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Didona D, Scarsella L, Hudemann C, Volkmann K, Zimmer CL, Beckert B, Tikkanen R, Korff V, Kühn K, Wienzek-Lischka S, Bein G, Di Zenzo G, Böhme J, Cunha T, Solimani F, Pieper J, Juratli HA, Göbel M, Schmidt T, Borradori L, Yazdi AS, Sitaru C, Garn H, Eming R, Fleischer S, Hertl M. Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris. J Invest Dermatol 2024; 144:263-272.e8. [PMID: 37717934 DOI: 10.1016/j.jid.2023.07.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 06/26/2023] [Accepted: 07/03/2023] [Indexed: 09/19/2023]
Abstract
Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion in vitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.
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Affiliation(s)
- Dario Didona
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Luca Scarsella
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Christoph Hudemann
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Karolin Volkmann
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Christine L Zimmer
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Benedikt Beckert
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Vera Korff
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Katja Kühn
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Sandra Wienzek-Lischka
- Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | - Gregor Bein
- Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | - Giovanni Di Zenzo
- Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata (IDI), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Jaqueline Böhme
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Tomas Cunha
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Farzan Solimani
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany; Department of Dermatology, Venereology and Allergology, Charité-Universitätsmedizin Berlin, Berlin, Germany; Berlin Institute of Health at Charité-Universitätsmedizin Berlin, BIH Biomedical Innovation Academy, Berlin, Germany
| | - Josquin Pieper
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Hazem A Juratli
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany; Department of Dermatology, University Hospital Basel, Basel, Switzerland
| | - Manuel Göbel
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Thomas Schmidt
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany
| | - Luca Borradori
- Department of Dermatology, University of Bern, Bern, Switzerland
| | - Amir S Yazdi
- Department of Dermatology, RWTH Aachen University, Aachen, Germany
| | - Cassian Sitaru
- Department of Dermatology, Albert-Ludwigs University, Freiburg, Germany
| | - Holger Garn
- Translational Inflammation Research Division & Core Facility for Single Cell Multiomics, Philipps University, Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany; Klinik III Dermatologie, Venerologie & Allergologie, Bundeswehrzentralkrankenhaus Koblenz, Koblenz, Germany
| | | | - Michael Hertl
- Department of Dermatology and Allergology, Philipps University, Marburg, Germany.
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Schmidt T, Solimani F, Pollmann R, Stein R, Schmidt A, Stulberg I, Kühn K, Eming R, Eubel V, Kind P, Arweiler N, Sitaru C, Hertl M. T H1/T H17 cell recognition of desmoglein 3 and bullous pemphigoid antigen 180 in patients with lichen planus. J Allergy Clin Immunol 2018; 142:669-672.e7. [PMID: 29626572 DOI: 10.1016/j.jaci.2018.02.044] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/02/2018] [Accepted: 02/21/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Thomas Schmidt
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Farzan Solimani
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Robert Pollmann
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Ronja Stein
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Ansgar Schmidt
- Department of Pathology, Philipps-University, Marburg, Germany
| | - Inna Stulberg
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Katja Kühn
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Rüdiger Eming
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Verena Eubel
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany
| | - Peter Kind
- Hautzentrum Offenbach, Offenbach, Germany
| | - Nicole Arweiler
- Department of Periodontology, Philipps-University, Marburg, Germany
| | - Cassian Sitaru
- Department of Dermatology, Albert-Ludwigs-University, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Freiburg, Germany
| | - Michael Hertl
- Department of Dermatology and Allergology, Philipps-University, Marburg, Germany.
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Kretschmer I, Kühn K, Baltus V, Fürst A, Kümmerle J. The Prevalence of degenerative radiographic findings in the small tarsal joints of two-year-old warmblood stallions and the development of these findings over five to sixteen months. PFERDEHEILKUNDE 2017. [DOI: 10.21836/pem20170207] [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: 11/27/2022]
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Cott C, Thuenauer R, Landi A, Kühn K, Juillot S, Imberty A, Madl J, Eierhoff T, Römer W. Pseudomonas aeruginosa lectin LecB inhibits tissue repair processes by triggering β-catenin degradation. Biochim Biophys Acta 2016; 1863:1106-18. [PMID: 26862060 PMCID: PMC4859328 DOI: 10.1016/j.bbamcr.2016.02.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 01/31/2016] [Accepted: 02/05/2016] [Indexed: 01/08/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that induces severe lung infections such as ventilator-associated pneumonia and acute lung injury. Under these conditions, the bacterium diminishes epithelial integrity and inhibits tissue repair mechanisms, leading to persistent infections. Understanding the involved bacterial virulence factors and their mode of action is essential for the development of new therapeutic approaches. In our study we discovered a so far unknown effect of the P. aeruginosa lectin LecB on host cell physiology. LecB alone was sufficient to attenuate migration and proliferation of human lung epithelial cells and to induce transcriptional activity of NF-κB. These effects are characteristic of impaired tissue repair. Moreover, we found a strong degradation of β-catenin, which was partially recovered by the proteasome inhibitor lactacystin. In addition, LecB induced loss of cell-cell contacts and reduced expression of the β-catenin targets c-myc and cyclin D1. Blocking of LecB binding to host cell plasma membrane receptors by soluble l-fucose prevented these changes in host cell behavior and signaling, and thereby provides a powerful strategy to suppress LecB function. Our findings suggest that P. aeruginosa employs LecB as a virulence factor to induce β-catenin degradation, which then represses processes that are directly linked to tissue recovery.
