1
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Garg N, Štibler UK, Eismann B, Mercker M, Bergheim BG, Linn A, Tuchscherer P, Engel U, Redl S, Marciniak-Czochra A, Holstein TW, Hess MW, Özbek S. Non-muscle myosin II drives critical steps of nematocyst morphogenesis. iScience 2023; 26:106291. [PMID: 36936784 PMCID: PMC10014300 DOI: 10.1016/j.isci.2023.106291] [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: 08/23/2022] [Revised: 10/04/2022] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
Nematocysts are generated by secretion of proteins into a post-Golgi compartment. They consist of a capsule that elongates into a long tube, which is coiled inside the capsule matrix and expelled during its nano-second discharge deployed for prey capture. The driving force for discharge is an extreme osmotic pressure of 150 bar. The complex processes of tube elongation and invagination under these biomechanical constraints have so far been elusive. Here, we show that a non-muscle myosin II homolog (HyNMII) is essential for nematocyst formation in Hydra. In early nematocysts, HyNMII assembles to a collar around the neck of the protruding tube. HyNMII then facilitates tube outgrowth by compressing it along the longitudinal axis as evidenced by inhibitor treatment and genetic knockdown. In addition, live imaging of a NOWA::NOWA-GFP transgenic line, which re-defined NOWA as a tube component facilitating invagination, allowed us to analyze the impact of HyNMII on tube maturation.
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Affiliation(s)
- Niharika Garg
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Urška Knez Štibler
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Björn Eismann
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Moritz Mercker
- Institute for Applied Mathematics, Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Bruno Gideon Bergheim
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Anna Linn
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Patrizia Tuchscherer
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Ulrike Engel
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
- Nikon Imaging Center at the University of Heidelberg, Bioquant, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Redl
- Institute of Neuroanatomy, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
- Institute of Zoology, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Anna Marciniak-Czochra
- Institute for Applied Mathematics, Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Thomas W. Holstein
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Michael W. Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
| | - Suat Özbek
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
- Corresponding author
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2
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Senju Y, Mushtaq T, Vihinen H, Manninen A, Saarikangas J, Ven K, Engel U, Varjosalo M, Jokitalo E, Lappalainen P. Actin-rich lamellipodia-like protrusions contribute to the integrity of epithelial cell-cell junctions. J Biol Chem 2023; 299:104571. [PMID: 36871754 PMCID: PMC10173786 DOI: 10.1016/j.jbc.2023.104571] [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: 12/04/2022] [Revised: 01/11/2023] [Accepted: 02/01/2023] [Indexed: 03/06/2023] Open
Abstract
Metastasis-suppressor 1 (MTSS1) is a membrane-interacting scaffolding protein that regulates the integrity of epithelial cell-cell junctions and functions as a tumor suppressor in a wide range of carcinomas. MTSS1 binds phosphoinositide-rich membranes through its I-BAR domain, and is capable of sensing and generating negative membrane curvature in vitro. However, the mechanisms by which MTSS1 localizes to intercellular junctions in epithelial cells, and contributes to their integrity and maintenance have remained elusive. By carrying out electron microscopy and live-cell imaging on cultured Madin-Darby canine kidney (MDCK) cell monolayers, we provide evidence that adherens junctions of epithelial cells harbor lamellipodia-like, dynamic actin-driven membrane folds, which exhibit high negative membrane curvature at their distal edges. BioID proteomics and imaging experiments demonstrated that MTSS1 associates with an Arp2/3 complex activator, the WAVE-2 complex, in dynamic actin-rich protrusions at cell-cell junctions. Inhibition of Arp2/3 or WAVE-2 suppressed actin filament assembly at adherens junctions, decreased the dynamics of junctional membrane protrusions, and led to defects in epithelial integrity. Together, these results support a model in which membrane-associated MTSS1, together with the WAVE-2 and Arp2/3 complexes, promotes the formation of dynamic lamellipodia-like actin protrusions that contribute to the integrity of cell-cell junctions in epithelial monolayers.
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Affiliation(s)
- Yosuke Senju
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Japan.
| | - Toiba Mushtaq
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
| | - Helena Vihinen
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
| | - Aki Manninen
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Finland
| | - Juha Saarikangas
- Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, Neuroscience Center, University of Helsinki, Finland
| | - Katharina Ven
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
| | - Ulrike Engel
- Nikon Imaging Center and Centre for Organismal Studies, Heidelberg University, Germany
| | - Markku Varjosalo
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
| | - Eija Jokitalo
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
| | - Pekka Lappalainen
- Helsinki Institute of Life Science (HiLIFE) - Institute of Biotechnology, University of Helsinki, Finland
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3
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Veschgini M, Suzuki R, Kling S, Petersen HO, Bergheim BG, Abuillan W, Linke P, Kaufmann S, Burghammer M, Engel U, Stein F, Özbek S, Holstein TW, Tanaka M. Wnt/β-Catenin Signaling Induces Axial Elasticity Patterns of Hydra Extracellular Matrix. iScience 2023; 26:106416. [PMID: 37009232 PMCID: PMC10050647 DOI: 10.1016/j.isci.2023.106416] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/11/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
The extracellular matrix (ECM) plays crucial roles in animal development and diseases. Here, we report that Wnt/β-catenin signaling induces the ECM remodeling during Hydra axis formation. We determined the micro- and nanoscopic arrangement of fibrillar type I collagen along Hydra's body axis using high-resolution microscopy and X-ray scattering. Elasticity mapping of the ECM ex vivo revealed distinctive elasticity patterns along the body axis. A proteomic analysis of the ECM showed that these elasticity patterns correlate with a gradient-like distribution of metalloproteases along the body axis. Activation of the Wnt/β-catenin pathway in wild-type and transgenic animals alters these patterns toward low ECM elasticity patterns. This suggests a mechanism whereby high protease activity under control of Wnt/β-catenin signaling causes remodeling and softening of the ECM. This Wnt-dependent spatiotemporal coordination of biochemical and biomechanical cues in ECM formation was likely a central evolutionary innovation for animal tissue morphogenesis.
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4
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Preuß SL, Oehrl S, Zhang H, Döbel T, Engel U, Young JL, Spatz JP, Schäkel K. Immune complex-induced haptokinesis in human non-classical monocytes. Front Immunol 2023; 14:1078241. [PMID: 36936904 PMCID: PMC10014541 DOI: 10.3389/fimmu.2023.1078241] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
Formation and deposition of immune complexes (ICs) are hallmarks of various autoimmune diseases. Detection of ICs by IC receptors on leukocytes induces downstream signaling and shapes the local immune response. In many cases the pathological relevance of ICs is not well understood. We here show that ICs induce a distinct migratory response, i.e. haptokinesis in 6-sulfo LacNAc+ monocytes (slanMo) and in non-classical monocytes (ncMo) but not in intermediate (imMo) and classical monocytes (cMo). Using live imaging combined with automated cell tracking, we show that the main features of IC-dependent haptokinesis are elongation of the cell body, actin polarization at the leading edge, and highly directional migration. We find that CD16-dependent signaling mediates haptokinesis as blocking of CD16 or blocking SYK-signaling inhibited the migratory response. The activity of the metalloproteinase ADAM17 also modifies IC-dependent haptokinesis, likely at least partially via cleavage of CD16. Furthermore, using matrices with defined ligand spacing, we show that ligand density impacts the magnitude of the migratory response. Taken together, we have demonstrated that ICs induce a specific migratory response in ncMo but not in other monocyte subsets. Therefore, our work lays the groundwork for the investigation of IC-dependent haptokinesis in ncMo as a potential pathomechanism in IC-mediated autoimmune diseases.
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Affiliation(s)
- Sophie L. Preuß
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephanie Oehrl
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Hao Zhang
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Thomas Döbel
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ulrike Engel
- Nikon Imaging Center, Heidelberg University, Heidelberg, Germany
| | - Jennifer L. Young
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
- Biomedical Engineering Department, National University of Singapore, Singapore, Singapore
| | - Joachim P. Spatz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
- Department of Biophysical Chemistry, Heidelberg University, Heidelberg, Germany
| | - Knut Schäkel
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
- *Correspondence: Knut Schäkel,
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5
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Kokate SB, Ciuba K, Tran VD, Kumari R, Tojkander S, Engel U, Kogan K, Kumar S, Lappalainen P. Caldesmon controls stress fiber force-balance through dynamic cross-linking of myosin II and actin-tropomyosin filaments. Nat Commun 2022; 13:6032. [PMID: 36229430 PMCID: PMC9561149 DOI: 10.1038/s41467-022-33688-w] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 09/28/2022] [Indexed: 11/09/2022] Open
Abstract
Contractile actomyosin bundles are key force-producing and mechanosensing elements in muscle and non-muscle tissues. Whereas the organization of muscle myofibrils and mechanism regulating their contractility are relatively well-established, the principles by which myosin-II activity and force-balance are regulated in non-muscle cells have remained elusive. We show that Caldesmon, an important component of smooth muscle and non-muscle cell actomyosin bundles, is an elongated protein that functions as a dynamic cross-linker between myosin-II and tropomyosin-actin filaments. Depletion of Caldesmon results in aberrant lateral movement of myosin-II filaments along actin bundles, leading to irregular myosin distribution within stress fibers. This manifests as defects in stress fiber network organization and contractility, and accompanied problems in cell morphogenesis, migration, invasion, and mechanosensing. These results identify Caldesmon as critical factor that ensures regular myosin-II spacing within non-muscle cell actomyosin bundles, and reveal how stress fiber networks are controlled through dynamic cross-linking of tropomyosin-actin and myosin filaments.
