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Ran Q, Li A, Tan Y, Zhang Y, Zhang Y, Chen H. Action and therapeutic targets of myosin light chain kinase, an important cardiovascular signaling mechanism. Pharmacol Res 2024; 206:107276. [PMID: 38944220 DOI: 10.1016/j.phrs.2024.107276] [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: 05/18/2024] [Accepted: 06/19/2024] [Indexed: 07/01/2024]
Abstract
The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is complex and not fully understood, and the physiological function of the heart is inextricably linked to well-regulated cardiac muscle movement. Myosin light chain kinase (MLCK) is essential for myocardial contraction and diastole, cardiac electrophysiological homeostasis, vasoconstriction of vascular nerves and blood pressure regulation. In this sense, MLCK appears to be an attractive therapeutic target for cardiac diseases. MLCK participates in myocardial cell movement and migration through diverse pathways, including regulation of calcium homeostasis, activation of myosin light chain phosphorylation, and stimulation of vascular smooth muscle cell contraction or relaxation. Recently, phosphorylation of myosin light chains has been shown to be closely associated with the activation of myocardial exercise signaling, and MLCK mediates systolic and diastolic functions of the heart through the interaction of myosin thick filaments and actin thin filaments. It works by upholding the integrity of the cytoskeleton, modifying the conformation of the myosin head, and modulating innervation. MLCK governs vasoconstriction and diastolic function and is associated with the activation of adrenergic and sympathetic nervous systems, extracellular transport, endothelial permeability, and the regulation of nitric oxide and angiotensin II. Additionally, MLCK plays a crucial role in the process of cardiac aging. Multiple natural products/phytochemicals and chemical compounds, such as quercetin, cyclosporin, and ML-7 hydrochloride, have been shown to regulate cardiomyocyte MLCK. The MLCK-modifying capacity of these compounds should be considered in designing novel therapeutic agents. This review summarizes the mechanism of action of MLCK in the cardiovascular system and the therapeutic potential of reported chemical compounds in cardiac diseases by modifying MLCK processes.
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Affiliation(s)
- Qingzhi Ran
- Guang'anmen Hospital, China Academy of Traditional Chinese Medicine, Beijing 100070, China
| | - Aoshuang Li
- Dongzhimen Hospital, Beijing University of Traditional Chinese Medicine, Beijing 100053, China
| | - Yuqing Tan
- Guang'anmen Hospital, China Academy of Traditional Chinese Medicine, Beijing 100070, China
| | - Yue Zhang
- Guang'anmen Hospital, China Academy of Traditional Chinese Medicine, Beijing 100070, China.
| | - Yongkang Zhang
- Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200082, China.
| | - Hengwen Chen
- Guang'anmen Hospital, China Academy of Traditional Chinese Medicine, Beijing 100070, China.
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Sazdova I, Hadzi-Petrushev N, Keremidarska-Markova M, Stojchevski R, Sopi R, Shileiko S, Mitrokhin V, Gagov H, Avtanski D, Lubomirov LT, Mladenov M. SIRT-associated attenuation of cellular senescence in vascular wall. Mech Ageing Dev 2024; 220:111943. [PMID: 38762036 DOI: 10.1016/j.mad.2024.111943] [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: 04/13/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
This review focuses on the vital function that SIRT1 and other sirtuins play in promoting cellular senescence in vascular smooth muscle cells, which is a key element in the pathogenesis of vascular aging and associated cardiovascular diseases. Vascular aging is a gradual process caused by the accumulation of senescent cells, which results in increased vascular remodeling, stiffness, and diminished angiogenic ability. Such physiological alterations are characterized by a complex interplay of environmental and genetic variables, including oxidative stress and telomere attrition, which affect gene expression patterns and trigger cell growth arrest. SIRT1 has been highlighted for its potential to reduce cellular senescence through modulation of multiple signaling cascades, particularly the endothelial nitric oxide (eNOS)/NO signaling pathway. It also modulates cell cycle through p53 inactivation and suppresses NF-κB mediated expression of adhesive molecules at the vascular level. The study also examines the therapeutic potential of sirtuin modulation in vascular health, identifying SIRT1 and its sirtuin counterparts as potential targets for reducing vascular aging. This study sheds light on the molecular basis of vascular aging and the beneficial effects of sirtuins, paving the way for the development of tailored therapies aimed at enhancing vascular health and prolonging life.
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Affiliation(s)
- Iliyana Sazdova
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University 'St. Kliment Ohridski', Sofia 1504, Bulgaria
| | - Nikola Hadzi-Petrushev
- Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, Skopje 1000, North Macedonia
| | - Milena Keremidarska-Markova
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University 'St. Kliment Ohridski', Sofia 1504, Bulgaria
| | - Radoslav Stojchevski
- Friedman Diabetes Institute, Lenox Hill Hospital, Northwell Health, 110 E 59th Street, New York, NY 10022, USA
| | - Ramadan Sopi
- Faculty of Medicine, University of Prishtina, Prishtina 10 000, Kosovo
| | - Stanislav Shileiko
- Department of Fundamental and Applied Physiology, Russian States Medical University, Moscow 117997, Russia
| | - Vadim Mitrokhin
- Department of Fundamental and Applied Physiology, Russian States Medical University, Moscow 117997, Russia
| | - Hristo Gagov
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University 'St. Kliment Ohridski', Sofia 1504, Bulgaria
| | - Dimitar Avtanski
- Friedman Diabetes Institute, Lenox Hill Hospital, Northwell Health, 110 E 59th Street, New York, NY 10022, USA
| | - Lubomir T Lubomirov
- Vascular Biology Research Group (RenEVA), Research Institute, Medical University-Varna, Varna, Bulgaria; Institute of Physiology and Pathophysiology, Faculty of Health - School of Medicine, Biomedical Center for Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Mitko Mladenov
- Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, Skopje 1000, North Macedonia; Department of Fundamental and Applied Physiology, Russian States Medical University, Moscow 117997, Russia.
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Eisner D, Neher E, Taschenberger H, Smith G. Physiology of intracellular calcium buffering. Physiol Rev 2023; 103:2767-2845. [PMID: 37326298 DOI: 10.1152/physrev.00042.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/08/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023] Open
Abstract
Calcium signaling underlies much of physiology. Almost all the Ca2+ in the cytoplasm is bound to buffers, with typically only ∼1% being freely ionized at resting levels in most cells. Physiological Ca2+ buffers include small molecules and proteins, and experimentally Ca2+ indicators will also buffer calcium. The chemistry of interactions between Ca2+ and buffers determines the extent and speed of Ca2+ binding. The physiological effects of Ca2+ buffers are determined by the kinetics with which they bind Ca2+ and their mobility within the cell. The degree of buffering depends on factors such as the affinity for Ca2+, the Ca2+ concentration, and whether Ca2+ ions bind cooperatively. Buffering affects both the amplitude and time course of cytoplasmic Ca2+ signals as well as changes of Ca2+ concentration in organelles. It can also facilitate Ca2+ diffusion inside the cell. Ca2+ buffering affects synaptic transmission, muscle contraction, Ca2+ transport across epithelia, and the killing of bacteria. Saturation of buffers leads to synaptic facilitation and tetanic contraction in skeletal muscle and may play a role in inotropy in the heart. This review focuses on the link between buffer chemistry and function and how Ca2+ buffering affects normal physiology and the consequences of changes in disease. As well as summarizing what is known, we point out the many areas where further work is required.
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Affiliation(s)
- David Eisner
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Erwin Neher
- Membrane Biophysics Laboratory, 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
| | - Holger Taschenberger
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Godfrey Smith
- School of Cardiovascular and Metabolic Health, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Physiological Overview of the Potential Link between the UPS and Ca2+ Signaling. Antioxidants (Basel) 2022; 11:antiox11050997. [PMID: 35624861 PMCID: PMC9137615 DOI: 10.3390/antiox11050997] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/10/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
The ubiquitin–proteasome system (UPS) is the main proteolytic pathway by which damaged target proteins are degraded after ubiquitination and the recruit of ubiquitinated proteins, thus regulating diverse physiological functions and the maintenance in various tissues and cells. Ca2+ signaling is raised by oxidative or ER stress. Although the basic function of the UPS has been extensively elucidated and has been continued to define its mechanism, the precise relationship between the UPS and Ca2+ signaling remains unclear. In the present review, we describe the relationship between the UPS and Ca2+ signaling, including Ca2+-associated proteins, to understand the end point of oxidative stress. The UPS modulates Ca2+ signaling via the degradation of Ca2+-related proteins, including Ca2+ channels and transporters. Conversely, the modulation of UPS is driven by increases in the intracellular Ca2+ concentration. The multifaceted relationship between the UPS and Ca2+ plays critical roles in different tissue systems. Thus, we highlight the potential crosstalk between the UPS and Ca2+ signaling by providing an overview of the UPS in different organ systems and illuminating the relationship between the UPS and autophagy.
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Louadi Z, Elkjaer ML, Klug M, Lio CT, Fenn A, Illes Z, Bongiovanni D, Baumbach J, Kacprowski T, List M, Tsoy O. Functional enrichment of alternative splicing events with NEASE reveals insights into tissue identity and diseases. Genome Biol 2021; 22:327. [PMID: 34857024 PMCID: PMC8638120 DOI: 10.1186/s13059-021-02538-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/10/2021] [Indexed: 01/27/2023] Open
Abstract
Alternative splicing (AS) is an important aspect of gene regulation. Nevertheless, its role in molecular processes and pathobiology is far from understood. A roadblock is that tools for the functional analysis of AS-set events are lacking. To mitigate this, we developed NEASE, a tool integrating pathways with structural annotations of protein-protein interactions to functionally characterize AS events. We show in four application cases how NEASE can identify pathways contributing to tissue identity and cell type development, and how it highlights splicing-related biomarkers. With a unique view on AS, NEASE generates unique and meaningful biological insights complementary to classical pathways analysis.
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Affiliation(s)
- Zakaria Louadi
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Maria L Elkjaer
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Melissa Klug
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Department of Internal Medicine I, School of Medicine, University hospital rechts der Isar, Technical University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Chit Tong Lio
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Amit Fenn
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
| | - Zsolt Illes
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Dario Bongiovanni
- Department of Internal Medicine I, School of Medicine, University hospital rechts der Isar, Technical University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Cardiovascular Medicine, Humanitas Clinical and Research Center IRCCS and Humanitas University, Rozzano, Milan, Italy
| | - Jan Baumbach
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany
- Institute of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, 5000, Odense, Denmark
| | - Tim Kacprowski
- Division Data Science in Biomedicine, Peter L. Reichertz Institute for Medical Informatics of Technische Universität Braunschweig and Hannover Medical School, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology (BRICS), TU Braunschweig, Braunschweig, Germany
| | - Markus List
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
| | - Olga Tsoy
- Institute for Computational Systems Biology, University of Hamburg, Notkestrasse 9, 22607, Hamburg, Germany.
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A Free-Energy Landscape Analysis of Calmodulin Obtained from an NMR Data-Utilized Multi-Scale Divide-and-Conquer Molecular Dynamics Simulation. Life (Basel) 2021; 11:life11111241. [PMID: 34833117 PMCID: PMC8617919 DOI: 10.3390/life11111241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/16/2022] Open
Abstract
Calmodulin (CaM) is a multifunctional calcium-binding protein, which regulates a variety of biochemical processes. CaM acts through its conformational changes and complex formation with its target enzymes. CaM consists of two globular domains (N-lobe and C-lobe) linked by an extended linker region. Upon calcium binding, the N-lobe and C-lobe undergo local conformational changes, followed by a major conformational change of the entire CaM to wrap the target enzyme. However, the regulation mechanisms, such as allosteric interactions, which regulate the large structural changes, are still unclear. In order to investigate the series of structural changes, the free-energy landscape of CaM was obtained by multi-scale divide-and-conquer molecular dynamics (MSDC-MD). The resultant free-energy landscape (FEL) shows that the Ca2+ bound CaM (holo-CaM) would take an experimentally famous elongated structure, which can be formed in the early stage of structural change, by breaking the inter-domain interactions. The FEL also shows that important interactions complete the structural change from the elongated structure to the ring-like structure. In addition, the FEL might give a guiding principle to predict mutational sites in CaM. In this study, it was demonstrated that the movement process of macroscopic variables on the FEL may be diffusive to some extent, and then, the MSDC-MD is suitable to the parallel computation.