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Affiliation(s)
- Catherine Cott
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Roland Thuenauer
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Alessia Landi
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Katja Kühn
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Samuel Juillot
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Albertstraße 19, 79104 Freiburg, Germany
| | - Anne Imberty
- Centre de Recherches sur les Macromolécules Végétales, UPR5301 CNRS and University of Grenoble Alpes, BP53, 38041 Grenoble cédex 09, France
| | - Josef Madl
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Thorsten Eierhoff
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Winfried Römer
- Faculty of Biology, Schänzlestraße 1, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Schänzlestraße 18, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany; Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Albertstraße 19, 79104 Freiburg, Germany.
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Affiliation(s)
- K Kühn
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, Freiburg 79104, Germany
- BIOSS—Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, Freiburg 79104, Germany
| | - W Römer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, Freiburg 79104, Germany
- BIOSS—Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, Freiburg 79104, Germany
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Kühn K, Cott C, Bohler S, Aigal S, Zheng S, Villringer S, Imberty A, Claudinon J, Römer W. The interplay of autophagy and β-Catenin signaling regulates differentiation in acute myeloid leukemia. Cell Death Discov 2015; 1:15031. [PMID: 27551462 PMCID: PMC4979480 DOI: 10.1038/cddiscovery.2015.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/03/2015] [Accepted: 08/07/2015] [Indexed: 12/18/2022] Open
Abstract
The major feature of leukemic cells is an arrest of differentiation accompanied by highly active proliferation. In many subtypes of acute myeloid leukemia, these features are mediated by the aberrant Wnt/β-Catenin pathway. In our study, we established the lectin LecB as inducer of the differentiation of the acute myeloid leukemia cell line THP-1 and used it for the investigation of the involved processes. During differentiation, functional autophagy and low β-Catenin levels were essential. Corresponding to this, a high β-Catenin level stabilized proliferation and inhibited autophagy, resulting in low differentiation ability. Initiated by LecB, β-Catenin was degraded, autophagy became active and differentiation took place within hours. Remarkably, the reduction of β-Catenin sensitized THP-1 cells to the autophagy-stimulating mTOR inhibitors. As downmodulation of E-Cadherin was sufficient to significantly reduce LecB-mediated differentiation, we propose E-Cadherin as a crucial interaction partner in this signaling pathway. Upon LecB treatment, E-Cadherin colocalized with β-Catenin and thereby prevented the induction of β-Catenin target protein expression and proliferation. That way, our study provides for the first time a link between E-Cadherin, the aberrant Wnt/β-Catenin signaling, autophagy and differentiation in acute myeloid leukemia. Importantly, LecB was a valuable tool to elucidate the underlying molecular mechanisms of acute myeloid leukemia pathogenesis and may help to identify novel therapy approaches.
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Affiliation(s)
- K Kühn
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - C Cott
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - S Bohler
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - S Aigal
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS-MCB), Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg, Germany
| | - S Zheng
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - S Villringer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - A Imberty
- Centre de Recherches sur les Macromolécules Végétales (CERMAV), CNRS and Université Grenoble Alpes , 601 rue de la chimie, 38000 Grenoble, France
| | - J Claudinon
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - W Römer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraβe 1, 79104 Freiburg, Germany; BIOSS-Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
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Schurek HJ, Panzer J, Wiemeyer A, Kühn K, Aeikens B, Brod J. Effects of aging on the glomerular capillaries, blood pressure, and renal function in rats. Contrib Nephrol 2015; 30:157-62. [PMID: 7116855 DOI: 10.1159/000406435] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Abstract
Isolated glomeruli of the rat kidney were investigated using the freeze-fracture method. The observations were consistent with those made on thin sections. Only exceptionally components of zonulae occludentes were seen between the capillary endothelial cells. The split membrane of mesangial cells revealed aspects of gap junctions.
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Nonnast-Daniel B, Creutzig A, Kühn K, Bahlmann J, Reimers E, Brunkhorst R, Caspary L, Koch KM. Effect of treatment with recombinant human erythropoietin on peripheral hemodynamics and oxygenation. Contrib Nephrol 2015; 66:185-94. [PMID: 3292147 DOI: 10.1159/000416017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Slow progressive improvement of renal anemia from 21 up to 33% hematocrit by rhEPO treatment results in an increase of tissue oxygenation as indicated by a rise of the transcutaneous oxygen pressure. In normotensive patients this was accompanied by an increase in MAP (delta 6 mm Hg) within the normal range and a significant fall of the regional blood flow. These hemodynamic changes are caused by increases of the regional and presumably also of the total peripheral vascular resistance. Most likely the increase in total peripheral vascular resistance represents an autoregulatory event triggered by the rising tissue oxygenation. From the present data it is difficult to estimate to what extent the observed rise in hematocrit affects peripheral vascular resistance also via an increase of blood viscosity.
