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Dhar A, Bagyashree VT, Biswas S, Kumari J, Sridhara A, Jeevan Subodh B, Shekhar S, Palani S. Functional redundancy and formin-independent localization of tropomyosin isoforms in Saccharomyces cerevisiae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.587703. [PMID: 38617342 PMCID: PMC11014519 DOI: 10.1101/2024.04.04.587703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Tropomyosin is an actin binding protein which protects actin filaments from cofilin-mediated disassembly. Distinct tropomyosin isoforms have long been hypothesized to differentially sort to subcellular actin networks and impart distinct functionalities. Nevertheless, a mechanistic understanding of the interplay between Tpm isoforms and their functional contributions to actin dynamics has been lacking. In this study, we present acetylation-mimic engineered mNeonGreen-Tpm fusion proteins that exhibit complete functionality as a sole copy, surpassing limitations of existing probes and enabling real-time dynamic tracking of Tpm-actin filaments in vivo. Using these functional Tpm fusion proteins, we find that both Tpm1 and Tpm2 indiscriminately bind to actin filaments nucleated by either formin isoform- Bnr1 and Bni1 in vivo, in contrast to the long-held paradigm of Tpm-formin pairing. We also show that Tpm2 can protect and organize functional actin cables in absence of Tpm1. Overall, our work supports a concentration-dependent and formin-independent model of Tpm-actin binding and demonstrates for the first time, the functional redundancy of the paralog Tpm2 in actin cable maintenance in S. cerevisiae.
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Affiliation(s)
- Anubhav Dhar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
- equal contribution
| | - VT Bagyashree
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
- equal contribution
| | - Sudipta Biswas
- Departments of Physics, Cell Biology and Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Jayanti Kumari
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Amruta Sridhara
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - B Jeevan Subodh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Shashank Shekhar
- Departments of Physics, Cell Biology and Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Saravanan Palani
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka 560012, India
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2
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Buerger M, Klein O, Kapahnke S, Mueller V, Frese JP, Omran S, Greiner A, Sommerfeld M, Kaschina E, Jannasch A, Dittfeld C, Mahlmann A, Hinterseher I. Use of MALDI Mass Spectrometry Imaging to Identify Proteomic Signatures in Aortic Aneurysms after Endovascular Repair. Biomedicines 2021; 9:biomedicines9091088. [PMID: 34572274 PMCID: PMC8465851 DOI: 10.3390/biomedicines9091088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/15/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Endovascular repair (EVAR) has become the standard procedure in treating thoracic (TAA) or abdominal aortic aneurysms (AAA). Not entirely free of complications, a persisting perfusion of the aneurysm after EVAR, called Endoleak (EL), leads to reintervention and risk of secondary rupture. How the aortic wall responds to the implantation of a stentgraft and EL is mostly uncertain. We present a pilot study to identify peptide signatures and gain new insights in pathophysiological alterations of the aortic wall after EVAR using matrix-assisted laser desorption or ionization mass spectrometry imaging (MALDI-MSI). In course of or accompanying an open aortic repair, tissue sections from 15 patients (TAA = 5, AAA = 5, EVAR = 5) were collected. Regions of interest (tunica media and tunica adventitia) were defined and univariate (receiver operating characteristic analysis) statistical analysis for subgroup comparison was used. This proof-of-concept study demonstrates that MALDI-MSI is feasible to identify discriminatory peptide signatures separating TAA, AAA and EVAR. Decreased intensity distributions for actin, tropomyosin, and troponin after EVAR suggest impaired contractility in vascular smooth muscle cells. Furthermore, inability to provide energy caused by impaired respiratory chain function and continuous degradation of extracellular matrix components (collagen) might support aortic wall destabilization. In case of EL after EVAR, this mechanism may result in a weakened aortic wall with lacking ability to react on reinstating pulsatile blood flow.
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Affiliation(s)
- Matthias Buerger
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Oliver Klein
- BIH Center for Regenerative Therapies BCRT, Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
| | - Sebastian Kapahnke
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Verena Mueller
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Jan Paul Frese
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Safwan Omran
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Andreas Greiner
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
| | - Manuela Sommerfeld
- Center for Cardiovascular Research (CCR), Institute of Pharmacology, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hessische Str. 3-4, 10115 Berlin, Germany; (M.S.); (E.K.)
| | - Elena Kaschina
- Center for Cardiovascular Research (CCR), Institute of Pharmacology, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hessische Str. 3-4, 10115 Berlin, Germany; (M.S.); (E.K.)
| | - Anett Jannasch
- Department of Cardiac Surgery, Herzzentrum Dresden, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (A.J.); (C.D.)
| | - Claudia Dittfeld
- Department of Cardiac Surgery, Herzzentrum Dresden, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (A.J.); (C.D.)
| | - Adrian Mahlmann
- University Center for Vascular Medicine, Department of Medicine—Section Angiology, University Hospital Carl Gustav Carus, Technische Universität, 01307 Dresden, Germany;
| | - Irene Hinterseher
- Berlin Institute of Health, Vascular Surgery Clinic, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; (M.B.); (S.K.); (V.M.); (J.P.F.); (S.O.); (A.G.)