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7
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Vasiliadis ES, Evangelopoulos DS, Kaspiris A, Vlachos C, Pneumaticos SG. Sclerostin and Its Involvement in the Pathogenesis of Idiopathic Scoliosis. J Clin Med 2021; 10:jcm10225286. [PMID: 34830568 PMCID: PMC8618875 DOI: 10.3390/jcm10225286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/07/2021] [Accepted: 11/12/2021] [Indexed: 12/28/2022] Open
Abstract
Idiopathic scoliosis is a disorder of unknown etiology. Bone biopsies from idiopathic scoliosis patients revealed changes at cellular and molecular level. Osteocytic sclerostin is downregulated, and serum level of sclerostin is decreased. Osteocytes in idiopathic scoliosis appear to be less active with abnormal canaliculi network. Differentiation of osteoblasts to osteocytes is decelerated, while Wnt/β-catenin signaling pathway is overactivated and affects normal bone mineralization that leads to inferior mechanical properties of the bone, which becomes susceptible to asymmetrical forces and causes deformity of the spinal column. Targeting bone metabolism during growth by stimulating sclerostin secretion from osteocytes and restoring normal function of Wnt/β-catenin signaling pathway could, in theory, increase bone strength and prevent deterioration of the scoliotic deformity.
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Affiliation(s)
- Elias S. Vasiliadis
- 3rd Department of Orthopaedics, School of Medicine, National and Kapodistrian University of Athens, KAT Hospital, 16541 Athens, Greece; (D.S.E.); (C.V.); (S.G.P.)
- Correspondence: ; Tel.: +30-2132-086-000
| | - Dimitrios Stergios Evangelopoulos
- 3rd Department of Orthopaedics, School of Medicine, National and Kapodistrian University of Athens, KAT Hospital, 16541 Athens, Greece; (D.S.E.); (C.V.); (S.G.P.)
| | - Angelos Kaspiris
- Laboratory of Molecular Pharmacology, Division for Orthopaedic Research, School of Health Sciences, University of Patras, 26504 Rion, Greece;
| | - Christos Vlachos
- 3rd Department of Orthopaedics, School of Medicine, National and Kapodistrian University of Athens, KAT Hospital, 16541 Athens, Greece; (D.S.E.); (C.V.); (S.G.P.)
| | - Spyros G. Pneumaticos
- 3rd Department of Orthopaedics, School of Medicine, National and Kapodistrian University of Athens, KAT Hospital, 16541 Athens, Greece; (D.S.E.); (C.V.); (S.G.P.)
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8
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Marcinkowski M, Pilžys T, Garbicz D, Piwowarski J, Przygońska K, Winiewska-Szajewska M, Ferenc K, Skorobogatov O, Poznański J, Grzesiuk E. Calmodulin as Ca 2+-Dependent Interactor of FTO Dioxygenase. Int J Mol Sci 2021; 22:ijms221910869. [PMID: 34639211 PMCID: PMC8509707 DOI: 10.3390/ijms221910869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 09/24/2021] [Accepted: 10/06/2021] [Indexed: 11/16/2022] Open
Abstract
FTO is an N6-methyladenosine demethylase removing methyl groups from nucleic acids. Several studies indicate the creation of FTO complexes with other proteins. Here, we looked for regulatory proteins recognizing parts of the FTO dioxygenase region. In the Calmodulin (CaM) Target Database, we found the FTO C-domain potentially binding CaM, and we proved this finding experimentally. The interaction was Ca2+-dependent but independent on FTO phosphorylation. We found that FTO–CaM interaction essentially influences calcium-binding loops in CaM, indicating the presence of two peptide populations—exchanging as CaM alone and differently, suggesting that only one part of CaM interacts with FTO, and the other one reminds free. The modeling of FTO–CaM interaction showed its stable structure when the half of the CaM molecule saturated with Ca2+ interacts with the FTO C-domain, whereas the other part is disconnected. The presented data indicate calmodulin as a new FTO interactor and support engagement of the FTO protein in calcium signaling pathways.
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Affiliation(s)
- Michał Marcinkowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Tomaš Pilžys
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Damian Garbicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Jan Piwowarski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Kaja Przygońska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Maria Winiewska-Szajewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Karolina Ferenc
- Center of Translational Medicine, Warsaw University of Life Sciences, Nowoursynowska 100, 02-797 Warsaw, Poland;
| | - Oleksandr Skorobogatov
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
| | - Jarosław Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
- Correspondence: (J.P.); (E.G.)
| | - Elżbieta Grzesiuk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland; (M.M.); (T.P.); (D.G.); (J.P.); (K.P.); (M.W.-S.); (O.S.)
- Correspondence: (J.P.); (E.G.)
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9
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Ottolini M, Sonkusare SK. The Calcium Signaling Mechanisms in Arterial Smooth Muscle and Endothelial Cells. Compr Physiol 2021; 11:1831-1869. [PMID: 33792900 PMCID: PMC10388069 DOI: 10.1002/cphy.c200030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The contractile state of resistance arteries and arterioles is a crucial determinant of blood pressure and blood flow. Physiological regulation of arterial contractility requires constant communication between endothelial and smooth muscle cells. Various Ca2+ signals and Ca2+ -sensitive targets ensure dynamic control of intercellular communications in the vascular wall. The functional effect of a Ca2+ signal on arterial contractility depends on the type of Ca2+ -sensitive target engaged by that signal. Recent studies using advanced imaging methods have identified the spatiotemporal signatures of individual Ca2+ signals that control arterial and arteriolar contractility. Broadly speaking, intracellular Ca2+ is increased by ion channels and transporters on the plasma membrane and endoplasmic reticular membrane. Physiological roles for many vascular Ca2+ signals have already been confirmed, while further investigation is needed for other Ca2+ signals. This article focuses on endothelial and smooth muscle Ca2+ signaling mechanisms in resistance arteries and arterioles. We discuss the Ca2+ entry pathways at the plasma membrane, Ca2+ release signals from the intracellular stores, the functional and physiological relevance of Ca2+ signals, and their regulatory mechanisms. Finally, we describe the contribution of abnormal endothelial and smooth muscle Ca2+ signals to the pathogenesis of vascular disorders. © 2021 American Physiological Society. Compr Physiol 11:1831-1869, 2021.
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Affiliation(s)
- Matteo Ottolini
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Swapnil K Sonkusare
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.,Department of Molecular Physiology & Biological Physics, University of Virginia, Charlottesville, Virginia, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, Virginia, USA
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10
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Oliveira MA, Lino-Alvarado AE, Moriya HT, Vitorasso RL. Drug class effects on respiratory mechanics in animal models: access and applications. Exp Biol Med (Maywood) 2021; 246:1094-1103. [PMID: 33601911 DOI: 10.1177/1535370221993095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Assessment of respiratory mechanics extends from basic research and animal modeling to clinical applications in humans. However, to employ the applications in human models, it is desirable and sometimes mandatory to study non-human animals first. To acquire further precise and controlled signals and parameters, the animals studied must be further distant from their spontaneous ventilation. The majority of respiratory mechanics studies use positive pressure ventilation to model the respiratory system. In this scenario, a few drug categories become relevant: anesthetics, muscle blockers, bronchoconstrictors, and bronchodilators. Hence, the main objective of this study is to briefly review and discuss each drug category, and the impact of a drug on the assessment of respiratory mechanics. Before and during the positive pressure ventilation, the experimental animal must be appropriately sedated and anesthetized. The sedation will lower the pain and distress of the studied animal and the plane of anesthesia will prevent the pain. With those drugs, a more controlled procedure is carried out; further, because many anesthetics depress the respiratory system activity, a minimum interference of the animal's respiration efforts are achieved. The latter phenomenon is related to muscle blockers, which aim to minimize respiratory artifacts that may interfere with forced oscillation techniques. Generally, the respiratory mechanics are studied under appropriate anesthesia and muscle blockage. The application of bronchoconstrictors is prevalent in respiratory mechanics studies. To verify the differences among studied groups, it is often necessary to challenge the respiratory system, for example, by pharmacologically inducing bronchoconstriction. However, the selected bronchoconstrictor, doses, and administration can affect the evaluation of respiratory mechanics. Although not prevalent, studies have applied bronchodilators to return (airway resistance) to the basal state after bronchoconstriction. The drug categories can influence the mathematical modeling of the respiratory system, systemic conditions, and respiratory mechanics outcomes.
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Affiliation(s)
- Maria A Oliveira
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo (USP) Sao Paulo, SP 05508-000, Brazil
| | - Alembert E Lino-Alvarado
- Biomedical Engineering Laboratory - University of Sao Paulo (USP) Sao Paulo, SP 05508-010, Brazil
| | - Henrique T Moriya
- Biomedical Engineering Laboratory - University of Sao Paulo (USP) Sao Paulo, SP 05508-010, Brazil
| | - Renato L Vitorasso
- Biomedical Engineering Laboratory - University of Sao Paulo (USP) Sao Paulo, SP 05508-010, Brazil
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11
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Kärki T, Rajakylä EK, Acheva A, Tojkander S. TRPV6 calcium channel directs homeostasis of the mammary epithelial sheets and controls epithelial mesenchymal transition. Sci Rep 2020; 10:14683. [PMID: 32895467 PMCID: PMC7477193 DOI: 10.1038/s41598-020-71645-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 08/14/2020] [Indexed: 12/17/2022] Open
Abstract
Epithelial integrity is lost upon cancer progression as cancer cells detach from the primary tumor site and start to invade to the surrounding tissues. Invasive cancers of epithelial origin often express altered levels of TRP-family cation channels. Upregulation of TRPV6 Ca2+-channel has been associated with a number of human malignancies and its high expression in breast cancer has been linked to both proliferation and invasive disease. The mechanisms behind the potential of TRPV6 to induce invasive progression have, however, not been well elucidated. Here we show that TRPV6 is connected to both E-cadherin-based adherens junctions and intracellular cytoskeletal structures. Loss of TRPV6 from normal mammary epithelial cells led to disruption of epithelial integrity and abnormal 3D-mammo sphere morphology. Furthermore, expression level of TRPV6 was tightly linked to the levels of common EMT markers, suggesting that TRPV6 may have a role in the mesenchymal invasion of breast cancer cells. Thus, either too low or too high TRPV6 levels compromise homeostasis of the mammary epithelial sheets and may promote the progression of pathophysiological conditions.
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Affiliation(s)
- Tytti Kärki
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Agnes Sjöberginkatu 2, 00014, Helsinki, Finland
- Department of Applied Physics, Aalto University School of Science, Puumiehenkuja 2, 02150, Espoo, Finland
| | - Eeva Kaisa Rajakylä
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Agnes Sjöberginkatu 2, 00014, Helsinki, Finland
| | - Anna Acheva
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Agnes Sjöberginkatu 2, 00014, Helsinki, Finland
| | - Sari Tojkander
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Agnes Sjöberginkatu 2, 00014, Helsinki, Finland.
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12
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Miao H, Blankenship JT. The pulse of morphogenesis: actomyosin dynamics and regulation in epithelia. Development 2020; 147:dev186502. [PMID: 32878903 PMCID: PMC7490518 DOI: 10.1242/dev.186502] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Actomyosin networks are some of the most crucial force-generating components present in developing tissues. The contractile forces generated by these networks are harnessed during morphogenesis to drive various cell and tissue reshaping events. Recent studies of these processes have advanced rapidly, providing us with insights into how these networks are initiated, positioned and regulated, and how they act via individual contractile pulses and/or the formation of supracellular cables. Here, we review these studies and discuss the mechanisms that underlie the construction and turnover of such networks and structures. Furthermore, we provide an overview of how ratcheted processivity emerges from pulsed events, and how tissue-level mechanics are the coordinated output of many individual cellular behaviors.
