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Yuan B, Scholz J, Wald J, Thuenauer R, Hennell James R, Ellenberg I, Windhorst S, Faix J, Marlovits TC. Structural basis for subversion of host cell actin cytoskeleton during Salmonella infection. Sci Adv 2023; 9:eadj5777. [PMID: 38064550 PMCID: PMC10708208 DOI: 10.1126/sciadv.adj5777] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023]
Abstract
Secreted bacterial type III secretion system (T3SS) proteins are essential for successful infection by many human pathogens. Both T3SS translocator SipC and effector SipA are critical for Salmonella infection by subversion of the host cell cytoskeleton, but the precise molecular interplay between them remains unknown. Here, using cryo-electron microscopy, we show that SipA binds along the F-actin grooves with a unique binding pattern. SipA stabilizes F-actin through charged interface residues and appears to prevent inorganic phosphate release through closure of the "back door" of adenosine 5'-triphosphate pocket. We also show that SipC enhances the binding of SipA to F-actin, thus demonstrating that a sequential presence of T3SS proteins in host cells is associated with a sequence of infection events-starting with actin nucleation, filament growth, and stabilization. Together, our data explain the coordinated interplay of a precisely tuned and highly effective mechanism during Salmonella infection and provide a blueprint for interfering with Salmonella effectors acting on actin.
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Affiliation(s)
- Biao Yuan
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Deutsches Elektronen-Synchrotron Zentrum (DESY), Hamburg, Germany
| | - Jonas Scholz
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Jiri Wald
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Deutsches Elektronen-Synchrotron Zentrum (DESY), Hamburg, Germany
| | - Roland Thuenauer
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Technology Platform Light Microscopy (TPLM), University of Hamburg, Hamburg, Germany
- Technology Platform Microscopy and Image Analysis (TP MIA), Leibniz Institute of Virology (LIV), Hamburg, Germany
| | - Rory Hennell James
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Deutsches Elektronen-Synchrotron Zentrum (DESY), Hamburg, Germany
| | - Irina Ellenberg
- University Medical Center Hamburg-Eppendorf (UKE), Institute for Biochemistry and Signal Transduction, Hamburg, Germany
| | - Sabine Windhorst
- University Medical Center Hamburg-Eppendorf (UKE), Institute for Biochemistry and Signal Transduction, Hamburg, Germany
| | - Jan Faix
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Thomas C. Marlovits
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- Deutsches Elektronen-Synchrotron Zentrum (DESY), Hamburg, Germany
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Dahlstroem C, Paraschiakos T, Sun H, Windhorst S. Cryo-EM structures of actin binding proteins as tool for drug discovery. Biochem Pharmacol 2023:115680. [PMID: 37399949 DOI: 10.1016/j.bcp.2023.115680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/05/2023]
Abstract
Cellular actin dynamic is controlled by a plethora of actin binding proteins (ABPs), including actin nucleating, bundling, cross-linking, capping, and severing proteins. In this review, regulation of actin dynamics by ABPs will be introduced, and the role of the F-actin severing protein cofilin-1 and the F-actin bundling protein L-plastin in actin dynamics discussed in more detail. Since up-regulation of these proteins in different kinds of cancers is associated with malignant progression of cancer cells, we suggest the cryogenic electron microscopy (Cryo-EM) structure of F- actin with the respective ABP as template for in silico drug design to specifically disrupt the interaction of these ABPs with F-actin.
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Affiliation(s)
- Christian Dahlstroem
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg
| | - Themistoklis Paraschiakos
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg
| | - Han Sun
- Structural Chemistry and Computational Biophysics Group, Leipniz-Forschungsinstitut für Moekulare Pharmakologie, Robert-Rössle-Strasse 10, D-13125, Berlin; Institute of Chemistry, Technical University of Berlin, D-10623, Berlin
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg.
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Schäfer P, Muhs S, Turnbull L, Garwal P, Maar H, Yorgan TA, Tolosa E, Lange T, Windhorst S. Ex Vivo Model of Neuroblastoma Plasticity. Cancers (Basel) 2023; 15:cancers15041274. [PMID: 36831616 PMCID: PMC9954615 DOI: 10.3390/cancers15041274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/19/2023] Open
Abstract
Tumor plasticity is essential for adaptation to changing environmental conditions, in particular during the process of metastasis. In this study, we compared morphological and biochemical differences between LAN-1 neuroblastoma (NB) cells recovered from a subcutaneous xenograft primary tumor (PT) and the corresponding three generations of bone metastasis (BM I-III). Moreover, growth behavior, as well as the response to chemotherapy and immune cells were assessed. For this purpose, F-actin was stained, mRNA and protein expression assessed, and lactate secretion analyzed. Further, we measured adhesion to collagen I, the growth rate of spheroids in the presence and absence of vincristine, and the production of IL-6 by peripheral blood mononuclear cells (PBMCs) co-incubated with PT or BM I-III. Analysis of PT and the three BM generations revealed that their growth rate decreased from PT to BM III, and accordingly, PT cells reacted most sensitively to vincristine. In addition, morphology, adaption to hypoxic conditions, as well as transcriptomes showed strong differences between the cell lines. Moreover, BM I and BM II cells exhibited a significantly different ability to stimulate human immune cells compared to PT and BM III cells. Interestingly, the differences in immune cell stimulation corresponded to the expression level of the cancer-testis antigen MAGE-A3. In conclusion, our ex vivo model allows to analyze the adaption of tumor populations to different microenvironments and clearly demonstrates the strong alteration of tumor cell populations during this process.
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Affiliation(s)
- Paula Schäfer
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Stefanie Muhs
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Lucas Turnbull
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Palwasha Garwal
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Hanna Maar
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Timur A. Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Eva Tolosa
- Department of Immunology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Tobias Lange
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
- Institute of Anatomy I, Jena University Hospital, Teichgraben 7, D-07743 Jena, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
- Correspondence: ; Tel.: +49-40-7410-56013
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Hamester F, Stürken C, Legler K, Eylmann K, Möller K, Roßberg M, Gorzelanny C, Bauer AT, Windhorst S, Schmalfeldt B, Laakmann E, Müller V, Witzel I, Oliveira-Ferrer L. Key Role of Hyaluronan Metabolism for the Development of Brain Metastases in Triple-Negative Breast Cancer. Cells 2022; 11:3275. [PMID: 36291142 PMCID: PMC9600690 DOI: 10.3390/cells11203275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/08/2022] [Accepted: 10/12/2022] [Indexed: 09/21/2023] Open
Abstract
Breast cancer (BC) is the second-most common cause of brain metastases (BM) and BCBM patients have a reduced quality of life and a poor prognosis. Hyaluronan (HA), and in particular the hyaluronidase Hyal-1, has been already linked to the development of BCBM, and therefore presents an interesting opportunity to develop new effective therapeutic options. HA metabolism was further discovered by the CRISPR/Cas9-mediated knockout of HYAL1 and the shRNA-mediated down-regulation of HA-receptor CD44 in the brain-seeking triple-negative breast cancer (TNBC) cell line MDA-MB-231-BR. Therefore, the impact of Hyal-1 on adhesion, disruption, and invasion through the brain endothelium, both in vitro and in vivo, was studied. Our analysis points out a key role of Hyal-1 and low-molecular-weight HA (LMW-HA) in the formation of a pericellular HA-coat in BC cells, which in turn promotes tumor cell adhesion, disruption, and migration through the brain endothelium in vitro as well as the extent of BM in vivo. CD44 knockdown in MDA-MB-231-BR significantly reduced the pericellular HA-coat on these cells, and, consequently, tumor cell adhesion and invasion through the brain endothelium. Thus, the interaction between Hyal-1-generated LMW-HA fragments and the HA-receptor CD44 might represent a potential target for future therapeutic options in BC patients with a high risk of cerebral metastases formation.
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Affiliation(s)
- Fabienne Hamester
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Christine Stürken
- Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
- MSH Medical School Hamburg, Faculty of Medicine, Medical University, 20251 Hamburg, Germany
| | - Karen Legler
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Kathrin Eylmann
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Katrin Möller
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Maila Roßberg
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Christian Gorzelanny
- Department of Dermatology and Venerology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Alexander T. Bauer
- Department of Dermatology and Venerology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Barbara Schmalfeldt
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Elena Laakmann
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Volkmar Müller
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Isabell Witzel
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Leticia Oliveira-Ferrer
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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Middelkamp M, Ruck L, Krisp C, Sumislawski P, Mohammadi B, Dottermusch M, Meister V, Küster L, Schlüter H, Windhorst S, Neumann JE. ETMR-02. Overexpression of Lin28A in neural progenitor cells in vivo does not lead to brain tumor formation but results in reduced spine density. Neuro Oncol 2022. [PMCID: PMC9165115 DOI: 10.1093/neuonc/noac079.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
The RNA binding protein LIN28A is a stem- and progenitor marker and one of the factors necessary to induce pluripotent stem cells. An overexpression of LIN28A has been identified in malignant brain tumors called embryonal tumors with multilayered rosettes (ETMR) but its specific role during brain development remains largely unknown. Radial glia cells of the ventricular zone (VZ) are proposed as a cell of origin for ETMR. We asked whether an overexpression of LIN28A in such cells might affect brain development or result in the formation of brain tumors. Constitutive overexpression of LIN28A in hGFAP-cre::lsl-Lin28A (GL) mice led to a transient increase of proliferation in the cortical VZ at embryonic stages but no postnatal brain tumor formation. Postnatally, GL mice displayed a pyramidal cell layer dispersion of the hippocampus and altered spine and dendrite morphology, including reduced dendritic spine densities in the hippocampus and cortex. GL mice displayed hyperkinetic activity and differential quantitative MS-based proteomics revealed altered time dependent molecular functions regarding mRNA processing and spine morphogenesis. Phosphoproteomic analyses indicated a downregulation of mTOR pathway modulated proteins such as Map1b being involved in microtubule dynamics within a crosstalk of Gsk3b/Rho-Rac/Map1b signaling. In conclusion, we show that Lin28A overexpression transiently increases proliferation of neural precursor cells but it is not sufficient to drive brain tumors in vivo. In contrast, Lin28A impacts on protein abundancy patterns related to spine morphogenesis and phosphorylation levels of proteins involved in microtubule dynamics, resulting in decreased spine densities of neurons in the hippocampus and cortex as well as in altered behavior. Our work provides new insights into the role of LIN28A for neuronal morphogenesis and development and may reveal future targets for treatment of ETMR patients.