- Medizinische Hochschule Brandenburg Theordor Fontane, 16816 Neuruppin, Germany
- Correspondence: ; Tel.: +49-30-450-522725
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Pham AK, Miller M, Rosenthal P, Das S, Weng N, Jang S, Kurten RC, Badrani J, Doherty TA, Oliver B, Broide DH. ORMDL3 expression in ASM regulates hypertrophy, hyperplasia via TPM1 and TPM4, and contractility. JCI Insight 2021; 6:136911. [PMID: 33661765 PMCID: PMC8119187 DOI: 10.1172/jci.insight.136911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 02/26/2021] [Indexed: 12/21/2022] Open
Abstract
ORM1-like 3 (ORMDL3) has strong genetic linkage to childhood onset asthma. To determine whether ORMDL3 selective expression in airway smooth muscle (ASM) influences ASM function, we used Cre-loxP techniques to generate transgenic mice (hORMDL3Myh11eGFP-cre), which express human ORMDL3 selectively in smooth muscle cells. In vitro studies of ASM cells isolated from the bronchi of hORMDL3Myh11eGFP-cre mice demonstrated that they developed hypertrophy (quantitated by FACS and image analysis), developed hyperplasia (assessed by BrdU incorporation), and expressed increased levels of tropomysin proteins TPM1 and TPM4. siRNA knockdown of TPM1 or TPM4 demonstrated their importance to ORMDL3-mediated ASM proliferation but not hypertrophy. In addition, ASM derived from hORMDL3Myh11eGFP-cre mice had increased contractility to histamine in vitro, which was associated with increased levels of intracellular Ca2+; increased cell surface membrane Orai1 Ca2+ channels, which mediate influx of Ca2+ into the cytoplasm; and increased expression of ASM contractile genes sarco/endoplasmic reticulum Ca2+ ATPase 2b and smooth muscle 22. In vivo studies of hORMDL3Myh11eGFP-cre mice demonstrated that they had a spontaneous increase in ASM and airway hyperreactivity (AHR). ORMDL3 expression in ASM thus induces changes in ASM (hypertrophy, hyperplasia, increased contractility), which may explain the contribution of ORMDL3 to the development of AHR in childhood onset asthma, which is highly linked to ORMDL3 on chromosome 17q12-21.
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Affiliation(s)
- Alexa K. Pham
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Marina Miller
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Peter Rosenthal
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Sudipta Das
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Ning Weng
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Sunghoon Jang
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Richard C. Kurten
- Department of Pediatrics, Arkansas Children’s Research Institute, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jana Badrani
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Taylor A. Doherty
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- Veterans Affairs San Diego Health Care System, La Jolla, California, USA
| | - Brian Oliver
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - David H. Broide
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
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Bruijn LE, van den Akker BEWM, van Rhijn CM, Hamming JF, Lindeman JHN. Extreme Diversity of the Human Vascular Mesenchymal Cell Landscape. J Am Heart Assoc 2020; 9:e017094. [PMID: 33190596 PMCID: PMC7763765 DOI: 10.1161/jaha.120.017094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/05/2020] [Indexed: 12/17/2022]
Abstract
Background Human mesenchymal cells are culprit factors in vascular (patho)physiology and are hallmarked by phenotypic and functional heterogeneity. At present, they are subdivided by classic umbrella terms, such as "fibroblasts," "myofibroblasts," "smooth muscle cells," "fibrocytes," "mesangial cells," and "pericytes." However, a discriminative marker-based subclassification has to date not been established. Methods and Results As a first effort toward a classification scheme, a systematic literature search was performed to identify the most commonly used phenotypical and functional protein markers for characterizing and classifying vascular mesenchymal cell subpopulation(s). We next applied immunohistochemistry and immunofluorescence to inventory the expression pattern of identified markers on human aorta specimens representing early, intermediate, and end stages of human atherosclerotic disease. Included markers comprise markers for mesenchymal lineage (vimentin, FSP-1 [fibroblast-specific protein-1]/S100A4, cluster of differentiation (CD) 90/thymocyte differentiation antigen 1, and FAP [fibroblast activation protein]), contractile/non-contractile phenotype (α-smooth muscle actin, smooth muscle myosin heavy chain, and nonmuscle myosin heavy chain), and auxiliary contractile markers (h1-Calponin, h-Caldesmon, Desmin, SM22α [smooth muscle protein 22α], non-muscle myosin heavy chain, smooth muscle myosin heavy chain, Smoothelin-B, α-Tropomyosin, and Telokin) or adhesion proteins (Paxillin and Vinculin). Vimentin classified as the most inclusive lineage marker. Subset markers did not separate along classic lines of smooth muscle cell, myofibroblast, or fibroblast, but showed clear temporal and spatial diversity. Strong indications were found for presence of stem cells/Endothelial-to-Mesenchymal cell Transition and fibrocytes in specific aspects of the human atherosclerotic process. Conclusions This systematic evaluation shows a highly diverse and dynamic landscape for the human vascular mesenchymal cell population that is not captured by the classic nomenclature. Our observations stress the need for a consensus multiparameter subclass designation along the lines of the cluster of differentiation classification for leucocytes.
