemia.
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Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Christopher Y Ko
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
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45
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Yuan Q, Dridi H, Clarke OB, Reiken S, Melville Z, Wronska A, Kushnir A, Zalk R, Sittenfeld L, Marks AR. RyR1-related myopathy mutations in ATP and calcium binding sites impair channel regulation. Acta Neuropathol Commun 2021; 9:186. [PMID: 34809703 PMCID: PMC8609856 DOI: 10.1186/s40478-021-01287-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 10/31/2021] [Indexed: 11/10/2022] Open
Abstract
The type 1 ryanodine receptor (RyR1) is an intracellular calcium (Ca2+) release channel on the sarcoplasmic/endoplasmic reticulum that is required for skeletal muscle contraction. RyR1 channel activity is modulated by ligands, including the activators Ca2+ and ATP. Patients with inherited mutations in RyR1 may exhibit muscle weakness as part of a heterogeneous, complex disorder known as RYR1-related myopathy (RYR1-RM) or more recently termed RYR1-related disorders (RYR1-RD). Guided by high-resolution structures of skeletal muscle RyR1, obtained using cryogenic electron microscopy, we introduced mutations into putative Ca2+ and ATP binding sites and studied the function of the resulting mutant channels. These mutations confirmed the functional significance of the Ca2+ and ATP binding sites identified by structural studies based on the effects on channel regulation. Under normal conditions, Ca2+ activates RyR1 at low concentrations (µM) and inhibits it at high concentrations (mM). Mutations in the Ca2+-binding site impaired both activating and inhibitory regulation of the channel, suggesting a single site for both high and low affinity Ca2+-dependent regulation of RyR1 function. Mutation of residues that interact with the adenine ring of ATP abrogated ATP binding to the channel, whereas mutating residues that interact with the triphosphate tail only affected the degree of activation. In addition, patients with mutations at the Ca2+ or ATP binding sites suffer from muscle weakness, therefore impaired RyR1 channel regulation by either Ca2+ or ATP may contribute to the pathophysiology of RYR1-RM in some patients.
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46
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Husti Z, Varró A, Baczkó I. Arrhythmogenic Remodeling in the Failing Heart. Cells 2021; 10:cells10113203. [PMID: 34831426 PMCID: PMC8623396 DOI: 10.3390/cells10113203] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic heart failure is a clinical syndrome with multiple etiologies, associated with significant morbidity and mortality. Cardiac arrhythmias, including ventricular tachyarrhythmias and atrial fibrillation, are common in heart failure. A number of cardiac diseases including heart failure alter the expression and regulation of ion channels and transporters leading to arrhythmogenic electrical remodeling. Myocardial hypertrophy, fibrosis and scar formation are key elements of arrhythmogenic structural remodeling in heart failure. In this article, the mechanisms responsible for increased arrhythmia susceptibility as well as the underlying changes in ion channel, transporter expression and function as well as alterations in calcium handling in heart failure are discussed. Understanding the mechanisms of arrhythmogenic remodeling is key to improving arrhythmia management and the prevention of sudden cardiac death in patients with heart failure.
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Affiliation(s)
- Zoltán Husti
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6720 Szeged, Hungary
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, University of Szeged, 6720 Szeged, Hungary; (Z.H.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6720 Szeged, Hungary
- Correspondence:
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47
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Detrimental proarrhythmogenic interaction of Ca 2+/calmodulin-dependent protein kinase II and Na V1.8 in heart failure. Nat Commun 2021; 12:6586. [PMID: 34782600 PMCID: PMC8593192 DOI: 10.1038/s41467-021-26690-1] [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: 05/21/2019] [Accepted: 10/14/2021] [Indexed: 12/19/2022] Open
Abstract
An interplay between Ca2+/calmodulin-dependent protein kinase IIδc (CaMKIIδc) and late Na+ current (INaL) is known to induce arrhythmias in the failing heart. Here, we elucidate the role of the sodium channel isoform NaV1.8 for CaMKIIδc-dependent proarrhythmia. In a CRISPR-Cas9-generated human iPSC-cardiomyocyte homozygous knock-out of NaV1.8, we demonstrate that NaV1.8 contributes to INaL formation. In addition, we reveal a direct interaction between NaV1.8 and CaMKIIδc in cardiomyocytes isolated from patients with heart failure (HF). Using specific blockers of NaV1.8 and CaMKIIδc, we show that NaV1.8-driven INaL is CaMKIIδc-dependent and that NaV1.8-inhibtion reduces diastolic SR-Ca2+ leak in human failing cardiomyocytes. Moreover, increased mortality of CaMKIIδc-overexpressing HF mice is reduced when a NaV1.8 knock-out is introduced. Cellular and in vivo experiments reveal reduced ventricular arrhythmias without changes in HF progression. Our work therefore identifies a proarrhythmic CaMKIIδc downstream target which may constitute a prognostic and antiarrhythmic strategy.