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Affiliation(s)
- Hui Miao
- Department of Biological Sciences, Molecular and Cellular Biophysics Program, University of Denver, Denver, CO 80208, USA
| | - J Todd Blankenship
- Department of Biological Sciences, Molecular and Cellular Biophysics Program, University of Denver, Denver, CO 80208, USA
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13
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Heaps CL, Bray JF, Parker JL. Enhanced KCl-mediated contractility and Ca 2+ sensitization in porcine collateral-dependent coronary arteries persist after exercise training. Am J Physiol Heart Circ Physiol 2020; 319:H915-H926. [PMID: 32857599 DOI: 10.1152/ajpheart.00384.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have previously reported enhanced Ca2+ sensitivity of coronary arteries that is dependent upon collateral circulation for their blood supply. For the current study, we hypothesized that small collateral-dependent arteries would exhibit an enhanced KCl-mediated contractile response attributable to Ca2+ sensitization and increased Ca2+ channel current. Ameroid constrictors were surgically placed around the left circumflex (LCX) artery of female Yucatan miniature swine. Eight weeks postoperatively, pigs were randomized into sedentary or exercise-trained (treadmill run; 5 days/wk; 14 wk) groups. Small coronary arteries (150-300 μm luminal diameter) were isolated from myocardial regions distal to the collateral-dependent LCX and the nonoccluded left anterior descending arteries. Contractile tension and simultaneous measures of both tension and intracellular free Ca2+ levels (fura-2) were measured in response to increasing concentrations of KCl. In addition, whole cell Ca2+ currents were also obtained. Chronic occlusion enhanced contractile responses to KCl and increased Ca2+ sensitization in collateral-dependent compared with nonoccluded arteries of both sedentary and exercise-trained pigs. In contrast, smooth muscle cell Ca2+ channel current was not altered by occlusion or exercise training. Ca2+/calmodulin-dependent protein kinase II (CaMKII; inhibited by KN-93, 0.3-1 μM) contributed to the enhanced contractile response in collateral-dependent arteries of sedentary pigs, whereas both CaMKII and Rho-kinase (inhibited by hydroxyfasudil, 30 μM or Y27632, 10 μM) contributed to increased contraction in exercise-trained animals. Taken together, these data suggest that chronic occlusion leads to enhanced contractile responses to KCl in collateral-dependent coronary arteries via increased Ca2+ sensitization, a response that is further augmented with exercise training.NEW & NOTEWORTHY Small coronary arteries distal to chronic occlusion displayed enhanced contractile responses, which were further augmented after exercise training and attributable to enhanced calcium sensitization without alterations in calcium channel current. The calcium sensitization mediators Rho-kinase and CaMKII significantly contributed to enhanced contraction in collateral-dependent arteries of exercise-trained, but not sedentary, pigs. Exercise-enhanced contractile responses may increase resting arterial tone, creating an enhanced coronary flow reserve that is accessible during periods of increased metabolic demand.
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Affiliation(s)
- Cristine L Heaps
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas.,Michael E. DeBakey Institute for Comparative Cardiovascular Science and Biomedical Devices, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Jeff F Bray
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Janet L Parker
- Michael E. DeBakey Institute for Comparative Cardiovascular Science and Biomedical Devices, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas.,Department of Medical Physiology, Texas A&M Health Science Center, Texas A&M University, College Station, Texas
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14
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Isobe K, Raghuram V, Krishnan L, Chou CL, Yang CR, Knepper MA. CRISPR-Cas9/phosphoproteomics identifies multiple noncanonical targets of myosin light chain kinase. Am J Physiol Renal Physiol 2020; 318:F600-F616. [PMID: 31904282 DOI: 10.1152/ajprenal.00431.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prior studies have implicated myosin light chain kinase (MLCK) in the regulation of aquaporin-2 (AQP2) in the renal collecting duct. To discover signaling targets of MLCK, we used CRISPR-Cas9 to delete the MLCK gene (Mylk) to obtain MLCK-null mpkCCD cells and carried out comprehensive phosphoproteomics using stable isotope labeling with amino acids in cell culture for quantification. Immunocytochemistry and electron microscopy demonstrated a defect in the processing of AQP2-containing early endosomes to late endosomes. The phosphoproteomics experiments revealed that, of the 1,743 phosphopeptides quantified over multiple replicates, 107 were changed in abundance by MLCK deletion (29 decreased and 78 increased). One of the decreased phosphopeptides corresponded to the canonical target site in myosin regulatory light chain. Network analysis indicated that targeted phosphoproteins clustered into distinct structural/functional groups: actomyosin, signaling, nuclear envelope, gene transcription, mRNA processing, energy metabolism, intermediate filaments, adherens junctions, and tight junctions. There was significant overlap between the derived MLCK signaling network and a previously determined PKA signaling network. The presence of multiple proteins in the actomyosin category prompted experiments showing that MLCK deletion inhibits the normal effect of vasopressin to depolymerize F-actin, providing a potential explanation for the AQP2 trafficking defect. Changes in phosphorylation of multiple proteins in the nuclear envelope prompted measurement of nuclear size, showing a significant increase in average nuclear volume. We conclude that MLCK is part of a multicomponent signaling pathway in both the cytoplasm and nucleus that includes much more than simple regulation of conventional nonmuscle myosins through myosin regulatory light chain phosphorylation.
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Affiliation(s)
- Kiyoshi Isobe
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Viswanathan Raghuram
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Laya Krishnan
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Chung-Lin Chou
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Chin-Rang Yang
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Mark A Knepper
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
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15
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Jude J, Botelho D, Karmacharya N, Cao GY, Jester W, Panettieri RA. Salicylic acid amplifies Carbachol-induced bronchoconstriction in human precision-cut lung slices. Respir Res 2019; 20:72. [PMID: 30971247 PMCID: PMC6458705 DOI: 10.1186/s12931-019-1034-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/26/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Asthma exacerbations evoke emergency room visits, progressive loss of lung function and increased mortality. Environmental and industrial toxicants exacerbate asthma, although the underlying mechanisms are unknown. We assessed whether 3 distinct toxicants, salicylic acid (SA), toluene diisocyanate (TDI), and 1-chloro-2,4-dinitrobenzene (DNCB) induced airway hyperresponsiveness (AHR) through modulating excitation-contraction coupling in human airway smooth muscle (HASM) cells. The toxicants include a non-sensitizing irritant (SA), respiratory sensitizer (TDI) and dermal sensitizer (DNCB), respectively. We hypothesized that these toxicants induce AHR by modulating excitation-contraction (EC) coupling in airway smooth muscle (ASM) cells. METHODS Carbachol-induced bronchoconstriction was measured in precision-cut human lung slices (hPCLS) following exposure to SA, TDI, DNCB or vehicle. Culture supernatants of hPCLS were screened for mediator release. In HASM cells treated with the toxicants, surrogate readouts of EC coupling were measured by phosphorylated myosin light chain (pMLC) and agonist-induced Ca2+ mobilization ([Ca2+]i). In addition, Nrf-2-dependent antioxidant response was determined by NAD(P) H quinone oxidoreductase 1 (NQO1) expression in HASM cells. RESULTS In hPCLS, SA, but not TDI or DNCB, potentiated carbachol-induced bronchoconstriction. The toxicants had little effect on release of inflammatory mediators, including IL-6, IL-8 and eotaxin from hPCLS. In HASM cells, TDI amplified carbachol-induced MLC phosphorylation. The toxicants also had little effect on agonist-induced [Ca2+]i. CONCLUSION: SA, a non-sensitizing irritant, amplifies agonist-induced bronchoconstriction in hPCLS via mechanisms independent of inflammation and Ca2+ homeostasis in HASM cells. The sensitizers TDI and DNCB, had little effect on bronchoconstriction or inflammatory mediator release in hPCLS. IMPLICATIONS Our findings suggest that non-sensitizing irritant salicylic acid may evoke AHR and exacerbate symptoms in susceptible individuals or in those with underlying lung disease.
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Affiliation(s)
- Joseph Jude
- Rutgers Institute for Translational Medicine and Science (RITMS), Rutgers, The State University of New Jersey, Rm# 4276, 89 French Street, New Brunswick, NJ08901, USA.
| | - Danielle Botelho
- Research Institute for Fragrance Materials (RIFM), Woodcliff Lake, New Jersey, USA
| | - Nikhil Karmacharya
- Rutgers Institute for Translational Medicine and Science (RITMS), Rutgers, The State University of New Jersey, Rm# 4276, 89 French Street, New Brunswick, NJ08901, USA
| | - Gao Yuan Cao
- Rutgers Institute for Translational Medicine and Science (RITMS), Rutgers, The State University of New Jersey, Rm# 4276, 89 French Street, New Brunswick, NJ08901, USA
| | - William Jester
- Rutgers Institute for Translational Medicine and Science (RITMS), Rutgers, The State University of New Jersey, Rm# 4276, 89 French Street, New Brunswick, NJ08901, USA
| | - Reynold A Panettieri
- Rutgers Institute for Translational Medicine and Science (RITMS), Rutgers, The State University of New Jersey, Rm# 4276, 89 French Street, New Brunswick, NJ08901, USA
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16
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Evasovic JM, Singer CA. Regulation of IL-17A and implications for TGF-β1 comodulation of airway smooth muscle remodeling in severe asthma. Am J Physiol Lung Cell Mol Physiol 2019; 316:L843-L868. [PMID: 30810068 PMCID: PMC6589583 DOI: 10.1152/ajplung.00416.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Severe asthma develops as a result of heightened, persistent symptoms that generally coincide with pronounced neutrophilic airway inflammation. In individuals with severe asthma, symptoms are poorly controlled by high-dose inhaled glucocorticoids and often lead to elevated morbidity and mortality rates that underscore the necessity for novel drug target identification that overcomes limitations in disease management. Many incidences of severe asthma are mechanistically associated with T helper 17 (TH17) cell-derived cytokines and immune factors that mediate neutrophilic influx to the airways. TH17-secreted interleukin-17A (IL-17A) is an independent risk factor for severe asthma that impacts airway smooth muscle (ASM) remodeling. TH17-derived cytokines and diverse immune mediators further interact with structural cells of the airway to induce pathophysiological processes that impact ASM functionality. Transforming growth factor-β1 (TGF-β1) is a pivotal mediator involved in airway remodeling that correlates with enhanced TH17 activity in individuals with severe asthma and is essential to TH17 differentiation and IL-17A production. IL-17A can also reciprocally enhance activation of TGF-β1 signaling pathways, whereas combined TH1/TH17 or TH2/TH17 immune responses may additively impact asthma severity. This review seeks to provide a comprehensive summary of cytokine-driven T cell fate determination and TH17-mediated airway inflammation. It will further review the evidence demonstrating the extent to which IL-17A interacts with various immune factors, specifically TGF-β1, to contribute to ASM remodeling and altered function in TH17-driven endotypes of severe asthma.
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Affiliation(s)
- Jon M Evasovic
- Department of Pharmacology, School of Medicine, University of Nevada , Reno, Nevada
| | - Cherie A Singer
- Department of Pharmacology, School of Medicine, University of Nevada , Reno, Nevada
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Tan CMJ, Green P, Tapoulal N, Lewandowski AJ, Leeson P, Herring N. The Role of Neuropeptide Y in Cardiovascular Health and Disease. Front Physiol 2018; 9:1281. [PMID: 30283345 PMCID: PMC6157311 DOI: 10.3389/fphys.2018.01281] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
Neuropeptide Y (NPY) is an abundant sympathetic co-transmitter, widely found in the central and peripheral nervous systems and with diverse roles in multiple physiological processes. In the cardiovascular system it is found in neurons supplying the vasculature, cardiomyocytes and endocardium, and is involved in physiological processes including vasoconstriction, cardiac remodeling, and angiogenesis. It is increasingly also implicated in cardiovascular disease pathogenesis, including hypertension, atherosclerosis, ischemia/infarction, arrhythmia, and heart failure. This review will focus on the physiological and pathogenic role of NPY in the cardiovascular system. After summarizing the NPY receptors which predominantly mediate cardiovascular actions, along with their signaling pathways, individual disease processes will be considered. A thorough understanding of these roles may allow therapeutic targeting of NPY and its receptors.