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Affiliation(s)
- Shrikant B Kokate
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Katarzyna Ciuba
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.,Nencki Institute of Experimental Biology PAS, 3 Pasteur Street, 02-093, Warszawa, Poland
| | - Vivien D Tran
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Reena Kumari
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Sari Tojkander
- Faculty of Medicine and Health Technology, Tampere University, Kauppi Campus, Arvo Building, E318, Arvo Ylpön katu 34, 33520, Tampere, Finland
| | - Ulrike Engel
- Nikon Imaging Center at Heidelberg University and Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Germany
| | - Konstantin Kogan
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.
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6
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Grimm E, van der Hoeven F, Sardella D, Willig KI, Engel U, Veits N, Engel R, Cavalcanti-Adam EA, Bestvater F, Bordoni L, Jennemann R, Schönig K, Schiessl IM, Sandhoff R. A Clathrin light chain A reporter mouse for in vivo imaging of endocytosis. PLoS One 2022; 17:e0273660. [PMID: 36149863 PMCID: PMC9506643 DOI: 10.1371/journal.pone.0273660] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 08/13/2022] [Indexed: 11/20/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is one of the best studied cellular uptake pathways and its contributions to nutrient uptake, receptor signaling, and maintenance of the lipid membrane homeostasis have been already elucidated. Today, we still have a lack of understanding how the different components of this pathway cooperate dynamically in vivo. Therefore, we generated a reporter mouse model for CME by fusing eGFP endogenously in frame to clathrin light chain a (Clta) to track endocytosis in living mice. The fusion protein is expressed in all tissues, but in a cell specific manner, and can be visualized using fluorescence microscopy. Recruitment to nanobeads recorded by TIRF microscopy validated the functionality of the Clta-eGFP reporter. With this reporter model we were able to track the dynamics of Alexa594-BSA uptake in kidneys of anesthetized mice using intravital 2-photon microscopy. This reporter mouse model is not only a suitable and powerful tool to track CME in vivo in genetic or disease mouse models it can also help to shed light into the differential roles of the two clathrin light chain isoforms in health and disease.
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Affiliation(s)
- Elisabeth Grimm
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- * E-mail: (EG); (RS)
| | | | - Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Katrin I. Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Ulrike Engel
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- Nikon Imaging Center at Heidelberg University and Centre of Organismal Studies (COS), Bioquant, Heidelberg, Germany
| | - Nisha Veits
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Robert Engel
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | | | - Felix Bestvater
- Light Microscopy Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Richard Jennemann
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Mannheim, Germany
| | | | - Roger Sandhoff
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- * E-mail: (EG); (RS)
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7
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Peng F, Engel U, Aliyu H, Rudat J. Origin and Evolution of Enzymes with MIO Prosthetic Group: Microbial Coevolution After the Mass Extinction Event. Front Genet 2022; 13:851738. [PMID: 35422843 PMCID: PMC9002059 DOI: 10.3389/fgene.2022.851738] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/16/2022] [Indexed: 11/20/2022] Open
Abstract
After major mass extinction events, ancient plants and terrestrial vertebrates were faced with various challenges, especially ultraviolet (UV) light. These stresses probably resulted in changes in the biosynthetic pathways, which employed the MIO (3,5-dihydro-5-methylidene-4H-imidazole-4-one)-dependent enzymes (ammonia-lyase and aminomutase), leading to enhanced accumulation of metabolites for defense against UV radiation, pathogens, and microorganisms. Up to now, the origin and evolution of genes from this superfamily have not been extensively studied. In this report, we perform an analysis of the phylogenetic relations between the members of the aromatic amino acid MIO-dependent enzymes (AAM), which demonstrate that they most probably have a common evolutionary origin from ancient bacteria. In early soil environments, numerous bacterial species with tyrosine ammonia-lyase genes (TAL; EC 4.3.1.23) developed tyrosine aminomutase (TAM; EC 5.4.3.6) activity as a side reaction for competing with their neighbors in the community. These genes also evolved into other TAL-like enzymes, such as histidine ammonia-lyase (HAL, EC 4.3.1.3) and phenylalanine ammonia-lyase (PAL; EC 4.3.1.24), in different bacterial species for metabolite production and accumulation for adaptation to adverse terrestrial environmental conditions. On the other hand, the existence of phenylalanine aminomutase (PAM; EC 5.4.3.10) and phenylalanine/tyrosine ammonia-lyase (PTAL; EC 4.3.1.25) strongly indicates the horizontal gene transfer (HGT) between bacteria, fungi, and plants in symbiotic association after acquiring the PAL gene from their ancestor.
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Affiliation(s)
- Fei Peng
- Institute of Process Engineering in Life Sciences, II, Technical Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Ulrike Engel
- Institute of Process Engineering in Life Sciences, II, Technical Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Habibu Aliyu
- Institute of Process Engineering in Life Sciences, II, Technical Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Jens Rudat
- Institute of Process Engineering in Life Sciences, II, Technical Biology, Karlsruhe Institute of Technology, Karlsruhe, Germany
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8
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Donders G, Greenhouse P, Donders F, Engel U, Paavonen J, Mendling W. Genital Tract GAS Infection ISIDOG Guidelines. J Clin Med 2021; 10:jcm10092043. [PMID: 34068785 PMCID: PMC8126195 DOI: 10.3390/jcm10092043] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 03/14/2021] [Revised: 04/18/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023] Open
Abstract
There has been an increasing worldwide incidence of invasive group A streptococcal (GAS) disease in pregnancy and in the puerperal period over the past 30 years. Postpartum Group A streptococci infection, and in particular streptococcal toxic shock syndrome (TSS) and necrotizing fasciitis, can be life threatening and difficult to treat. Despite antibiotics and supportive therapy, and in some cases advanced extensive surgery, mortality associated with invasive group A streptococcal postpartum endometritis, necrotizing fasciitis, and toxic shock syndrome remains high, up to 40% of postpartum septic deaths. It now accounts for more than 75,000 deaths worldwide every year. Postpartum women have a 20-fold increased incidence of GAS disease compared to non-pregnant women. Despite the high incidence, many invasive GAS infections are not diagnosed in a timely manner, resulting in potentially preventable maternal and neonatal deaths. In this paper the specific characteristics of GAS infection in the field of Ob/Gyn are brought to our attention, resulting in guidelines to improve our awareness, early recognition and timely treatment of the disease. New European prevalence data of vaginal GAS colonization are presented, alongside two original case histories. Additionally, aerobic vaginitis is proposed as a supplementary risk factor for invasive GAS diseases.
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Affiliation(s)
- Gilbert Donders
- Femicare, Clinical Research for Women, 3300 Tienen, Belgium;
- Department of Obstetrics and Gynecology, University Hospital Antwerp, 2000 Antwerp, Belgium
- Regional Hospital H Hart, 3300 Tienen, Belgium
- Correspondence: ; Tel.: +32-38-214413
| | | | | | - Ulrike Engel
- Department of Ob/Gyn Maternité, Centre Hospitalier, 1210 Luxembourg, Luxembourg;
| | - Jorma Paavonen
- Department of Obstetrics and Gynecology, Helsinki University Hospital, 00260 Helsinki, Finland;
| | - Werner Mendling
- German Centre for Infections in Gynaecology and Obstetrics, St. Anna Hospital, 42109 Wuppertal, Germany;
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9
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Ciuba K, Hawkes W, Tojkander S, Kogan K, Engel U, Iskratsch T, Lappalainen P. Calponin-3 is critical for coordinated contractility of actin stress fibers. Sci Rep 2018; 8:17670. [PMID: 30518778 PMCID: PMC6281606 DOI: 10.1038/s41598-018-35948-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [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: 09/28/2018] [Accepted: 11/05/2018] [Indexed: 01/05/2023] Open
Abstract
Contractile actomyosin bundles, stress fibers, contribute to morphogenesis, migration, and mechanosensing of non-muscle cells. In addition to actin and non-muscle myosin II (NMII), stress fibers contain a large array of proteins that control their assembly, turnover, and contractility. Calponin-3 (Cnn3) is an actin-binding protein that associates with stress fibers. However, whether Cnn3 promotes stress fiber assembly, or serves as either a positive or negative regulator of their contractility has remained obscure. Here, we applied U2OS osteosarcoma cells as a model system to study the function of Cnn3. We show that Cnn3 localizes to both NMII-containing contractile ventral stress fibers and transverse arcs, as well as to non-contractile dorsal stress fibers that do not contain NMII. Fluorescence-recovery-after-photobleaching experiments revealed that Cnn3 is a dynamic component of stress fibers. Importantly, CRISPR/Cas9 knockout and RNAi knockdown studies demonstrated that Cnn3 is not essential for stress fiber assembly. However, Cnn3 depletion resulted in increased and uncoordinated contractility of stress fibers that often led to breakage of individual actomyosin bundles within the stress fiber network. Collectively these results provide evidence that Cnn3 is dispensable for the assembly of actomyosin bundles, but that it is required for controlling proper contractility of the stress fiber network.