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48
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Lin DJ, Lee WS, Chien YC, Chen TY, Yang KT. The link between abnormalities of calcium handling proteins and catecholaminergic polymorphic ventricular tachycardia. Tzu Chi Med J 2021; 33:323-331. [PMID: 34760626 PMCID: PMC8532576 DOI: 10.4103/tcmj.tcmj_288_20] [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: 12/03/2020] [Revised: 02/09/2021] [Accepted: 03/03/2021] [Indexed: 01/18/2023] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare autosomal dominant or recessive disease, usually results in syncope or sudden cardiac death. Most CPVT patients do not show abnormal cardiac structure and electrocardiogram features and symptoms, usually onset during adrenergically mediated physiological conditions. CPVT tends to occur at a younger age and is not easy to be diagnosed and managed. The main cause of CPVT is associated with mishandling Ca2+ in cardiomyocytes. Intracellular Ca2+ is strictly controlled by a protein located in the sarcoplasm reticulum (SR), such as ryanodine receptor, histidine-rich Ca2+-binding protein, triadin, and junctin. Mutation in these proteins results in misfolding or malfunction of these proteins, thereby affecting their Ca2+-binding affinity, and subsequently disturbs Ca2+ homeostasis during excitation–contraction coupling (E-C coupling). Furthermore, transient disturbance of Ca2+ homeostasis increases membrane potential and causes Ca2+ store overload-induced Ca2+ release, which in turn leads to delayed after depolarization and arrhythmia. Previous studies have focused on the interaction between ryanodine receptors and protein kinase or phosphatase in the cytosol. However, recent studies showed the regulation signaling for ryanodine receptor not only from the cytosol but also within the SR. The changing of Ca2+ concentration is critical for protein interaction inside the SR which changes protein conformation to regulate the open probability of ryanodine receptors. Thus, it influences the threshold of Ca2+ released from the SR, making it easier to release Ca2+ during E-C coupling. In this review, we briefly discuss how Ca2+ handling protein variations affect the Ca2+ handling in CPVT.
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Affiliation(s)
- Ding-Jyun Lin
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Wen-Sen Lee
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | | | - Tsung-Yu Chen
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Kun-Ta Yang
- Master Program in Medical Physiology, School of Medicine, Tzu Chi University, Hualien, Taiwan.,Department of Physiology, School of Medicine, Tzu Chi University, Hualien, Taiwan
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Reinhardt F, Beneke K, Pavlidou NG, Conradi L, Reichenspurner H, Hove-Madsen L, Molina CE. Abnormal Calcium Handling in Atrial Fibrillation Is Linked to Changes in Cyclic AMP Dependent Signaling. Cells 2021; 10:cells10113042. [PMID: 34831263 PMCID: PMC8616167 DOI: 10.3390/cells10113042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 01/03/2023] Open
Abstract
Both, the decreased L-type Ca2+ current (ICa,L) density and increased spontaneous Ca2+ release from the sarcoplasmic reticulum (SR), have been associated with atrial fibrillation (AF). In this study, we tested the hypothesis that remodeling of 3′,5′-cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) signaling is linked to these compartment-specific changes (up- or down-regulation) in Ca2+-handling. Perforated patch-clamp experiments were performed in atrial myocytes from 53 patients with AF and 104 patients in sinus rhythm (Ctl). A significantly higher frequency of transient inward currents (ITI) activated by spontaneous Ca2+ release was confirmed in myocytes from AF patients. Next, inhibition of PKA by H-89 promoted a stronger effect on the ITI frequency in these myocytes compared to myocytes from Ctl patients (7.6-fold vs. 2.5-fold reduction), while the β-agonist isoproterenol (ISO) caused a greater increase in Ctl patients (5.5-fold vs. 2.1-fold). ICa,L density was larger in myocytes from Ctl patients at baseline (p < 0.05). However, the effect of ISO on ICa,L density was only slightly stronger in AF than in Ctl myocytes (3.6-fold vs. 2.7-fold). Interestingly, a significant reduction of ICa,L and Ca2+ sparks was observed upon Ca2+/Calmodulin-dependent protein kinase II inhibition by KN-93, but this inhibition had no effect on ITI. Fluorescence resonance energy transfer (FRET) experiments showed that although AF promoted cytosolic desensitization to β-adrenergic stimulation, ISO increased cAMP to similar levels in both groups of patients in the L-type Ca2+ channel and ryanodine receptor compartments. Basal cAMP signaling also showed compartment-specific regulation by phosphodiesterases in atrial myocytes from 44 Ctl and 43 AF patients. Our results suggest that AF is associated with opposite changes in compartmentalized PKA/cAMP-dependent regulation of ICa,L (down-regulation) and ITI (up-regulation).
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Affiliation(s)
- Franziska Reinhardt
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
| | - Kira Beneke
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Nefeli Grammatica Pavlidou
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Lenard Conradi
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona, IIBB-CSIC and IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain;
| | - Cristina E. Molina
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
- Correspondence: ; Tel.: +49-407-4105-7095
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Ferroportin-mediated ferroptosis involved in new-onset atrial fibrillation with LPS-induced endotoxemia. Eur J Pharmacol 2021; 913:174622. [PMID: 34748769 DOI: 10.1016/j.ejphar.2021.174622] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/29/2022]
Abstract
Sepsis is a known risk factor for new-onset atrial fibrillation (AF), and previous studies have demonstrated that ferroptosis participates in sepsis-induced organ injury development. Nevertheless, the role of ferroptosis in new-onset AF with sepsis remains largely unknown. This study aims to investigate the underlying mechanisms linking ferroptosis and AF caused by sepsis. LPS-induced endotoxemia is often used to model the acute inflammatory response associated with sepsis. Herein, we reported that ferroptosis was significantly activated in LPS-induced endotoxemia rat model. We also observed that ferroportin (Fpn), the only identified mammalian non-heme iron exporter, was downregulated in the atrium of endotoxemia model. Vulnerability to AF was also significantly increased in a endotoxemia rat model. Additionally, Fpn knockdown by shFpn further increased intracellular iron concentration and oxidative stress and exaggerated the AF vulnerability, which was alleviated by ferroptosis inhibition. Mechanistically, silencing Fpn worsened the alterations in calcium handling proteins expression in a endotoxemia rat model. These findings suggest that Fpn-mediated ferroptosis is involved in the new-onset AF with LPS-induced endotoxemia via worsening the calcium handling proteins dysregulation and provides a novel and promising strategy for preventing AF development in sepsis.
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