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Affiliation(s)
- Cheryl M J Tan
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peregrine Green
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
| | - Nidi Tapoulal
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
| | - Adam J Lewandowski
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul Leeson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
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18
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Huang C, Wu P, Jiang WD, Liu Y, Zeng YY, Jiang J, Kuang SY, Tang L, Zhang YA, Zhou XQ, Feng L. Deoxynivalenol decreased the growth performance and impaired intestinal physical barrier in juvenile grass carp (Ctenopharyngodon idella). FISH & SHELLFISH IMMUNOLOGY 2018; 80:376-391. [PMID: 29906621 DOI: 10.1016/j.fsi.2018.06.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 06/01/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
Deoxynivalenol (DON) is one of the most common mycotoxin contaminants of animal feed worldwide and brings significant threats to the animal production. However, studies concerning the effect of DON on fish intestine are scarce. This study explored the effects of DON on intestinal physical barrier in juvenile grass carp (Ctenopharyngodon idella). A total of 1440 juvenile grass carp (12.17 ± 0.01 g) were fed six diets containing graded levels of DON (27, 318, 636, 922, 1243 and 1515 μg/kg diet) for 60 days. This study for the first time documented that DON caused body malformation in fish, and histopathological lesions, oxidative damage, declining antioxidant capacity, cell apoptosis and destruction of tight junctions in the intestine of fish. The results indicated that compared with control group (27 μg/kg diet), DON: (1) increased the reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC) content, and up-regulated the mRNA levels of Kelch-like-ECH-associated protein 1 (Keap1: Keap1a but not Keap1b), whereas decreased glutathione (GSH) content and antioxidant enzymes activities, and down-regulated the mRNA levels of antioxidant enzymes (except GSTR in MI) and NF-E2-related factor 2 (Nrf2), as well as the protein levels of Nrf2 in fish intestine. (2) up-regulated cysteinyl aspartic acid-protease (caspase) -3, -7, -8, -9, apoptotic protease activating factor-1 (Apaf-1), Bcl2-associated X protein (Bax), Fas ligand (FasL) and c-Jun N-terminal protein kinase (JNK) mRNA levels, whereas down-regulated B-cell lymphoma-2 (bcl-2) and myeloid cell leukemia-1 (Mcl-1) mRNA levels in fish intestine. (3) down-regulated the mRNA levels of ZO-1, ZO-2b, occludin, claudin-c, -f, -7a, -7b, -11 (except claudin-b and claudin-3c), whereas up-regulated the mRNA levels of claudin-12, -15a (not -15b) and myosin light chain kinase (MLCK) in fish intestine. All above data indicated that DON caused the oxidative damage, apoptosis and the destruction of tight junctions via Nrf2, JNK and MLCK signaling in the intestine of fish, respectively. Finally, based on PWG, FE, PC and MDA, the safe dose of DON for grass carp were all estimated to be 318 μg/kg diet.
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Affiliation(s)
- Chen Huang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Pei Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wei-Dan Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yang Liu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yun-Yun Zeng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jun Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Sheng-Yao Kuang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Ling Tang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Yong-An Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China; Fish Nutrition and safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, 611130, China.
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Shimoyama H. A structural comparison of ‘real’ and ‘model’ calmodulin clarified allosteric interactions regulating domain motion. J Biomol Struct Dyn 2018; 37:1567-1581. [DOI: 10.1080/07391102.2018.1462730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hiromitsu Shimoyama
- School of Pharmacy, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
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20
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Lin L, Liu C, Nayak BC, He W, You M, Yuchi Z. A two-step purification strategy using calmodulin as an affinity tag. J Chromatogr A 2018; 1544:16-22. [PMID: 29499842 DOI: 10.1016/j.chroma.2018.02.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/01/2018] [Accepted: 02/21/2018] [Indexed: 11/19/2022]
Abstract
Calmodulin (CaM) is a Ca2+-binding protein that plays an important role in cellular Ca2+-signaling. CaM interacts with diverse downstream target proteins and regulates their functions in a Ca2+-dependent manner. CaM changes its conformation and hydrophobicity upon [Ca2+] change and consequently changes its interaction with CaM-binding domains from the targets. Based on these special properties of CaM, it was used as an affinity tag to develop a novel purification strategy by using it for two sequential orthogonal purification steps: 1) an affinity purification step, in which CaM-tag interacts with an immobilized CaM-binding domain; and 2) a hydrophobic interaction chromatography step, during which CaM binds to a phenyl sepharose column. In both steps, the CaM-tagged protein binds in the presence of Ca2+ and unbinds in the presence of ethylenediaminetetraacetic acid (EDTA). An optional third step can be added to remove the CaM-tag if necessary. We used green fluorescent protein (GFP) as a test protein to demonstrate the effectiveness of the method. High yield and high purity of GFP with proper function was obtained using this novel strategy. We believe that this method can be applied to a wide range of protein targets for structural and functional studies.
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Affiliation(s)
- Lianyun Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Fujian-Taiwan Joint Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Chen Liu
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Bidhan Chandra Nayak
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Weiyi He
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Fujian-Taiwan Joint Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China; Fujian-Taiwan Joint Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
| | - Zhiguang Yuchi
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China.
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21
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Xu Z, Liang H, Zhang M, Tao X, Dou D, Hu L, Kang T. Ardipusilloside-I stimulates gastrointestinal motility and phosphorylation of smooth muscle myosin by myosin light chain kinase. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:609-616. [PMID: 29200903 PMCID: PMC5709477 DOI: 10.4196/kjpp.2017.21.6.609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/01/2017] [Indexed: 12/17/2022]
Abstract
Ardipusilloside-I is a natural triterpenoid saponin, which was isolated from Ardisia pusilla A. DC. The aim of the study was to evaluate the stimulation of ardipusilloside-I on gastrointestinal motility in vitro and in vivo. The experiment of smooth muscle contraction directly monitored the contractions of the isolated jejunal segment (IJS) in different contractile states, and the effects of ardipusilloside-I on myosin were measured in the presence of Ca2+-calmodulin using the activities of 20 kDa myosin light chain (MLC20) phosphorylation and myosin Mg2+-ATPase. The effects of ardipusilloside-I on gastro emptying and intestinal transit in constipation-predominant rats were observed, and the MLCK expression in jejuna of constipated rats was determined by western blot. The results showed that, ardipusilloside-I increased the contractility of IJS in a dose-dependent manner and reversed the low contractile state (LCS) of IJS induced by low Ca2+, adrenaline, and atropine respectively. There were synergistic effects on contractivity of IJS between ardipusilloside-I and ACh, high Ca2+, and histamine, respectively. Ardipusilloside-I could stimulate the phosphorylation of MLC20 and Mg2+-ATPase activities of Ca2+- dependent phosphorylated myosin. Ardipusilloside-I also stimulated the gastric emptying and intestinal transit in normal and constipated rats in vivo, respectively, and increased the MLCK expression in the jejuna of constipation-predominant rats. Briefly, the findings demonstrated that ardipusilloside-I could effectively excite gastrointestinal motility in vitro and in vivo.
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Affiliation(s)
- Zhili Xu
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
| | - Hanye Liang
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
| | - Mingbo Zhang
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
| | - Xiaojun Tao
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
| | - Deqiang Dou
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
| | - Liping Hu
- College of Information Science & Technology, Liaoning University of Traditional Chinese Medicine, Liaoning 110847, PR China
| | - Tingguo Kang
- College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Liaoning 116600, PR China
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Prasad AM, Ketsawatsomkron P, Nuno DW, Koval OM, Dibbern ME, Venema AN, Sigmund CD, Lamping KG, Grumbach IM. Role of CaMKII in Ang-II-dependent small artery remodeling. Vascul Pharmacol 2016; 87:172-179. [PMID: 27658984 DOI: 10.1016/j.vph.2016.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/22/2016] [Accepted: 09/18/2016] [Indexed: 01/21/2023]
Abstract
Angiotensin-II (Ang-II) is a well-established mediator of vascular remodeling. The multifunctional calcium-calmodulin-dependent kinase II (CaMKII) is activated by Ang-II and regulates Erk1/2 and Akt-dependent signaling in cultured smooth muscle cells in vitro. Its role in Ang-II-dependent vascular remodeling in vivo is far less defined. Using a model of transgenic CaMKII inhibition selectively in smooth muscle cells, we found that CaMKII inhibition exaggerated remodeling after chronic Ang-II treatment and agonist-dependent vasoconstriction in second-order mesenteric arteries. These findings were associated with increased mRNA and protein expression of smooth muscle structural proteins. As a potential mechanism, CaMKII reduced serum response factor-dependent transcriptional activity. In summary, our findings identify CaMKII as an important regulator of smooth muscle function in Ang-II hypertension in vivo.
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Affiliation(s)
- Anand M Prasad
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States
| | - Pimonrat Ketsawatsomkron
- Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Daniel W Nuno
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States; Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Olha M Koval
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States
| | - Megan E Dibbern
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States
| | - Ashlee N Venema
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States
| | - Curt D Sigmund
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States; Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, United States; Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Kathryn G Lamping
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States; Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, United States; Iowa City VA Healthcare System, Iowa City, United States
| | - Isabella M Grumbach
- Department of Medicine, Carver College, University of Iowa, Iowa City, United States; Iowa City VA Healthcare System, Iowa City, United States.
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23
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Fernandes VS, Recio P, López-Oliva E, Martínez MP, Ribeiro AS, Barahona MV, Martínez AC, Benedito S, Agis-Torres Á, Cabañero A, Muñoz GM, García-Sacristán A, Orensanz LM, Hernández M. Role of endogenous hydrogen sulfide in nerve-evoked relaxation of pig terminal bronchioles. Pulm Pharmacol Ther 2016; 41:1-10. [PMID: 27603231 DOI: 10.1016/j.pupt.2016.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/05/2016] [Accepted: 09/02/2016] [Indexed: 12/26/2022]
Abstract
Hydrogen sulfide (H2S) is a gasotransmitter employed for intra- and inter-cellular communication in almost all organ systems. This study investigates the role of endogenous H2S in nerve-evoked relaxation of pig terminal bronchioles with 260 μm medium internal lumen diameter. High expression of the H2S synthesis enzyme cystathionine γ-lyase (CSE) in the bronchiolar muscle layer and strong CSE-immunoreactivity within nerve fibers distributed along smooth muscle bundles were observed. Further, endogenous H2S generated in bronchiolar membranes was reduced by CSE inhibition. In contrast, cystathionine β-synthase expression, another H2S synthesis enzyme, however was not consistently detected in the bronchiolar smooth muscle layer. Electrical field stimulation (EFS) and the H2S donor P-(4-methoxyphenyl)-P-4-morpholinylphosphinodithioic acid (GYY4137) evoked smooth muscle relaxation. Inhibition of CSE, nitric oxide (NO) synthase, soluble guanylyl cyclase (sGC) and of ATP-dependent K+, transient receptor potential A1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) channels reduced the EFS relaxation but failed to modify the GYY4137 response. Raising extracellular K+ concentration inhibited the GYY4137 relaxation. Large conductance Ca2+-activated K+ channel blockade reduced both EFS and GYY4137 responses. GYY4137 inhibited the contractions induced by histamine and reduced to a lesser extent the histamine-induced increases in intracellular [Ca2+]. These results suggest that relaxation induced by EFS in the pig terminal bronchioles partly involves the H2S/CSE pathway. H2S response is produced via NO/sGC-independent mechanisms involving K+ channels and intracellular Ca2+ desensitization-dependent pathways. Thus, based on our current results H2S donors might be useful as bronchodilator agents for the treatment of lung diseases with persistent airflow limitation, such as asthma and chronic obstructive lung disease.