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Affiliation(s)
- Laura E. Bruijn
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | | | - Connie M. van Rhijn
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | - Jaap F. Hamming
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
| | - Jan H. N. Lindeman
- Division of Vascular SurgeryDepartment of SurgeryLeiden University Medical CenterLeidenthe Netherlands
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Huhtinen A, Hongisto V, Laiho A, Löyttyniemi E, Pijnenburg D, Scheinin M. Gene expression profiles and signaling mechanisms in α 2B-adrenoceptor-evoked proliferation of vascular smooth muscle cells. BMC SYSTEMS BIOLOGY 2017; 11:65. [PMID: 28659168 PMCID: PMC5490158 DOI: 10.1186/s12918-017-0439-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 06/09/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND α2-adrenoceptors are important regulators of vascular tone and blood pressure. Regulation of cell proliferation is a less well investigated consequence of α2-adrenoceptor activation. We have previously shown that α2B-adrenoceptor activation stimulates proliferation of vascular smooth muscle cells (VSMCs). This may be important for blood vessel development and plasticity and for the pathology and therapeutics of cardiovascular disorders. The underlying cellular mechanisms have remained mostly unknown. This study explored pathways of regulation of gene expression and intracellular signaling related to α2B-adrenoceptor-evoked VSMC proliferation. RESULTS The cellular mechanisms and signaling pathways of α2B-adrenoceptor-evoked proliferation of VSMCs are complex and include redundancy. Functional enrichment analysis and pathway analysis identified differentially expressed genes associated with α2B-adrenoceptor-regulated VSMC proliferation. They included the upregulated genes Egr1, F3, Ptgs2 and Serpine1 and the downregulated genes Cx3cl1, Cav1, Rhoa, Nppb and Prrx1. The most highly upregulated gene, Lypd8, represents a novel finding in the VSMC context. Inhibitor library screening and kinase activity profiling were applied to identify kinases in the involved signaling pathways. Putative upstream kinases identified by two different screens included PKC, Raf-1, Src, the MAP kinases p38 and JNK and the receptor tyrosine kinases EGFR and HGF/HGFR. As a novel finding, the Src family kinase Lyn was also identified as a putative upstream kinase. CONCLUSIONS α2B-adrenoceptors may mediate their pro-proliferative effects in VSMCs by promoting the activity of bFGF and PDGF and the growth factor receptors EGFR, HGFR and VEGFR-1/2. The Src family kinase Lyn was also identified as a putative upstream kinase. Lyn is known to be expressed in VSMCs and has been identified as an important regulator of GPCR trafficking and GPCR effects on cell proliferation. Identified Ser/Thr kinases included several PKC isoforms and the β-adrenoceptor kinases 1 and 2. Cross-talk between the signaling mechanisms involved in α2B-adrenoceptor-evoked VSMC proliferation thus appears to involve PKC activation, subsequent changes in gene expression, transactivation of EGFR, and modulation of kinase activities and growth factor-mediated signaling. While many of the identified individual signals were relatively small in terms of effect size, many of them were validated by combining pathway analysis and our integrated screening approach.
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Affiliation(s)
- Anna Huhtinen
- Department of Pharmacology, Drug Development and Therapeutics, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
- Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Vesa Hongisto
- Toxicology Division, Misvik Biology Oy, Turku, Finland
| | - Asta Laiho
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Eliisa Löyttyniemi
- Department of Biostatistics, Department of Clinical Medicine, University of Turku, Turku, Finland
| | - Dirk Pijnenburg
- PamGene International BV, Wolvenhoek 10, 5211HH s’Hertogenbosch, The Netherlands
| | - Mika Scheinin
- Department of Pharmacology, Drug Development and Therapeutics, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
- Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
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6
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Customizable engineered blood vessels using 3D printed inserts. Methods 2015; 99:20-7. [PMID: 26732049 DOI: 10.1016/j.ymeth.2015.12.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/15/2015] [Accepted: 12/24/2015] [Indexed: 11/21/2022] Open
Abstract
Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment.
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Khaitlina SY. Tropomyosin as a Regulator of Actin Dynamics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 318:255-91. [PMID: 26315888 DOI: 10.1016/bs.ircmb.2015.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tropomyosin is a major regulatory protein of contractile systems and cytoskeleton, an actin-binding protein that positions laterally along actin filaments and modulates actin-myosin interaction. About 40 tropomyosin isoforms have been found in a variety of cytoskeleton systems, not necessarily connected with actin-myosin interaction and contraction. Involvement of specific tropomyosin isoforms in the regulation of key cell processes was shown, and specific features of tropomyosin genes and protein structure have been investigated with molecular biology and genetics approaches. However, the mechanisms underlying the effects of tropomyosin on cytoskeleton dynamics are still unclear. As tropomyosin is primarily an F-actin-binding protein, it is important to understand how it interacts both with actin and actin-binding proteins functioning in muscles and cytoskeleton to regulate actin dynamics. This review focuses on biochemical data on the effects of tropomyosin on actin assembly and dynamics, as well as on the modulation of these effects by actin-binding proteins. The data indicate that tropomyosin can efficiently regulate actin dynamics via allosteric conformational changes within actin filaments.
