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Judina A, Niglas M, Leonov V, Kirkby NS, Diakonov I, Wright PT, Zhao L, Mitchell JA, Gorelik J. Pulmonary Hypertension-Associated Right Ventricular Cardiomyocyte Remodelling Reduces Treprostinil Function. Cells 2023; 12:2764. [PMID: 38067192 PMCID: PMC10705885 DOI: 10.3390/cells12232764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
(1) Pulmonary hypertension (PH)-associated right ventricular (RV) failure is linked to a reduction in pulmonary vasodilators. Treprostinil has shown effectiveness in PAH patients with cardiac decompensation, hinting at potential cardiac benefits. We investigated treprostinil's synergy with isoprenaline in RV and LV cardiomyocytes. We hypothesised that disease-related RV structural changes in cardiomyocytes would reduce contractile responses and cAMP/PKA signalling activity. (2) We induced PH in male Sprague Dawley rats using monocrotaline and isolated their ventricular cardiomyocytes. The effect of in vitro treprostinil and isoprenaline stimulation on contraction was assessed. FRET microscopy was used to study PKA activity associated with treprostinil stimulation in AKAR3-NES FRET-based biosensor-expressing cells. (3) RV cells exhibited maladaptive remodelling with hypertrophy, impaired contractility, and calcium transients compared to control and LV cardiomyocytes. Combining treprostinil and isoprenaline failed to enhance inotropy in PH RV cardiomyocytes. PH RV cardiomyocytes displayed an aberrant contractile behaviour, which the combination treatment could not rectify. Finally, we observed decreased PKA activity in treprostinil-treated PH RV cardiomyocytes. (4) PH-associated RV cardiomyocyte remodelling reduced treprostinil sensitivity, inotropic support, and impaired relaxation. Overall, this study highlights the complexity of RV dysfunction in advanced PH and suggests the need for alternative therapeutic strategies.
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Affiliation(s)
- Aleksandra Judina
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Marili Niglas
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Vladislav Leonov
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
- Department of Surgery, Dentistry, Pediatrics and Gynecology, Cardiovascular Science, The University of Verona, 37134 Verona, Italy
| | - Nicholas S. Kirkby
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Ivan Diakonov
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Peter T. Wright
- Definitely School of Life and Health Sciences, Whitelands College, University of Roehampton, Holybourne Avenue, London SW15 4JD, UK;
| | - Lan Zhao
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Jane A. Mitchell
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
| | - Julia Gorelik
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK; (A.J.); (M.N.); (V.L.); (N.S.K.); (I.D.); (L.Z.); (J.A.M.)
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2
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Kwan Z, Paulose Nadappuram B, Leung MM, Mohagaonkar S, Li A, Amaradasa KS, Chen J, Rothery S, Kibreab I, Fu J, Sanchez-Alonso JL, Mansfield CA, Subramanian H, Kondrashov A, Wright PT, Swiatlowska P, Nikolaev VO, Wojciak-Stothard B, Ivanov AP, Edel JB, Gorelik J. Microtubule-Mediated Regulation of β 2AR Translation and Function in Failing Hearts. Circ Res 2023; 133:944-958. [PMID: 37869877 PMCID: PMC10635332 DOI: 10.1161/circresaha.123.323174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/24/2023]
Abstract
BACKGROUND β1AR (beta-1 adrenergic receptor) and β2AR (beta-2 adrenergic receptor)-mediated cyclic adenosine monophosphate signaling has distinct effects on cardiac function and heart failure progression. However, the mechanism regulating spatial localization and functional compartmentation of cardiac β-ARs remains elusive. Emerging evidence suggests that microtubule-dependent trafficking of mRNP (messenger ribonucleoprotein) and localized protein translation modulates protein compartmentation in cardiomyocytes. We hypothesized that β-AR compartmentation in cardiomyocytes is accomplished by selective trafficking of its mRNAs and localized translation. METHODS The localization pattern of β-AR mRNA was investigated using single molecule fluorescence in situ hybridization and subcellular nanobiopsy in rat cardiomyocytes. The role of microtubule on β-AR mRNA localization was studied using vinblastine, and its effect on receptor localization and function was evaluated with immunofluorescent and high-throughput Förster resonance energy transfer microscopy. An mRNA protein co-detection assay identified plausible β-AR translation sites in cardiomyocytes. The mechanism by which β-AR mRNA is redistributed post-heart failure was elucidated by single molecule fluorescence in situ hybridization, nanobiopsy, and high-throughput Förster resonance energy transfer microscopy on 16 weeks post-myocardial infarction and detubulated cardiomyocytes. RESULTS β1AR and β2AR mRNAs show differential localization in cardiomyocytes, with β1AR found in the perinuclear region and β2AR showing diffuse distribution throughout the cell. Disruption of microtubules induces a shift of β2AR transcripts toward the perinuclear region. The close proximity between β2AR transcripts and translated proteins suggests that the translation process occurs in specialized, precisely defined cellular compartments. Redistribution of β2AR