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Affiliation(s)
- Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ana Sofía Ribeiro
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Victoria Barahona
- Departamento de Toxicología y Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ana Cristina Martínez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ángel Agis-Torres
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Alberto Cabañero
- Servicio de Cirugía Torácica, Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain
| | - Gemma M Muñoz
- Servicio de Cirugía Torácica, Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain
| | - Albino García-Sacristán
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Luis M Orensanz
- Servicio de Neurobiología-Investigación, Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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24
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Differentiation of Human Adipose Derived Stem Cells into Smooth Muscle Cells Is Modulated by CaMKIIγ. Stem Cells Int 2016; 2016:1267480. [PMID: 27493668 PMCID: PMC4963582 DOI: 10.1155/2016/1267480] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 12/13/2022] Open
Abstract
The multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is known to participate in maintenance and switches of smooth muscle cell (SMC) phenotypes. However, which isoform of CaMKII is involved in differentiation of adult mesenchymal stem cells into contractile SMCs remains unclear. In the present study, we detected γ isoform of CaMKII in differentiation of human adipose derived stem cells (hASCs) into SMCs that resulted from treatment with TGF-β1 and BMP4 in combination for 7 days. The results showed that CaMKIIγ increased gradually during differentiation of hASCs as determined by real-time PCR and western blot analysis. The siRNA-mediated knockdown of CaMKIIγ decreased the protein levels and transcriptional levels of smooth muscle contractile markers (a-SMA, SM22a, calponin, and SM-MHC), while CaMKIIγ overexpression increases the transcriptional and protein levels of smooth muscle contractile markers. These results suggested that γ isoform of CaMKII plays a significant role in smooth muscle differentiation of hASCs.
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25
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CaMKII in addition to MLCK contributes to phosphorylation of regulatory light chain in cardiomyocytes. Biochem Biophys Res Commun 2016; 471:219-25. [PMID: 26809094 DOI: 10.1016/j.bbrc.2016.01.132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 01/21/2016] [Indexed: 11/23/2022]
Abstract
The aim was to identify kinase activities involved in the phosphorylation of regulatory light chain (RLC) in situ in cardiomyocytes. In electrically stimulated rat cardiomyocytes, phosphatase inhibition by calyculin A unmasked kinase activities evoking an increase of phosphorylated RLC (P-RLC) from about 16% to about 80% after 80 min. The phosphorylation rate in cardiomyocytes was reduced by about 40% by the myosin light chain kinase (MLCK) inhibitor, ML-7. In rat ventricular muscle strips, calyculin A induced a positive inotropic effect that correlated with P-RLC levels. The inotropic effect and P-RLC elevation were abolished by ML-7 treatment. The kinase activities phosphorylating RLC in cardiomyocytes were reduced by about 60% by the non-selective kinase inhibitor staurosporine and by about 50% by the calmodulin antagonist W7. W7 eliminated the inhibitory effect of ML-7, suggesting that the cardiac MLCK is Ca(2+)/calmodulin (CaM)-dependent. The CaM-dependent kinase II (CaMKII) inhibitor KN-93 attenuated the calyculin A-induced RLC phosphorylation by about 40%, indicating a contribution from CaMKII. The residual phosphorylation in the presence of W7 indicated that also CaM-independent kinase activities might contribute. RLC phosphorylation was insensitive to protein kinase C inhibition. In conclusion, in addition to MLCK, CaMKII phosphorylates RLC in cardiomyocytes. Involvement of other kinases cannot be excluded.
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26
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Anderson CD, Kendig DM, Al-Qudah M, Mahavadi S, Murthy KS, Grider JR. Role of various kinases in muscarinic M3 receptor-mediated contraction of longitudinal muscle of rat colon. J Smooth Muscle Res 2015; 50:103-19. [PMID: 25891767 PMCID: PMC4862207 DOI: 10.1540/jsmr.50.103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The longitudinal muscle layer in gut is the functional opponent to the circular muscle
layer during peristalsis. Differences in innervation of the layers allow for the
contraction of one layer concurrently with the relaxation of the other, enabling the
passage of gut contents in a controlled fashion. Differences in development have given the
cells of the two layers differences in receptor populations, membrane lipid handling, and
calcium handling profiles/behaviors. The contractile activity of the longitudinal muscle
is largely mediated by cholinergic neural input from myenteric plexus. Activation of
muscarinic receptors leads to rapid activation of several kinases including MLC kinase,
ERK1/2, CaMKII and Rho kinase. Phosphorylation of myosin light chain (MLC20) by
MLC kinase (MLCK) is a prerequisite for contraction in both circular and longitudinal
muscle cells. In rat colonic longitudinal muscle strips, we measured muscarinic
receptor-mediated contraction following incubation with kinase inhibitors. Basal tension
was differentially regulated by Rho kinase, ERK1/2, CaMKII and CaMKK. Selective inhibitors
of Rho kinase, ERK1/2, CaMKK/AMPK, and CaMKII each reduced carbachol-induced contraction
in the innervated muscle strips. These inhibitors had no direct effect on MLCK activity.
Thus unlike previously reported for isolated muscle cells where CaMKII and ERK1/2 are not
involved in contraction, we conclude that the regulation of carbachol-induced contraction
in innervated longitudinal muscle strips involves the interplay of Rho kinase, ERK1/2,
CaMKK/AMPK, and CAMKII.
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Affiliation(s)
- Charles D Anderson
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, USA
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27
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Chen C, Tao T, Wen C, He WQ, Qiao YN, Gao YQ, Chen X, Wang P, Chen CP, Zhao W, Chen HQ, Ye AP, Peng YJ, Zhu MS. Myosin light chain kinase (MLCK) regulates cell migration in a myosin regulatory light chain phosphorylation-independent mechanism. J Biol Chem 2014; 289:28478-88. [PMID: 25122766 DOI: 10.1074/jbc.m114.567446] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Myosin light chain kinase (MLCK) has long been implicated in the myosin phosphorylation and force generation required for cell migration. Here, we surprisingly found that the deletion of MLCK resulted in fast cell migration, enhanced protrusion formation, and no alteration of myosin light chain phosphorylation. The mutant cells showed reduced membrane tether force and fewer membrane F-actin filaments. This phenotype was rescued by either kinase-dead MLCK or five-DFRXXL motif, a MLCK fragment with potent F-actin-binding activity. Pull-down and co-immunoprecipitation assays showed that the absence of MLCK led to attenuated formation of transmembrane complexes, including myosin II, integrins and fibronectin. We suggest that MLCK is not required for myosin phosphorylation in a migrating cell. A critical role of MLCK in cell migration involves regulating the cell membrane tension and protrusion necessary for migration, thereby stabilizing the membrane skeleton through F-actin-binding activity. This finding sheds light on a novel regulatory mechanism of protrusion during cell migration.
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Affiliation(s)
- Chen Chen
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Tao Tao
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Cheng Wen
- School of Electronics Engineering and Computer Science, Key Laboratory for the Physics & Chemistry of Nanodevices of Ministry of Education, Peking University, Beijing 100871, P.R. China, and
| | - Wei-Qi He
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Yan-Ning Qiao
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Yun-Qian Gao
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Xin Chen
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Pei Wang
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Cai-Ping Chen
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Wei Zhao
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China
| | - Hua-Qun Chen
- School of Life Science, Nanjing Normal University, Nanjing 210009, P.R. China
| | - An-Pei Ye
- School of Electronics Engineering and Computer Science, Key Laboratory for the Physics & Chemistry of Nanodevices of Ministry of Education, Peking University, Beijing 100871, P.R. China, and
| | - Ya-Jing Peng
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China,
| | - Min-Sheng Zhu
- From the Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing 210061, P.R. China, School of Life Science, Nanjing Normal University, Nanjing 210009, P.R. China
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28
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Tang ZY, Lin Y, Yang XL, Wei W, Tang ZY. Inhibitory effect of potassium alum on smooth muscle contraction of rabbit and its mechanism. Chin J Integr Med 2014. [PMID: 25012630 DOI: 10.1007/s11655-014-1330-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To investigate the effects of potassium alum (Alunite) on smooth muscle contraction and phosphorylation of myosin light chain by myosin light chain kinase (MLCK) and to try to find out the clue of its mechanism. METHODS An isolated rabbit duodenum smooth muscle strip was selected to study the effects of potassium alum on its contractile activity under the condition of Krebs' solution using HW-400S constant temperature smooth muscle trough. The myosin and MLCK were purified from chicken gizzard smooth muscle. Myosin light chain phosphorylation was determined by glycerol-polyacrylamide gel electrophoresis; myosin Mg2+-ATPase activity was measured by inorganic phosphate liberation method. RESULTS Potassium alum (2.5-20 mmol/L) inhibited the contraction on duodenum in a dose-related and a time-dependent manner; potassium alum could also inhibit the extent of phosphorylation of myosin light chain in a dose-related and a time-dependent manner; and potassium alum inhibited the extent of Mg2+-ATPase activity in a dose-related manner. CONCLUSIONS Potassium alum inhibited smooth muscle contraction in a way of inhibiting phosphorylation of myosin light chain and Mg2+-ATPase activity. This has revealed the molecular mechanism of treatment of gastrointestinal spastic disorders by potassium alum.
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Affiliation(s)
- Zhong-Yuan Tang
- Department of Pharmacology, Dalian Medical University, Dalian, Liaoning Province, 116044, China
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29
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Tsai MH, Chang AN, Huang J, He W, Sweeney HL, Zhu M, Kamm KE, Stull JT. Constitutive phosphorylation of myosin phosphatase targeting subunit-1 in smooth muscle. J Physiol 2014; 592:3031-51. [PMID: 24835173 DOI: 10.1113/jphysiol.2014.273011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Smooth muscle contraction initiated by myosin regulatory light chain (RLC) phosphorylation is dependent on the relative activities of Ca(2+)-calmodulin-dependent myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP). We have investigated the physiological role of the MLCP regulatory subunit MYPT1 in bladder smooth muscle containing a smooth muscle-specific deletion of MYPT1 in adult mice. Deep-sequencing analyses of mRNA and immunoblotting revealed that MYPT1 depletion reduced the amount of PP1cδ with no compensatory changes in expression of other MYPT1 family members. Phosphatase activity towards phosphorylated smooth muscle heavy meromyosin was proportional to the amount of PP1cδ in total homogenates from wild-type or MYPT1-deficient tissues. Isolated MYPT1-deficient tissues from MYPT1(SM-/-) mice contracted with moderate differences in response to KCl and carbachol treatments, and relaxed rapidly with comparable rates after carbachol removal and only 1.5-fold slower after KCl removal. Measurements of phosphorylated proteins in the RLC signalling and actin polymerization modules during contractions revealed moderate changes. Using a novel procedure to quantify total phosphorylation of MYPT1 at Thr696 and Thr853, we found substantial phosphorylation in wild-type tissues under resting conditions, predicting attenuation of MLCP activity. Reduced PP1cδ activity in MYPT1-deficient tissues may be similar to the attenuated MLCP activity in wild-type tissues resulting from constitutively phosphorylated MYPT1. Constitutive phosphorylation of MYPT1 Thr696 and Thr853 may thus represent a physiological mechanism acting in concert with agonist-induced MYPT1 phosphorylation to inhibit MLCP activity. In summary, MYPT1 deficiency may not cause significant derangement of smooth muscle contractility because the effective MLCP activity is not changed.
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Affiliation(s)
- Ming-Ho Tsai
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Audrey N Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jian Huang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Weiqi He
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China
| | - H Lee Sweeney
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Minsheng Zhu
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China
| | - Kristine E Kamm
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
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30
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Ribeiro AS, Fernandes VS, Martínez‐Sáenz A, Martínez P, Barahona MV, Orensanz LM, Blaha I, Serrano‐Margüello D, Bustamante S, Carballido J, García‐Sacristán A, Prieto D, Hernández M. Powerful Relaxation of Phosphodiesterase Type 4 Inhibitor Rolipram in the Pig and Human Bladder Neck. J Sex Med 2014; 11:930-941. [DOI: 10.1111/jsm.12456] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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31
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Hong F, Facemyer KC, Carter MS, Jackson DR, Haldeman BD, Ruana N, Sutherland C, Walsh MP, Cremo CR, Baker JE. Kinetics of myosin light chain kinase activation of smooth muscle myosin in an in vitro model system. Biochemistry 2013; 52:8489-500. [PMID: 24144337 DOI: 10.1021/bi401001x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
During activation of smooth muscle contraction, one myosin light chain kinase (MLCK) molecule rapidly phosphorylates many smooth muscle myosin (SMM) molecules, suggesting that muscle activation rates are influenced by the kinetics of MLCK-SMM interactions. To determine the rate-limiting step underlying activation of SMM by MLCK, we measured the kinetics of calcium-calmodulin (Ca²⁺CaM)-MLCK-mediated SMM phosphorylation and the corresponding initiation of SMM-based F-actin motility in an in vitro system with SMM attached to a coverslip surface. Fitting the time course of SMM phosphorylation to a kinetic model gave an initial phosphorylation rate, kp(o), of ~1.17 heads s⁻¹ MLCK⁻¹. Also, we measured the dwell time of single streptavidin-coated quantum dot-labeled MLCK molecules interacting with surface-attached SMM and phosphorylated SMM using total internal reflection fluorescence microscopy. From these data, the dissociation rate constant from phosphorylated SMM was 0.80 s⁻¹, which was similar to the kp(o) mentioned above and with rates measured in solution. This dissociation rate was essentially independent of the phosphorylation state of SMM. From calculations using our measured dissociation rates and Kd values, and estimates of SMM and MLCK concentrations in muscle, we predict that the dissociation of MLCK from phosphorylated SMM is rate-limiting and that the rate of the phosphorylation step is faster than this dissociation rate. Also, association with SMM (11-46 s⁻¹) would be much faster than with pSMM (<0.1-0.2 s⁻¹). This suggests that the probability of MLCK interacting with unphosphorylated versus phosphorylated SMM is 55-460 times greater. This would avoid sequestering MLCK to unproductive interactions with previously phosphorylated SMM, potentially leading to faster rates of phosphorylation in muscle.