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Affiliation(s)
- Sofia Yu Khaitlina
- Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg, Russia.
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Puzdrova VA, Kudryashova TV, Gaynullina DK, Mochalov SV, Aalkjaer C, Nilsson H, Vorotnikov AV, Schubert R, Tarasova OS. Trophic action of sympathetic nerves reduces arterial smooth muscle Ca2+sensitivity during early post-natal development in rats. Acta Physiol (Oxf) 2014; 212:128-41. [DOI: 10.1111/apha.12331] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/20/2014] [Accepted: 06/13/2014] [Indexed: 12/11/2022]
Affiliation(s)
- V. A. Puzdrova
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- Centre for Biomedicine and Medical Technology Mannheim (CBTM); Research Division Cardiovascular Physiology; Medical Faculty Mannheim; Heidelberg University; Mannheim Germany
| | - T. V. Kudryashova
- Institute of Experimental Cardiology; Cardiology Research Center; Moscow Russia
| | - D. K. Gaynullina
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- Department of Physiology; Russian National Research Medical University; Moscow Russia
| | - S. V. Mochalov
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
| | - C. Aalkjaer
- Department of Biomedicine; Aarhus University; Aarhus Denmark
| | - H. Nilsson
- Department of Physiology; Institute of Neuroscience and Physiology; The Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
| | - A. V. Vorotnikov
- Institute of Experimental Cardiology; Cardiology Research Center; Moscow Russia
| | - R. Schubert
- Centre for Biomedicine and Medical Technology Mannheim (CBTM); Research Division Cardiovascular Physiology; Medical Faculty Mannheim; Heidelberg University; Mannheim Germany
| | - O. S. Tarasova
- Faculty of Biology; M.V. Lomonosov Moscow State University; Moscow Russia
- State Research Center of the Russian Federation - Institute for Biomedical Problems; Moscow Russia
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9
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Chacko S, Cortes E, Drake MJ, Fry CH. Does altered myogenic activity contribute to OAB symptoms from detrusor overactivity? ICI-RS 2013. Neurourol Urodyn 2014; 33:577-80. [DOI: 10.1002/nau.22599] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/03/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Sam Chacko
- Department of Pathobiology; Division of Urology; University of Pennsylvania; Philadelphia Pennsylvania
| | - Eduard Cortes
- Women's Health Academic Centre; King's College London; London United Kingdom
| | - Marcus J. Drake
- School of Clinical Sciences; University of Bristol; Bristol United Kingdom
| | - Christopher H. Fry
- Department of Biochemistry and Physiology; FHMS; University of Surrey; Guildford United Kingdom
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Hilbert L, Bates G, Roman HN, Blumenthal JL, Zitouni NB, Sobieszek A, Mackey MC, Lauzon AM. Molecular mechanical differences between isoforms of contractile actin in the presence of isoforms of smooth muscle tropomyosin. PLoS Comput Biol 2013; 9:e1003273. [PMID: 24204225 PMCID: PMC3812040 DOI: 10.1371/journal.pcbi.1003273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 08/28/2013] [Indexed: 11/19/2022] Open
Abstract
The proteins involved in smooth muscle's molecular contractile mechanism - the anti-parallel motion of actin and myosin filaments driven by myosin heads interacting with actin - are found as different isoforms. While their expression levels are altered in disease states, their relevance to the mechanical interaction of myosin with actin is not sufficiently understood. Here, we analyzed in vitro actin filament propulsion by smooth muscle myosin for [Formula: see text]-actin ([Formula: see text]A), [Formula: see text]-actin-tropomyosin-[Formula: see text] ([Formula: see text]A-Tm[Formula: see text]), [Formula: see text]-actin-tropomyosin-[Formula: see text] ([Formula: see text]A-Tm[Formula: see text]), [Formula: see text]-actin ([Formula: see text]A), [Formula: see text]-actin-tropomyosin-[Formula: see text] ([Formula: see text]A-Tm[Formula: see text]), and [Formula: see text]-actin-tropomoysin-[Formula: see text] ([Formula: see text]A-Tm[Formula: see text]). Actin sliding analysis with our specifically developed video analysis software followed by statistical assessment (Bootstrapped Principal Component Analysis) indicated that the in vitro motility of [Formula: see text]A, [Formula: see text]A, and [Formula: see text]A-Tm[Formula: see text] is not distinguishable. Compared to these three 'baseline conditions', statistically significant differences ([Formula: see text]) were: [Formula: see text]A-Tm[Formula: see text] - actin sliding velocity increased 1.12-fold, [Formula: see text]A-Tm[Formula: see text] - motile fraction decreased to 0.96-fold, stop time elevated 1.6-fold, [Formula: see text]A-Tm[Formula: see text] - run time elevated 1.7-fold. We constructed a mathematical model, simulated actin sliding data, and adjusted the kinetic parameters so as to mimic the experimentally observed differences: [Formula: see text]A-Tm[Formula: see text] - myosin binding to actin, the main, and the secondary myosin power stroke are accelerated, [Formula: see text]A-Tm[Formula: see text] - mechanical coupling between myosins is stronger, [Formula: see text]A-Tm[Formula: see text] - the secondary power stroke is decelerated and mechanical coupling between myosins is weaker. In summary, our results explain the different regulatory effects that specific combinations of actin and smooth muscle tropomyosin have on smooth muscle actin-myosin interaction kinetics.