transcripts is microtubule-dependent, as microtubule depolymerization markedly reduces the number of functional receptors on the membrane. In failing hearts, both β1AR and β2AR mRNAs are redistributed toward the cell periphery, similar to what is seen in cardiomyocytes undergoing drug-induced detubulation. This suggests that t-tubule remodeling contributes to β-AR mRNA redistribution and impaired β2AR function in failing hearts. CONCLUSIONS Asymmetrical microtubule-dependent trafficking dictates differential β1AR and β2AR localization in healthy cardiomyocyte microtubules, underlying the distinctive compartmentation of the 2 β-ARs on the plasma membrane. The localization pattern is altered post-myocardial infarction, resulting from transverse tubule remodeling, leading to distorted β2AR-mediated cyclic adenosine monophosphate signaling.
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MESH Headings
- Rats
- Animals
- In Situ Hybridization, Fluorescence
- Heart Failure/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Myocardial Infarction/metabolism
- Myocytes, Cardiac/metabolism
- Cyclic AMP/metabolism
- Receptors, Adrenergic, beta-1/metabolism
- Microtubules/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Adenosine Monophosphate/metabolism
- Adenosine Monophosphate/pharmacology
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Affiliation(s)
- Zoe Kwan
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Binoy Paulose Nadappuram
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
- Department of Pure and Applied Chemistry, University of Strathclyde, United Kingdom (B.P.N.)
| | - Manton M. Leung
- Sir William Dunn School of Pathology, University of Oxford, United Kingdom (M.M.L.)
| | - Sanika Mohagaonkar
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Ao Li
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Kumuthu S. Amaradasa
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Ji Chen
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Stephen Rothery
- FILM Facility, Imperial College London, United Kingdom (S.R.)
| | - Iyobel Kibreab
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Jiarong Fu
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Jose L. Sanchez-Alonso
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Catherine A. Mansfield
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | | | - Alexander Kondrashov
- Division of Cancer and Stem Cells, University of Nottingham Biodiscovery Institute, United Kingdom (A.K.)
| | - Peter T. Wright
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
- School of Life and Health Sciences, University of Roehampton, United Kingdom (P.T.W.)
| | - Pamela Swiatlowska
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Viacheslav O. Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center, Hamburg-Eppendorf, Germany (H.S., V.O.N.)
| | - Beata Wojciak-Stothard
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Aleksandar P. Ivanov
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Joshua B. Edel
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Julia Gorelik
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
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3
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Medvedev RY, Turner DGP, DeGuire FC, Leonov V, Lang D, Gorelik J, Alvarado FJ, Bondarenko VE, Glukhov AV. Caveolae-associated cAMP/Ca 2+-mediated mechano-chemical signal transduction in mouse atrial myocytes. J Mol Cell Cardiol 2023; 184:75-87. [PMID: 37805125 PMCID: PMC10842990 DOI: 10.1016/j.yjmcc.2023.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 09/11/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Caveolae are tiny invaginations in the sarcolemma that buffer extra membrane and contribute to mechanical regulation of cellular function. While the role of caveolae in membrane mechanosensation has been studied predominantly in non-cardiomyocyte cells, caveolae contribution to cardiac mechanotransduction remains elusive. Here, we studied the role of caveolae in the regulation of Ca2+ signaling in atrial cardiomyocytes. In Langendorff-perfused mouse hearts, atrial pressure/volume overload stretched atrial myocytes and decreased caveolae density. In isolated cells, caveolae were disrupted through hypotonic challenge that induced a temporal (<10 min) augmentation of Ca2+ transients and caused a rise in Ca2+ spark activity. Similar changes in Ca2+ signaling were observed after chemical (methyl-β-cyclodextrin) and genetic ablation of caveolae in cardiac-specific conditional caveolin-3 knock-out mice. Acute disruption of caveolae, both mechanical and chemical, led to the elevation of cAMP level in the cell interior, and cAMP-mediated augmentation of protein kinase A (PKA)-phosphorylated ryanodine receptors (at Ser2030 and Ser2808). Caveolae-mediated stimulatory effects on Ca2+ signaling were abolished via inhibition of cAMP production by adenyl cyclase antagonists MDL12330 and SQ22536, or reduction of PKA activity by H-89. A compartmentalized mathematical model of mouse atrial myocytes linked the observed changes to a microdomain-specific decrease in phosphodiesterase activity, which disrupted cAMP signaling and augmented PKA activity. Our findings add a new dimension to cardiac mechanobiology and highlight caveolae-associated cAMP/PKA-mediated phosphorylation of Ca2+ handling proteins as a novel component of mechano-chemical feedback in atrial myocytes.