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Affiliation(s)
- Maximilian Middelkamp
- Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf , Hamburg , Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Lisa Ruck
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Christoph Krisp
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Piotr Sumislawski
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Behnam Mohammadi
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Matthias Dottermusch
- Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf , Hamburg , Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Valerie Meister
- Institute of Neuropathology, Ludwig-Maximilians-University Munich , Munich , Germany
| | - Lukas Küster
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Hartmut Schlüter
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Julia E Neumann
- Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf , Hamburg , Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
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Flat W, Borowski S, Paraschiakos T, Blechner C, Windhorst S. DIAPH1 facilitates paclitaxel-mediated cytotoxicity of ovarian cancer cells. Biochem Pharmacol 2021; 197:114898. [PMID: 34968485 DOI: 10.1016/j.bcp.2021.114898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 11/17/2022]
Abstract
The chemotherapeutic agent paclitaxel (PTX) selectively binds to and stabilizes microtubule (MTs). Also, the activated formin Diaphanous Related Formin 1 (DIAPH1) binds to MTs and increases its stability. In a recent study, we found that high DIAPH1 levels correlated with increased survival of ovarian cancer (Ovca) patients. A possible explanation for this finding is that Ovca cells with high DIAPH1 levels are more sensitive to PTX. To examine this assumption, in this study the effect of DIAPH1 depletion on PTX-mediated cytotoxicity of OVCAR8 and OAW42 cells was analyzed. Our data showed that down-regulation of DIAPH1 expression decreased PTX sensitivity in both cell lines by reducing apoptosis or necrosis. Analysis of MT stability by Western blotting revealed a decreased concentration of stable, detyrosinated MTs in PTX-treated DIAPH1 knock-down compared to control cells. Also, in fixed metaphase cells the level of stable, detyrosinated spindle MTs decreased in cells with reduced DIAPH1 expression. In vitro analysis with recombinant DIAPH1 protein showed that PTX and DIAPH1 exhibited additive effects on MT-polymerization, showing that also in a cell-free system DIAPH1 increased the effect of PTX on MT-stability. Together, our data strongly indicate that DIAPH1 increases the response of Ovca cells to PTX by enhancing PTX-mediated MT-stability.
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Affiliation(s)
- Wilhelm Flat
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Sarah Borowski
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Themistoklis Paraschiakos
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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Löhndorf A, Hosang L, Dohle W, Odoardi F, Waschkowski SA, Rosche A, Bauche A, Winzer R, Tolosa E, Windhorst S, Marry S, Flügel A, Potter BVL, Diercks BP, Guse AH. 2-Methoxyestradiol and its derivatives inhibit store-operated Ca 2+ entry in T cells: Identification of a new and potent inhibitor. Biochim Biophys Acta Mol Cell Res 2021; 1868:118988. [PMID: 33581218 PMCID: PMC8062851 DOI: 10.1016/j.bbamcr.2021.118988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/29/2021] [Accepted: 02/04/2021] [Indexed: 12/15/2022]
Abstract
T cell activation starts with formation of second messengers that release Ca2+ from the endoplasmic reticulum (ER) and thereby activate store-operated Ca2+ entry (SOCE), one of the essential signals for T cell activation. Recently, the steroidal 2-methoxyestradiol was shown to inhibit nuclear translocation of the nuclear factor of activated T cells (NFAT). We therefore investigated 2-methoxyestradiol for inhibition of Ca2+ entry in T cells, screened a library of 2-methoxyestradiol analogues, and characterized the derivative 2-ethyl-3-sulfamoyloxy-17β-cyanomethylestra-1,3,5(10)-triene (STX564) as a novel, potent and specific SOCE inhibitor. STX564 inhibits Ca2+ entry via SOCE without affecting other ion channels and pumps involved in Ca2+ signaling in T cells. Downstream effects such as cytokine expression and cell proliferation were also inhibited by both 2-methoxyestradiol and STX564, which has potential as a new chemical biology tool.
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Affiliation(s)
- Anke Löhndorf
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Leon Hosang
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, Von-Siebold-Straße 3a, D-37075 Göttingen, Germany
| | - Wolfgang Dohle
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Francesca Odoardi
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, Von-Siebold-Straße 3a, D-37075 Göttingen, Germany
| | - Sissy-Alina Waschkowski
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Anette Rosche
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Andreas Bauche
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Riekje Winzer
- Department of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Eva Tolosa
- Department of Immunology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Stephen Marry
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, Von-Siebold-Straße 3a, D-37075 Göttingen, Germany
| | - Alexander Flügel
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Centre Göttingen, Von-Siebold-Straße 3a, D-37075 Göttingen, Germany
| | - Barry V L Potter
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Björn-Philipp Diercks
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Andreas H Guse
- The Ca(2+) Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
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Arnold J, Schattschneider J, Blechner C, Krisp C, Schlüter H, Schweizer M, Nalaskowski M, Oliveira-Ferrer L, Windhorst S. Tubulin Tyrosine Ligase Like 4 (TTLL4) overexpression in breast cancer cells is associated with brain metastasis and alters exosome biogenesis. J Exp Clin Cancer Res 2020; 39:205. [PMID: 32998758 PMCID: PMC7528497 DOI: 10.1186/s13046-020-01712-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The survival rate is poor in breast cancer patients with brain metastases. Thus, new concepts for therapeutic approaches are required. During metastasis, the cytoskeleton of cancer cells is highly dynamic and therefore cytoskeleton-associated proteins are interesting targets for tumour therapy. METHODS Screening for genes showing a significant correlation with brain metastasis formation was performed based on microarray data from breast cancer patients with long-term follow up information. Validation of the most interesting target was performed by MTT-, Scratch- and Transwell-assay. In addition, intracellular trafficking was analyzed by live-cell imaging for secretory vesicles, early endosomes and multiple vesicular bodies (MVB) generating extracellular vesicles (EVs). EVs were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), Western blotting, mass spectrometry, and ingenuity pathway analysis (IPA). Effect of EVs on the blood-brain-barrier (BBB) was examined by incubating endothelial cells of the BBB (hCMEC/D3) with EVs, and permeability as well as adhesion of breast cancer cells were analyzed. Clinical data of a breast cancer cohort was evaluated by χ2-tests, Kaplan-Meier-Analysis, and log-rank tests while for experimental data Student's T-test was performed. RESULTS Among those genes exhibiting a significant association with cerebral metastasis development, the only gene coding for a cytoskeleton-associated protein was Tubulin Tyrosine Ligase Like 4 (TTLL4). Overexpression of TTLL4 (TTLL4plus) in MDA-MB231 and MDA-MB468 breast cancer cells (TTLL4plus cells) significantly increased polyglutamylation of β-tubulin. Moreover, trafficking of secretory vesicles and MVBs was increased in TTLL4plus cells. EVs derived from TTLL4plus cells promote adhesion of MDA-MB231 and MDA-MB468 cells to hCMEC/D3 cells and increase permeability of hCMEC/D3 cell layer. CONCLUSIONS These data suggest that TTLL4-mediated microtubule polyglutamylation alters exosome homeostasis by regulating trafficking of MVBs. The TTLL4plus-derived EVs may provide a pre-metastatic niche for breast cancer cells by manipulating endothelial cells of the BBB.
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Affiliation(s)
- Julia Arnold
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Juliana Schattschneider
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Christoph Krisp
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Hartmut Schlüter
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Michaela Schweizer
- Core Facility Morphology und Electron Microscopy, Center for Molecular Neurobiology Hamburg, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Marcus Nalaskowski
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Leticia Oliveira-Ferrer
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
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Blechner C, Becker L, Fuchs H, Rathkolb B, Prehn C, Adler T, Calzada-Wack J, Garrett L, Gailus-Durner V, Morellini F, Conrad S, Hölter SM, Wolf E, Klopstock T, Adamski J, Busch D, de Angelis MH, Schmeisser MJ, Windhorst S. Physiological relevance of the neuronal isoform of inositol-1,4,5-trisphosphate 3-kinases in mice. Neurosci Lett 2020; 735:135206. [PMID: 32593773 DOI: 10.1016/j.neulet.2020.135206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/09/2020] [Accepted: 06/23/2020] [Indexed: 10/24/2022]
Abstract
Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA) is the neuronal isoform of ITPKs and exhibits both actin bundling and InsP3kinase activity. In addition to neurons, ITPKA is ectopically expressed in tumor cells, where its oncogenic activity increases tumor cell malignancy. In order to analyze the physiological relevance of ITPKA, here we performed a broad phenotypic screening of itpka deficient mice. Our data show that among the neurobehavioral tests analyzed, itpka deficient mice reacted faster to a hotplate, prepulse inhibition was impaired and the accelerating rotarod test showed decreased latency of itpka deficient mice to fall. These data indicate that ITPKA is involved in the regulation of nociceptive pathways, sensorimotor gating and motor learning. Analysis of extracerebral functions in control and itpka deficient mice revealed significantly reduced glucose, lactate, and triglyceride plasma concentrations in itpka deficient mice. Based on this finding, expression of ITPKA was analyzed in extracerebral tissues and the highest level was found in the small intestine. However, functional studies on CaCo-2 control and ITPKA depleted cells showed that glucose, as well as triglyceride uptake, were not significantly different between the cell lines. Altogether, these data show that ITPKA exhibits distinct functions in the central nervous system and reveal an involvement of ITPKA in energy metabolism.