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Affiliation(s)
- Lennart Hilbert
- Dept. Physiology, McGill University, Montréal, Québec, Canada
- Centre for Applied Mathematics in Bioscience and Medicine, Montréal, Québec, Canada
- Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada
| | - Genevieve Bates
- Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada
| | - Horia N. Roman
- Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada
- Dept. Biomedical Engineering, McGill University, Montréal, Québec, Canada
| | | | - Nedjma B. Zitouni
- Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada
| | - Apolinary Sobieszek
- Institute for Biomedical Aging Research, Austrian Academy of Sciences, Innsbruck, Austria
| | - Michael C. Mackey
- Dept. Physiology, McGill University, Montréal, Québec, Canada
- Centre for Applied Mathematics in Bioscience and Medicine, Montréal, Québec, Canada
- Dept. Physics and Dept. Mathematics, McGill University, Montréal, Québec, Canada
| | - Anne-Marie Lauzon
- Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada
- Dept. Biomedical Engineering, McGill University, Montréal, Québec, Canada
- Dept. Medicine, McGill University, Montréal, Québec, Canada
- * E-mail:
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Deng M, Boopathi E, Hypolite JA, Raabe T, Chang S, Zderic S, Wein AJ, Chacko S. Amino acid mutations in the caldesmon COOH-terminal functional domain increase force generation in bladder smooth muscle. Am J Physiol Renal Physiol 2013; 305:F1455-65. [PMID: 23986516 DOI: 10.1152/ajprenal.00174.2013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Caldesmon (CaD), a component of smooth muscle thin filaments, binds actin, tropomyosin, calmodulin, and myosin and inhibits actin-activated ATP hydrolysis by smooth muscle myosin. Internal deletions of the chicken CaD functional domain that spans from amino acids (aa) 718 to 731, which corresponds to aa 512-530 including the adjacent aa sequence in mouse CaD, lead to diminished CaD-induced inhibition of actin-activated ATP hydrolysis by myosin. Transgenic mice with mutations of five aa residues (Lys(523) to Gln, Val(524) to Leu, Ser(526) to Thr, Pro(527) to Cys, and Lys(529) to Ser), which encompass the ATPase inhibitory determinants located in exon 12, were generated by homologous recombination. Homozygous (-/-) animals did not develop, but heterozygous (+/-) mice carrying the expected mutations in the CaD ATPase inhibitory domain (CaD mutant) matured and reproduced normally. The peak force produced in response to KCl and electrical field stimulation by the detrusor smooth muscle from the CaD mutant was high compared with that of the wild type. CaD mutant mice revealed nonvoiding contractions during bladder filling on awake cystometry, suggesting that the CaD ATPase inhibitory domain suppresses force generation during the filling phase and this suppression is partially released by mutations in 50% of CaD in heterozygous. Our data show for the first time a functional phenotype, at the intact smooth muscle tissue and in vivo organ levels, following mutation of a functional domain at the COOH-terminal region of CaD.
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Affiliation(s)
- Maoxian Deng
- Dept. of Surgery and Dept. of Pathobiology, Univ. of Pennsylvania, 500 South Ridgeway Ave., Glenolden, PA 19036.
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12
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Dobrzhanskaya AV, Vyatchin IG, Lazarev SS, Matusovsky OS, Shelud'ko NS. Molluscan smooth catch muscle contains calponin but not caldesmon. J Muscle Res Cell Motil 2013; 34:23-33. [PMID: 23081709 DOI: 10.1007/s10974-012-9329-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022]
Abstract
We isolated Ca(2+)-regulated thin filaments from the smooth muscle of the mussel Crenomytilus grayanus and studied the protein composition of different preparations from this muscle: whole muscle, heat-stable extract, fractions from heat-stable extract, thin filaments and intermediate stages of thin filaments purification. Among the protein components of the above-listed preparations, we did not find caldesmon (CaD), although two isoforms of a calponin-like (CaP-like) protein, which along with CaD is characteristic of vertebrate smooth muscle, were present in thin filaments. Thus, CaD is not Ca(2+)-regulator of thin filaments of this muscle. On the other hand, the mussel CaP-like protein is also not such Ca(2+)-regulator since we have shown that this protein can be selectively removed from isolated mussel thin filaments without loss of their Ca(2+)-sensitivity. We suggest that thin filaments in the smooth catch muscle possess other type of Ca(2+)-regulation, different from that in vertebrate smooth muscles.