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Affiliation(s)
- Roman Y Medvedev
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Daniel G P Turner
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Frank C DeGuire
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Vladislav Leonov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Di Lang
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Francisco J Alvarado
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
| | - Alexey V Glukhov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
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4
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Grandi E, Navedo MF, Saucerman JJ, Bers DM, Chiamvimonvat N, Dixon RE, Dobrev D, Gomez AM, Harraz OF, Hegyi B, Jones DK, Krogh-Madsen T, Murfee WL, Nystoriak MA, Posnack NG, Ripplinger CM, Veeraraghavan R, Weinberg S. Diversity of cells and signals in the cardiovascular system. J Physiol 2023; 601:2547-2592. [PMID: 36744541 PMCID: PMC10313794 DOI: 10.1113/jp284011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/19/2023] [Indexed: 02/07/2023] Open
Abstract
This white paper is the outcome of the seventh UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. This biannual meeting aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2022 Symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies, and challenges in examining cell and signal diversity, co-ordination and interrelationships involved in cardiovascular function. This paper originates from the topics of formal presentations and informal discussions from the Symposium, which aimed to develop a holistic view of how the multiple cell types in the cardiovascular system integrate to influence cardiovascular function, disease progression and therapeutic strategies. The first section describes the major cell types (e.g. cardiomyocytes, vascular smooth muscle and endothelial cells, fibroblasts, neurons, immune cells, etc.) and the signals involved in cardiovascular function. The second section emphasizes the complexity at the subcellular, cellular and system levels in the context of cardiovascular development, ageing and disease. Finally, the third section surveys the technological innovations that allow the interrogation of this diversity and advancing our understanding of the integrated cardiovascular function and dysfunction.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Manuel F. Navedo
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Jeffrey J. Saucerman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis, Davis, CA, USA
- Department of Internal Medicine, University of California Davis, Davis, CA, USA
| | - Rose E. Dixon
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Canada
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Ana M. Gomez
- Signaling and Cardiovascular Pathophysiology-UMR-S 1180, INSERM, Université Paris-Saclay, Orsay, France
| | - Osama F. Harraz
- Department of Pharmacology, Larner College of Medicine, and Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, VT, USA
| | - Bence Hegyi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Trine Krogh-Madsen
- Department of Physiology & Biophysics, Weill Cornell Medicine, New York, New York, USA
| | - Walter Lee Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Matthew A. Nystoriak
- Department of Medicine, Division of Environmental Medicine, Center for Cardiometabolic Science, University of Louisville, Louisville, KY, 40202, USA
| | - Nikki G. Posnack
- Department of Pediatrics, Department of Pharmacology and Physiology, The George Washington University, Washington, DC, USA
- Sheikh Zayed Institute for Pediatric and Surgical Innovation, Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | | | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
| | - Seth Weinberg
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
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5
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Guarina L, Moghbel AN, Pourhosseinzadeh MS, Cudmore RH, Sato D, Clancy CE, Santana LF. Biological noise is a key determinant of the reproducibility and adaptability of cardiac pacemaking and EC coupling. J Gen Physiol 2022; 154:213185. [PMID: 35482009 PMCID: PMC9059386 DOI: 10.1085/jgp.202012613] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/16/2022] [Accepted: 04/07/2022] [Indexed: 12/23/2022] Open
Abstract