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Affiliation(s)
- B Nonnast-Daniel
- Department Innere Medizin und Dermatologie, Medizinische Hochschule Hannover, FRG
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Thiele J, Kühn K. Early lesions of the nephron in paraproteinemia. Contrib Nephrol 2015; 1:96-102. [PMID: 1235097 DOI: 10.1159/000398234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Electron microscopy of renal biopsies in eight patients with paraproteinemia (six multiple myeloma, one Waldenström's disease, one idiopathic paraproteinemia) and without impairment of renal function demonstrates an increase of mesangial matrix and thickening of the lamina rara interna of the basement membrane in the glomerulus by fibrillar material without periodicity. These lesions are thought to exhibit precursors of amyloid deposits. The proximal tubules show signs of increased cellular activity probably because of handling an increased protein load. In the basement membranes there are proteins with a fibrillar structure and definite periodicity. These are suggested to be consistent with large aggregates of immunoglobulin fragments.
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Bilges H, Brod J, Christ M, Kühn K, Hundeshagen H. Diagnosis of renal and urinary tract infection by recent techniques. Contrib Nephrol 2015; 16:27-30. [PMID: 380899 DOI: 10.1159/000402870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Kühn K, Castellucci M, Aikens B, Reale E. The human renal papilla: scanning and freeze-fracture studies. Contrib Nephrol 2015; 16:98-103. [PMID: 467075 DOI: 10.1159/000402881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Kühn K, Wiedemann K, Hellweg R, Möller H. Stellenwert von Depotformulierungen in der Langzeittherapie der Schizophrenie. Fortschr Neurol Psychiatr 2014; 82:557-65. [DOI: 10.1055/s-0034-1385108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- K. Kühn
- Klinik für Psychiatrie und Psychotherapie, Universitätsklinikum des Saarlandes
| | - K. Wiedemann
- Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsklinikum Hamburg-Eppendorf
| | - R. Hellweg
- Klinik für Psychiatrie und Psychotherapie, Campus Charité Mitte, Berlin
| | - H. Möller
- Klinik für Psychiatrie und Psychotherapie, Klinikum der Ludwig-Maximilians-Universität München
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Abstract
Kollagenfibrillen zeigen nach Behandeln mit gerbenden Chrom (III) komplexen im Elektronenmikroskop ein unterteiltes Querstreifungsmuster.
Es wird gezeigt, daß dabei die Ausbildung der Querstreifen auf eine ordnende Quervernetzung der Protofibrillen über die Seitenketten der sauren Aminosäuren zurückzuführen ist.
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Affiliation(s)
- K. Kühn
- Aus dem Eduard-Zintl Institut der Technischen Hochschule Darmstadt
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Kühn K, Grassmann W, Hofmann U. Über die Bildung der Kollagenfibrillen aus gelöstem Kollagen und die Funktion der kohlenhydrathaltigen Begleitkomponenten. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znb-1959-0706] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Citratlösliches Kollagen (Prokollagen) wurde möglichst weitgehend von seinen kohlenhydrathaltigen Komponenten befreit. Die glucosaminhaltige Fraktion, saure Mucopolysaccharide, konnte vollständig und die Hexosen bis auf 0,2 bis 0,15 Gew.-% abgetrennt werden.
Elektronenmikroskopische Untersuchungen ergaben; daß die kohlenhydrathaltigen Komponenten für die Ausbildung quergestreifter Kollagenfibrillen entbehrlich sind. Dagegen werden Fibrillendurchmesser und Kontrast von den im Bindegewebe vorkommenden Mucopolysacchariden wesentlich beeinflußt. So sind von Mucopolysacchariden gereinigte Fibrillen sehr dünn und kontrastarm.
Die Funktion der Mucopolysaccharide bei der Fibrillenbildung wird im Zusammenhang mit den Ursachen des Inlösunggehens und des Ausfällens der Fibrillen diskutiert.
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Affiliation(s)
- K. Kühn
- Aus dem Eduard-Zintl-Institut der Techn. Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung, München
| | - W. Grassmann
- Aus dem Eduard-Zintl-Institut der Techn. Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung, München
| | - U. Hofmann
- Aus dem Eduard-Zintl-Institut der Techn. Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung, München
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Abstract
Long-Spacing-Segmente enthalten im Gegensatz zu Fibrillen des nativen Typs kein oder nur sehr wenig Tyrosin.
Die nach „Anfärbung“ im Elektronenmikroskop sichtbare hochunterteilte Querstreifung entsteht bei Fibrillen und Segmenten nach dem gleichen Mechanismus.
Durch vergleichende Untersuchung der Querstreifungsmuster von mit Phosphorwolframsäure und mit Uranylacetat „angefärbten“ Segmenten wurden getrennte Anhäufungen von basischen und sauren Aminosäuren längs des Tropokollagen-Moleküls nachgewiesen und lokalisiert.
Die um ein Viertel ihrer Länge gegeneinander versetzte parallele Anordnung der Tropokollagen-Moleküle in den Fibrillen des nativen Typs und die antiparallele, mit den Enden ungefähr abschneidende Zusammenlagerung in den Fibrillen des Long-Spacing-Typs wurden durch graphische Addition entsprechend angeordnete Photometerkurven von Long-Spacing-Segmenten bewiesen.
Die seitliche Zusammenlagerung und die End-an-End-Verknüpfung der Tropokollagen-Moleküle sind auf elektrostatische Kräfte zurückzuführen.