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Affiliation(s)
- Anna V Dobrzhanskaya
- Laboratory of Cell Biophysics, A.V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia
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13
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Zhang J, Marshall KE, Westwood JT, Clark MS, Sinclair BJ. Divergent transcriptomic responses to repeated and single cold exposures in Drosophila melanogaster. J Exp Biol 2011; 214:4021-9. [DOI: 10.1242/jeb.059535] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SUMMARY
Insects in the field are exposed to multiple bouts of cold, and there is increasing evidence that the fitness consequences of repeated cold exposure differ from the impacts of a single cold exposure. We tested the hypothesis that different kinds of cold exposure (in this case, single short, prolonged and repeated cold exposure) would result in differential gene expression. We exposed 3 day old adult female wild-type Drosophila melanogaster (Diptera: Drosophilidae) to –0.5°C for a single 2 h exposure, a single 10 h exposure, or five 2 h exposures on consecutive days, and extracted RNA after 6 h of recovery. Global gene expression was quantified using an oligonucleotide microarray and validated with real-time PCR using different biological replicates. We identified 76 genes upregulated in response to multiple cold exposure, 69 in response to prolonged cold exposure and 20 genes upregulated in response to a single short cold exposure, with a small amount of overlap between treatments. Three genes – Turandot A, Hephaestus and CG11374 – were upregulated in response to all three cold exposure treatments. Key functional groups upregulated include genes associated with muscle structure and function, the immune response, stress response, carbohydrate metabolism and egg production. We conclude that cold exposure has wide-ranging effects on gene expression in D. melanogaster and that increased duration or frequency of cold exposure has impacts different to those of a single short cold exposure. This has important implications for extrapolating laboratory studies of insect overwintering that are based on only a single cold exposure.
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Affiliation(s)
- Jian Zhang
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - Katie E. Marshall
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - J. Timothy Westwood
- Canadian Drosophila Microarray Centre, Department of Biology, The University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Melody S. Clark
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB1 9XU, UK
| | - Brent J. Sinclair
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
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14
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Jamesdaniel S, Hu B, Kermany MH, Jiang H, Ding D, Coling D, Salvi R. Noise induced changes in the expression of p38/MAPK signaling proteins in the sensory epithelium of the inner ear. J Proteomics 2011; 75:410-24. [PMID: 21871588 DOI: 10.1016/j.jprot.2011.08.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 08/04/2011] [Accepted: 08/08/2011] [Indexed: 12/20/2022]
Abstract
Noise exposure is a major cause of hearing loss. Classical methods of studying protein involvement have provided a basis for understanding signaling pathways that mediate hearing loss and damage repair but do not lend themselves to studying large networks of proteins that are likely to increase or decrease during noise trauma. To address this issue, antibody microarrays were used to quantify the very early changes in protein expression in three distinct regions of the chinchilla cochlea 2h after exposure to a 0.5-8 kHz band of noise for 2h at 112 dB SPL. The noise exposure caused significant functional impairment 2h post-exposure which only partially recovered. Distortion product otoacoustic emissions were abolished 2h after the exposure, but at 4 weeks post-exposure, otoacoustic emissions were present, but still greatly depressed. Cochleograms obtained 4 weeks post-exposure demonstrated significant loss of outer hair cells in the basal 60% of the cochlea corresponding to frequencies in the noise spectrum. A comparative analysis of the very early (2h post-exposure) noise-induced proteomic changes indicated that the sensory epithelium, lateral wall and modiolus differ in their biological response to noise. Bioinformatic analysis of the cochlear protein profile using "The Database for Annotation, Visualization and Integrated Discovery 2008" (DAVID - http://david.abcc. ncifcrf.gov) revealed the initiation of the cell death process in sensory epithelium and modiolus. An increase in Fas and phosphorylation of FAK and p38/MAPK in the sensory epithelium suggest that noise-induced stress signals at the cell membrane are transmitted to the nucleus by Fas and focal adhesion signaling through the p38/MAPK signaling pathway. Up-regulation of downstream nuclear proteins E2F3 and WSTF in immunoblots and microarrays along with their immunolocalization in the outer hair cells supported the pivotal role of p38/MAPK signaling in the mechanism underlying noise-induced hearing loss.
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Affiliation(s)
- Samson Jamesdaniel
- Center for Hearing and Deafness, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
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15
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Wang M, Li W, Chang GQ, Ye CS, Ou JS, Li XX, Liu Y, Cheang TY, Huang XL, Wang SM. MicroRNA-21 regulates vascular smooth muscle cell function via targeting tropomyosin 1 in arteriosclerosis obliterans of lower extremities. Arterioscler Thromb Vasc Biol 2011; 31:2044-53. [PMID: 21817107 DOI: 10.1161/atvbaha.111.229559] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE The goal of this study was to determine the expression signature and the potential role of microRNAs in human arteries with arteriosclerosis obliterans (ASO). METHODS AND RESULTS The expression profiles of microRNAs in human arteries with ASO and in normal control arteries were determined by quantitative reverse transcription-polymerase chain reaction array. Among the 617 detected microRNAs, multiple microRNAs were aberrantly expressed in arteries with ASO. Some of these dysregulated microRNAs were further verified by quantitative reverse transcription-polymerase chain reaction. Among them, microRNA-21 (miR-21) was mainly located in arterial smooth muscle cells (ASMCs) and was increased by more than 7-fold in ASO that was related to hypoxia inducible factor 1-α. In cultured human ASMCs, cell proliferation and migration were significantly decreased by inhibition of miR-21. 3'-Untranslated region luciferase assay confirmed that tropomyosin 1 was a target of miR-21 that was involved in miR-21-mediated cellular effects, such as cell shape modulation. CONCLUSION The results suggest that miR-21 is able to regulate ASMC function by targeting tropomyosin 1. The hypoxia inducible factor-1 α/miR-21/tropomyosin 1 pathway may play a critical role in the pathogenesis of ASO. These findings might provide a new therapeutic target for human ASO.