Each heartbeat begins with the generation of an action potential in pacemaking cells in the sinoatrial node. This signal triggers contraction of cardiac muscle through a process termed excitation-contraction (EC) coupling. EC coupling is initiated in dyadic structures of cardiac myocytes, where ryanodine receptors in the junctional sarcoplasmic reticulum come into close apposition with clusters of CaV1.2 channels in invaginations of the sarcolemma. Cooperative activation of CaV1.2 channels within these clusters causes a local increase in intracellular Ca2+ that activates the juxtaposed ryanodine receptors. A salient feature of healthy cardiac function is the reliable and precise beat-to-beat pacemaking and amplitude of Ca2+ transients during EC coupling. In this review, we discuss recent discoveries suggesting that the exquisite reproducibility of this system emerges, paradoxically, from high variability at subcellular, cellular, and network levels. This variability is attributable to stochastic fluctuations in ion channel trafficking, clustering, and gating, as well as dyadic structure, which increase intracellular Ca2+ variance during EC coupling. Although the effects of these large, local fluctuations in function and organization are sometimes negligible at the macroscopic level owing to spatial-temporal summation within and across cells in the tissue, recent work suggests that the "noisiness" of these intracellular Ca2+ events may either enhance or counterintuitively reduce variability in a context-dependent manner. Indeed, these noisy events may represent distinct regulatory features in the tuning of cardiac contractility. Collectively, these observations support the importance of incorporating experimentally determined values of Ca2+ variance in all EC coupling models. The high reproducibility of cardiac contraction is a paradoxical outcome of high Ca2+ signaling variability at subcellular, cellular, and network levels caused by stochastic fluctuations in multiple processes in time and space. This underlying stochasticity, which counterintuitively manifests as reliable, consistent Ca2+ transients during EC coupling, also allows for rapid changes in cardiac rhythmicity and contractility in health and disease.
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Affiliation(s)
- Laura Guarina
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Ariana Neelufar Moghbel
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | | | - Robert H Cudmore
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA
| | - Colleen E Clancy
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Luis Fernando Santana
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
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6
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Okagu IU, Ezeorba TPC, Aham EC, Aguchem RN, Nechi RN. Recent findings on the cellular and molecular mechanisms of action of novel food-derived antihypertensive peptides. FOOD CHEMISTRY. MOLECULAR SCIENCES 2022; 4:100078. [PMID: 35415696 PMCID: PMC8991738 DOI: 10.1016/j.fochms.2022.100078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 01/07/2022] [Accepted: 01/21/2022] [Indexed: 12/14/2022]
Abstract
Hypertension has remained a silent-killer. Novel peptides recently isolated from food proteins. Molecular mechanism of blood pressure-lowering: renin and ACE-inhibition, and beyond. Proposed molecular mechanisms for future research. Novel peptides are excellent candidates for nutraceutical development.
Hypertension impacts negatively on the quality of life of sufferers, and complications associated with uncontrolled hypertension are life-threatening. Hence, many research efforts are exploring the antihypertensive properties of bioactive peptides derived from food proteins using in vitro ACE-inhibitory assay, experimentally-induced and spontaneous hypertensive rats, normotensive and hypertensive human models. In this study, the cellular and molecular mechanisms of blood pressure-lowering properties of novel peptides reported in recent studies (2015-July 30, 2021) were discussed. In addition to common mechanisms such as the inhibition of angiotensin I-converting enzyme (ACE) and renin activities, recently recognized mechanisms through which bioactive peptides exert their antihypertensive properties including the induction of vasodilation via upregulation of cyclo-oxygenase (COX) and prostaglandin receptor and endothelial nitric oxide synthase expression and L-type Ca2+ channel blockade were presented. Similarly, emerging mechanisms of blood pressure-lowering by bioactive peptides such as modulation of inflammation (TNF-α, and other cytokines signaling), oxidative stress (Keap-1/Nrf2/ARE/HO-1 and related signaling pathways), PPAR-γ/caspase3/MAPK signaling pathways and inhibition of lipid accumulation were discussed. The review also highlighted factors that influence the antihypertensive properties of peptides such as method of hydrolysis (type and number of enzymes, and chemical used for hydrolysis, and microbial fermentation), and amino acid sequence and chain length of peptides.