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Affiliation(s)
- K. Kühn
- Aus dem Anorganisch-Chemischen Institut der Universität Heidelberg und dem Max-Planck-Institut für Eiweiß- und Lederforschung in München
| | - E. Zimmer
- Aus dem Anorganisch-Chemischen Institut der Universität Heidelberg und dem Max-Planck-Institut für Eiweiß- und Lederforschung in München
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Kühn K, Graßmann W, Hofmann U. Die elektronenmikroskopische „Anfärbung“ des Kollagens und die Ausbildung einer hochunterteilten Querstreifung. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/znb-1958-0305] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An Kollagen mit systematisch veränderten Seitenketten wird gezeigt, daß der fester gebundene Anteil der Phosphorwolframsäure (480 mg PWS/g Kollagen) durch die Argininreste und der lockerer gebundene, auswaschbare Anteil (400 mg PWS/g Kollagen) durch die Lysin- und Oxylysinreste des Kollagens gebunden werden. Ein Phosphorwolframation reagiert dabei stöchiometrisch mit 3 Aminosäureresten.
Nur der fester gebundene Anteil ist für die Ausbildung der hochunterteilten Querstreifung verantwortlich.
Die Veränderung der Massendicke durch das „Anfärben“ ist bei der Ausbildung der Querstreifung nicht so wesentlich, da auch chromgegerbte Fibrillen trotz 10-fach geringerer Masseeinlagerung als bei der PWS-„Anfärbung” eine hochunterteilte Querstreifung zeigen.
Die wesentliche Wirkung der Phosphorwolframsäure beruht auf einem „in Register bringen“ der Polypeptidspiralen, auf einem Fixieren oder auch Verbessern des in der Fibrille schon vorliegenden Ordnungszustandes
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Affiliation(s)
- K. Kühn
- Aus dem Eduard-Zintl-Institut der Technischen Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung München
| | - W. Graßmann
- Aus dem Eduard-Zintl-Institut der Technischen Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung München
| | - U. Hofmann
- Aus dem Eduard-Zintl-Institut der Technischen Hochschule Darmstadt und dem Max-Planck-Institut für Eiweiß- und Lederforschung München
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Maischberger E, Jackson MA, Kühn K, Grest P, de Brot S, Wehrli Eser M. Ethmoid adenocarcinoma: Severe neurological complications after combined laser ablation and intralesional formalin injection. EQUINE VET EDUC 2014. [DOI: 10.1111/eve.12125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | - M. A. Jackson
- Equine Department; University of Zurich; Switzerland
| | - K. Kühn
- Small Animal Department; Division of Diagnostic Imaging; University of Zurich; Switzerland
| | - P. Grest
- Institute of Veterinary Pathology; Vetsuisse Faculty; University of Zurich; Switzerland
| | - S. de Brot
- Institute of Veterinary Pathology; Vetsuisse Faculty; University of Zurich; Switzerland
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Gutbrod A, Kühn K, Wiestner T, Kircher P, Hurter K. Repair of a canine patellar ligament rupture using the ComPact UniLock 2.4/3.0 mm System. SCHWEIZ ARCH TIERH 2013; 155:505-9. [PMID: 23985093 DOI: 10.1024/0036-7281/a000500] [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] [Indexed: 11/19/2022]
Abstract
An 11-year old, female, Mix Breed dog was presented after being hit by a car with a rupture of the left patellar ligament. Due to a suspected wound infection close to the stifle joint, surgical repair was delayed for 10 days. The ruptured ligament was sutured and augmented with fascia lata. Additionally, two ComPact UniLock 2.4/3.0 mm plates connected with 1.0 mm orthopaedic wire were used to protect the primary repair. No immobilization of the stifle joint was needed. The implants were removed after 7 weeks, because of suspected infection and loosening. The successful utilization of an alternative surgical technique for the repair of the patellar ligament rupture in the dog has also been documented by pre- and post-operative temporal-spatial gait analysis (GaitFour®).
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Affiliation(s)
- A Gutbrod
- Department of Small Animal Surgery, University of Zurich, Zurich, Switzerland.
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Kola A, Kohler C, Pfeifer Y, Schwab F, Kühn K, Schulz K, Balau V, Breitbach K, Bast A, Witte W, Gastmeier P, Steinmetz I. High prevalence of extended-spectrum-β-lactamase-producing Enterobacteriaceae in organic and conventional retail chicken meat, Germany. J Antimicrob Chemother 2012; 67:2631-4. [PMID: 22868643 DOI: 10.1093/jac/dks295] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES To determine the prevalence of extended-spectrum β-lactamase (ESBL) production in Enterobacteriaceae in retail chicken meat in Germany. METHODS A total of 399 chicken meat samples from nine supermarket chains, four organic food stores and one butcher's shop in two geographically distinct regions (Berlin and Greifswald) were screened for ESBL production using selective agar. Phenotypic ESBL isolates were tested for bla(TEM), bla(CTX-M) and bla(SHV) genes using PCR and DNA sequencing. Antibiotic coresistances were determined and strain typing was performed using PCR-based phylogenetic grouping and XbaI-PFGE. RESULTS A total of 185 confirmed ESBL isolates were obtained from 175 samples (43.9%) from all tested sources. The majority of isolates were Escherichia coli producing ESBL types SHV-12 (n = 82), CTX-M-1 (n = 77) and TEM-52 (n = 16). No differences could be observed in the prevalence of ESBL producers between organic and conventional samples. 73.0% of the ESBL producers showed coresistance to tetracycline, 35.7% to co-trimoxazole and 7.6% to ciprofloxacin. Strain typing of selected E. coli isolates from Berlin revealed identical macrorestriction patterns for several isolates from samples taken from the same stores. CONCLUSIONS This is the first comprehensive study from Germany showing a high prevalence of TEM-, CTX-M- and SHV-type ESBLs in Enterobacteriaceae isolated from retail chicken meat. The high rate of coresistance to different classes of antibiotics in the ESBL producers might reflect the common veterinary usage of these and related substances. There is an urgent need to further evaluate the role of poultry in the transmission of highly resistant ESBL-producing bacteria in humans.