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Affiliation(s)
- Mian Wang
- Division of Vascular Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
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16
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Gardiner J, Overall R, Marc J. Putative Arabidopsishomologues of metazoan coiled-coil cytoskeletal proteins. Cell Biol Int 2011; 35:767-774. [DOI: 10.1042/cbi20100719] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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17
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Gallant C, Appel S, Graceffa P, Leavis P, Lin JJC, Gunning PW, Schevzov G, Chaponnier C, DeGnore J, Lehman W, Morgan KG. Tropomyosin variants describe distinct functional subcellular domains in differentiated vascular smooth muscle cells. Am J Physiol Cell Physiol 2011; 300:C1356-65. [PMID: 21289288 DOI: 10.1152/ajpcell.00450.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tropomyosin (Tm) is known to be an important gatekeeper of actin function. Tm isoforms are encoded by four genes, and each gene produces several variants by alternative splicing, which have been proposed to play roles in motility, proliferation, and apoptosis. Smooth muscle studies have focused on gizzard smooth muscle, where a heterodimer of Tm from the α-gene (Tmsm-α) and from the β-gene (Tmsm-β) is associated with contractile filaments. In this study we examined Tm in differentiated mammalian vascular smooth muscle (dVSM). Liquid chromatography-tandem mass spectrometry (LC MS/MS) analysis and Western blot screening with variant-specific antibodies revealed that at least five different Tm proteins are expressed in this tissue: Tm6 (Tmsm-α) and Tm2 from the α-gene, Tm1 (Tmsm-β) from the β-gene, Tm5NM1 from the γ-gene, and Tm4 from the δ-gene. Tm6 is by far most abundant in dVSM followed by Tm1, Tm2, Tm5NM1, and Tm4. Coimmunoprecipitation and coimmunofluorescence studies demonstrate that Tm1 and Tm6 coassociate with different actin isoforms and display different intracellular localizations. Using an antibody specific for cytoplasmic γ-actin, we report here the presence of a γ-actin cortical cytoskeleton in dVSM cells. Tm1 colocalizes with cortical cytoplasmic γ-actin and coprecipitates with γ-actin. Tm6, on the other hand, is located on contractile bundles. These data indicate that Tm1 and Tm6 do not form a classical heterodimer in dVSM but rather describe different functional cellular compartments.
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Affiliation(s)
- Cynthia Gallant
- Health Sciences Dept., Boston University, 635 Commonwealth Ave., Boston, MA 02215, USA
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18
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Somara S, Gilmont RR, Varadarajan S, Bitar KN. Phosphorylated HSP20 modulates the association of thin-filament binding proteins: caldesmon with tropomyosin in colonic smooth muscle. Am J Physiol Gastrointest Liver Physiol 2010; 299:G1164-76. [PMID: 20829522 PMCID: PMC2993172 DOI: 10.1152/ajpgi.00479.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Small heat shock proteins HSP27 and HSP20 have been implicated in regulation of contraction and relaxation in smooth muscle. Activation of PKC-α promotes contraction by phosphorylation of HSP27 whereas activation of PKA promotes relaxation by phosphorylation of HSP20 in colonic smooth muscle cells (CSMC). We propose that the balance between the phosphorylation states of HSP27 and HSP20 represents a molecular signaling switch for contraction and relaxation. This molecular signaling switch acts downstream on a molecular mechanical switch [tropomyosin (TM)] regulating thin-filament dynamics. We have examined the role of phosphorylation state(s) of HSP20 on HSP27-mediated thin-filament regulation in CSMC. CSMC were transfected with different HSP20 phosphomutants. These transfections had no effect on the integrity of actin cytoskeleton. Cells transfected with 16D-HSP20 (phosphomimic) exhibited inhibition of acetylcholine (ACh)-induced contraction whereas cells transfected with 16A-HSP20 (nonphosphorylatable) had no effect on ACh-induced contraction. CSMC transfected with 16D-HSP20 cDNA showed significant decreases in 1) phosphorylation of HSP27 (ser78); 2) phosphorylation of PKC-α (ser657); 3) phosphorylation of TM and CaD (ser789); 4) ACh-induced phosphorylation of myosin light chain; 5) ACh-induced association of TM with HSP27; and 6) ACh-induced dissociation of TM from caldesmon (CaD). We thus propose the crucial physiological relevance of molecular signaling switch (phosphorylation state of HSP27 and HSP20), which dictates 1) the phosphorylation states of TM and CaD and 2) their dissociations from each other.