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Affiliation(s)
- Katarzyna Ciuba
- Insitute of Biotechnology, P.O. Box 56, 0014, University of Helsinki, Helsinki, Finland
| | - William Hawkes
- School of Engineering and Materials Science, Queen Mary University of London, E1 4NS, London, UK
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL, London, UK
| | - Sari Tojkander
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Konstantin Kogan
- Insitute of Biotechnology, P.O. Box 56, 0014, University of Helsinki, Helsinki, Finland
| | - Ulrike Engel
- Nikon Imaging Center at Heidelberg University and Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Germany
| | - Thomas Iskratsch
- School of Engineering and Materials Science, Queen Mary University of London, E1 4NS, London, UK
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL, London, UK
| | - Pekka Lappalainen
- Insitute of Biotechnology, P.O. Box 56, 0014, University of Helsinki, Helsinki, Finland.
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10
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Shah PNM, Stanifer ML, Höhn K, Engel U, Haselmann U, Bartenschlager R, Kräusslich HG, Krijnse-Locker J, Boulant S. Genome packaging of reovirus is mediated by the scaffolding property of the microtubule network. Cell Microbiol 2017; 19. [PMID: 28672089 DOI: 10.1111/cmi.12765] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 05/07/2017] [Revised: 06/19/2017] [Accepted: 06/28/2017] [Indexed: 12/12/2022]
Abstract
Reovirus replication occurs in the cytoplasm of the host cell, in virally induced mini-organelles called virus factories. On the basis of the serotype of the virus, the virus factories can manifest as filamentous (type 1 Lang strain) or globular structures (type 3 Dearing strain). The filamentous factories morphology is dependent on the microtubule cytoskeleton; however, the exact function of the microtubule network in virus replication remains unknown. Using a combination of fluorescent microscopy, electron microscopy, and tomography of high-pressure frozen and freeze-substituted cells, we determined the ultrastructural organisation of reovirus factories. Cells infected with the reovirus microtubule-dependent strain display paracrystalline arrays of progeny virions resulting from their tiered organisation around microtubule filaments. On the contrary, in cells infected with the microtubule-independent strain, progeny virions lacked organisation. Conversely to the microtubule-dependent strain, around half of the viral particles present in these viral factories did not contain genomes (genome-less particles). Complementarily, interference with the microtubule filaments in cells infected with the microtubule-dependent strain resulted in a significant increase of genome-less particle number. This decrease of genome packaging efficiency could be rescued by rerouting viral factories on the actin cytoskeleton. These findings demonstrate that the scaffolding properties of the microtubule, and not biochemical nature of tubulin, are critical determinants for reovirus efficient genome packaging. This work establishes, for the first time, a functional correlation between ultrastructural organisation of reovirus factories with genome packaging efficiency and provides novel information on how viruses coordinate assembly of progeny particles.
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Affiliation(s)
- Pranav N M Shah
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
| | - Megan L Stanifer
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
| | - Katharina Höhn
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Ulrike Engel
- Nikon Imaging Center, Heidelberg University, Heidelberg, Germany
| | - Uta Haselmann
- Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Jacomine Krijnse-Locker
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Ultrapole, Ultrastructural Bio-imaging, Center for Innovation and Technological Research, Institut Pasteur, Paris, France
| | - Steeve Boulant
- Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany.,Schaller Research Group at CellNetworks and DKFZ, Heidelberg, Germany
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11
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Rüthnick D, Neuner A, Dietrich F, Kirrmaier D, Engel U, Knop M, Schiebel E. Characterization of spindle pole body duplication reveals a regulatory role for nuclear pore complexes. J Cell Biol 2017; 216:2425-2442. [PMID: 28659328 PMCID: PMC5551709 DOI: 10.1083/jcb.201612129] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 12/19/2016] [Revised: 04/25/2017] [Accepted: 05/22/2017] [Indexed: 02/08/2023] Open
Abstract
The spindle pole body (SPB) of budding yeast duplicates once per cell cycle. In G1, the satellite, an SPB precursor, assembles next to the mother SPB (mSPB) on the cytoplasmic side of the nuclear envelope (NE). How the growing satellite subsequently inserts into the NE is an open question. To address this, we have uncoupled satellite growth from NE insertion. We show that the bridge structure that separates the mSPB from the satellite is a distance holder that prevents deleterious fusion of both structures. Binding of the γ-tubulin receptor Spc110 to the central plaque from within the nucleus is important for NE insertion of the new SPB. Moreover, we provide evidence that a nuclear pore complex associates with the duplicating SPB and helps to insert the SPB into the NE. After SPB insertion, membrane-associated proteins including the conserved Ndc1 encircle the SPB and retain it within the NE. Thus, uncoupling SPB growth from NE insertion unmasks functions of the duplication machinery.
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Affiliation(s)
- Diana Rüthnick
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Annett Neuner
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Franziska Dietrich
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Daniel Kirrmaier
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Ulrike Engel
- Nikon Imaging Center at the University of Heidelberg, Bioquant, Heidelberg, Germany
| | - Michael Knop
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie at the University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
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12
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Seleit A, Krämer I, Ambrosio E, Dross N, Engel U, Centanin L. Sequential organogenesis sets two parallel sensory lines in medaka. Development 2017; 144:687-697. [PMID: 28087632 PMCID: PMC5312036 DOI: 10.1242/dev.142752] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 07/26/2016] [Accepted: 12/29/2016] [Indexed: 01/10/2023]
Abstract
Animal organs are typically formed during embryogenesis by following one specific developmental programme. Here, we report that neuromast organs are generated by two distinct and sequential programmes that result in parallel sensory lines in medaka embryos. A ventral posterior lateral line (pLL) is composed of neuromasts deposited by collectively migrating cells whereas a midline pLL is formed by individually migrating cells. Despite the variable number of neuromasts among embryos, the sequential programmes that we describe here fix an invariable ratio between ventral and midline neuromasts. Mechanistically, we show that the formation of both types of neuromasts depends on the chemokine receptor genes cxcr4b and cxcr7b, illustrating how common molecules can mediate different morphogenetic processes. Altogether, we reveal a self-organising feature of the lateral line system that ensures a proper distribution of sensory organs along the body axis. Summary: Two parallel sensory lines in medaka share a common origin and are composed of identical organs that are, nevertheless, generated through different morphogenetic programmes.
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Affiliation(s)
- Ali Seleit
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany.,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology (HBIGS), University of Heidelberg, Heidelberg, Germany
| | - Isabel Krämer
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany.,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology (HBIGS), University of Heidelberg, Heidelberg, Germany
| | - Elizabeth Ambrosio
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany
| | - Nicolas Dross
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany.,Nikon Imaging Center at the University of Heidelberg, Heidelberg, Germany
| | - Ulrike Engel
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany.,Nikon Imaging Center at the University of Heidelberg, Heidelberg, Germany
| | - Lázaro Centanin
- Animal Physiology and Development, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, Heidelberg 69120, Germany
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13
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Platz T, Eickhof C, van Kaick S, Engel U, Pinkowski C, Kalok S, Pause M. Impairment-oriented training or Bobath therapy for severe arm paresis after stroke: a single-blind, multicentre randomized controlled trial. Clin Rehabil 2016; 19:714-24. [PMID: 16250190 DOI: 10.1191/0269215505cr904oa] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [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: 11/05/2022]
Abstract
Objective: To study the effects of augmented exercise therapy time for arm rehabilitation as either Bobath therapy or the impairment-oriented training (Arm BASIS training) in stroke patients with arm severe paresis. Design: Single blind, multicentre randomized control trial. Setting: Three inpatient neurorehabilitation centres. Subjects: Sixty-two anterior circulation ischaemic stroke patients. Interventions: Random assignment to three group: (A) no augmented exercise therapy time, (B) augmented exercise therapy time as Bobath therapy and (C) augmented exercise therapy time as Arm BASIS training. Main measures: Main outcome measure: Fugl-Meyer arm motor score. Secondary measure: Action Research Arm Test (ARA). Ancillary measures: Fugl-Meyer arm sensation and joint motion/pain scores and the Ashworth Scale (elbow flexors). Results: An overall effect of augmented exercise therapy time on Fugl-Meyer scores after four weeks was not corroborated (mean and 95% confidence interval (CI) of change scores: no augmented exercise therapy time ( n = 20) 8.8, 5.2–12.3; augmented exercise therapy time ( n = 40) 9.9, 6.8-13.9; p = 0.2657). The group who received the augmented exercise therapy time as Arm BASIS training ( n = 20) had, however, higher gains than the group receiving the augmented exercise therapy time as Bobath therapy ( n = 20) (mean and 95% CI of change scores: Bobath 7.2, 2.6-11.8; BASIS 12.6, 8.4 - 16.8; p = 0.0432). Passive joint motion/pain deteriorated less in the group who received BASIS training (mean and 95% CI of change scores: Bobath -3.2, -5.2 to -1.1; BASIS 0.1, -1.8-2.0; p = 0.0090). ARA, Fugl-Meyer arm sensation, and Ashworth Scale scores were not differentially affected. Conclusions: The augmented exercise therapy time as Arm BASIS training enhanced selective motor control. Type of training was more relevant for recovery of motor control than therapeutic time spent.