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Affiliation(s)
- A Kola
- Institut für Hygiene und Umweltmedizin, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Paschke R, Wuthe FG, Kühn K, Jochmann C, Wiedemann P. [Comparison of risk factors and guideline oriented prevention and therapy of diabetic retinopathy between type 2 diabetes patients undergoing laser therapy and type 2 diabetes outpatients]. Med Klin (Munich) 2010; 105:772-778. [PMID: 21136234 DOI: 10.1007/s00063-010-1131-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 08/27/2010] [Indexed: 05/30/2023]
Abstract
PURPOSE The purpose of this study was the comparison of risk factors for development or progression of diabetic retinopathy in patients with type 2 diabetes between patients of a laser therapy center and a diabetes outpatient clinic. Furthermore, the implementation of the guidelines of the German Diabetic Association for the prevention and therapy of diabetic retinopathy was analysed. PATIENTS AND METHODS In a prospective study, patients with type 2 diabetes and diabetic retinopathy of the laser therapy center at the ophthalmology department, Leipzig University, were interviewed and examined. Patients of the reference group without diabetic retinopathy were recruited from the diabetes outpatient clinic Leipzig University. RESULTS Between August 2004 and May 2008, a total of 180 patients with type 2 diabetes were included (48 patients with non-proliferative diabetic retinopathy (NPDR), 59 patients with proliferative diabetic retinopathy (PDR) and 73 patients belonging to the reference group). Patients with diabetic retinopathy had significantly higher mean blood pressures of 112 and 110 mmHg as compared to patients without diabetic retinopathy (96 mmHg). ACE/ AT1-inhibitors were used significantly less by patients with as compared to patients without diabetic retinopathy. Only 37% of patients with diabetic retinopathy were treated according to DDG and ADA guidelines. CONCLUSION There are striking deficits for the implementation of guideline oriented prevention and therapy of diabetic retinopathy in daily practice. The possible reasons are insufficient compliance of patients who consulted medical advice only when complications of diabetes occurred, the necessary improvement of the medical therapy and the suboptimal cooperation between ophthalmology and diabetes specialists.
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Affiliation(s)
- Ralf Paschke
- Medizinische Klinik und Poliklinik III in Klinik für Endokrinologie und Nephrologie, Universität Leipzig, Leipzig, Germany.
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Kühn K, Yildiz F, Hausdörfer J, Török M. Die präoperative Phase der limitierten normovolämischen Hamodilution. Transfus Med Hemother 2009. [DOI: 10.1159/000221615] [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: 11/19/2022] Open
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Abstract
INTRODUCTION Aggressive angiomyxoma (AA) is a rare mesenchymal tumour of the connective tissue of the pelvis, which was described mainly in women in their reproductive period of life. Until now 45 cases of AA in men are documented with predominantly inguinal, parafunicular or scrotal localisation. These tumours slowly infiltrate the adjacent tissue and since symptoms are noticed only later these tumours have reached a considerable size at the time of diagnosis. In contrast to their benign histological appearance and almost entire absence of metastasis AA tends to (multiple) relapse. CASE REPORT We report on a 46-year-old male with a large tumour in the perineum. After complete resection, histological analysis revealed an AA. 26 months after surgery there is no evidence of relapse. CONCLUSION AA has to be considered as a possible diagnosis for obscure tumours of the pelvis. Since these tumours tend to relapse, margin-negative resection is most important. Also in cases of relapse, secondary excision should be achieved within healthy tissue. Adjuvant hormonal chemotherapy or radiation can be considered in cases of multiple relapse. Because of the risk of local recurrence rather than metastasis, these patients need a long-term follow up.