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Affiliation(s)
- Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany
| | - Lore Becker
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Birgit Rathkolb
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Geman Center for Diabetes Research (DZD), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany; Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377, Munich, Germany
| | - Cornelia Prehn
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Thure Adler
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Julia Calzada-Wack
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Lillian Garrett
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Fabio Morellini
- Behavioral Biology, Center for Molecular Neurobiology Hamburg, Falkenried 94, D-20251 Hamburg, Germany
| | - Susanne Conrad
- Forschungstierhaltung University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany
| | - Sabine M Hölter
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377, Munich, Germany
| | - Thomas Klopstock
- Dept. of Neurology, Friedrich-Baur-Institute, Klinikum der Ludwig-Maximilians-Universität München, Ziemssenstr. 1a, 80336, Munich, Germany; Deutsches Institut für Neurodegenerative Erkrankungen (DZNE), Site Munich, 80336, München, Germany; Munich Cluster for Systems Neurology (SyNergy), Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, Schillerstr. 44, 80336, Munich, Germany
| | - Jerzy Adamski
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany
| | - Dirk Busch
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstrasse 30, 81675, Munich, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Geman Center for Diabetes Research (DZD), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany
| | - Michael J Schmeisser
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131, Mainz, Germany; Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131, Mainz, Germany; Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany.
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10
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Nelson N, Wundenberg T, Lin H, Rehbach C, Horn S, Windhorst S, Jücker M. Characterization of the substrate specificity of the inositol 5-phosphatase SHIP1. Biochem Biophys Res Commun 2020; 524:366-370. [PMID: 32005521 DOI: 10.1016/j.bbrc.2020.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 01/02/2020] [Indexed: 10/25/2022]
Abstract
SHIP1 is an inositol 5-phosphatase which is well established for its tumour suppressor potential in leukaemia. Enzymatically, two SHIP1 substrates, PtdIns(3,4,5)P3 and Ins(1,3,4,5)P4 have been identified to date. Additional substrates were found for the homologue SHIP2. In this study, we identified new inositol phosphate (InsP) substrates of SHIP1 by metal dye detection high-performance liquid chromatography and compared the substrate profiles of SHIP1 and SHIP2. We were able to verify Ins(1,3,4,5)P4 as a substrate of SHIP1 and interestingly found Ins(1,2,3,4,5)P5 and Ins(2,3,4,5)P4 to be preferably used as substrates and Ins(1,4,5,6)P4 and Ins(2,4,5,6)P4 to be weak substrates. All of those except Ins(2,3,4,5)P4 are also known substrates of SHIP2 indicating a possible exclusive role of Ins(2,3,4,5)P4 hydrolysis for SHIP1 but not SHIP2 function.
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Affiliation(s)
- Nina Nelson
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Torsten Wundenberg
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | | | - Christoph Rehbach
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Stefan Horn
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany; Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Sabine Windhorst
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Manfred Jücker
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
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11
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Hu C, Kanellopoulos AK, Richter M, Petersen M, Konietzny A, Tenedini FM, Hoyer N, Cheng L, Poon CLC, Harvey KF, Windhorst S, Parrish JZ, Mikhaylova M, Bagni C, Calderon de Anda F, Soba P. Conserved Tao Kinase Activity Regulates Dendritic Arborization, Cytoskeletal Dynamics, and Sensory Function in Drosophila. J Neurosci 2020; 40:1819-1833. [PMID: 31964717 PMCID: PMC7046460 DOI: 10.1523/jneurosci.1846-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Dendritic arborization is highly regulated and requires tight control of dendritic growth, branching, cytoskeletal dynamics, and ion channel expression to ensure proper function. Abnormal dendritic development can result in altered network connectivity, which has been linked to neurodevelopmental disorders, including autism spectrum disorders (ASDs). How neuronal growth control programs tune dendritic arborization to ensure function is still not fully understood. Using Drosophila dendritic arborization (da) neurons as a model, we identified the conserved Ste20-like kinase Tao as a negative regulator of dendritic arborization. We show that Tao kinase activity regulates cytoskeletal dynamics and sensory channel localization required for proper sensory function in both male and female flies. We further provide evidence for functional conservation of Tao kinase, showing that its ASD-linked human ortholog, Tao kinase 2 (Taok2), could replace Drosophila Tao and rescue dendritic branching, dynamic microtubule alterations, and behavioral defects. However, several ASD-linked Taok2 variants displayed impaired rescue activity, suggesting that Tao/Taok2 mutations can disrupt sensory neuron development and function. Consistently, we show that Tao kinase activity is required in developing and as well as adult stages for maintaining normal dendritic arborization and sensory function to regulate escape and social behavior. Our data suggest an important role for Tao kinase signaling in cytoskeletal organization to maintain proper dendritic arborization and sensory function, providing a strong link between developmental sensory aberrations and behavioral abnormalities relevant for Taok2-dependent ASDs.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are linked to abnormal dendritic arbors. However, the mechanisms of how dendritic arbors develop to promote functional and proper behavior are unclear. We identified Drosophila Tao kinase, the ortholog of the ASD risk gene Taok2, as a regulator of dendritic arborization in sensory neurons. We show that Tao kinase regulates cytoskeletal dynamics, controls sensory ion channel localization, and is required to maintain somatosensory function in vivo Interestingly, ASD-linked human Taok2 mutations rendered it nonfunctional, whereas its WT form could restore neuronal morphology and function in Drosophila lacking endogenous Tao. Our findings provide evidence for a conserved role of Tao kinase in dendritic development and function of sensory neurons, suggesting that aberrant sensory function might be a common feature of ASDs.
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Affiliation(s)
- Chun Hu
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | | | - Melanie Richter
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Meike Petersen
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Anja Konietzny
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nina Hoyer
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lin Cheng
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Carole L C Poon
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
- Department of Anatomy and Developmental Biology, and Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Sabine Windhorst
- Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, 98195 Washington, and
| | - Marina Mikhaylova
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Froylan Calderon de Anda
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Peter Soba
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany,
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12
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Yorgan TA, Sari H, Rolvien T, Windhorst S, Failla AV, Kornak U, Oheim R, Amling M, Schinke T. Mice lacking plastin-3 display a specific defect of cortical bone acquisition. Bone 2020; 130:115062. [PMID: 31678489 DOI: 10.1016/j.bone.2019.115062] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/20/2022]
Abstract
Although inactivating mutations of PLS3, encoding the actin-bundling protein plastin-3, have been identified to cause X-linked osteoporosis, the cellular and molecular influence of PLS3 on bone remodeling is poorly defined. Moreover, although a previous study has demonstrated moderate osteopenia in 12 week-old Pls3-deficient mice based on μCT scanning, there is no reported analysis of such a model on the basis of undecalcified histology and bone-specific histomorphometry. To fill this knowledge gap we applied a deep phenotyping approach and studied Pls3-deficient mice at different ages. Surprisingly, we did not detect significant differences between wildtype and Pls3-deficient littermates with respect to trabecular bone mass, and the same was the case for all histomorphometric parameters determined at 12 weeks of age. Remarkably however, the cortical thickness in both, tibia and femur, was significantly reduced in Pls3-deficient mice in all age groups. We additionally studied the ex vivo behavior of Pls3-deficient primary osteoblasts, which displayed moderately impaired mineralization capacity. Of note, while most osteoblastogenesis markers were not differentially expressed between wildtype and Pls3-deficient cultures, the expression of Sfrp4 was significantly reduced in the latter, a potentially relevant finding, since Sfrp4 inactivation, in mice and humans, specifically causes cortical thinning. We finally addressed the question, if Pls3-deficiency would impair the osteoanabolic influence of parathyroid hormone (PTH). For this purpose we applied daily injection of PTH into wildtype and Pls3-deficient mice and found a similar response regardless of the genotype. Taken together, our data reveal that Pls3-deficiency in mice only recapitulates the cortical bone phenotype of individuals with X-linked osteoporosis by negatively affecting the early stage of cortical bone acquisition.
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Affiliation(s)
- Timur Alexander Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Hatice Sari
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Antonio Virgilio Failla
- Microscopy Core Facility, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Uwe Kornak
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany; Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
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13
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Meka DP, Scharrenberg R, Zhao B, Kobler O, König T, Schaefer I, Schwanke B, Klykov S, Richter M, Eggert D, Windhorst S, Dotti CG, Kreutz MR, Mikhaylova M, Calderon de Anda F. Radial somatic F-actin organization affects growth cone dynamics during early neuronal development. EMBO Rep 2019; 20:e47743. [PMID: 31650708 PMCID: PMC6893363 DOI: 10.15252/embr.201947743] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 09/06/2019] [Accepted: 09/27/2019] [Indexed: 11/16/2022] Open
Abstract
The centrosome is thought to be the major neuronal microtubule‐organizing center (MTOC) in early neuronal development, producing microtubules with a radial organization. In addition, albeit in vitro, recent work showed that isolated centrosomes could serve as an actin‐organizing center, raising the possibility that neuronal development may, in addition, require a centrosome‐based actin radial organization. Here, we report, using super‐resolution microscopy and live‐cell imaging of cultured rodent neurons, F‐actin organization around the centrosome with dynamic F‐actin aster‐like structures with F‐actin fibers extending and retracting actively. Photoactivation/photoconversion experiments and molecular manipulations of F‐actin stability reveal a robust flux of somatic F‐actin toward the cell periphery. Finally, we show that somatic F‐actin intermingles with centrosomal PCM‐1 (pericentriolar material 1 protein) satellites. Knockdown of PCM‐1 and disruption of centrosomal activity not only affect F‐actin dynamics near the centrosome but also in distal growth cones. Collectively, the data show a radial F‐actin organization during early neuronal development, which might be a cellular mechanism for providing peripheral regions with a fast and continuous source of actin polymers, hence sustaining initial neuronal development.