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Affiliation(s)
- T Platz
- Department of Neurological Rehabilitation, Campus Benjamin Franklin, Charité-Universitatsmedizin Berlin, Germany.
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14
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Abstract
The rapid development of transparent zebrafish embryos (Danio rerio) in combination with fluorescent labelings of cells and tissues allows visualizing developmental processes as they happen in the living animal. Cells of interest can be labeled by using a tissue specific promoter to drive the expression of a fluorescent protein (FP) for the generation of transgenic lines. Using fluorescent photoconvertible proteins for this purpose additionally allows to precisely follow defined structures within the expression domain. Illuminating the protein in the region of interest, changes its emission spectrum and highlights a particular cell or cell cluster leaving other transgenic cells in their original color. A major limitation is the lack of known promoters for a large number of tissues in the zebrafish. Conversely, gene- and enhancer trap screens have generated enormous transgenic resources discretely labeling literally all embryonic structures mostly with GFP or to a lesser extend red or yellow FPs. An approach to follow defined structures in such transgenic backgrounds would be to additionally introduce a ubiquitous photoconvertible protein, which could be converted in the cell(s) of interest. However, the photoconvertible proteins available involve a green and/or less frequently a red emission state and can therefore often not be used to track cells in the FP-background of existing transgenic lines. To circumvent this problem, we have established the PSmOrange system for the zebrafish. Simple microinjection of synthetic mRNA encoding a nuclear form of this protein labels all cell nuclei with orange/red fluorescence. Upon targeted photoconversion of the protein, it switches its emission spectrum to far red. The quantum efficiency and stability of the protein makes PSmOrange a superb cell-tracking tool for zebrafish and possibly other teleost species.
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Affiliation(s)
- Carlo A Beretta
- Medical Faculty Mannheim, Department of Cell and Molecular Biology, Heidelberg University; COS and Nikon Imaging Center at the University of Heidelberg, Heidelberg University; Excellenzcluster CellNetworks, University of Heidelberg
| | - Nicolas Dross
- COS and Nikon Imaging Center at the University of Heidelberg, Heidelberg University
| | - Ulrike Engel
- COS and Nikon Imaging Center at the University of Heidelberg, Heidelberg University
| | - Matthias Carl
- Medical Faculty Mannheim, Department of Cell and Molecular Biology, Heidelberg University;
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15
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Slomka C, Zhong S, Fellinger A, Engel U, Syldatk C, Bräse S, Rudat J. Chemical synthesis and enzymatic, stereoselective hydrolysis of a functionalized dihydropyrimidine for the synthesis of β-amino acids. AMB Express 2015; 5:85. [PMID: 26705241 PMCID: PMC4690820 DOI: 10.1186/s13568-015-0174-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/11/2015] [Indexed: 11/29/2022] Open
Abstract
A novel substrate, 6-(4-nitrophenyl)dihydropyrimidine-2,4(1H,3H)-dione (pNO2PheDU), was chemically synthesized and analytically verified for the potential biocatalytic synthesis of enantiopure β-amino acids. The hydantoinase (EC 3.5.2.2) from Arthrobacter crystallopoietes DSM20117 was chosen to prove the enzymatic hydrolysis of this substrate, since previous investigations showed activities of this enzyme toward 6-monosubstituted dihydrouracils. Whole cell biotransformations with recombinant Escherichia coli expressing the hydantoinase showed degradation of pNO2PheDU. Additionally, the corresponding N-carbamoyl-β-amino acid (NCarbpNO2βPhe) was chemically synthesized, an HPLC-method with chiral stationary phases for detection of this product was established and thus (S)-enantioselectivity toward pNO2PheDU has been shown. Consequently this novel substrate is a potential precursor for the enantiopure β-amino acid para-nitro-β-phenylalanine (pNO2βPhe).
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16
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Wang Y, Arjonen A, Pouwels J, Ta H, Pausch P, Bange G, Engel U, Pan X, Fackler OT, Ivaska J, Grosse R. Formin-like 2 Promotes β1-Integrin Trafficking and Invasive Motility Downstream of PKCα. Dev Cell 2015; 34:475-83. [PMID: 26256210 DOI: 10.1016/j.devcel.2015.06.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/01/2015] [Accepted: 06/18/2015] [Indexed: 11/28/2022]
Abstract
Regulated turnover of integrin receptors is essential for cell adhesion and migration. Pathways selectively regulating β1-integrin recycling are implicated in cancer invasion and metastasis, yet proteins required for the internalization of this pro-invasive integrin remain to be identified. Here, we uncover formin-like 2 (FMNL2) as a critical regulator of β1-integrin internalization downstream of protein kinase C (PKC). PKCα associates with and phosphorylates FMNL2 at S1072 within its Diaphanous autoregulatory region, leading to the release of formin autoinhibition. Phosphorylation of FMNL2 triggers its rapid relocation and promotes its interaction with the cytoplasmic tails of the α-integrin subunits for β1-integrin endocytosis. FMNL2 drives β1-integrin internalization and invasive motility in a phosphorylation-dependent manner, while a FMNL2 mutant defective in actin assembly interferes with β1-integrin endocytosis and cancer cell invasion. Our data establish a role for FMNL2 in the regulation of β1-integrin and provide a mechanistic understanding of the function of FMNL2 in cancer invasiveness.
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Affiliation(s)
- Ying Wang
- Institute of Pharmacology, University of Marburg, 35043 Marburg, Germany
| | - Antti Arjonen
- Turku Centre for Biotechnology, University of Turku, 20520 Turku, Finland
| | - Jeroen Pouwels
- Turku Centre for Biotechnology, University of Turku, 20520 Turku, Finland
| | - Haisen Ta
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Patrick Pausch
- LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, University of Marburg, 35043 Marburg, Germany
| | - Gert Bange
- LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, University of Marburg, 35043 Marburg, Germany
| | - Ulrike Engel
- Nikon Imaging Center and COS, University of Heidelberg, 69120 Heidelberg, Germany
| | - Xiaoyu Pan
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Oliver T Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Johanna Ivaska
- Turku Centre for Biotechnology, University of Turku, 20520 Turku, Finland; Department of Biochemistry and Food Chemistry, University of Turku, 20520 Turku, Finland
| | - Robert Grosse
- Institute of Pharmacology, University of Marburg, 35043 Marburg, Germany.
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17
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Heinrich D, Ecke M, Jasnin M, Engel U, Gerisch G. Reversible membrane pearling in live cells upon destruction of the actin cortex. Biophys J 2014; 106:1079-91. [PMID: 24606932 DOI: 10.1016/j.bpj.2013.12.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/07/2013] [Accepted: 12/11/2013] [Indexed: 02/02/2023] Open
Abstract
Membrane pearling in live cells is observed when the plasma membrane is depleted of its support, the cortical actin network. Upon efficient depolymerization of actin, pearls of variable size are formed, which are connected by nanotubes of ~40 nm diameter. We show that formation of the membrane tubes and their transition into chains of pearls do not require external tension, and that they neither depend on microtubule-based molecular motors nor pressure generated by myosin-II. Pearling thus differs from blebbing. The pearling state is stable as long as actin is prevented from polymerizing. When polymerization is restored, the pearls are retracted into the cell, indicating continuity of the membrane. Our data suggest that the alternation of pearls and strings is an energetically favored state of the unsupported plasma membrane, and that one of the functions of the actin cortex is to prevent the membrane from spontaneously assuming this configuration.