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Affiliation(s)
- Innocent U Okagu
- Department of Biochemistry, University of Nigeria, Nsukka 410001, Nigeria
| | | | - Emmanuel C Aham
- Department of Biochemistry, University of Nigeria, Nsukka 410001, Nigeria
| | - Rita N Aguchem
- Department of Biochemistry, University of Nigeria, Nsukka 410001, Nigeria
| | - Regina N Nechi
- Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka 410001, Nigeria
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7
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Lang D, Medvedev RY, Ratajczyk L, Zheng J, Yuan X, Lim E, Han OY, Valdivia HH, Glukhov AV. Region-specific distribution of transversal-axial tubule system organization underlies heterogeneity of calcium dynamics in the right atrium. Am J Physiol Heart Circ Physiol 2022; 322:H269-H284. [PMID: 34951544 PMCID: PMC8782648 DOI: 10.1152/ajpheart.00381.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The atrial myocardium demonstrates the highly heterogeneous organization of the transversal-axial tubule system (TATS), although its anatomical distribution and region-specific impact on Ca2+ dynamics remain unknown. Here, we developed a novel method for high-resolution confocal imaging of TATS in intact live mouse atrial myocardium and applied a custom-developed MATLAB-based computational algorithm for the automated analysis of TATS integrity. We observed a twofold higher (P < 0.01) TATS density in the right atrial appendage (RAA) than in the intercaval regions (ICR, the anatomical region between the superior vena cava and atrioventricular junction and between the crista terminalis and interatrial septum). Whereas RAA predominantly consisted of well-tubulated myocytes, ICR showed partially tubulated/untubulated cells. Similar TATS distribution was also observed in healthy human atrial myocardium sections. In both mouse atrial preparations and isolated mouse atrial myocytes, we observed a strong anatomical correlation between TATS distribution and Ca2+ transient synchronization and rise-up time. This region-specific difference in Ca2+ transient morphology disappeared after formamide-induced detubulation. ICR myocytes showed a prolonged action potential duration at 80% of repolarization as well as a significantly lower expression of RyR2 and Cav1.2 proteins but similar levels of NCX1 and Cav1.3 compared with RAA tissue. Our findings provide a detailed characterization of the region-specific distribution of TATS in mouse and human atrial myocardium, highlighting the structural foundation for anatomical heterogeneity of Ca2+ dynamics and contractility in the atria. These results could indicate different roles of TATS in Ca2+ signaling at distinct anatomical regions of the atria and provide mechanistic insight into pathological atrial remodeling.NEW & NOTEWORTHY Mouse and human atrial myocardium demonstrate high variability in the organization of the transversal-axial tubule system (TATS), with more organized TATS expressed in the right atrial appendage. TATS distribution governs anatomical heterogeneity of Ca2+ dynamics and thus could contribute to integral atrial contractility, mechanics, and arrhythmogenicity.
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Affiliation(s)
- Di Lang
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Roman Y Medvedev
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Lucas Ratajczyk
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Jingjing Zheng
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Xiaoyu Yuan
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Evi Lim
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Owen Y Han
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Hector H Valdivia
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Alexey V Glukhov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
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Dixon RE. Nanoscale Organization, Regulation, and Dynamic Reorganization of Cardiac Calcium Channels. Front Physiol 2022; 12:810408. [PMID: 35069264 PMCID: PMC8769284 DOI: 10.3389/fphys.2021.810408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 11/30/2021] [Indexed: 12/19/2022] Open
Abstract
The architectural specializations and targeted delivery pathways of cardiomyocytes ensure that L-type Ca2+ channels (CaV1.2) are concentrated on the t-tubule sarcolemma within nanometers of their intracellular partners the type 2 ryanodine receptors (RyR2) which cluster on the junctional sarcoplasmic reticulum (jSR). The organization and distribution of these two groups of cardiac calcium channel clusters critically underlies the uniform contraction of the myocardium. Ca2+ signaling between these two sets of adjacent clusters produces Ca2+ sparks that in health, cannot escalate into Ca2+ waves because there is sufficient separation of adjacent clusters so that the release of Ca2+ from one RyR2 cluster or supercluster, cannot activate and sustain the release of Ca2+ from neighboring clusters. Instead, thousands of these Ca2+ release units (CRUs) generate near simultaneous Ca2+ sparks across every cardiomyocyte during the action potential when calcium induced calcium release from RyR2 is stimulated by depolarization induced Ca2+ influx through voltage dependent CaV1.2 channel clusters. These sparks summate to generate a global