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Affiliation(s)
- Sita Somara
- Gastrointestinal Molecular Motors Laboratory, Department of Pediatrics, Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Robert R. Gilmont
- Gastrointestinal Molecular Motors Laboratory, Department of Pediatrics, Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Saranyaraajan Varadarajan
- Gastrointestinal Molecular Motors Laboratory, Department of Pediatrics, Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Khalil N. Bitar
- Gastrointestinal Molecular Motors Laboratory, Department of Pediatrics, Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
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Davuluri G, Seiler C, Abrams J, Soriano AJ, Pack M. Differential effects of thin and thick filament disruption on zebrafish smooth muscle regulatory proteins. Neurogastroenterol Motil 2010; 22:1100-e285. [PMID: 20591105 PMCID: PMC3902778 DOI: 10.1111/j.1365-2982.2010.01545.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The smooth muscle actin binding proteins Caldesmon and Tropomyosin (Tm) promote thin filament assembly by stabilizing actin polymerization, however, whether filament assembly affects either the stability or activation of these and other smooth muscle regulatory proteins is not known. METHODS Measurement of smooth muscle regulatory protein levels in wild type zebrafish larvae following antisense knockdown of smooth muscle actin (Acta2) and myosin heavy chain (Myh11) proteins, and in colourless mutants that lack enteric nerves. Comparison of intestinal peristalsis in wild type and colourless larvae. KEY RESULTS Knockdown of Acta2 led to reduced levels of phospho-Caldesmon and Tm. Total Caldesmon and phospho-myosin light chain (p-Mlc) levels were unaffected. Knockdown of Myh11 had no effect on the levels of either of these proteins. Phospho-Caldesmon and p-Mlc levels were markedly reduced in colourless mutants that have intestinal motility comparable with wild type larvae. CONCLUSIONS & INFERENCES These in vivo findings provide new information regarding the activation and stability of smooth muscle regulatory proteins in zebrafish larvae and their role in intestinal peristalsis in this model organism.
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Affiliation(s)
- G. Davuluri
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - C. Seiler
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - J. Abrams
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - A. J. Soriano
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - M. Pack
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA,Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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20
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Abstract
The control of force production in vascular smooth muscle is critical to the normal regulation of blood flow and pressure, and altered regulation is common to diseases such as hypertension, heart failure, and ischemia. A great deal has been learned about imbalances in vasoconstrictor and vasodilator signals, e.g., angiotensin, endothelin, norepinephrine, and nitric oxide, that regulate vascular tone in normal and disease contexts. In contrast there has been limited study of how the phenotypic state of the vascular smooth muscle cell may influence the contractile response to these signaling pathways dependent upon the developmental, tissue-specific (vascular bed) or disease context. Smooth, skeletal, and cardiac muscle lineages are traditionally classified into fast or slow sublineages based on rates of contraction and relaxation, recognizing that this simple dichotomy vastly underrepresents muscle phenotypic diversity. A great deal has been learned about developmental specification of the striated muscle sublineages and their phenotypic interconversions in the mature animal under the control of mechanical load, neural input, and hormones. In contrast there has been relatively limited study of smooth muscle contractile phenotypic diversity. This is surprising given the number of diseases in which smooth muscle contractile dysfunction plays a key role. This review focuses on smooth muscle contractile phenotypic diversity in the vascular system, how it is generated, and how it may determine vascular function in developmental and disease contexts.
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Affiliation(s)
- Steven A Fisher
- Department of Medicine, and Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio 44106-7290, USA.
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21
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Somara S, Gilmont R, Bitar KN. Role of thin-filament regulatory proteins in relaxation of colonic smooth muscle contraction. Am J Physiol Gastrointest Liver Physiol 2009; 297:G958-66. [PMID: 20501443 PMCID: PMC2777455 DOI: 10.1152/ajpgi.00201.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Coordinated regulation of smooth muscle contraction and relaxation is required for colonic motility. Contraction is associated with phosphorylation of myosin light chain (MLC(20)) and interaction of actin with myosin. Thin-filament regulation of actomyosin interaction is modulated by two actin-binding regulatory proteins: tropomyosin (TM) and caldesmon (CaD). TM and CaD are known to play crucial role in actomyosin interaction promoting contraction. Contraction is associated with phosphorylation of the small heat shock protein HSP27, concomitant with the phosphorylation of TM and CaD. Phosphorylation of HSP27 is attributed as being the prime modulator of thin-filament regulation of contraction. Preincubation of colonic smooth muscle cells (CSMC) with the relaxant neurotransmitter vasoactive intestinal peptide (VIP) showed inhibition in phosphorylation of HSP27 (ser78). Attenuation of HSP27 phosphorylation can result in modulation of thin-filament-mediated regulation of contraction leading to relaxation; thus the role of thin-filament regulatory proteins in a relaxation milieu was investigated. Preincubation of CSMC with VIP exhibited a decrease in phosphorylation of TM and CaD. Furthermore, CSMC preincubated with VIP showed a reduced association of TM with HSP27 and with phospho-HSP27 (ser78) whereas there was reduced dissociation of TM from CaD and from phospho-CaD. We thus propose that, in addition to alteration in phosphorylation of MLC(20), relaxation is associated with alterations in thin-filament-mediated regulation that results in termination of contraction.
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Affiliation(s)
- Sita Somara
- Department of Pediatrics-Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Robert Gilmont
- Department of Pediatrics-Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
| | - Khalil N. Bitar
- Department of Pediatrics-Gastroenterology, University of Michigan Medical Center, Ann Arbor, Michigan
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