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Affiliation(s)
- Doris Heinrich
- Leiden Institute of Physics, LION, Leiden University, The Netherlands; Fraunhofer-Institut für Silicatforschung ISC, Würzburg, Germany
| | - Mary Ecke
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Marion Jasnin
- Max Planck Institute of Biochemistry, Martinsried, Germany
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18
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Slomka C, Engel U, Syldatk C, Rudat J. Synthesis of β-Amino Acids Using a Modified Hydantoinase Process as Enzymatic Reaction Cascade. CHEM-ING-TECH 2014. [DOI: 10.1002/cite.201450367] [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: 11/07/2022]
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19
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Engel U, Zhan Y, Long JB, Boyle SN, Ballif BA, Dorey K, Gygi SP, Koleske AJ, Vanvactor D. Abelson phosphorylation of CLASP2 modulates its association with microtubules and actin. Cytoskeleton (Hoboken) 2014; 71:195-209. [PMID: 24520051 PMCID: PMC4054870 DOI: 10.1002/cm.21164] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [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: 06/04/2013] [Revised: 12/21/2013] [Accepted: 12/30/2013] [Indexed: 11/20/2022]
Abstract
The Abelson (Abl) non-receptor tyrosine kinase regulates the cytoskeleton during multiple stages of neural development, from neurulation, to the articulation of axons and dendrites, to synapse formation and maintenance. We previously showed that Abl is genetically linked to the microtubule (MT) plus end tracking protein (+TIP) CLASP in Drosophila. Here we show in vertebrate cells that Abl binds to CLASP and phosphorylates it in response to serum or PDGF stimulation. In vitro, Abl phosphorylates CLASP with a Km of 1.89 µM, indicating that CLASP is a bona fide substrate. Abl-phosphorylated tyrosine residues that we detect in CLASP by mass spectrometry lie within previously mapped F-actin and MT plus end interaction domains. Using purified proteins, we find that Abl phosphorylation modulates direct binding between purified CLASP2 with both MTs and actin. Consistent with these observations, Abl-induced phosphorylation of CLASP2 modulates its localization as well as the distribution of F-actin structures in spinal cord growth cones. Our data suggest that the functional relationship between Abl and CLASP2 is conserved and provides a means to control the CLASP2 association with the cytoskeleton. © 2014 The Authors. Cytoskeleton Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Ulrike Engel
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts; Nikon Imaging Center, the University of Heidelberg, Bioquant, 69120, Heidelberg, Germany
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20
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Abstract
Structured illumination microscopy (SIM) with a 3-dimensional illumination pattern allows to double image resolution laterally and axially. For cell biologists, SIM may become an attractive tool for refined colocalization studies and to investigate the assembly of components at higher resolution. In this chapter, we focus on the use of a commercial available SIM setup and provide guidance on sample preparation and image acquisition. We present superresolution images of the cytoskeleton in fixed cells and discuss the potential and limitations for SIM in live imaging.
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Affiliation(s)
- Ulrike Engel
- Center for Organismal Studies and Nikon Imaging Center, Bioquant, University of Heidelberg, Heidelberg, Germany
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21
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Marx A, Godinez WJ, Tsimashchuk V, Bankhead P, Rohr K, Engel U. Xenopus cytoplasmic linker-associated protein 1 (XCLASP1) promotes axon elongation and advance of pioneer microtubules. Mol Biol Cell 2013; 24:1544-58. [PMID: 23515224 PMCID: PMC3655815 DOI: 10.1091/mbc.e12-08-0573] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [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] [Indexed: 11/11/2022] Open
Abstract
Dynamic microtubules (MTs) are required for neuronal guidance, in which axons extend directionally toward their target tissues. We found that depletion of the MT-binding protein Xenopus cytoplasmic linker-associated protein 1 (XCLASP1) or treatment with the MT drug Taxol reduced axon outgrowth in spinal cord neurons. To quantify the dynamic distribution of MTs in axons, we developed an automated algorithm to detect and track MT plus ends that have been fluorescently labeled by end-binding protein 3 (EB3). XCLASP1 depletion reduced MT advance rates in neuronal growth cones, very much like treatment with Taxol, demonstrating a potential link between MT dynamics in the growth cone and axon extension. Automatic tracking of EB3 comets in different compartments revealed that MTs increasingly slowed as they passed from the axon shaft into the growth cone and filopodia. We used speckle microscopy to demonstrate that MTs experience retrograde flow at the leading edge. Microtubule advance in growth cone and filopodia was strongly reduced in XCLASP1-depleted axons as compared with control axons, but actin retrograde flow remained unchanged. Instead, we found that XCLASP1-depleted growth cones lacked lamellipodial actin organization characteristic of protrusion. Lamellipodial architecture depended on XCLASP1 and its capacity to associate with MTs, highlighting the importance of XCLASP1 in actin-microtubule interactions.
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Affiliation(s)
- Astrid Marx
- Exzellenzcluster CellNetworks, University of Heidelberg, 69120 Heidelberg, Germany
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22
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Grzmil P, Altmann ME, Adham IM, Engel U, Jarry H, Schweyer S, Wolf S, Mänz J, Engel W. Embryo implantation failure and other reproductive defects in Ube2q1-deficient female mice. Reproduction 2013; 145:45-56. [PMID: 23108111 DOI: 10.1530/rep-12-0054] [Citation(s) in RCA: 11] [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: 11/08/2022]
Abstract
The ubiquitination process is indispensable for proteome regulation. Three classes of ubiquitin (Ub)-related proteins can be distinguished: E1, E2 and E3. Proteins from the E2 class are responsible for the transfer of Ubls from E1 to the target protein. For this activity, interaction with class E3 ligases is usually required. Ub-conjugating enzyme E2Q 1 (UBE2Q1) belongs to the E2 class of Ub-related enzymes and is demonstrated to be involved in the regulation of membrane B4GALT1 protein. Here, we demonstrate that human UBE2Q1 and mouse Ube2q1 are widely expressed and highly conserved genes. To elucidate the function of UBE2Q1 protein, we generated knockout mouse model. No overt phenotype was detected in UBE2Q1-deficient males, but in mutant females, pleiotropic reproductive defects were observed including altered oestrus cycle, abnormal sexual behaviour and reduced offspring care. Moreover, in the uterus of mutant females, significantly increased embryonic lethality and decreased implantation capacity of homozygous mutant embryos were noticed. We found that Ube2q1 is not expressed in the uterus of non-pregnant females but its expression is up-regulated during pregnancy. Taken together, Ube2q1 is involved in different aspects of female fertility.
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Affiliation(s)
- Pawel Grzmil
- Institute of Human Genetics, University of Göttingen, Heinrich Düker Weg 12, 37073 Göttingen, Germany.
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23
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Schneegans SM, Rosenberger A, Engel U, Sander M, Emons G, Shoukier M. Validation of three BRCA1/2 mutation-carrier probability models Myriad, BRCAPRO and BOADICEA in a population-based series of 183 German families. Fam Cancer 2012; 11:181-8. [PMID: 22160602 PMCID: PMC3365232 DOI: 10.1007/s10689-011-9498-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [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] [Indexed: 12/13/2022]
Abstract
Many studies have evaluated the performance of risk assessment models for BRCA1/2 mutation carrier probabilities in different populations, but to our knowledge very few studies have been conducted in the German population so far. In the recent study, we validated the performance of three risk calculation models by names BRCAPRO, Myriad and BOADICEA in 183 German families who had undergone molecular testing of mutations in BRCA1 and BRCA2 with an indication based on clinical criteria regarding their family history of cancer. The sensitivity and specificity at the conventional threshold of 10% as well as for a threshold of 20% were evaluated. The ability to discriminate between carriers and non-carriers was judged by the area under the receiver operating characteristics curve. We further focused on the performance characteristic of these models in patients carrying large genomic rearrangements as a subtype of mutations which is currently gaining increasing importance. BRCAPRO and BOADICEA performed almost equally well in our patient population, but we found a lack of agreement to Myriad. The results obtained from this study were consistent with previously published results from other population and racial/ethnic groups. We suggest using model specific decision thresholds instead of the recommended universal value of 10%. We further suggest integrating the CaGene5 software package, which includes BRCAPRO and Myriad, in the genetic counselling of German families with suspected inherited breast and ovarian cancer because of the good performance of BRCAPRO and the substantial ease of use of this software.
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Affiliation(s)
- S M Schneegans
- Institute of Human Genetics, University Medical Center, Georg August University Göttingen, Heinrich-Düker-Weg 12, 37073, Göttingen, Germany
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24
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Abraham L, Bankhead P, Pan X, Engel U, Fackler OT. HIV-1 Nef limits communication between linker of activated T cells and SLP-76 to reduce formation of SLP-76-signaling microclusters following TCR stimulation. J Immunol 2012; 189:1898-910. [PMID: 22802418 DOI: 10.4049/jimmunol.1200652] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Signal initiation by engagement of the TCR triggers actin rearrangements, receptor clustering, and dynamic organization of signaling complexes to elicit and sustain downstream signaling. Nef, a pathogenicity factor of HIV, disrupts early TCR signaling in target T cells. To define the mechanism underlying this Nef-mediated signal disruption, we employed quantitative single-cell microscopy following surface-mediated TCR stimulation that allows for dynamic visualization of distinct signaling complexes as microclusters (MCs). Despite marked inhibition of actin remodeling and cell spreading, the induction of MCs containing TCR-CD3 or ZAP70 was not affected significantly by Nef. However, Nef potently inhibited the subsequent formation of MCs positive for the signaling adaptor Src homology-2 domain-containing leukocyte protein of 76 kDa (SLP-76) to reduce MC density in Nef-expressing and HIV-1-infected T cells. Further analyses suggested that Nef prevents formation of SLP-76 MCs at the level of the upstream adaptor protein, linker of activated T cells (LAT), that couples ZAP70 to SLP-76. Nef did not disrupt pre-existing MCs positive for LAT. However, the presence of the viral protein prevented de novo recruitment of active LAT into MCs due to retargeting of LAT to an intracellular compartment. These modulations in MC formation and composition depended on Nef's ability to simultaneously disrupt both actin remodeling and subcellular localization of TCR-proximal machinery. Nef thus employs a dual mechanism to disturb early TCR signaling by limiting the communication between LAT and SLP-76 and preventing the dynamic formation of SLP-76-signaling MCs.