Ca2+ transient that activates the myofilaments and thus the electrical signal of the action potential is transduced into a functional output, myocardial contraction. To generate more, or less contractile force to match the hemodynamic and metabolic demands of the body, the heart responds to β-adrenergic signaling by altering activity of calcium channels to tune excitation-contraction coupling accordingly. Recent accumulating evidence suggests that this tuning process also involves altered expression, and dynamic reorganization of CaV1.2 and RyR2 channels on their respective membranes to control the amplitude of Ca2+ entry, SR Ca2+ release and myocardial function. In heart failure and aging, altered distribution and reorganization of these key Ca2+ signaling proteins occurs alongside architectural remodeling and is thought to contribute to impaired contractile function. In the present review we discuss these latest developments, their implications, and future questions to be addressed.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, United States
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Dixon RE, Navedo MF, Binder MD, Santana LF. Mechanisms and Physiological Implications of Cooperative Gating of Ion Channels Clusters. Physiol Rev 2021; 102:1159-1210. [PMID: 34927454 DOI: 10.1152/physrev.00022.2021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ion channels play a central role in the regulation of nearly every cellular process. Dating back to the classic 1952 Hodgkin-Huxley model of the generation of the action potential, ion channels have always been thought of as independent agents. A myriad of recent experimental findings exploiting advances in electrophysiology, structural biology, and imaging techniques, however, have posed a serious challenge to this long-held axiom as several classes of ion channels appear to open and close in a coordinated, cooperative manner. Ion channel cooperativity ranges from variable-sized oligomeric cooperative gating in voltage-gated, dihydropyridine-sensitive Cav1.2 and Cav1.3 channels to obligatory dimeric assembly and gating of voltage-gated Nav1.5 channels. Potassium channels, transient receptor potential channels, hyperpolarization cyclic nucleotide-activated channels, ryanodine receptors (RyRs), and inositol trisphosphate receptors (IP3Rs) have also been shown to gate cooperatively. The implications of cooperative gating of these ion channels range from fine tuning excitation-contraction coupling in muscle cells to regulating cardiac function and vascular tone, to modulation of action potential and conduction velocity in neurons and cardiac cells, and to control of pace-making activity in the heart. In this review, we discuss the mechanisms leading to cooperative gating of ion channels, their physiological consequences and how alterations in cooperative gating of ion channels may induce a range of clinically significant pathologies.
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Affiliation(s)
- Rose Ellen Dixon
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, United States
| | - Marc D Binder
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, CA, United States
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Chaklader M, Rothermel BA. Calcineurin in the heart: New horizons for an old friend. Cell Signal 2021; 87:110134. [PMID: 34454008 PMCID: PMC8908812 DOI: 10.1016/j.cellsig.2021.110134] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023]
Abstract
Calcineurin, also known as PP2B or PPP3, is a member of the PPP family of protein phosphatases that also includes PP1 and PP2A. Together these three phosphatases carryout the majority of dephosphorylation events in the heart. Calcineurin is distinct in that it is activated by the binding of calcium/calmodulin (Ca2+/CaM) and therefore acts as a node for integrating Ca2+ signals with changes in phosphorylation, two fundamental intracellular signaling cascades. In the heart, calcineurin is primarily thought of in the context of pathological cardiac remodeling, acting through the Nuclear Factor of Activated T-cell (NFAT) family of transcription factors. However, calcineurin activity is also essential for normal heart development and homeostasis in the adult heart. Furthermore, it is clear that NFAT-driven changes in transcription are not the only relevant processes initiated by calcineurin in the setting of pathological remodeling. There is a growing appreciation for the diversity of calcineurin substrates that can impact cardiac function as well as the diversity of mechanisms for targeting calcineurin to specific sub-cellular domains in cardiomyocytes and other cardiac cell types. Here, we will review the basics of calcineurin structure, regulation, and function in the context of cardiac biology. Particular attention will be given to: the development of improved tools to identify and validate new calcineurin substrates; recent studies identifying new calcineurin isoforms with unique properties and targeting mechanisms; and the role of calcineurin in cardiac development and regeneration.
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Affiliation(s)
- Malay Chaklader
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Beverly A Rothermel
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
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