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Affiliation(s)
- Feng Hong
- Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine , Reno, Nevada 99557, United States
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32
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Woody S, Stall R, Ramos J, Patel YM. Regulation of myosin light chain kinase during insulin-stimulated glucose uptake in 3T3-L1 adipocytes. PLoS One 2013; 8:e77248. [PMID: 24116218 PMCID: PMC3792908 DOI: 10.1371/journal.pone.0077248] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/09/2013] [Indexed: 11/25/2022] Open
Abstract
Myosin II (MyoII) is required for insulin-responsive glucose transporter 4 (GLUT4)-mediated glucose uptake in 3T3-L1 adipocytes. Our previous studies have shown that insulin signaling stimulates phosphorylation of the regulatory light chain (RLC) of MyoIIA via myosin light chain kinase (MLCK). The experiments described here delineate upstream regulators of MLCK during insulin-stimulated glucose uptake. Since 3T3-L1 adipocytes express two MyoII isoforms, we wanted to determine which isoform was required for insulin-stimulated glucose uptake. Using a siRNA approach, we demonstrate that a 60% decrease in MyoIIA protein expression resulted in a 40% inhibition of insulin-stimulated glucose uptake. We also show that insulin signaling stimulates the phosphorylation of MLCK. We further show that MLCK can be activated by calcium as well as signaling pathways. We demonstrate that adipocytes treated with the calcium chelating agent, 1,2-b (iso-aminophenoxy) ethane-N,N,N',N'-tetra acetic acid, (BAPTA) (in the presence of insulin) impaired the insulin-induced phosphorylation of MLCK by 52% and the RLC of MyoIIA by 45% as well as impairing the recruitment of MyoIIA to the plasma membrane when compared to cells treated with insulin alone. We further show that the calcium ionophore, A23187 alone stimulated the phosphorylation of MLCK and the RLC associated with MyoIIA to the same extent as insulin. To identify signaling pathways that might regulate MLCK, we examined ERK and CaMKII. Inhibition of ERK2 impaired phosphorylation of MLCK and insulin-stimulated glucose uptake. In contrast, while inhibition of CaMKII did inhibit phosphorylation of the RLC associated with MyoIIA, inhibition of CAMKIIδ did not impair MLCK phosphorylation or translocation to the plasma membrane or glucose uptake. Collectively, our results are the first to delineate a role for calcium and ERK in the activation of MLCK and thus MyoIIA during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.
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Affiliation(s)
- Shelly Woody
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
| | - Richard Stall
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
| | - Joseph Ramos
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
| | - Yashomati M. Patel
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
- * E-mail:
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33
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Fernandes VS, Ribeiro AS, Barahona MV, Orensanz LM, Martínez-Sáenz A, Recio P, Martínez AC, Bustamante S, Carballido J, García-Sacristán A, Prieto D, Hernández M. Hydrogen Sulfide Mediated Inhibitory Neurotransmission to the Pig Bladder Neck: Role of K
ATP
Channels, Sensory Nerves and Calcium Signaling. J Urol 2013; 190:746-56. [DOI: 10.1016/j.juro.2013.02.103] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 02/21/2013] [Indexed: 10/27/2022]
Affiliation(s)
- Vítor S. Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ana S.F. Ribeiro
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - María Victoria Barahona
- Departamento de Toxicología y Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - Luis M. Orensanz
- Departamento de Investigación, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Ana Martínez-Sáenz
- Departamento de Urología, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ana Cristina Martínez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Salvador Bustamante
- Departamento de Urología, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain
| | - Joaquín Carballido
- Departamento de Urología, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain
| | - Albino García-Sacristán
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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Prasad AM, Nuno DW, Koval OM, Ketsawatsomkron P, Li W, Li H, Shen FY, Joiner MLA, Kutschke W, Weiss RM, Sigmund CD, Anderson ME, Lamping KG, Grumbach IM. Differential control of calcium homeostasis and vascular reactivity by Ca2+/calmodulin-dependent kinase II. Hypertension 2013; 62:434-41. [PMID: 23753415 DOI: 10.1161/hypertensionaha.113.01508] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The multifunctional Ca(2+)/calmodulin-dependent kinase II (CaMKII) is activated by vasoconstrictors in vascular smooth muscle cells (VSMC), but its impact on vasoconstriction remains unknown. We hypothesized that CaMKII inhibition in VSMC decreases vasoconstriction. Using novel transgenic mice that express the inhibitor peptide CaMKIIN in smooth muscle (TG SM-CaMKIIN), we investigated the effect of CaMKII inhibition on L-type Ca(2+) channel current (ICa), cytoplasmic and sarcoplasmic reticulum Ca(2+), and vasoconstriction in mesenteric arteries. In mesenteric VSMC, CaMKII inhibition significantly reduced action potential duration and the residual ICa 50 ms after peak amplitude, indicative of loss of L-type Ca(2+) channel-dependent ICa facilitation. Treatment with angiotensin II or phenylephrine increased the intracellular Ca(2+) concentration in wild-type but not TG SM-CaMKIIN VSMC. The difference in intracellular Ca(2+) concentration was abolished by pretreatment with nifedipine, an L-type Ca(2+) channel antagonist. In TG SM-CaMKIIN VSMC, the total sarcoplasmic reticulum Ca(2+) content was reduced as a result of diminished sarcoplasmic reticulum Ca(2+) ATPase activity via impaired derepression of the sarcoplasmic reticulum Ca(2+) ATPase inhibitor phospholamban. Despite the differences in intracellular Ca(2+) concentration, CaMKII inhibition did not alter myogenic tone or vasoconstriction of mesenteric arteries in response to KCl, angiotensin II, and phenylephrine. However, it increased myosin light chain kinase activity. These data suggest that CaMKII activity maintains intracellular calcium homeostasis but is not required for vasoconstriction of mesenteric arteries.
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Affiliation(s)
- Anand M Prasad
- Department of Medicine, University of Iowa, Iowa City, IA 52242, USA
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35
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Gao N, Huang J, He W, Zhu M, Kamm KE, Stull JT. Signaling through myosin light chain kinase in smooth muscles. J Biol Chem 2013; 288:7596-7605. [PMID: 23362260 DOI: 10.1074/jbc.m112.427112] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK) phosphorylates smooth muscle myosin regulatory light chain (RLC) to initiate contraction. We used a tamoxifen-activated, smooth muscle-specific inactivation of MLCK expression in adult mice to determine whether MLCK was differentially limiting in distinct smooth muscles. A 50% decrease in MLCK in urinary bladder smooth muscle had no effect on RLC phosphorylation or on contractile responses, whereas an 80% decrease resulted in only a 20% decrease in RLC phosphorylation and contractile responses to the muscarinic agonist carbachol. Phosphorylation of the myosin light chain phosphatase regulatory subunit MYPT1 at Thr-696 and Thr-853 and the inhibitor protein CPI-17 were also stimulated with carbachol. These results are consistent with the previous findings that activation of a small fraction of MLCK by limiting amounts of free Ca(2+)/calmodulin combined with myosin light chain phosphatase inhibition is sufficient for robust RLC phosphorylation and contractile responses in bladder smooth muscle. In contrast, a 50% decrease in MLCK in aortic smooth muscle resulted in 40% inhibition of RLC phosphorylation and aorta contractile responses, whereas a 90% decrease profoundly inhibited both responses. Thus, MLCK content is limiting for contraction in aortic smooth muscle. Phosphorylation of CPI-17 and MYPT1 at Thr-696 and Thr-853 were also stimulated with phenylephrine but significantly less than in bladder tissue. These results indicate differential contributions of MLCK to signaling. Limiting MLCK activity combined with modest Ca(2+) sensitization responses provide insights into how haploinsufficiency of MLCK may result in contractile dysfunction in vivo, leading to dissections of human thoracic aorta.
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Affiliation(s)
- Ning Gao
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Jian Huang
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Weiqi He
- Model Animal Research Center and Ministry of Education Key Laboratory of Model Animal for Disease Study, Nanjing University, 210061 Nanjing, China
| | - Minsheng Zhu
- Model Animal Research Center and Ministry of Education Key Laboratory of Model Animal for Disease Study, Nanjing University, 210061 Nanjing, China
| | - Kristine E Kamm
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390.
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36
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The pivotal role of airway smooth muscle in asthma pathophysiology. J Allergy (Cairo) 2011; 2011:742710. [PMID: 22220184 PMCID: PMC3246780 DOI: 10.1155/2011/742710] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 08/30/2011] [Indexed: 12/13/2022] Open
Abstract
Asthma is characterized by the association of airway hyperresponsiveness (AHR), inflammation, and remodelling. The aim of the present article is to review the pivotal role of airway smooth muscle (ASM) in the pathophysiology of asthma. ASM is the main effector of AHR. The mechanisms of AHR in asthma may involve a larger release of contractile mediators and/or a lower release of relaxant mediators, an improved ASM cell excitation/contraction coupling, and/or an alteration in the contraction/load coupling. Beyond its contractile function, ASM is also involved in bronchial inflammation and remodelling. Whereas ASM is a target of the inflammatory process, it can also display proinflammatory and immunomodulatory functions, through its synthetic properties and the expression of a wide range of cell surface molecules. ASM remodelling represents a key feature of asthmatic bronchial remodelling. ASM also plays a role in promoting complementary airway structural alterations, in particular by its synthetic function.
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37
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Borysova L, Shabir S, Walsh MP, Burdyga T. The importance of Rho-associated kinase-induced Ca2+ sensitization as a component of electromechanical and pharmacomechanical coupling in rat ureteric smooth muscle. Cell Calcium 2011; 50:393-405. [PMID: 21839512 DOI: 10.1016/j.ceca.2011.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/05/2011] [Accepted: 07/07/2011] [Indexed: 01/30/2023]
Abstract
Ureteric peristalsis, which occurs via alternating contraction and relaxation of ureteric smooth muscle, ensures the unidirectional flow of urine from the kidney to the bladder. Understanding of the molecular mechanisms underlying ureteric excitation-contraction coupling, however, is limited. To address these knowledge deficits, and in particular to test the hypothesis that Ca2+ sensitization via activation of the RhoA/Rho-associated kinase (ROK) pathway plays an important role in ureteric smooth muscle contraction, we carried out a thorough characterization of the electrical activity, Ca2+ signaling, MYPT1 (myosin targeting subunit of myosin light chain phosphatase, MLCP) and myosin regulatory light chain (LC20) phosphorylation, and force responses to membrane depolarization induced by KCl (electromechanical coupling) and carbachol (CCh) (pharmacomechanical coupling). The effects of ROK inhibition on these parameters were investigated. We conclude that the tonic, but not the phasic component of KCl- or CCh-induced ureteric smooth muscle contraction is highly dependent on ROK-catalyzed phosphorylation of MYPT1 at T855, leading to inhibition of MLCP and increased LC20 phosphorylation.