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Affiliation(s)
- Libin Abraham
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany
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25
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Yoshikawa HY, Cui J, Kratz K, Matsuzaki T, Nakabayashi S, Marx A, Engel U, Lendlein A, Tanaka M. Quantitative Evaluation of Adhesion of Osteosarcoma Cells to Hydrophobic Polymer Substrate with Tunable Elasticity. J Phys Chem B 2012; 116:8024-30. [DOI: 10.1021/jp212385p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hiroshi Y. Yoshikawa
- Physical Chemistry
of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany
- Department of Chemistry, Saitama University, 338-8570 Saitama, Japan
| | - Jing Cui
- Centre for Biomaterial Development
and Berlin-Brandenburg Center for Regenerative Therapies, Institute
of Polymer Research, Helmholtz-Zentrum Geesthacht, 14513 Teltow, Germany
| | - Karl Kratz
- Centre for Biomaterial Development
and Berlin-Brandenburg Center for Regenerative Therapies, Institute
of Polymer Research, Helmholtz-Zentrum Geesthacht, 14513 Teltow, Germany
| | | | | | - Astrid Marx
- Nikon Imaging Center at the University of Heidelberg, BIOQUANT, 69120 Heidelberg, Germany
| | - Ulrike Engel
- Nikon Imaging Center at the University of Heidelberg, BIOQUANT, 69120 Heidelberg, Germany
| | - Andreas Lendlein
- Centre for Biomaterial Development
and Berlin-Brandenburg Center for Regenerative Therapies, Institute
of Polymer Research, Helmholtz-Zentrum Geesthacht, 14513 Teltow, Germany
| | - Motomu Tanaka
- Cell Biophysics Group, Institute for Toxicology and
Genetics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
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Engel U, Syldatk C, Rudat J. Novel amidases of two Aminobacter sp. strains: Biotransformation experiments and elucidation of gene sequences. AMB Express 2012; 2:33. [PMID: 22738219 PMCID: PMC3546935 DOI: 10.1186/2191-0855-2-33] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 05/15/2012] [Indexed: 12/02/2022] Open
Abstract
The amidase activities of two Aminobacter sp. strains (DSM24754 and DSM24755) towards the aryl-substituted substrates phenylhydantoin, indolylmethyl hydantoin, D,L-6-phenyl-5,6-dihydrouracil (PheDU) and para-chloro-D,L-6-phenyl-5,6-dihydrouracil were compared. Both strains showed hydantoinase and dihydropyrimidinase activity by hydrolyzing all substrates to the corresponding N-carbamoyl-α- or N-carbamoyl-β-amino acids. However, carbamoylase activity and thus a further degradation of these products to α- and β-amino acids was not detected. Additionally, the genes coding for a dihydropyrimidinase and a carbamoylase of Aminobacter sp. DSM24754 were elucidated. For Aminobacter sp. DSM24755 a dihydropyrimidinase gene flanked by two genes coding for putative ABC transporter proteins was detected. The deduced amino acid sequences of both dihydropyrimidinases are highly similar to the well-studied dihydropyrimidinase of Sinorhizobium meliloti CECT4114. The latter enzyme is reported to accept substituted hydantoins and dihydropyrimidines as substrates. The deduced amino acid sequence of the carbamoylase gene shows a high similarity to the very thermostable enzyme of Pseudomonas sp. KNK003A.
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Abraham L, Bankhead P, Pan X, Engel U, Fackler O. HIV-1 Nef limits communication between LAT and Slp-76 to reduce formation of Slp-76 signaling microclusters (170.20). The Journal of Immunology 2012. [DOI: 10.4049/jimmunol.188.supp.170.20] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Signal transduction through the T cell receptor (TCR) triggers actin rearrangements, receptor clustering and dynamic organization of signaling microclusters (SM) to form a stable Immunological synapse (IS). Nef, a pathogenicity factor of Human Immunodeficiency Virus (HIV), disrupts early TCR signaling in target T cells. To define the mechanism underlying this Nef-mediated signal disruption we employed quantitative microscopy to analyze the effects Nef exerts on formation and composition of TCR proximal SM. Despite marked inhibition of actin remodeling and cell spreading, the induction of SM containing the TCR itself or Zap70 was not affected by Nef. However, Nef potently inhibited the subsequent formation of SM that contained Slp-76 to reduce microcluster density in Nef expressing or HIV-1 infected T cells. Using a Nef mutant selectively defective in inhibition of actin remodeling (Nef F195I), we found that Nef-mediated disruption of actin remodeling and Slp-76 SM are independent activities. Strikingly, the effects of Nef on Slp-76 SM correlated with trans-golgi network targeting of LAT, an adaptor protein that couples Zap-70 to Slp-76. Nef-induced disruption of SM formation and composition depended on its ability to disrupt both, actin remodeling and subcellular localization of TCR-proximal machinery. Nef thus disrupts early TCR signaling by limiting the communication between LAT and Slp-76 and preventing the dynamic formation of Slp-76 SM.
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Affiliation(s)
- Libin Abraham
- 1Dept of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
| | - Peter Bankhead
- 2Nikon Imaging Center, University of Heidelberg, Heidelberg, Germany
| | - Xiaoyu Pan
- 1Dept of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
| | - Ulrike Engel
- 2Nikon Imaging Center, University of Heidelberg, Heidelberg, Germany
| | - Oliver Fackler
- 1Dept of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
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Engel U, Syldatk C, Rudat J. Stereoselective hydrolysis of aryl-substituted dihydropyrimidines by hydantoinases. Appl Microbiol Biotechnol 2011; 94:1221-31. [DOI: 10.1007/s00253-011-3691-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/12/2011] [Accepted: 10/31/2011] [Indexed: 12/29/2022]
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Yoshikawa HY, Rossetti FF, Kaufmann S, Kaindl T, Madsen J, Engel U, Lewis AL, Armes SP, Tanaka M. Quantitative evaluation of mechanosensing of cells on dynamically tunable hydrogels. J Am Chem Soc 2011; 133:1367-74. [PMID: 21218794 DOI: 10.1021/ja1060615] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thin hydrogel films based on an ABA triblock copolymer gelator [where A is pH-sensitive poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) and B is biocompatible poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC)] were used as a stimulus-responsive substrate that allows fine adjustment of the mechanical environment experienced by mouse myoblast cells. The hydrogel film elasticity could be reversibly modulated by a factor of 40 via careful pH adjustment without adversely affecting cell viability. Myoblast cells exhibited pronounced stress fiber formation and flattening on increasing the hydrogel elasticity. As a new tool to evaluate the strength of cell adhesion, we combined a picosecond laser with an inverted microscope and utilized the strong shock wave created by the laser pulse to determine the critical pressure required for cell detachment. Furthermore, we demonstrate that an abrupt jump in the hydrogel elasticity can be utilized to monitor how cells adapt their morphology to changes in their mechanical environment.
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Affiliation(s)
- Hiroshi Y Yoshikawa
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, D69120 Heidelberg, Germany
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Clarke M, Engel U, Giorgione J, Müller-Taubenberger A, Prassler J, Veltman D, Gerisch G. Curvature recognition and force generation in phagocytosis. BMC Biol 2010; 8:154. [PMID: 21190565 PMCID: PMC3022777 DOI: 10.1186/1741-7007-8-154] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [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: 09/21/2010] [Accepted: 12/29/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The uptake of particles by actin-powered invagination of the plasma membrane is common to protozoa and to phagocytes involved in the immune response of higher organisms. The question addressed here is how a phagocyte may use geometric cues to optimize force generation for the uptake of a particle. We survey mechanisms that enable a phagocyte to remodel actin organization in response to particles of complex shape. RESULTS Using particles that consist of two lobes separated by a neck, we found that Dictyostelium cells transmit signals concerning the curvature of a surface to the actin system underlying the plasma membrane. Force applied to a concave region can divide a particle in two, allowing engulfment of the portion first encountered. The phagosome membrane that is bent around the concave region is marked by a protein containing an inverse Bin-Amphiphysin-Rvs (I-BAR) domain in combination with an Src homology (SH3) domain, similar to mammalian insulin receptor tyrosine kinase substrate p53. Regulatory proteins enable the phagocyte to switch activities within seconds in response to particle shape. Ras, an inducer of actin polymerization, is activated along the cup surface. Coronin, which limits the lifetime of actin structures, is reversibly recruited to the cup, reflecting a program of actin depolymerization. The various forms of myosin-I are candidate motor proteins for force generation in particle uptake, whereas myosin-II is engaged only in retracting a phagocytic cup after a switch to particle release. Thus, the constriction of a phagocytic cup differs from the contraction of a cleavage furrow in mitosis. CONCLUSIONS Phagocytes scan a particle surface for convex and concave regions. By modulating the spatiotemporal pattern of actin organization, they are capable of switching between different modes of interaction with a particle, either arresting at a concave region and applying force in an attempt to sever the particle there, or extending the cup along the particle surface to identify the very end of the object to be ingested. Our data illustrate the flexibility of regulatory mechanisms that are at the phagocyte's disposal in exploring an environment of irregular geometry.