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Tömmers S, Kühn K, Hass VC. Prozesskontrolle und Modellierung von Fruchtreifeprozessen. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200750397] [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: 11/11/2022]
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Hass V, Kuhnen F, Kühn K. Entwicklung und Einsatz von Echtzeittrainingssimulatoren in der (Bio-)Verfahrenstechnik. CHEM-ING-TECH 2006. [DOI: 10.1002/cite.200650414] [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: 11/11/2022]
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Tömmers S, Kühn K, Kuhnen F, Hass V. Systemanalyse und Prozessautomation der Fruchtreifung. CHEM-ING-TECH 2006. [DOI: 10.1002/cite.200650213] [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: 11/09/2022]
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Affiliation(s)
- K Kühn
- Division of Arthritis Research, Department of Molecular and Experimental Medicine, The Scripps Research Institute, CA, La Jolla 92037, USA
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Komuro H, Olee T, Kühn K, Quach J, Brinson DC, Shikhman A, Valbracht J, Creighton-Achermann L, Lotz M. The osteoprotegerin/receptor activator of nuclear factor kappaB/receptor activator of nuclear factor kappaB ligand system in cartilage. Arthritis Rheum 2001; 44:2768-76. [PMID: 11762937 DOI: 10.1002/1529-0131(200112)44:12<2768::aid-art464>3.0.co;2-i] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The receptor activator of nuclear factor kappaB (RANK) is a member of the tumor necrosis factor receptor family. It is activated by the secreted or cell surface-bound RANK ligand (RANKL). Osteoprotegerin (OPG) is a soluble nonsignaling receptor for RANKL and interferes with RANK activation. This receptor-ligand system regulates the differentiation of osteoclasts and dendritic cells. The present study examined human articular cartilage for the expression of these molecules and the role of RANKL in the regulation of chondrocyte function. METHODS Normal and osteoarthritic (OA) human articular cartilage was used for explant tissue culture or for isolation of chondrocytes and cell culture. Expression of RANK, RANKL, and OPG was analyzed by immunohistochemistry, Western blotting, or reverse transcription-polymerase chain reaction. Recombinant RANKL was added to cartilage or chondrocyte cultures, and gene expression, collagenase and nitric oxide production, and NF-kappaB activation were determined. RESULTS RANK, RANKL, and OPG messenger RNA (mRNA) were expressed in normal cartilage. By immunohistochemistry, RANK, RANKL, and OPG were detected in the superficial zone of normal cartilage. OA cartilage contained increased levels of OPG mRNA, and expression of the 3 proteins extended into the midzone of OA cartilage. OPG was detected by Western blotting, and was increased in response to interleukin-1beta stimulation. OPG, RANK, and RANKL protein were also detected in cultured chondrocytes. Addition of exogenous RANKL did not activate NF-kappaB, induce expression of genes encoding proinflammatory mediators in chondrocytes, or stimulate the production of collagenase and nitric oxide. CONCLUSION These results demonstrate the expression of OPG, RANK, and RANKL in cartilage. However, RANKL does not activate human articular chondrocytes.
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Affiliation(s)
- H Komuro
- Division of Arthritis Research, The Scripps Research Institute, La Jolla, California 92037, USA
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Morais F, Kühn K, Stewart DH, Barber J, Brudvig GW, Nixon PJ. Photosynthetic water oxidation in cytochrome b(559) mutants containing a disrupted heme-binding pocket. J Biol Chem 2001; 276:31986-93. [PMID: 11390403 DOI: 10.1074/jbc.m103935200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The role of cytochrome b(559) in photosynthetic oxygen evolution has been investigated in three chloroplast mutants of Chlamydomonas reinhardtii, in which one of the two histidine axial ligands to the heme, provided by the alpha subunit, has been replaced by the residues methionine, tyrosine, and glutamine. Photosystem two complexes functional for oxygen evolution could be assembled in the methionine and tyrosine mutants up to approximately 15% of wild type levels, whereas no complexes with oxygen evolution activity could be detected in the glutamine mutant. PSII supercomplexes isolated from the tyrosine and methionine mutants were as active as wild type in terms of light-saturated rates of oxygen evolution but in contrast to wild type contained no bound heme despite the presence of the alpha subunit. Oxygen evolution in the tyrosine and methionine mutants was, however, more sensitive to photoinactivation than the WT. Overall, these data establish unambiguously that a redox role for the heme of cytochrome b(559) is not required for photosynthetic oxygen evolution. Instead, our data provide new evidence of a role for cytochrome b(559) in the protection of the photosystem two complex in vivo.
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Affiliation(s)
- F Morais
- Department of Biochemistry, Imperial College of Science, Technology, and Medicine, London, SW7 2AY, United Kingdom
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Abstract
OBJECTIVE To examine the role of nuclear factor kappaB (NF-kappaB) and caspases 3, 8, and 9 in CD95-mediated apoptosis of normal chondrocytes. METHODS First-passage chondrocytes from normal human knee cartilage were stimulated with CD95 antibody, and cell death was determined by annexin V binding and by an enzyme-linked immunosorbent assay. Activation of caspases 3, 8, and 9 was measured by Western blotting, and their role in death signaling was evaluated using caspase-specific small peptide inhibitors. The influence of NF-kappaB was determined by electrophoretic mobility shift assay (EMSA) and proteasome inhibition-dependent blocking of the degradation of inhibitor of NF-kappaB. RESULTS Low levels of NF-kappaB activity were detected by EMSA in unstimulated chondrocytes. NF-kappaB activity was increased in response to agonistic CD95 antibody. CD95 antibody-induced apoptosis was potentiated by the proteasome inhibitors MG-132 and PS1, and this was associated with a reduced nuclear translocation of NF-kappaB. Proteasome inhibitors also caused the induction of DNA fragmentation by tumor necrosis factor alpha. Procaspase 3 processing was enhanced by the proteasome inhibitor MG-132. Procaspase 8 was undetectable by immunoblotting in whole cell lysates of chondrocytes, but caspase 8 messenger RNA was detected by reverse transcription-polymerase chain reaction. Furthermore, apoptosis induced by CD95 stimulation and proteasome inhibitors was blocked by the caspase 8-specific inhibitor Ac-IETD-CHO. Processing of procaspase 9 was not observed, and inhibition of CD95-dependent cell death by the caspase 9 inhibitor Ac-LEHD-CHO was not significant. CONCLUSION These results suggest that CD95-dependent cell death is enhanced by NF-kappaB inhibition at and/or downstream of caspase 8 activation and that caspase 9 activation is not involved in CD95-mediated apoptosis in chondrocytes.