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Affiliation(s)
- Lyudmyla Borysova
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK
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38
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Arora PD, Wang Y, Janmey PA, Bresnick A, Yin HL, McCulloch CA. Gelsolin and non-muscle myosin IIA interact to mediate calcium-regulated collagen phagocytosis. J Biol Chem 2011; 286:34184-98. [PMID: 21828045 DOI: 10.1074/jbc.m111.247783] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The formation of adhesion complexes is the rate-limiting step for collagen phagocytosis by fibroblasts, but the role of Ca(2+) and the potential interactions of actin-binding proteins in regulating collagen phagocytosis are not well defined. We found that the binding of collagen beads to fibroblasts was temporally and spatially associated with actin assembly at nascent phagosomes, which was absent in gelsolin null cells. Analysis of tryptic digests isolated from gelsolin immunoprecipitates indicated that non-muscle (NM) myosin IIA may bind to gelsolin. Immunostaining and immunoprecipitation showed that gelsolin and NM myosin IIA associated at collagen adhesion sites. Gelsolin and NM myosin IIA were both required for collagen binding and internalization. Collagen binding to cells initiated a prolonged increase of [Ca(2+)](i), which was absent in cells null for gelsolin or NM myosin IIA. Collagen bead-induced increases of [Ca(2+)](i) were associated with phosphorylation of the myosin light chain, which was dependent on gelsolin. NM myosin IIA filament assembly, which was dependent on myosin light chain phosphorylation and increased [Ca(2+)](i), also required gelsolin. Ionomycin-induced increases of [Ca(2+)](i) overcame the block of myosin filament assembly in gelsolin null cells. We conclude that gelsolin and NM myosin IIA interact at collagen adhesion sites to enable NM myosin IIA filament assembly and localized, Ca(2+)-dependent remodeling of actin at the nascent phagosome and that these steps are required for collagen phagocytosis.
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Affiliation(s)
- Pamma D Arora
- Matrix Dynamics Group, University of Toronto, Toronto, Ontario M5S 3E2, Canada
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39
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Biochemistry of smooth muscle myosin light chain kinase. Arch Biochem Biophys 2011; 510:135-46. [PMID: 21565153 DOI: 10.1016/j.abb.2011.04.018] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 04/22/2011] [Accepted: 04/25/2011] [Indexed: 11/23/2022]
Abstract
The smooth muscle isoform of myosin light chain kinase (MLCK) is a Ca(2+)-calmodulin-activated kinase that is found in many tissues. It is particularly important for regulating smooth muscle contraction by phosphorylation of myosin. This review summarizes selected aspects of recent biochemical work on MLCK that pertains to its function in smooth muscle. In general, the focus of the review is on new findings, unresolved issues, and areas with the potential for high physiological significance that need further study. The review includes a concise summary of the structure, substrates, and enzyme activity, followed by a discussion of the factors that may limit the effective activity of MLCK in the muscle. The interactions of each of the many domains of MLCK with the proteins of the contractile apparatus, and the multi-domain interactions of MLCK that may control its behaviors in the cell are summarized. Finally, new in vitro approaches to studying the mechanism of phosphorylation of myosin are introduced.
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Abstract
The sarcoplasmic reticulum (SR) of smooth muscles presents many intriguing facets and questions concerning its roles, especially as these change with development, disease, and modulation of physiological activity. The SR's function was originally perceived to be synthetic and then that of a Ca store for the contractile proteins, acting as a Ca amplification mechanism as it does in striated muscles. Gradually, as investigators have struggled to find a convincing role for Ca-induced Ca release in many smooth muscles, a role in controlling excitability has emerged. This is the Ca spark/spontaneous transient outward current coupling mechanism which reduces excitability and limits contraction. Release of SR Ca occurs in response to inositol 1,4,5-trisphosphate, Ca, and nicotinic acid adenine dinucleotide phosphate, and depletion of SR Ca can initiate Ca entry, the mechanism of which is being investigated but seems to involve Stim and Orai as found in nonexcitable cells. The contribution of the elemental Ca signals from the SR, sparks and puffs, to global Ca signals, i.e., Ca waves and oscillations, is becoming clearer but is far from established. The dynamics of SR Ca release and uptake mechanisms are reviewed along with the control of luminal Ca. We review the growing list of the SR's functions that still includes Ca storage, contraction, and relaxation but has been expanded to encompass Ca homeostasis, generating local and global Ca signals, and contributing to cellular microdomains and signaling in other organelles, including mitochondria, lysosomes, and the nucleus. For an integrated approach, a review of aspects of the SR in health and disease and during development and aging are also included. While the sheer versatility of smooth muscle makes it foolish to have a "one model fits all" approach to this subject, we have tried to synthesize conclusions wherever possible.
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Affiliation(s)
- Susan Wray
- Department of Physiology, School of Biomedical Sciences, University of Liverpool, Liverpool, Merseyside L69 3BX, United Kingdom.
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41
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Dhaese I, Van Colen I, Lefebvre RA. Mechanisms of action of hydrogen sulfide in relaxation of mouse distal colonic smooth muscle. Eur J Pharmacol 2009; 628:179-86. [PMID: 19919833 DOI: 10.1016/j.ejphar.2009.11.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 10/29/2009] [Accepted: 11/10/2009] [Indexed: 12/24/2022]
Abstract
Hydrogen sulfide (H(2)S) has been suggested as a gaseous neuromodulator in mammals. The aim of this study was to examine the influence of H(2)S on contractility in mouse distal colon. The effect of sodium hydrogen sulfide (NaHS; H(2)S donor) on prostaglandin F(2alpha) (PGF(2alpha))-contracted circular muscle strips of mouse distal colon was investigated. In addition, tension and cytosolic calcium concentration ([Ca(2+)](cyt)) in the mouse distal colon strips were measured simultaneously in the presence of NaHS. NaHS caused concentration-dependent relaxation of the pre-contracted mouse distal colon strips. The NaHS-induced relaxation was not influenced by the K(+) channels blockers glibenclamide, apamin, charybdotoxin, barium chloride and 4-aminopyridine. The relaxation by NaHS was also not influenced by the nitric oxide inhibitor L-NAME, by the soluble guanylate cyclase respectively adenylate cyclase inhibitors ODQ and SQ 22536, by the nerve blockers capsazepine, omega-conotoxin and tetrodotoxin or by several channel and receptor blockers (ouabain, nifedipine, 2-aminoethyl diphenylborinate, ryanodine and thapsigargin). The initiation of the NaHS-induced relaxation was accompanied by an increase in [Ca(2+)](cyt), but once the relaxation was maximal and sustained, no change in [Ca(2+)](cyt) was measured. This calcium desensitization is not related to the best known calcium desensitizing mechanism as the myosin light chain phosphatase (MLCP) inhibitor calyculin-A and the Rho-kinase inhibitor Y-27632 had no influence. We conclude that NaHS caused concentration-dependent relaxations in mouse distal colon not involving the major known K(+) channels and without a change in [Ca(2+)](cyt). This calcium desensitization is not related to inhibition of Rho-kinase or activation of MLCP.
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Affiliation(s)
- Ingeborg Dhaese
- Heymans Institute of Pharmacology, Ghent University, Ghent, Belgium
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42
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Hong F, Haldeman BD, John OA, Brewer PD, Wu YY, Ni S, Wilson DP, Walsh MP, Baker JE, Cremo CR. Characterization of tightly associated smooth muscle myosin-myosin light-chain kinase-calmodulin complexes. J Mol Biol 2009; 390:879-92. [PMID: 19477187 DOI: 10.1016/j.jmb.2009.05.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 05/15/2009] [Accepted: 05/19/2009] [Indexed: 11/19/2022]
Abstract
A current popular model to explain phosphorylation of smooth muscle myosin (SMM) by myosin light-chain kinase (MLCK) proposes that MLCK is bound tightly to actin but weakly to SMM. We found that MLCK and calmodulin (CaM) co-purify with unphosphorylated SMM from chicken gizzard, suggesting that they are tightly bound. Although the MLCK:SMM molar ratio in SMM preparations was well below stoichiometric (1:73+/-9), the ratio was approximately 23-37% of that in gizzard tissue. Fifteen to 30% of MLCK was associated with CaM at approximately 1 nM free [Ca(2+)]. There were two MLCK pools that bound unphosphorylated SMM with K(d) approximately 10 and 0.2 microM and phosphorylated SMM with K(d) approximately 20 and 0.2 microM. Using an in vitro motility assay to measure actin sliding velocities, we showed that the co-purifying MLCK-CaM was activated by Ca(2+) and phosphorylation of SMM occurred at a pCa(50) of 6.1 and at a Hill coefficient of 0.9. Similar properties were observed from reconstituted MLCK-CaM-SMM. Using motility assays, co-sedimentation assays, and on-coverslip enzyme-linked immunosorbent assays to quantify proteins on the motility assay coverslip, we provide strong evidence that most of the MLCK is bound directly to SMM through the telokin domain and some may also be bound to both SMM and to co-purifying actin through the N-terminal actin-binding domain. These results suggest that this MLCK may play a role in the initiation of contraction.
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Affiliation(s)
- Feng Hong
- Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine, Reno, 89557, USA
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43
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Raina H, Zacharia J, Li M, Wier WG. Activation by Ca2+/calmodulin of an exogenous myosin light chain kinase in mouse arteries. J Physiol 2009; 587:2599-612. [PMID: 19403597 DOI: 10.1113/jphysiol.2008.165258] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Activation of myosin light chain kinase (MLCK) and other kinases was studied in the arteries of transgenic mice that express an optical fluorescence resonance energy transfer (FRET) MLCK activity biosensor. Binding of Ca(2+)/calmodulin (Ca(2+)/CaM) induces an increase in MLCK activity and a change in FRET. After exposure to high external [K(+)], intracellular [Ca(2+)] (fura-2 ratio or fluo-4 fluorescence) and MLCK activity both increased rapidly to an initial peak and then declined, rapidly at first and then very slowly. After an initial peak ('phasic') force was constant or increased slowly (termed 'tonic' force). Inhibition of rho-kinase (Y-27632) decreased tonic force more than phasic, but had little effect on [Ca(2+)] and MLCK activation. Inhibition of PKCalpha and PKCbeta with Gö6976 had no effect. KN-93, an inhibitor of CaMK II, markedly reduced force, MLCK FRET and [Ca(2+)]. Applied during tonic force, forskolin caused a rapid decrease in MLCK FRET ratio and force, but no change in Ca(2+), suggesting a cAMP mediated decrease in affinity of MLCK for Ca(2+)/CaM. However, receptor (beta-adrenergic) activated increases in cAMP during KCl were ineffective in causing relaxation, changes in [Ca(2+)], or MLCK FRET. At the same tonic force, MLCK FRET ratio activated by alpha(1)-adrenoceptors was approximately 60% of that activated by KCl. In conclusion, MLCK activity of arterial smooth muscle during KCl-induced contraction is determined primarily by Ca(2+)/CaM. Rho-kinase is activated, by unknown mechanisms, and increases 'Ca(2+) sensitivity' significantly. Forskolin mediated increases in cAMP, but not receptor mediated increases in cAMP cause a rapid decrease in the affinity of MLCK for Ca(2+)/CaM.