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Affiliation(s)
- Durga Praveen Meka
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robin Scharrenberg
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bing Zhao
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kobler
- Combinatorial Neuroimaging Core Facility (CNI), Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Theresa König
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irina Schaefer
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Birgit Schwanke
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sergei Klykov
- Emmy-Noether Group "Neuronal Protein Transport", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Melanie Richter
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dennis Eggert
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.,Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carlos G Dotti
- Centro de Biología Molecular "Severo Ochoa", CSIC-UAM, Madrid, Spain
| | - Michael R Kreutz
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Leibniz Guest Group "Dendritic Organelles and Synaptic Function", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marina Mikhaylova
- Emmy-Noether Group "Neuronal Protein Transport", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Froylan Calderon de Anda
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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14
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Grueb SS, Muhs S, Popp Y, Schmitt S, Geyer M, Lin YN, Windhorst S. The formin Drosophila homologue of Diaphanous2 (Diaph2) controls microtubule dynamics in colorectal cancer cells independent of its FH2-domain. Sci Rep 2019; 9:5352. [PMID: 30926831 PMCID: PMC6441084 DOI: 10.1038/s41598-019-41731-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 03/12/2019] [Indexed: 12/21/2022] Open
Abstract
In this study, we analyzed the functional role of the formin Drosophila Homologue of Diaphanous2 (Diaph2) in colorectal cancer cells. We show that stable down-regulation of Diaph2 expression in HT29 cells decreased chromosome alignment and the velocity of chromosome movement during M-phase, thus reducing the proliferation rate and colony formation. In interphase cells, Diaph2 was diffusely distributed in the cytosol, while in metaphase cells the protein was located to spindle microtubules (MTs). Diaph2-depletion increased the concentration of stable spindle MTs, showing that the formin is required to control spindle MT-dynamics. Our cellular data indicate that Diaph2-controls spindle MT-dynamics independent of Cdc42 activity and our in vitro results reveal that bacterially produced full-length (FL) Diaph2 strongly altered MT-dynamics in absence of Cdc42, where its actin-nucleating activity is auto-inhibited. FL-Diaph2 mediates a 10-fold increase in MT-polymerization compared to the Diaph2-FH2-domain. Interestingly, a Diaph2-mutant lacking the FH2-domain (ΔFH2) increased MT-polymerization to a similar extent as the FH2-domain, indicating the existence of a second MT-binding domain. However, in contrast to FL-Diaph2 and the FH2-domain, ΔFH2 did not alter the density of taxol-stabilized MTs. Thus, the FH2-domain and the second Diaph2-binding domain appear to control MT-dynamics by different mechanisms. In summary, our data indicate that Diaph2 controls M-phase progression under basal conditions by regulating spindle MT-dynamics. In addition, a region outside of the canonical MT-regulating FH2-domain is involved in Diaph2-mediated control of MT-dynamics.
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Affiliation(s)
- Saskia S Grueb
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf Martinistrasse 52, D-20246, Hamburg, Germany
| | - Stefanie Muhs
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf Martinistrasse 52, D-20246, Hamburg, Germany
| | - Yannes Popp
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf Martinistrasse 52, D-20246, Hamburg, Germany
| | - Sebastian Schmitt
- Institute of Structural Biology, University of Bonn, Sigmund-Freud-Str. 25, D-53127, Bonn, Germany
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Sigmund-Freud-Str. 25, D-53127, Bonn, Germany
| | - Yuan-Na Lin
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf Martinistrasse 52, D-20246, Hamburg, Germany
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf Martinistrasse 52, 52 D-20246, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf Martinistrasse 52, D-20246, Hamburg, Germany.
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15
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Abstract
Many mechanistic studies have been performed to analyze the cellular functions of the highly phosphorylated molecule inositol hexakisphosphate (InsP6) in health and disease. While the physiological intracellular functions are well described, the mechanism of potential pharmacological effects on cancer cell proliferation is still controversial. There are numerous studies demonstrating that a high InsP6 concentration (≥75 µM) inhibits growth of cancer cells in vitro and in vivo. Thus, there is no doubt that InsP6 exhibits anticancer activity but the mechanism underlying the cellular effects of extracellular InsP6 on cancer cells is far from being understood. In addition, studies on the inhibitory effect of InsP6 on cancer progression in animal models ignore aspects of its bioavailability. Here, we review and critically discuss the uptake mechanism and the intracellular involvement in signaling pathways of InsP6 in cancer cells. We take into account the controversial findings on InsP6 plasma concentration, which is a critical aspect of pharmacological accessibility of InsP6 for cancer treatment. Further, we discuss novel findings with respect to the effect of InsP6 on normal and immune cells as well as on platelet aggregate size. Our goal is to stimulate further mechanistic studies into novel directions considering previously disregarded aspects of InsP6. Only when we fully understand the mechanism underlying the anticancer activity of InsP6 novel and more efficient treatment options can be developed.
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Affiliation(s)
- Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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16
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Brehm MA, Klemm U, Rehbach C, Erdmann N, Kolšek K, Lin H, Aponte-Santamaría C, Gräter F, Rauch BH, Riley AM, Mayr GW, Potter BVL, Windhorst S. Inositol hexakisphosphate increases the size of platelet aggregates. Biochem Pharmacol 2018; 161:14-25. [PMID: 30557554 PMCID: PMC6372069 DOI: 10.1016/j.bcp.2018.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/13/2018] [Indexed: 12/28/2022]
Abstract
The inositol phosphates, InsP5 and InsP6, have recently been identified as binding partners of fibrinogen, which is critically involved in hemostasis by crosslinking activated platelets at sites of vascular injury. Here, we investigated the putative physiological role of this interaction and found that platelets increase their InsP6 concentration upon stimulation with the PLC-activating agonists thrombin, collagen I and ADP and present a fraction of it at the outer plasma membrane. Cone and plate analysis in whole blood revealed that InsP6 specifically increases platelet aggregate size. This effect is fibrinogen-dependent, since it is inhibited by an antibody that blocks fibrinogen binding to platelets. Furthermore, InsP6 has only an effect on aggregate size of washed platelets when fibrinogen is present, while it has no influence in presence of von Willebrand factor or collagen. By employing blind docking studies we predicted the binding site for InsP6 at the bundle between the γ and β helical subunit of fibrinogen. Since InsP6 is unable to directly activate platelets and it did not exhibit an effect on thrombin formation or fibrin structure, our data indicate that InsP6 might be a hemostatic agent that is produced by platelets upon stimulation with PLC-activating agonists to promote platelet aggregation by supporting crosslinking of fibrinogen and activated platelets.
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Affiliation(s)
- Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrike Klemm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Rehbach
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Nina Erdmann
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Katra Kolšek
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Hongying Lin
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | | | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Bernhard H Rauch
- Institute of Pharmacology, University Medicine Greifswald, Ernst-Moritz-Arndt University, Felix-Hausdorff-Str. 3, 17487 Greifswald, Germany
| | - Andrew M Riley
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Georg W Mayr
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Barry V L Potter
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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17
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Schiewek J, Schumacher U, Lange T, Joosse SA, Wikman H, Pantel K, Mikhaylova M, Kneussel M, Linder S, Schmalfeldt B, Oliveira-Ferrer L, Windhorst S. Clinical relevance of cytoskeleton associated proteins for ovarian cancer. J Cancer Res Clin Oncol 2018; 144:2195-2205. [PMID: 30094535 DOI: 10.1007/s00432-018-2710-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/16/2018] [Indexed: 02/07/2023]
Abstract
PURPOSE Ovarian cancer has a high mortality rate and up to now no reliable molecular prognostic biomarkers have been established. During malignant progression, the cytoskeleton is strongly altered. Hence we analyzed if expression of certain cytoskeleton-associated proteins is correlated with clinical outcome of ovarian cancer patients. METHODS First, in silico analysis was performed using the cancer genome atlas (TCGA), the human expression atlas and Pubmed. Selected candidates were validated on 270 ovarian cancer patients by qRT-PCR and/or by western blotting. RESULTS In silico analysis revealed that mRNAs of 214 cytoskeleton-associated proteins are detectable in ovarian cancer tissue. Among these, we selected 17 proteins that participate in cancer disease progression and cytoskeleton modulation: KIF14, KIF20A, KIF18A, ASPM, CEP55, DLGAP5, MAP9, EB1, KATNA1, DIAPH1, ANLN, SCIN, CCDC88A, FSCN1, GSN, VASP and CDC42. The first ten candidates interact with microtubules (MTs) and the others bind to actin filaments. Validation on clinical samples of ovarian cancer patients revealed that the expression levels of DIAPH1, EB1, KATNA1, KIF14 and KIF18A significantly correlated with clinical and histological parameters of ovarian cancer. High DIAPH1, EB1, KATNA1 and KIF14 protein levels were associated with increased overall survival (OAS) of ovarian cancer patients, while high DIAPH1 and EB1 protein levels were also associated with low differentiation of respective tumors (G2/3). Moreover, DIAPH1 was the only protein, whose expression significantly correlated with increased recurrence-free interval (RFI). CONCLUSION Mainly the expression levels of the MT-associated proteins analyzed in this study, correlated with prolonged survival of ovarian cancer patients. From > 200 genes initially considered, 17 cytoskeletal proteins are involved in cancer progression according to the literature. Among these, four proteins significantly correlated with improved survival of ovarian cancer patients.