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Affiliation(s)
- K Kühn
- The Scripps Research Institute, La Jolla, California 92037, USA
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Stichel CC, Augustin M, Kühn K, Zhu XR, Engels P, Ullmer C, Lübbert H. Parkin expression in the adult mouse brain. Eur J Neurosci 2000; 12:4181-94. [PMID: 11122330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Mutations in a protein designated Parkin were shown to be involved in the pathogenesis of autosomal recessive juvenile parkinsonism. Nothing is known about its regional and subcellular distribution in the mouse. In order to elucidate the Parkin mRNA and protein distribution in the adult mouse, the mouse cDNA was cloned and polyclonal antisera were generated against the N-terminal part of mouse Parkin. The antibodies were shown to be specific using Western blot analysis, immunostaining of cells transfected with mouse Parkin and pre-absorption tests. The Parkin protein expression profile was studied using immunohistochemistry and Western blot analysis and was compared with that of the mRNA yielded by in situ hybridization and RT-PCR analysis. Parkin protein was widely distributed in all subdivisions of the mouse brain. Low levels were found in the telencephalon and diencephalon, while the brainstem contained a large number of cells heavily expressing Parkin. Ultrastructural analysis and double immunohistochemistry revealed that the majority of Parkin-expressing cells were neurons, while only single glial cells exhibited immunostaining. The protein was distributed nonhomogeneously throughout the entire cytoplasm. A subpopulation of Parkin-immunopositive cells displayed speckled immunodeposits in the nucleus. Dopaminergic cells of the substantia nigra pars compacta exhibited high levels of Parkin mRNA but no Parkin protein, while the striatum contained immunopositive profiles but no mRNA signals. Our data indicate that Parkin is neither restricted to a single functional system nor associated with a particular transmitter system. The speckled nuclear distribution of Parkin immunoreactivity strongly suggests a role for Parkin in gene expression.
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Affiliation(s)
- C C Stichel
- Department of Animal Physiology, ND5/132, Ruhr-University of Bochum, D-44780 Bochum, Germany.
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Golbik R, Eble JA, Ries A, Kühn K. The spatial orientation of the essential amino acid residues arginine and aspartate within the alpha1beta1 integrin recognition site of collagen IV has been resolved using fluorescence resonance energy transfer. J Mol Biol 2000; 297:501-9. [PMID: 10715216 DOI: 10.1006/jmbi.2000.3575] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [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: 11/22/2022]
Abstract
The interaction of collagen IV with cells is mediated mainly by the integrin alpha1beta1. The recognition site has been located to a segment of the triple-helical domain 100 nm away from the N terminus of the collagen molecule. The three essential amino acid residues of the alpha1beta1 binding site, arginine alpha2(IV)461 and the two aspartate residues alpha1(IV)461, are all located on different chains. Since the spatial array of the three residues depends on the stagger of the chains within the triple helix, the stagger has been elucidated using fluorescence resonance energy transfer with phenylalanine alpha1(IV)473 and tryptophan alpha2(IV)479 as the fluorescent donor/acceptor pair. The distance R between phenylalanine and tryptophan was determined by analysis of the energy transfer efficiency, E, and the orientation factor, kappa(2). In parallel, distance R and orientation factor, kappa(2 )were also calculated from the coordinates of the triple helix. Comparison of the calculated and empirically determined values unequivocally showed the stagger to be alpha1'alpha1alpha2. This arrangement of the three alpha chains describes the conformation of the alpha1beta1 integrin recognition site, that is the distinct orientation of the side-chains of the essential residues aspartate and arginine in respect to the helix axis.
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Affiliation(s)
- R Golbik
- Max-Planck-Institut für Biochemie, Martinsried, D-82152, Germany
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Abstract
This study addresses the effects of IL-1 beta on apoptosis induced by agonistic anti-CD95 (Fas) Ab. IL-1 beta inhibited anti-CD95 Ab-induced apoptosis in all preparations of normal human articular chondrocytes tested. Inhibitors of nitric oxide synthase or cyclooxygenase did not influence the protective effect of IL-1 beta, indicating that nitric oxide and PGs were not involved in the modulation of CD95-induced apoptosis. However, when the IL-1 beta-dependent induction of NF-kappa B was inhibited, the antiapoptotic effect of IL-1 beta was partially reversed, suggesting that NF-kappa B-mediated gene activation is part of the protective mechanism. In addition, IL-1 beta significantly increased the expression of Bcl-2. The protein tyrosine kinase inhibitor herbimycin A completely eliminated the protective effect of IL-1 beta on CD95-induced apoptosis. These findings suggest that IL-1 beta modulates the CD95 death cascade in chondrocytes by mechanisms that involve tyrosine phosphorylation events and NF-kappa B-dependent gene activation.