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Affiliation(s)
- H Raina
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
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44
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Ding HL, Ryder JW, Stull JT, Kamm KE. Signaling processes for initiating smooth muscle contraction upon neural stimulation. J Biol Chem 2009; 284:15541-8. [PMID: 19349274 DOI: 10.1074/jbc.m900888200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Relationships among biochemical signaling processes involved in Ca2+/calmodulin (CaM)-dependent phosphorylation of smooth muscle myosin regulatory light chain (RLC) by myosin light chain kinase (MLCK) were determined. A genetically-encoded biosensor MLCK for measuring Ca(2+)-dependent CaM binding and activation was expressed in smooth muscles of transgenic mice. We performed real-time evaluations of the relationships among [Ca2+](i), MLCK activation, and contraction in urinary bladder smooth muscle strips neurally stimulated for 3 s. Latencies for the onset of [Ca2+](i) and kinase activation were 55 +/- 8 and 65 +/- 6 ms, respectively. Both increased with RLC phosphorylation at 100 ms, whereas force latency was 109 +/- 3 ms. [Ca2+](i), kinase activation, and RLC phosphorylation responses were maximal by 1.2 s, whereas force increased more slowly to a maximal value at 3 s. A delayed temporal response between RLC phosphorylation and force is probably due to mechanical effects associated with elastic elements in the tissue. MLCK activation partially declined at 3 s of stimulation with no change in [Ca2+](i) and also declined more rapidly than [Ca2+](i) during relaxation. The apparent desensitization of MLCK to Ca2+ activation appears to be due to phosphorylation in its calmodulin binding segment. Phosphorylation of two myosin light chain phosphatase regulatory proteins (MYPT1 and CPI-17) or a protein implicated in strengthening membrane adhesion complexes for force transmission (paxillin) did not change during force development. Thus, neural stimulation leads to rapid increases in [Ca2+](i), MLCK activation, and RLC phosphorylation in phasic smooth muscle, showing a tightly coupled Ca2+ signaling complex as an elementary mechanism initiating contraction.
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Affiliation(s)
- Hai-Lei Ding
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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45
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Injeti ER, Sandoval RJ, Williams JM, Smolensky AV, Ford LE, Pearce WJ. Maximal stimulation-induced in situ myosin light chain kinase activity is upregulated in fetal compared with adult ovine carotid arteries. Am J Physiol Heart Circ Physiol 2008; 295:H2289-98. [PMID: 18835918 DOI: 10.1152/ajpheart.00606.2008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Postnatal decreases in vascular reactivity involve decreases in the thick filament component of myofilament calcium sensitivity, which is measured as the relationship between cytosolic calcium concentration and myosin light chain (MLC20) phosphorylation. The present study tests the hypothesis that downregulation of thick filament reactivity is due to downregulation of myosin light chain kinase (MLCK) activity in adult compared with fetal arteries. Total MLCK activity, calculated as %MLC20 phosphorylated per second in intact arteries during optimal inhibition of myosin light chain phosphatase activity, was significantly less in adult (6.56+/-0.29%) than in fetal preparations (7.39+/-0.53%). In situ MLC20 concentrations (microM) in adult (198+/-28) and fetal arteries (236+/-44) did not differ significantly. In situ MLCK concentrations (microM), however, were significantly greater in adult (8.21+/-0.59) than in fetal arteries (1.83+/-0.13). In situ MLCK activities (ng MLC20 phosphorylated.s(-1).ng MLCK(-1)) were significantly less in adult (0.26+/-0.01) than in fetal arteries (1.52+/-0.11). In contrast, MLCK activities in adult (15.8+/-1.5) and fetal artery homogenates (17.3+/-1.3) were not significantly different. When in situ fractional activation was calculated, adult values (1.72+/-0.17%) were significantly less than fetal values (9.08+/-0.83%). Together, these results indicate that decreased thick filament reactivity in adult compared with fetal ovine carotid arteries is due at least in part to greater MLCK activity in fetal arteries, which in turn cannot be explained by differences in MLCK, MLC20, or calmodulin concentrations. Instead, this difference appears to involve age-related differences in fractional activation of the MLCK enzyme.
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Affiliation(s)
- Elisha R Injeti
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
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46
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Song Q, Saucerman JJ, Bossuyt J, Bers DM. Differential integration of Ca2+-calmodulin signal in intact ventricular myocytes at low and high affinity Ca2+-calmodulin targets. J Biol Chem 2008; 283:31531-40. [PMID: 18790737 DOI: 10.1074/jbc.m804902200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cardiac myocyte intracellular calcium varies beat-to-beat and calmodulin (CaM) transduces Ca2+ signals to regulate many cellular processes (e.g. via CaM targets such as CaM-dependent kinase and calcineurin). However, little is known about the dynamics of how CaM targets process the Ca2+ signals to generate appropriate biological responses in the heart. We hypothesized that the different affinities of CaM targets for the Ca2+-bound CaM (Ca2+-CaM) shape their actions through dynamic and tonic interactions in response to the repetitive Ca2+ signals in myocytes. To test our hypothesis, we used two fluorescence resonance energy transfer-based biosensors, BsCaM-45 (Kd = approximately 45 nm) and BsCaM-2 (Kd = approximately 2 nm), to monitor the real time Ca2+-CaM dynamics at low and high affinity CaM targets in paced adult ventricular myocytes. Compared with BsCaM-2, BsCaM-45 tracks the beat-to-beat Ca2+-CaM alterations more closely following the Ca2+ oscillations at each myocyte contraction. When pacing frequency is raised from 0.1 to 1.0 Hz, the higher affinity BsCaM-2 demonstrates significant elevation of diastolic Ca2+-CaM binding compared with the lower affinity BsCaM-45. Biochemically detailed computational models of Ca2+-CaM biosensors in beating cardiac myocytes revealed that the different Ca2+-CaM binding affinities of BsCaM-2 and BsCaM-45 are sufficient to predict their differing kinetics and diastolic integration. Thus, data from both experiments and computational modeling suggest that CaM targets with low versus high Ca2+-CaM affinities (like CaM-dependent kinase versus calcineurin) respond differentially to the same Ca2+ signal (phasic versus integrating), presumably tuned appropriately for their respective and distinct Ca2+ signaling pathways.
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Affiliation(s)
- Qiujing Song
- Department of Physiology, Loyola University Chicago, Maywood, Illinois 60153, USA
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47
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Calmodulin mediates differential sensitivity of CaMKII and calcineurin to local Ca2+ in cardiac myocytes. Biophys J 2008; 95:4597-612. [PMID: 18689454 DOI: 10.1529/biophysj.108.128728] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Calmodulin (CaM) mediates Ca-dependent regulation of numerous pathways in the heart, including CaM-dependent kinase (CaMKII) and calcineurin (CaN), yet the local Ca(2+) signals responsible for their selective activation are unclear. To assess when and where CaM, CaMKII, and CaN may be activated in the cardiac myocyte, we integrated new mechanistic computational models of CaM, CaMKII, and CaN with the Shannon-Bers model of excitation-contraction coupling in the rabbit ventricular myocyte. These models are validated with independent in vitro data. In the intact myocyte, model simulations predict that CaM is highly activated in the dyadic cleft during each beat, but not appreciably in the cytosol. CaMKII-delta(C) was almost insensitive to cytosolic Ca due to relatively low CaM affinity. Dyadic cleft CaMKII exhibits dynamic frequency-dependent responses to Ca, yet autophosphorylates only when local phosphatases are suppressed. In contrast, dyadic cleft CaN in beating myocytes is predicted to be constitutively active, whereas the extremely high affinity of CaN for CaM allows gradual integration of small cytosolic CaM signals. Reversing CaM affinities for CaMKII and CaN also reverses their characteristic local responses. Deactivation of both CaMKII and CaN seems dominated by Ca dissociation from the complex (versus Ca-CaM dissociation from the target). In summary, the different affinities of CaM for CaMKII and CaN determine their sensitivity to local Ca signals in cardiac myocytes.
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48
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Huang J, Shelton JM, Richardson JA, Kamm KE, Stull JT. Myosin regulatory light chain phosphorylation attenuates cardiac hypertrophy. J Biol Chem 2008; 283:19748-56. [PMID: 18474588 DOI: 10.1074/jbc.m802605200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Hyperphosphorylation of myosin regulatory light chain (RLC) in cardiac muscle is proposed to cause compensatory hypertrophy. We therefore investigated potential mechanisms in genetically modified mice. Transgenic (TG) mice were generated to overexpress Ca2+/calmodulin-dependent myosin light chain kinase specifically in cardiomyocytes. Phosphorylation of sarcomeric cardiac RLC and cytoplasmic nonmuscle RLC increased markedly in hearts from TG mice compared with hearts from wild-type (WT) mice. Quantitative measures of RLC phosphorylation revealed no spatial gradients. No significant hypertrophy or structural abnormalities were observed up to 6 months of age in hearts of TG mice compared with WT animals. Hearts and cardiomyocytes from WT animals subjected to voluntary running exercise and isoproterenol treatment showed hypertrophic cardiac responses, but the responses for TG mice were attenuated. Additional biochemical measurements indicated that overexpression of the Ca2+/calmodulin-binding kinase did not perturb other Ca2+/calmodulin-dependent processes involving Ca2+/calmodulin-dependent protein kinase II or the protein phosphatase calcineurin. Thus, increased myosin RLC phosphorylation per se does not cause cardiac hypertrophy and probably inhibits physiological and pathophysiological hypertrophy by contributing to enhanced contractile performance and efficiency.
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Affiliation(s)
- Jian Huang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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49
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Kanaporis G, Mese G, Valiuniene L, White TW, Brink PR, Valiunas V. Gap junction channels exhibit connexin-specific permeability to cyclic nucleotides. J Gen Physiol 2008; 131:293-305. [PMID: 18378798 PMCID: PMC2279171 DOI: 10.1085/jgp.200709934] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 03/05/2008] [Indexed: 11/30/2022] Open
Abstract
Gap junction channels exhibit connexin dependent biophysical properties, including selective intercellular passage of larger solutes, such as second messengers and siRNA. Here, we report the determination of cyclic nucleotide (cAMP) permeability through gap junction channels composed of Cx43, Cx40, or Cx26 using simultaneous measurements of junctional conductance and intercellular transfer of cAMP. For cAMP detection the recipient cells were transfected with a reporter gene, the cyclic nucleotide-modulated channel from sea urchin sperm (SpIH). cAMP was introduced via patch pipette into the cell of the pair that did not express SpIH. SpIH-derived currents (I(h)) were recorded from the other cell of a pair that expressed SpIH. cAMP diffusion through gap junction channels to the neighboring SpIH-transfected cell resulted in a five to sixfold increase in I(h) current over time. Cyclic AMP transfer was observed for homotypic Cx43 channels over a wide range of conductances. However, homotypic Cx40 and homotypic Cx26 exhibited reduced cAMP permeability in comparison to Cx43. The cAMP/K(+) permeability ratios were 0.18, 0.027, and 0.018 for Cx43, Cx26, and Cx40, respectively. Cx43 channels were approximately 10 to 7 times more permeable to cAMP than Cx40 or Cx26 (Cx43 > Cx26 > or = Cx40), suggesting that these channels have distinctly different selectivity for negatively charged larger solutes involved in metabolic/biochemical coupling. These data suggest that Cx43 permeability to cAMP results in a rapid delivery of cAMP from cell to cell in sufficient quantity before degradation by phosphodiesterase to trigger relevant intracellular responses. The data also suggest that the reduced permeability of Cx26 and Cx40 might compromise their ability to deliver cAMP rapidly enough to cause functional changes in a recipient cell.
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Affiliation(s)
- Giedrius Kanaporis
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA
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Christ GJ, Andersson KE. Rho-kinase and effects of Rho-kinase inhibition on the lower urinary tract. Neurourol Urodyn 2008; 26:948-54. [PMID: 17696159 DOI: 10.1002/nau.20475] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Altered smooth muscle cell contractility/tone contributes, at least in part, to the lower urinary tract symptoms (LUTS) seen in men with benign prostatic obstruction (BPO). Accordingly, many of the therapies to date have focused largely on blockade of individual membrane receptors to diminish smooth muscle contractility and provide symptomatic relief. This pharmacologic approach has been associated with variable results, limited efficacy, and untoward side effects. Such limited clinical success is not surprising given the plethora of neurotransmitters, neuromodulators, and hormones that are now known to modulate LUT smooth muscle cell tone. In the pursuit of improved treatment options, more recent investigations have focused attention on intracellular signal transduction events that represent convergence points for membrane receptor activation. In particular, calcium sensitization and the role of the Rho-kinase pathway has received much attention. In this report, we review the literature on the role of the Rho-kinase pathway in the modulation of LUT smooth muscle cell tone. In short, the available data support an important role for Rho-kinase in the physiologic and pathophysiologic regulation of LUT smooth muscle cell tone. Rho-kinase inhibitors thus appear to represent a potentially attractive therapeutic possibility for the treatment of LUTS.
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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