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Affiliation(s)
- Johanna Schiewek
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Udo Schumacher
- Institute of Anatomy and Experimental Morphology, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Tobias Lange
- Institute of Anatomy and Experimental Morphology, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Simon A Joosse
- Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Harriet Wikman
- Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Klaus Pantel
- Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Marina Mikhaylova
- DFG Emmy Noether Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Stefan Linder
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Barbara Schmalfeldt
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Leticia Oliveira-Ferrer
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
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18
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Volksdorf T, Heilmann J, Eming SA, Schawjinski K, Zorn-Kruppa M, Ueck C, Vidal-Y-Sy S, Windhorst S, Jücker M, Moll I, Brandner JM. Tight Junction Proteins Claudin-1 and Occludin Are Important for Cutaneous Wound Healing. Am J Pathol 2017; 187:1301-1312. [PMID: 28412298 DOI: 10.1016/j.ajpath.2017.02.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 02/07/2017] [Indexed: 12/31/2022]
Abstract
Tight junction (TJ) proteins are known to be involved in proliferation and differentiation. These processes are essential for normal skin wound healing. Here, we investigated the TJ proteins claudin-1 and occludin in ex vivo skin wound healing models and tissue samples of acute and chronic human wounds and observed major differences in localization/expression of these proteins, with chronic wounds often showing a loss of the proteins at the wound margins and/or in the regenerating epidermis. Knockdown experiments in primary human keratinocytes showed that decreased claudin-1 expression resulted in significantly impaired scratch wound healing, with delayed migration and reduced proliferation. Activation of AKT pathway was significantly attenuated after claudin-1 knockdown, and protein levels of extracellular signal-related kinase 1/2 were reduced. For occludin, down-regulation had no impact on wound healing in normal scratch assays, but after subjecting the cells to mechanical stress, which is normally present in wounds, wound healing was impaired. For both proteins we show that most of these actions are independent from the formation of barrier-forming TJ structures, thus demonstrating nonbarrier-related functions of TJ proteins in the skin. However, for claudin-1 effects on scratch wound healing were more pronounced when TJs could form. Together, our findings provide evidence for a role of claudin-1 and occludin in epidermal regeneration with potential clinical importance.
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Affiliation(s)
- Thomas Volksdorf
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Janina Heilmann
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine A Eming
- Department of Dermatology, University of Cologne, Cologne, Germany
| | - Kathrin Schawjinski
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Michaela Zorn-Kruppa
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Christopher Ueck
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine Vidal-Y-Sy
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine Windhorst
- Institute of Biochemistry and Signal Transduction, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Manfred Jücker
- Institute of Biochemistry and Signal Transduction, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Ingrid Moll
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Johanna M Brandner
- Department of Dermatology and Venerology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
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19
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Fester L, Brandt N, Windhorst S, Pröls F, Bläute C, Rune GM. Control of aromatase in hippocampal neurons. J Steroid Biochem Mol Biol 2016; 160:9-14. [PMID: 26472556 DOI: 10.1016/j.jsbmb.2015.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/01/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
Our knowledge on estradiol-induced modulation of synaptic function in the hippocampus is widely based on results following the application of the steroid hormone to either cell cultures, or after the treatment of gonadectomized animals, thus ignoring local neuronal estrogen synthesis. We and others, however, have shown that hippocampus-derived estradiol also controls synaptic plasticity in the hippocampus. Estradiol synthesis in the hippocampus is regulated by several mechanisms, which are reviewed in this report. The regulation of the activity of aromatase, the final enzyme of estrogen biosynthesis, by Ca(2+) transients, is of particular interest. Aromatase becomes inactivated as soon as it is phosphorylated by Ca(2+)-dependent kinases upon calcium release from internal stores. Accordingly, thapsigargin dephosphorylates aromatase and stimulates estradiol synthesis by depletion of internal Ca(2+) stores. Vice versa, letrozole, an aromatase inhibitor, phosphorylates aromatase and reduces estradiol synthesis. Treatment of the cultures with 17β-estradiol results in phosphorylation of the enzyme and increased aromatase protein expression, which suggests that estradiol synthesis in hippocampal neurons is regulated in an autocrine manner.
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Affiliation(s)
- Lars Fester
- University Medical Center Hamburg Eppendorf, Institute of Neuroanatomy, Martinistr. 52, 20246 Hamburg, Germany
| | - Nicola Brandt
- University Medical Center Hamburg Eppendorf, Institute of Neuroanatomy, Martinistr. 52, 20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, Martinistr. 52, 20246 Hamburg, Germany
| | - Felicitas Pröls
- University Medical Center Hamburg Eppendorf, Institute of Neuroanatomy, Martinistr. 52, 20246 Hamburg, Germany
| | - Corinna Bläute
- University Medical Center Hamburg Eppendorf, Institute of Neuroanatomy, Martinistr. 52, 20246 Hamburg, Germany
| | - Gabriele M Rune
- University Medical Center Hamburg Eppendorf, Institute of Neuroanatomy, Martinistr. 52, 20246 Hamburg, Germany.
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20
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Lin YN, Bhuwania R, Gromova K, Failla AV, Lange T, Riecken K, Linder S, Kneussel M, Izbicki JR, Windhorst S. Drosophila homologue of Diaphanous 1 (DIAPH1) controls the metastatic potential of colon cancer cells by regulating microtubule-dependent adhesion. Oncotarget 2016; 6:18577-89. [PMID: 26124177 PMCID: PMC4621911 DOI: 10.18632/oncotarget.4094] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/11/2015] [Indexed: 11/25/2022] Open
Abstract
Drosophila homologue of Diaphanous 1 (DIAPH1) regulates actin polymerization and microtubule (MT) stabilization upon stimulation with lysophosphatidic acid (LPA). Recently, we showed strongly reduced lung metastasis of DIAPH1-depleted colon cancer cells but we found accumulations of DIAPH1-depleted cells in bone marrow. Here, we analyzed possible organ- or tissue-specific metastasis of DIAPH1-depleted HCT-116 cells. Our data confirmed that depletion of DIAPH1 strongly inhibited lung metastasis and revealed that, in contrast to control cells, DIAPH1-depleted cells did not form metastases in further organs. Detailed mechanistic analysis on cells that were not stimulated with LPA to activate the cytoskeleton-modulating activity of DIAPH1, revealed that even under basal conditions DIAPH1 was essential for cellular adhesion to collagen. In non-stimulated cells DIAPH1 did not control actin dynamics but, interestingly, was essential for stabilization of microtubules (MTs). Additionally, DIAPH1 controlled directed vesicle trafficking and with this, local clustering of the adhesion protein integrin-β1 at the plasma membrane. Therefore, we conclude that under non-stimulating conditions DIAPH1 controls cellular adhesion by stabilizing MTs required for local clustering of integrin-β1 at the plasma membrane. Thus, blockade of DIAPH1-tubulin interaction may be a promising approach to inhibit one of the earliest steps in the metastatic cascade of colon cancer.
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Affiliation(s)
- Yuan-Na Lin
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ridhirama Bhuwania
- Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kira Gromova
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Tobias Lange
- Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kristoffer Riecken
- Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Linder
- Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jakob R Izbicki
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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21
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Chen L, DeWispelaere A, Dastvan F, Osborne WRA, Blechner C, Windhorst S, Daum G. Smooth Muscle-Alpha Actin Inhibits Vascular Smooth Muscle Cell Proliferation and Migration by Inhibiting Rac1 Activity. PLoS One 2016; 11:e0155726. [PMID: 27176050 PMCID: PMC4866761 DOI: 10.1371/journal.pone.0155726] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 05/03/2016] [Indexed: 12/28/2022] Open
Abstract
Smooth muscle alpha-actin (SMA) is a marker for the contractile, non-proliferative phenotype of adult smooth muscle cells (SMCs). Upon arterial injury, expression of SMA and other structural proteins decreases and SMCs acquire a pro-migratory and proliferative phenotype. To what extent SMA regulates migration and proliferation of SMCs is unclear and putative signaling pathways involved remain to be elucidated. Here, we used lentiviral-mediated gene transfer and siRNA technology to manipulate expression of SMA in carotid mouse SMCs and studied effects of SMA. Overexpression of SMA results in decreased proliferation and migration and blunts serum-induced activation of the small GTPase Rac, but not RhoA. All inhibitory effects of SMA are rescued by expression of a constitutively active Rac1 mutant (V12rac1). Moreover, reduction of SMA expression by siRNA technology results in an increased activation of Rac. Taken together, this study identifies Rac1 as a downstream target for SMA to inhibit SMC proliferation and migration.
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Affiliation(s)
- Lihua Chen
- Department of Surgery and Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States of America
| | - Allison DeWispelaere
- Department of Surgery and Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States of America
| | - Frank Dastvan
- Department of Surgery and Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States of America
| | - William R. A. Osborne
- Department of Pediatrics and Diabetes and Obesity Center of Excellence at the University of Washington, Seattle, WA, United States of America
| | - Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Germany
| | - Guenter Daum
- Department of Surgery and Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States of America
- * E-mail:
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22
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Köster JD, Leggewie B, Blechner C, Brandt N, Fester L, Rune G, Schweizer M, Kindler S, Windhorst S. Inositol-1,4,5-trisphosphate-3-kinase-A controls morphology of hippocampal dendritic spines. Cell Signal 2015; 28:83-90. [PMID: 26519023 DOI: 10.1016/j.cellsig.2015.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 01/10/2023]
Abstract
Long-lasting synaptic plasticity is often accompanied by morphological changes as well as formation and/or loss of dendritic spines. Since the spine cytoskeleton mainly consists of actin filaments, morphological changes are primarily controlled by actin binding proteins (ABPs). Inositol-1,4,5-trisphosphate-3-kinase-A (ITPKA) is a neuron-specific, actin bundling protein concentrated at dendritic spines. Here, we demonstrate that ITPKA depletion in mice increases the number of hippocampal spine-synapses while reducing average spine length. By employing actin to ABP ratios similar to those occurring at post synaptic densities, in addition to cross-linking actin filaments, ITPKA strongly inhibits Arp2/3-complex induced actin filament branching by displacing the complex from F-actin. In summary, our data show that in vivo ITPKA negatively regulates formation and/or maintenance of synaptic contacts in the mammalian brain. On the molecular level this effect appears to result from the ITPKA-mediated inhibition of Arp2/3-complex F-actin branching activity.