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Affiliation(s)
- K Kühn
- Division of Arthritis Research, Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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Abstract
This study addresses the effects of cell density and serum on CD95 (APO-1/Fas) and CD95L (Fas Ligand) expression and on the induction of CD95-dependent apoptosis in human articular chondrocytes from normal knees. Subsets of articular chondrocytes in first passage monolayer culture expressed CD95 and CD95L on the cell surface. The expression of both molecules was influenced by cell density: 22.3% of chondrocytes plated at subconfluent density expressed CD95L while expression in confluent cultures was reduced to 8.2%. CD95 expression was 32.1% under subconfluent and 12.2% under confluent conditions. Induction of specific apoptosis by agonistic antibody to CD95 was 15 times higher in confluent cultures than in subconfluent cultures despite higher levels of CD95 and CD95L expression in subconfluent cells, suggesting that protective antiapoptotic mechanisms were activated in low-density cultures. In subconfluent cultures, serum withdrawal had no effect on the sensitivity of the cells toward CD95 antibody-induced apoptosis. However, in confluent cultures, serum withdrawal led to a significant reduction of CD95-dependent apoptosis. Together, these findings demonstrate that cell density is an important modulator of CD95/CD95L expression and susceptibility to CD95-mediated apoptosis in cultured human chondrocytes.
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Affiliation(s)
- K Kühn
- Division of Arthritis Research, The Scripps Research Institute, La Jolla, California 92037, USA
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Stephan R, Kühn K. Prevalence of verotoxin-producing Escherichia coli (VTEC) in bovine coli mastitis and their antibiotic resistance patterns. Zentralbl Veterinarmed B 1999; 46:423-7. [PMID: 10481626 DOI: 10.1046/j.1439-0450.1999.00244.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Between December 1996 and October 1997, milk samples from a total of 145 cows with coli mastitis were screened for the presence of verotoxin-producing E. coli (VTEC). VTEC were found in four (2.8%) out of the 145 samples. The four isolated strains proved to be verotoxin (VT) 1-, VT2- or VT1- and VT2-positive. However, no strain contained all three virulence factors tested. Further strain characterization was carried out by serotyping as well as by resistance pattern analysis.
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Affiliation(s)
- R Stephan
- Institute of Food Safety and Hygiene, University of Zurich, Switzerland
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Abstract
This study addresses the occurrence and significance of chondrocyte apoptosis in the pathogenesis of cartilage destruction. Chondrocyte apoptosis can be induced in vitro by nitric oxide donors, but not by pro-inflammatory cytokines, such as IL-1 or TNF. A subset of chondrocytes, located in the superficial zone of cartilage, expresses the Fas antigen. Activation of the Fas receptor triggers apoptosis in these cells. In human and experimental osteoarthritis (OA) induced in rabbits by anterior cruciate ligament transection increased numbers of chondrocytes were undergoing apoptosis. Cartilage areas that contained apoptotic cells showed proteoglycan depletion and the number of apoptotic cells was significantly correlated with the levels of nitric oxide production and with the severity of OA. Articular cartilage is not vascularized and does not contain mononuclear phagocytes. There is, thus, no apparent mechanism for the clearance of apoptotic bodies. Chondrocyte-derived apoptotic bodies produced pyrophosphate and precipitated calcium. These results suggest that chondrocyte-derived apoptotic bodies express functional properties that may contribute to the pathologic cartilage degradation and calcification. Inhibition of chondrocyte apoptosis may be of therapeutic value after cartilage injury and in arthritis.
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Affiliation(s)
- M Lotz
- Division of Arthritis Research, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
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Kühn K, Wieseler B, Leng G, Idel H. Toxicokinetics of pyrethroids in humans: consequences for biological monitoring. Bull Environ Contam Toxicol 1999; 62:101-108. [PMID: 9933305 DOI: 10.1007/s001289900847] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- K Kühn
- Institute of Hygiene, Heinrich-Heine-University Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany
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Greger R, Kühn K. Abstracts 146–159. Kidney Blood Press Res 1999. [DOI: 10.1159/000025933] [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: 11/19/2022] Open
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Affiliation(s)
- H Felten
- I Medizinische Klinik, Schwerpunkt Nephrologie/Rheumatologie, Klinikum Karlsruhe
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Greger R, Kühn K. Abstracts 248–258. Kidney Blood Press Res 1999. [DOI: 10.1159/000025937] [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: 11/19/2022] Open
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Greger R, Kühn K. Abstracts 416–464. Kidney Blood Press Res 1999. [DOI: 10.1159/000025940] [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: 11/19/2022] Open
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Greger R, Kühn K. Abstracts 371–415. Kidney Blood Press Res 1999. [DOI: 10.1159/000025939] [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: 11/19/2022] Open
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Greger R, Kühn K. Abstracts 140–145. Kidney Blood Press Res 1999. [DOI: 10.1159/000025932] [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: 11/19/2022] Open
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Greger R, Kühn K. Abstracts 242–247. Kidney Blood Press Res 1999. [DOI: 10.1159/000025936] [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: 11/19/2022] Open
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Greger R, Kühn K. Abstracts 465–480. Kidney Blood Press Res 1999. [DOI: 10.1159/000025941] [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: 11/19/2022] Open
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