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Affiliation(s)
- Margaret Clarke
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73121, USA
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Engel U, Syldatk C, Rudat J. Synthese enantiomerenreiner β-Aminosäuren mithilfe neuer cyclischer Amidasen. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050243] [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: 11/08/2022]
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Kaindl T, Oelke J, Pasc A, Kaufmann S, Konovalov OV, Funari SS, Engel U, Wixforth A, Tanaka M. Regulation of adhesion behavior of murine macrophage using supported lipid membranes displaying tunable mannose domains. J Phys Condens Matter 2010; 22:285102. [PMID: 21399291 DOI: 10.1088/0953-8984/22/28/285102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Highly uniform, strongly correlated domains of synthetically designed lipids can be incorporated into supported lipid membranes. The systematic characterization of membranes displaying a variety of domains revealed that the equilibrium size of domains significantly depends on the length of fluorocarbon chains, which can be quantitatively interpreted within the framework of an equivalent dipole model. A mono-dispersive, narrow size distribution of the domains enables us to treat the inter-domain correlations as two-dimensional colloidal crystallization and calculate the potentials of mean force. The obtained results demonstrated that both size and inter-domain correlation can precisely be controlled by the molecular structures. By coupling α-D-mannose to lipid head groups, we studied the adhesion behavior of the murine macrophage (J774A.1) on supported membranes. Specific adhesion and spreading of macrophages showed a clear dependence on the density of functional lipids. The obtained results suggest that such synthetic lipid domains can be used as a defined platform to study how cells sense the size and distribution of functional molecules during adhesion and spreading.
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Affiliation(s)
- T Kaindl
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, Heidelberg D-69120, Germany
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Kins S, Hunzelmann S, Szodorai A, Kuan YH, Engel U, Müller U, Beyreuther K, Brady S, Morfini G. O2‐03‐03: Assembly of APP anterograde transport vesicles. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Stefan Kins
- Technical University of KaiserslauternKaiserslautern Germany
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Affiliation(s)
- Stephan Hegge
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
| | - Sylvia Munter
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
| | - Marion Steinbüchel
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
| | - Kirsten Heiss
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
| | | | - Kai Matuschewski
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
| | - Friedrich Frischknecht
- Department of ParasitologyHygiene InstituteUniversity of Heidelberg Medical SchoolHeidelbergGermany
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Clarke M, Maddera L, Engel U, Gerisch G. Retrieval of the vacuolar H-ATPase from phagosomes revealed by live cell imaging. PLoS One 2010; 5:e8585. [PMID: 20052281 PMCID: PMC2796722 DOI: 10.1371/journal.pone.0008585] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [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: 08/27/2009] [Accepted: 12/07/2009] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The vacuolar H+-ATPase, or V-ATPase, is a highly-conserved multi-subunit enzyme that transports protons across membranes at the expense of ATP. The resulting proton gradient serves many essential functions, among them energizing transport of small molecules such as neurotransmitters, and acidifying organelles such as endosomes. The enzyme is not present in the plasma membrane from which a phagosome is formed, but is rapidly delivered by fusion with endosomes that already bear the V-ATPase in their membranes. Similarly, the enzyme is thought to be retrieved from phagosome membranes prior to exocytosis of indigestible material, although that process has not been directly visualized. METHODOLOGY To monitor trafficking of the V-ATPase in the phagocytic pathway of Dictyostelium discoideum, we fed the cells yeast, large particles that maintain their shape during trafficking. To track pH changes, we conjugated the yeast with fluorescein isothiocyanate. Cells were labeled with VatM-GFP, a fluorescently-tagged transmembrane subunit of the V-ATPase, in parallel with stage-specific endosomal markers or in combination with mRFP-tagged cytoskeletal proteins. PRINCIPAL FINDINGS We find that the V-ATPase is commonly retrieved from the phagosome membrane by vesiculation shortly before exocytosis. However, if the cells are kept in confined spaces, a bulky phagosome may be exocytosed prematurely. In this event, a large V-ATPase-rich vacuole coated with actin typically separates from the acidic phagosome shortly before exocytosis. This vacuole is propelled by an actin tail and soon acquires the properties of an early endosome, revealing an unexpected mechanism for rapid recycling of the V-ATPase. Any V-ATPase that reaches the plasma membrane is also promptly retrieved. CONCLUSIONS/SIGNIFICANCE Thus, live cell microscopy has revealed both a usual route and alternative means of recycling the V-ATPase in the endocytic pathway.
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Affiliation(s)
- Margaret Clarke
- Program in Genetic Models of Disease, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America.
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Münter S, Sabass B, Selhuber-Unkel C, Kudryashev M, Hegge S, Engel U, Spatz JP, Matuschewski K, Schwarz US, Frischknecht F. Plasmodium Sporozoite Motility Is Modulated by the Turnover of Discrete Adhesion Sites. Cell Host Microbe 2009; 6:551-62. [DOI: 10.1016/j.chom.2009.11.007] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 10/21/2009] [Accepted: 11/19/2009] [Indexed: 01/19/2023]
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Ercan E, Momburg F, Engel U, Temmerman K, Nickel W, Seedorf M. A Conserved, Lipid-Mediated Sorting Mechanism of Yeast Ist2 and Mammalian STIM Proteins to the Peripheral ER. Traffic 2009; 10:1802-18. [PMID: 19845919 DOI: 10.1111/j.1600-0854.2009.00995.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Ebru Ercan
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
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Mentz RG, Engel U, Kjaer I. Nasal bone length in trisomy 18, triploidy and Turner syndrome analyzed on postmortem radiographs. Ultrasound Obstet Gynecol 2009; 34:607-608. [PMID: 19852045 DOI: 10.1002/uog.7436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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39
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Gerisch G, Ecke M, Schroth-Diez B, Gerwig S, Engel U, Maddera L, Clarke M. Self-organizing actin waves as planar phagocytic cup structures. Cell Adh Migr 2009; 3:373-82. [PMID: 19855162 DOI: 10.4161/cam.3.4.9708] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [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] Open
Abstract
Actin waves that travel on the planar membrane of a substrate-attached cell underscore the capability of the actin system to assemble into dynamic structures by the recruitment of proteins from the cytoplasm. The waves have no fixed shape, can reverse their direction of propagation and can fuse or divide. Actin waves separate two phases of the plasma membrane that are distinguished by their lipid composition. The area circumscribed by a wave resembles in its phosphoinositide content the interior of a phagocytic cup, leading us to explore the possibility that actin waves are in-plane phagocytic structures generated without the localized stimulus of an attached particle. Consistent with this view, wave-forming cells were found to exhibit a high propensity for taking up particles. Cells fed rod-shaped particles produced elongated phagocytic cups that displayed a zonal pattern that reflected in detail the actin and lipid pattern of free-running actin waves. Neutrophils and macrophages are known to spread on surfaces decorated with immune complexes, a process that has been interpreted as "frustrated" phagocytosis. We suggest that actin waves enable a phagocyte to scan a surface for particles that might be engulfed.
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40
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Affiliation(s)
- Ulrike Engel
- Nikon Imaging Center at University of Heidelberg, Bioquant, University of Heidelberg, Heidelberg, Germany.
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Heinrich D, Youssef S, Schroth-Diez B, Engel U, Aydin D, Blümmel J, Spatz JP, Gerisch G. Actin-cytoskeleton dynamics in non-monotonic cell spreading. Cell Adh Migr 2008; 2:58-68. [PMID: 19262103 DOI: 10.4161/cam.2.2.6190] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The spreading of motile cells on a substrate surface is accompanied by reorganization of their actin network. We show that spreading in the highly motile cells of Dictyostelium is non-monotonic, and thus differs from the passage of spreading cells through a regular series of stages. Quantification of the gain and loss of contact area revealed fluctuating forces of protrusion and retraction that dominate the interaction of Dictyostelium cells with a substrate. The molecular basis of these fluctuations is elucidated by dual-fluorescence labeling of filamentous actin together with proteins that highlight specific activities in the actin system. Front-to-tail polarity is established by the sorting out of myosin-II from regions where dense actin assemblies are accumulating. Myosin-IB identifies protruding front regions, and the Arp2/3 complex localizes to lamellipodia protruded from the fronts. Coronin is used as a sensitive indicator of actin disassembly to visualize the delicate balance of polymerization and depolymerization in spreading cells. Short-lived actin patches that co-localize with clathrin suggest that membrane internalization occurs even when the substrate-attached cell surface expands. We conclude that non-monotonic cell spreading is characterized by spatiotemporal patterns formed by motor proteins together with regulatory proteins that either promote or terminate actin polymerization on the scale of seconds.