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Affiliation(s)
- Jan-Dietrich Köster
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Birthe Leggewie
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Nicola Brandt
- Department of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Lars Fester
- Department of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Gabriele Rune
- Department of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Michaela Schweizer
- Center for Molecular Neurobiology Hamburg, Falkenried 94, D-20251 Hamburg, Germany
| | - Stefan Kindler
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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23
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Lin YN, Thata RN, Failla AV, Geissen M, Daum G, Windhorst S. Ex vivo aorta patch model for analysis of cellular adhesion. Tissue Cell 2015; 47:266-72. [PMID: 25890870 DOI: 10.1016/j.tice.2015.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/11/2015] [Accepted: 03/13/2015] [Indexed: 11/25/2022]
Abstract
The vascular endothelium as well as subendothelium are objects of many researches as it is directly involved in a multiplicity of physiological and pathological settings. Detailed study of endothelial function became feasible with the development of techniques to culture endothelial cells (EC) in vitro. Limitations of this approach have become apparent with the realization that cell culture dedifferentiate with time and do not exhibit properties of intact tissue. Here we describe the development of a novel ex vivo tissue model to study cell-vascular wall interactions by using isolated mouse aorta patches. Validation of this model was performed by demonstrating cell attachment and changes in cell shape typical for cell spreading during adhesion. A major advantage of this model is that cell-endothelium interaction and its molecular backgrounds can now be studied more feasibly on an intact and native tissue.
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Affiliation(s)
- Yuan-Na Lin
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany; Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
| | - Raymond Nqobizitha Thata
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
| | - Antonio Virgilio Failla
- Microscopy Imaging Facility, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
| | - Markus Geissen
- Department of Vascular Medicine, University Heart Center, Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
| | - Guenter Daum
- Department of Vascular Medicine, University Heart Center, Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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24
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Ashour DJ, Pelka B, Jaaks P, Wundenberg T, Blechner C, Zobiak B, Failla AV, Windhorst S. The catalytic domain of inositol-1,4,5-trisphosphate 3-kinase-a contributes to ITPKA-induced modulation of F-actin. Cytoskeleton (Hoboken) 2015; 72:93-100. [DOI: 10.1002/cm.21208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/22/2014] [Accepted: 01/07/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Dina Julia Ashour
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
| | - Benjamin Pelka
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
| | - Patricia Jaaks
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
| | - Torsten Wundenberg
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
| | - Christine Blechner
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
| | - Bernd Zobiak
- Microscopy Imaging Facility; University Medical Center Hamburg-Eppendorf; Martinistrasse Hamburg Germany
| | - Antonio Virgilio Failla
- Microscopy Imaging Facility; University Medical Center Hamburg-Eppendorf; Martinistrasse Hamburg Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction; University Medical Center Hamburg-Eppendorf; Martinistrasse 52 Hamburg Germany
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25
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Abstract
When applied extracellularly, myo-inositol hexakisphosphate (InsP6 ) and myo-inositol pentakisphosphate (InsP5 ) can inhibit the growth and proliferation of tumour cells. There is debate about whether these effects result from interactions of InsP6 and InsP5 with intracellular or extracellular targets. We synthesised FAM-InsP5 , a fluorescent conjugate of InsP5 that allows direct visualisation of its interaction with cells. FAM-InsP5 was internalised by H1229 tumour cells, a finding that supports earlier reports that externally applied inositol phosphates can-perhaps surprisingly-enter into cells. Close examination of the process of FAM-InsP5 uptake suggests a mechanism of non-receptor-mediated endocytosis, which is blocked at 4 °C and probably involves interaction of the ligand with the glycocalyx. However, our results are difficult to reconcile with antiproliferative mechanisms that require direct interactions of externally applied InsP5 or InsP6 with cytosolic proteins, because internalised FAM-InsP5 appears in lysosomes and apparently does not enter the cytoplasm. Studies using FAM-InsP5 are less difficult and time-consuming than experiments using InsP5 or InsP6 , a factor that allowed us to analyse cellular uptake across a range of human cell types, identifying strong cell-specific differences.
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Affiliation(s)
- Andrew M Riley
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY (UK)
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26
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Ewald F, Grabinski N, Grottke A, Windhorst S, Nörz D, Carstensen L, Staufer K, Hofmann BT, Diehl F, David K, Schumacher U, Nashan B, Jücker M. Combined targeting of AKT and mTOR using MK-2206 and RAD001 is synergistic in the treatment of cholangiocarcinoma. Int J Cancer 2013; 133:2065-76. [PMID: 23588885 DOI: 10.1002/ijc.28214] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/14/2013] [Indexed: 01/12/2023]
Abstract
Cholangiocarcinoma (CCA) is a rare, but devastating disease arising from the epithelium of intrahepatic and extrahepatic bile ducts. There are neither effective systemic therapies nor satisfying treatment options for inoperable CCA. Histopathological and biochemical studies of CCA show frequent dysregulation of the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) pathway. Therefore, we investigated the efficacy of the mTOR inhibitor RAD001 and the impact of AKT signaling following mTOR inhibition in the treatment of CCA. RAD001 significantly inhibits proliferation of CCA cell lines, however, a concentration-dependent and isoform specific feedback activation of the three AKT isoforms (AKT1, AKT2 and AKT3) was observed after mTOR inhibition. As activation of AKT might limit the RAD001-mediated anti-tumor effect, the efficacy of combined mTOR and AKT inhibition was investigated using the allosteric AKT inhibitor MK-2206. Our results show that inhibition of AKT potentiates the efficacy of mTOR inhibition both in vitro and in a xenograft mouse model in vivo. Mechanistically, the antiproliferative effect of the pan-AKT inhibitor MK2206 in the CCA cell line TFK-1 was due to inhibition of AKT1 and AKT2, because knockdown of either AKT1 or AKT2, but not AKT3, showed a synergistic reduction of cell proliferation in combination with mTOR treatment. Finally, using an AKT isoform specific in vitro kinase assay, enzymatic activity of each of the three AKT isoforms was detected in all tissue samples from CCA patients, analyzed. In summary, our preclinical data suggest that combined targeting of mTOR and AKT using RAD001 and MK-2206 might be a new, effective strategy for the treatment of CCA.
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Affiliation(s)
- Florian Ewald
- Department of Hepatobiliary and Transplant Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Lin YN, Izbicki JR, König A, Habermann JK, Blechner C, Lange T, Schumacher U, Windhorst S. Expression of DIAPH1 is up-regulated in colorectal cancer and its down-regulation strongly reduces the metastatic capacity of colon carcinoma cells. Int J Cancer 2013; 134:1571-82. [PMID: 24105619 DOI: 10.1002/ijc.28486] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 08/27/2013] [Indexed: 12/25/2022]
Abstract
In most cases, metastatic colorectal cancer is not curable, thus new approaches are necessary to identify novel targets for colorectal cancer therapy. Actin-binding-proteins (ABPs) directly regulate motility of metastasising tumor cells, and for cortactin an association with colon cancer metastasis has been already shown. However, as its depletion only incompletely inhibits metastasis, additional, more suitable cellular targets have to be identified. Here we analyzed expression of the ABPs, DIAPH1, VASP, N-WASP, and fascin in comparison with cortactin and found that, besides cortactin, DIAPH1 was expressed with the highest frequency (63%) in colorectal cancer. As well as cortactin, DIAPH1 was not detectable in normal colon tissue and expression of both proteins was positively correlated with metastasis of colorectal cancer. To analyse the mechanistic role of DIAPH1 for metastasis of colon carcinoma cells in comparison with cortactin, expression of the proteins was stably down-regulated in the human colon carcinoma cell lines HT-29, HROC-24 and HCT-116. Analysis of metastasis of colon carcinoma cells in SCID mice revealed that depletion of DIAPH1 reduced metastasis 60-fold and depletion of cortactin 16-fold as compared with control cells. Most likely the stronger effect of DIAPH1 depletion on colon cancer metastasis is due to the fact that in vitro knock down of DIAPH1 impaired all steps of metastasis; adhesion, invasion and migration while down-regulation of cortactin only reduced adhesion and invasion. This very strong reducing effect of DIAPH1 depletion on colon carcinoma cell metastasis makes the protein a promising therapeutic target for individualized colorectal cancer therapy.
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Affiliation(s)
- Yuan-Na Lin
- Department of General Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Schröder D, Rehbach C, Seyffarth C, Neuenschwander M, Kries JV, Windhorst S. Identification of a new membrane-permeable inhibitor against inositol-1,4,5-trisphosphate-3-kinase A. Biochem Biophys Res Commun 2013; 439:228-34. [PMID: 23981806 DOI: 10.1016/j.bbrc.2013.08.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/16/2013] [Indexed: 12/28/2022]
Abstract
Ectopic expression of the neuron-specific inositol-1,4,5-trisphosphate-3-kinase A (ITPKA) in lung cancer cells increases their metastatic potential because the protein exhibits two actin regulating activities; it bundles actin filaments and regulates inositol-1,4,5-trisphosphate (InsP3)-mediated calcium signals by phosphorylating InsP3. Thus, in order to inhibit the metastasis-promoting activity of ITPKA, both its actin bundling and its InsP3kinase activity has to be blocked. In this study, we performed a high throughput screen in order to identify specific and membrane-permeable substances against the InsP3kinase activity. Among 341,44 small molecules, 237 compounds (0.7%) were identified as potential InsP3kinase inhibitors. After determination of IC50-values, the three compounds with highest specificity and highest hydrophobicity (EPPC-3, BAMB-4, MEPTT-3) were further characterized. Only BAMB-4 was nearly completely taken up by H1299 cells and remained stable after cellular uptake, thus exhibiting a robust stability and a high membrane permeability. Determination of the inhibitor type revealed that BAMB-4 belongs to the group of mixed type inhibitors. Taken together, for the first time we identified a highly membrane-permeable inhibitor against the InsP3kinase activity of ITPKA providing the possibility to partly inhibit the metastasis-promoting effect of ITPKA in lung tumor cells.
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Affiliation(s)
- Dominik Schröder
- Institut für Biochemie und Signaltransduktion, UKE Hamburg, Martinistr. 52, 20246 Hamburg, Germany
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Windhorst S, Minge D, Bähring R, Hüser S, Schob C, Blechner C, Lin HY, Mayr GW, Kindler S. Inositol-1,4,5-trisphosphate 3-kinase A regulates dendritic morphology and shapes synaptic Ca2+ transients. Cell Signal 2012; 24:750-7. [DOI: 10.1016/j.cellsig.2011.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/25/2011] [Accepted: 11/08/2011] [Indexed: 10/15/2022]
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Chang L, Schwarzenbach H, Meyer-Staeckling S, Brandt B, Mayr GW, Weitzel JM, Windhorst S. Expression Regulation of the Metastasis-Promoting Protein InsP3-Kinase-A in Tumor Cells. Mol Cancer Res 2011; 9:497-506. [PMID: 21460179 DOI: 10.1158/1541-7786.mcr-10-0556] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Under physiologic conditions, the inositol-1,4,5-trisphosphate (InsP(3))-metabolizing, F-actin-bundling InsP(3)-kinase-A (ITPKA) is expressed only in neurons. Tumor cells that have gained the ability to express ITPKA show an increased metastatic potential due to the migration-promoting properties of ITPKA. Here we investigated the mechanism how tumor cells have gained the ability to reexpress ITPKA by using a breast cancer cell line (T47D) with no expression and a lung carcinoma cell line (H1299) with ectopic ITPKA expression. Cloning of a 1,250-bp ITPKA promoter fragment revealed that methylation of CpG islands was reduced in H1299 as compared with T47D cells, but DNA demethylation did not alter the expression of ITPKA. Instead, we showed that the repressor-element-1-silencing transcription factor (REST)/neuron-restrictive silencer factor (NRSF), which suppresses expression of neuronal genes in nonneuronal tissues, regulates expression of ITPKA. Knockdown of REST/NRSF induced expression of ITPKA in T47D cells, whereas its overexpression in H1299 cells strongly reduced the level of ITPKA. In T47D cells, REST/NRSF was bound to the RE-1 site of the ITPKA promoter and strongly reduced its activity. In H1299 cells, in contrast, expressing comparable REST/NRSF levels as T47D cells, REST/NRSF only slightly reduced ITPKA promoter activity. This reduced suppressor activity most likely results from expression of a dominant-negative isoform of REST/NRSF, REST4, which impairs binding of REST/NRSF to the RE-1 site. Thus, ITPKA may belong to the neuronal metastasis-promoting proteins whose ectopic reexpression in tumor cells is associated with impaired REST/NRSF activity. Mol Cancer Res; 9(4); 1-10. ©2011 AACR.
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Affiliation(s)
- Lydia Chang
- Universitätsklinikum Hamburg-Eppendorf, Hamburg; and 3Leibniz-Institut für Nutztierbiologie, Dummerstorf, Dummerstorf, Mecklenburg-Vorpommern, Germany
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Nalaskowski MM, Fliegert R, Ernst O, Brehm MA, Fanick W, Windhorst S, Lin H, Giehler S, Hein J, Lin YN, Mayr GW. Human inositol 1,4,5-trisphosphate 3-kinase isoform B (IP3KB) is a nucleocytoplasmic shuttling protein specifically enriched at cortical actin filaments and at invaginations of the nuclear envelope. J Biol Chem 2011; 286:4500-10. [PMID: 21148483 PMCID: PMC3039344 DOI: 10.1074/jbc.m110.173062] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 12/02/2010] [Indexed: 11/06/2022] Open
Abstract
Recent studies have shown that inositol 1,4,5-trisphosphate 3-kinase isoform B (IP3KB) possesses important roles in the development of immune cells. IP3KB can be targeted to multiple cellular compartments, among them nuclear localization and binding in close proximity to the plasma membrane. The B isoform is the only IP3K that is almost ubiquitously expressed in mammalian cells. Detailed mechanisms of its targeting regulation will be important in understanding the role of Ins(1,4,5)P(3) phosphorylation on subcellular calcium signaling and compartment-specific initiation of pathways leading to regulatory active higher phosphorylated inositol phosphates. Here, we identified an exportin 1-dependent nuclear export signal ((134)LQRELQNVQV) and characterized the amino acids responsible for nuclear localization of IP3KB ((129)RKLR). These two targeting domains regulate the amount of nuclear IP3KB in cells. We also demonstrated that the localization of IP3KB at the plasma membrane is due to its binding to cortical actin structures. Intriguingly, all three of these targeting activities reside in one small polypeptide segment (amino acids 104-165), which acts as a multitargeting domain (MTD). Finally, a hitherto unknown subnuclear localization of IP3KB could be demonstrated in rapidly growing H1299 cells. IP3KB is specifically enriched at nuclear invaginations extending perpendicular between the apical and basal surface of the nucleus of these flat cells. Such nuclear invaginations are known to be involved in Ins(1,4,5)P(3)-mediated Ca(2+) signaling of the nucleus. Our findings indicate that IP3KB not only regulates cytoplasmic Ca(2+) signals by phosphorylation of subplasmalemmal and cytoplasmic Ins(1,4,5)P(3) but may also be involved in modulating nuclear Ca(2+) signals generated from these nuclear envelope invaginations.
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Affiliation(s)
- Marcus M Nalaskowski
- Institute of Biochemistry and Molecular Biology I-Cellular Signal Transduction, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany.
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Windhorst S, Kalinina T, Schmid K, Blechner C, Kriebitzsch N, Hinsch R, Chang L, Herich L, Schumacher U, Mayr GW. Functional role of inositol-1,4,5-trisphosphate-3-kinase-A for motility of malignant transformed cells. Int J Cancer 2011; 129:1300-9. [DOI: 10.1002/ijc.25782] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 11/02/2010] [Indexed: 11/09/2022]
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Windhorst S, Fliegert R, Blechner C, Möllmann K, Hosseini Z, Günther T, Eiben M, Chang L, Lin HY, Fanick W, Schumacher U, Brandt B, Mayr GW. Inositol 1,4,5-trisphosphate 3-kinase-A is a new cell motility-promoting protein that increases the metastatic potential of tumor cells by two functional activities. J Biol Chem 2010; 285:5541-54. [PMID: 20022963 PMCID: PMC2820782 DOI: 10.1074/jbc.m109.047050] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 12/16/2009] [Indexed: 11/06/2022] Open
Abstract
Cellular migration is an essential prerequisite for metastatic dissemination of cancer cells. This study demonstrates that the neuron/testis-specific F-actin-targeted inositol 1,4,5-trisphosphate 3-kinase-A (ITPKA) is ectopically expressed in different human tumor cell lines and during tumor progression in the metastatic tumor model Balb-neuT. High expression of ITPKA increases invasive migration in vitro and metastasis in a xenograft SCID mouse model. Mechanistic studies show that ITPKA promotes migration of tumor cells by two different mechanisms as follows: growth factor independently high levels of ITPKA induce the formation of large cellular protrusions by directly modulating the actin cytoskeleton. The F-actin binding activity of ITPKA stabilizes and bundles actin filaments and thus increases the levels of cellular F-actin. In growth factor-stimulated cells, the catalytically active domain enhances basal ITPKA-induced migration by activating store-operated calcium entry through production of inositol 1,3,4,5-tetrakisphosphate and subsequent inhibition of inositol phosphate 5-phosphatase. These two functional activities of ITPKA stimulating tumor cell migration place the enzyme among the potential targets of anti-metastatic therapy.
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Affiliation(s)
- Sabine Windhorst
- Institut für Biochemie und Molekularbiologie I, Zelluläre Signaltransduktion, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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Weber W, Windhorst S, Larsen U, Perbandt M, Gabdoulkhakov A, Betzel C. Crystal structure of the extracellular protease of the nosocomial pathogen Stenotrophomonas maltophilia. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308088582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Brehm M, Schenk T, Zhou X, Fanick W, Lin H, Windhorst S, Nalaskowski M, Kobras M, Shears S, Mayr G. Intracellular localization of human Ins(1,3,4,5,6)P5 2-kinase. Biochem J 2007; 408:335-45. [PMID: 17705785 PMCID: PMC2267366 DOI: 10.1042/bj20070382] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 07/18/2007] [Accepted: 08/17/2007] [Indexed: 01/05/2023]
Abstract
InsP6 is an intracellular signal with several proposed functions that is synthesized by IP5K [Ins(1,3,4,5,6)P5 2-kinase]. In the present study, we overexpressed EGFP (enhanced green fluorescent protein)-IP5K fusion proteins in NRK (normal rat kidney), COS7 and H1299 cells. The results indicate that there is spatial microheterogeneity in the intracellular localization of IP5K that could also be confirmed for the endogenous enzyme. This may facilitate changes in InsP6 levels at its sites of action. For example, overexpressed IP5K showed a structured organization within the nucleus. The kinase was preferentially localized in euchromatin and nucleoli, and co-localized with mRNA. In the cytoplasm, the overexpressed IP5K showed locally high concentrations in discrete foci. The latter were attributed to stress granules by using mRNA, PABP [poly(A)-binding protein] and TIAR (TIA-1-related protein) as markers. The incidence of stress granules, in which IP5K remained highly concentrated, was further increased by puromycin treatment. Using FRAP (fluorescence recovery after photobleaching) we established that IP5K was actively transported into the nucleus. By site-directed mutagenesis we identified a nuclear import signal and a peptide segment mediating the nuclear export of IP5K.
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Key Words
- euchromatin
- ins(1,3,4,5,6)p5 2-kinase (ip5k)
- in situ hybridization
- nuclear localization
- stress granule
- dapi, 4′,6-diamidino-2-phenylindole
- dtt, dithiothreitol
- egfp, enhanced green fluorescent protein
- fish, fluorescence in situ hybridization
- frap, fluorescence recover after photobleaching
- ipmk, inositol phosphate multikinase
- ipk, inositol phosphate kinase
- ip3k, ins(1,4,5)p3 3-kinase
- ip5k, ins(1,3,4,5,6)p5 2-kinase
- lmb, leptomycin b
- mdd-hplc, metal-dye-detection-hplc
- mrnp, messenger ribonucleoprotein
- nls, nuclear localization sequence
- nrk, normal rat kidney
- orf, open reading frame
- pabp, poly(a)-binding protein
- rnai, rna interference
- roi, region of interest
- sg, stress granule
- sirna, small-interfering rna
- tiar, tia-1-related protein
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Affiliation(s)
- Maria A. Brehm
- *NIEHS/NIH, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, U.S.A
| | - Tobias M. H. Schenk
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Xuefei Zhou
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Werner Fanick
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Hongying Lin
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Sabine Windhorst
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Marcus M. Nalaskowski
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Mario Kobras
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
| | - Stephen B. Shears
- *NIEHS/NIH, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, U.S.A
| | - Georg W. Mayr
- †Universitätsklinikum Hamburg-Eppendorf, Institut für Medizinische Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Martinistraße 52, 20246 Hamburg, Germany
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Mayr GW, Windhorst S, Hillemeier K. Antiproliferative plant and synthetic polyphenolics are specific inhibitors of vertebrate inositol-1,4,5-trisphosphate 3-kinases and inositol polyphosphate multikinase. VOLUME 280 (2005) PAGES 13229-13240. J Biol Chem 2007. [DOI: 10.1016/s0021-9258(20)54678-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Kasten-Pisula U, Windhorst S, Dahm-Daphi J, Mayr G, Dikomey E. Radiosensitization of tumour cell lines by the polyphenol Gossypol results from depressed double-strand break repair and not from enhanced apoptosis. Radiother Oncol 2007; 83:296-303. [PMID: 17521756 DOI: 10.1016/j.radonc.2007.04.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Revised: 04/25/2007] [Accepted: 04/29/2007] [Indexed: 11/24/2022]
Abstract
PURPOSE New drugs are needed to increase the efficiency of radiotherapy in order to improve the therapeutic outcome of tumour patients. In this respect, the polyphenol Gossypol might be of interest, because of its effect on apoptosis and DNA repair, which is either mediated directly or indirectly via the inositol phosphate metabolism. It was investigated, whether these effects result in enhanced radiosensitivity of tumour cells. MATERIAL AND METHODS Tumour cell lines investigated: A549, FaDu, H1299, MCF7 and Du145. Cell cycle distribution was determined by FACS analysis, apoptosis was measured by DAPI staining and caspase3/7 activity. Double-strand breaks (DSB) were investigated via gammaH2AX-foci and cell survival by colony formation assay. The level of inositol phosphates was determined by HPLC, protein expression by Western blot. RESULTS In A549 cells, Gossypol at concentrations 1microM strongly affects proliferation with only a modest arrest in the G1-phase, but with no increase in the fraction of apoptotic cells or the number of additional DSB. Additional DSB were only seen in FaDu cells, where Gossypol (2microM) was extremely toxic with a plating efficiency <0.002. When combined with irradiation, incubation with Gossypol (1-2microM) was found to result in an enhanced radiosensitivity with, however, a substantial variation. While there was a strong radiosensitization for FaDu and Du145 cells, there was an intermediate response for A549 cells, but almost no effect for H1299 and MCF7 cells. This sensitization was not caused from an elevated rate of apoptosis, but primarily resulted from reduced DSB repair capacity. The reduction in DSB repair could be ascribed neither to changes in the level of repair proteins relevant for non-homologous end-joining (Ku70, Ku80, DNA-PKcs) nor to changes in the level of higher phosphorylated inositols, whereby the latter were even found to be enhanced by Gossypol. CONCLUSIONS For some tumour cell lines treatment with low concentrations of Gossypol can be used to inhibit DSB repair capacity and with that to increase the cellular radiosensitivity.
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Affiliation(s)
- Ulla Kasten-Pisula
- Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Germany
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Nalaskowski MM, Windhorst S, Stockebrand MC, Mayr GW. Subcellular localisation of human inositol 1,4,5-trisphosphate 3-kinase C: species-specific use of alternative export sites for nucleo-cytoplasmic shuttling indicates divergent roles of the catalytic and N-terminal domains. Biol Chem 2006; 387:583-93. [PMID: 16740130 DOI: 10.1515/bc.2006.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The three isoforms of human Ins(1,4,5)P3 3-kinase (IP3K) show remarkable differences in their intracellular targeting. Whereas predominant targeting to the cytoskeleton and endoplasmic reticulum has been shown for IP3K-A and IP3K-B, rat IP3K-C shuttles actively between the nucleus and cytoplasm. In the present study we examined the expression and intracellular localisation of endogenous IP3K-C in different mammalian cell lines using an isoform-specific antibody. In addition, human IP3K-C, showing remarkable differences to its rat homologue in the N-terminal targeting domain, was tagged with EGFP and used to examine active transport mechanisms into and out of the nucleus. We found both a nuclear import activity residing in its N-terminal domain and a nuclear export activity sensitive to treatment with leptomycin B. Different from the rat isoform, an exportin 1-dependent nuclear export site of the human enzyme resides outside the N-terminal targeting domain in the catalytic enzyme domain. A phylogenetic survey of vertebrate IP3K sequences indicates that in each of the three isoforms a nuclear export signal has evolved in the catalytic domain either de novo (IP3K-A) or as a substitute for an earlier evolved corresponding N-terminal signal (IP3K-B and IP3K-C). In higher vertebrates, and in particular in primates, re-export of nuclear IP3K activity may be guaranteed by the mechanism discovered.
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Affiliation(s)
- Marcus M Nalaskowski
- Institut für Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany
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Mayr GW, Windhorst S, Hillemeier K. Antiproliferative plant and synthetic polyphenolics are specific inhibitors of vertebrate inositol-1,4,5-trisphosphate 3-kinases and inositol polyphosphate multikinase. J Biol Chem 2005; 280:13229-40. [PMID: 15659385 DOI: 10.1074/jbc.m500545200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inositol-1,4,5-trisphosphate 3-kinases (IP3K) A, B, and C as well as inositol polyphosphate multikinase (IPMK) catalyze the first step in the formation of the higher phosphorylated inositols InsP5 and InsP6 by metabolizing Ins(1,4,5)P3 to Ins(1,3,4,5)P4. In order to clarify the special role of these InsP3 phosphorylating enzymes and of subsequent anabolic inositol phosphate reactions, a search was conducted for potent enzyme inhibitors starting with a fully active IP3K-A catalytic domain. Seven polyphenolic compounds could be identified as potent inhibitors with IC50 < 200 nM (IC50 given): ellagic acid (36 nM), gossypol (58 nM), (-)-epicatechin-3-gallate (94 nM), (-)-epigallocatechin-3-gallate (EGCG, 120 nM), aurintricarboxylic acid (ATA, 150 nM), hypericin (170 nM), and quercetin (180 nM). All inhibitors displayed a mixed-type inhibition with respect to ATP and a non-competitive inhibition with respect to Ins(1,4,5)P3. Examination of these inhibitors toward IP3K-A, -B, and -C and IPMK from mammals revealed that ATA potently inhibits all kinases while the other inhibitors do not markedly affect IPMK but differentially inhibit IP3K isoforms. We identified chlorogenic acid as a specific IPMK inhibitor whereas the flavonoids myricetin, 3',4',7,8-tetrahydroxyflavone and EGCG inhibit preferentially IP3K-A and IP3K-C. Mutagenesis studies revealed that both the calmodulin binding and the ATP [corrected] binding domain in IP3K are involved in inhibitor binding. Their absence in IPMK and the presence of a unique insertion in IPMK were found to be important for selectivity differences from IP3K. The fact that all identified IP3K and IPMK inhibitors have been reported as antiproliferative agents and that IP3Ks or IPMK often are the best binding targets deserves further investigation concerning their antitumor potential.
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Affiliation(s)
- Georg W Mayr
- Institut für Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.
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Windhorst S, Frank E, Georgieva DN, Genov N, Buck F, Borowski P, Weber W. The major extracellular protease of the nosocomial pathogen Stenotrophomonas maltophilia: characterization of the protein and molecular cloning of the gene. J Biol Chem 2002; 277:11042-9. [PMID: 11796713 DOI: 10.1074/jbc.m109525200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Stenotrophomonas maltophilia is increasingly emerging as a multiresistant pathogen in the hospital environment. In immunosuppressed patients, these bacteria may cause severe infections associated with tissue lesions such as pulmonary hemorrhage. This suggests proteolysis as a possible pathogenic mechanism in these infections. This study describes a protease with broad specificity secreted by S. maltophilia. The gene, termed StmPr1, codes for a 63-kDa precursor that is processed to the mature protein of 47 kDa. The enzyme is an alkaline serine protease that, by sequence homology and enzymic properties, can be further classified as a new member of the family of subtilases. It differs from the classic subtilisins in molecular size, in substrate specificity, and probably in the architecture of the active site. The StmPr1 protease is able to degrade several human proteins from serum and connective tissue. Furthermore, pan-protease inhibitors such as alpha(1)-antitrypsin and alpha(2)-macroglobulin were unable to abolish the activity of the bacterial protease. The data support the interpretation that the extracellular protease of S. maltophilia functions as a pathogenic factor and thus could serve as a target for the development of therapeutic agents.
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Affiliation(s)
- Sabine Windhorst
- Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany
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