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Affiliation(s)
- Doris Heinrich
- Department für Physik, Ludwig-Maximilians-Universität, München, Germany
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Appel N, Zayas M, Miller S, Krijnse-Locker J, Schaller T, Friebe P, Kallis S, Engel U, Bartenschlager R. Essential role of domain III of nonstructural protein 5A for hepatitis C virus infectious particle assembly. PLoS Pathog 2008; 4:e1000035. [PMID: 18369481 PMCID: PMC2268006 DOI: 10.1371/journal.ppat.1000035] [Citation(s) in RCA: 366] [Impact Index Per Article: 22.9] [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: 12/27/2007] [Accepted: 03/03/2008] [Indexed: 12/16/2022] Open
Abstract
Persistent infection with the hepatitis C virus (HCV) is a major risk factor for the development of liver cirrhosis and hepatocellular carcinoma. With an estimated about 3% of the world population infected with this virus, the lack of a prophylactic vaccine and a selective therapy, chronic hepatitis C currently is a main indication for liver transplantation. The establishment of cell-based replication and virus production systems has led to first insights into the functions of HCV proteins. However, the role of nonstructural protein 5A (NS5A) in the viral replication cycle is so far not known. NS5A is a membrane-associated RNA-binding protein assumed to be involved in HCV RNA replication. Its numerous interactions with the host cell suggest that NS5A is also an important determinant for pathogenesis and persistence. In this study we show that NS5A is a key factor for the assembly of infectious HCV particles. We specifically identify the C-terminal domain III as the primary determinant in NS5A for particle formation. We show that both core and NS5A colocalize on the surface of lipid droplets, a proposed site for HCV particle assembly. Deletions in domain III of NS5A disrupting this colocalization abrogate infectious particle formation and lead to an enhanced accumulation of core protein on the surface of lipid droplets. Finally, we show that mutations in NS5A causing an assembly defect can be rescued by trans-complementation. These data provide novel insights into the production of infectious HCV and identify NS5A as a major determinant for HCV assembly. Since domain III of NS5A is one of the most variable regions in the HCV genome, the results suggest that viral isolates may differ in their level of virion production and thus in their level of fitness and pathogenesis. The hepatitis C virus (HCV) is a major cause of acute and chronic liver diseases worldwide. In spite of high medical need there is no selective antiviral therapy available and a prophylactic vaccine is not in sight. Their development requires cellular replication systems that have become available just recently. One of the most fascinating insights gained with these systems is the finding that infectious HCV particles assemble in close association with an intracellular lipid storage compartment termed lipid droplets. In this study we show that nonstructural protein 5A (NS5A), a component of the viral RNA replication machinery is a key factor for the formation of infectious HCV particles. We identify a distinct domain in NS5A as the primary “assembly determinant” and show that NS5A and the core protein, which is a major constituent of the virus particle, accumulate on the surface of lipid droplets. Deletions in NS5A disrupting the colocalization of core and NS5A on lipid droplets abrogate infectious HCV production. These studies unravel a unique pathway of infectious virus formation and identify NS5A as a factor modulating HCV replication and assembly and thus viral fitness.
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Affiliation(s)
- Nicole Appel
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Margarita Zayas
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Sven Miller
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | | | - Torsten Schaller
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Peter Friebe
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Stephanie Kallis
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Ulrike Engel
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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Abstract
Regulation of cell polarity is a process observed in all cells. During directed migration, cells orientate their microtubule cytoskeleton and the microtubule-organizing-center (MTOC), which involves integrins and downstream Cdc42 and glycogen synthase kinase-3beta activity. However, the contribution of G protein-coupled receptor signal transduction for MTOC polarity is less well understood. Here, we report that the heterotrimeric Galpha(12) and Galpha(13) proteins are necessary for MTOC polarity and microtubule dynamics based on studies using Galpha(12/13)-deficient mouse embryonic fibroblasts. Cell polarization involves the Galpha(12/13)-interacting leukemia-associated RhoGEF (LARG) and the actin-nucleating diaphanous formin mDia1. Interestingly, LARG associates with pericentrin and localizes to the MTOC and along microtubule tracks. We propose that Galpha(12/13) proteins exert essential functions linking extracellular signals to microtubule dynamics and cell polarity via RhoGEF and formin activity.
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Affiliation(s)
- Polyxeni Goulimari
- Institute of Pharmacology, University of Heidelberg, 69120 Heidelberg, Germany
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Lanng C, Hoffmann J, Galatius H, Engel U. Assessment of clinical palpation of the axilla as a criterion for performing the sentinel node procedure in breast cancer. Eur J Surg Oncol 2007; 33:281-4. [PMID: 17084579 DOI: 10.1016/j.ejso.2006.09.032] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [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: 06/16/2006] [Accepted: 09/28/2006] [Indexed: 11/30/2022] Open
Abstract
AIMS Clinically palpable lymph nodes (LNs) are regarded as a contraindication for performing the sentinel node (SN) procedure. Many studies have shown, however, that clinical assessment of axillary LNs is inaccurate. This study evaluated the reliability of clinical axillary LN assessment by experts and assessed whether inaccuracy can be related to LN size. METHODS Three hundred and one consecutive breast cancer patients undergoing either axillary dissection or SN were studied prospectively. RESULTS The risk of having metastasis to the LN was 40.4% if the preoperative clinical assessment was "non-palpable LN", 61.5% if the assessment was "palpable but benign LN" and 84.4% if it was "suspicious LN". There were no clinically significant differences in mean size either when the LN was palpable versus non-palpable, or when the LN had metastasis or not. CONCLUSIONS The clinical assessment of axillary LNs as a criterion for offering the SN procedure is of little value.
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Affiliation(s)
- C Lanng
- Breast Surgery Clinic, Horsholm Hospital, Usserod Kongevej 102, DK-2970 Horsholm, Denmark.
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Schulz C, Engel U, Kreienberg R, Biesalski HK. Vitamin A and beta-carotene supply of women with gemini or short birth intervals: a pilot study. Eur J Nutr 2006; 46:12-20. [PMID: 17103079 DOI: 10.1007/s00394-006-0624-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [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: 03/31/2006] [Accepted: 10/12/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND An adequate supply of vitamin A during pregnancy and breastfeeding plays an important role for development of foetus and neonate, especially in lung development and function. AIM OF THE STUDY Aim of this pilot study was to analyze vitamin A and beta-carotene status and to investigate the contribution of nutrition to the vitamin A and beta-carotene supply in mother-infant pairs of gemini or births within short birth intervals. METHODS Twenty-nine volunteers aged between 21 and 36 years were evaluated for 48 h after delivery. During this time frame a food frequency protocol considering 3 months retrospective was obtained from all participants. In order to establish overall supply retinol and beta-carotene levels were determined in maternal plasma, cord blood and colostrum via HPLC analysis. RESULTS Regardless of the high to moderate socio-economic background, 27.6% of participants showed plasma retinol levels below 1.4 micromol/l which can be taken as borderline deficiency. In addition, 46.4% showed retinol intake <66% of RDA and 50.0% did not consume liver at all although liver contributes as a main source for preformed retinol. Despite high total carotenoid intake of 6.9 +/- 3.6 mg/d, 20.7% of mothers showed plasma levels <0.5 micromol/l beta-carotene. Retinol and beta-carotene levels were highly significantly correlated between maternal plasma versus cord blood and colostrum. In addition, significantly lower levels were found in cord blood (31.2 +/- 13.0% (retinol), 4.1 +/- 1.4% (beta-carotene) compared with maternal plasma. CONCLUSIONS Despite the fact that vitamin A and beta-carotene rich food is generally available, risk groups for low vitamin A supply exist in the western world.
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Abstract
Actin polymerization can be induced in Dictyostelium by compressing the cells to bring phagosomes filled with large particles into contact with the plasma membrane. Asymmetric actin assembly results in rocketing movement of the phagosomes. We show that the compression-induced assembly of actin at the cytoplasmic face of the plasma membrane involves the Arp2/3 complex. We also identify two other proteins associated with the mechanically induced actin assembly. The class I myosin MyoB accumulates at the plasma membrane-phagosome interface early during the initiation of the response, and coronin is recruited as the actin filaments are disassembling. The forces generated by rocketing phagosomes are sufficient to push the entire microtubule apparatus forward and to dislocate the nucleus.
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Affiliation(s)
- Margaret Clarke
- Program in Molecular, Cell, and Developmental Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73121, USA.
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48
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Abstract
Telephone surveys have gained considerable importance in recent years. The present article describes advantages and drawbacks of this mode of data collection. Particular attention is devoted to a number of aspects involved: costs, computer-assisted fieldwork, response rates, special demands on sampling, use of incentives, survey participation and the role of telephone surveys in flexible mixed-mode survey designs. A concluding section offers some practical recommendations on carrying out telephone surveys.
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Platz T, Kim IH, Engel U, Pinkowski C, Eickhof C, Kutzner M. Amphetamine fails to facilitate motor performance and to enhance motor recovery among stroke patients with mild arm paresis: interim analysis and termination of a double blind, randomised, placebo-controlled trial. Restor Neurol Neurosci 2005; 23:271-80. [PMID: 16477089] [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: 05/06/2023]
Abstract
PURPOSE To assess the effects of d-amphetamine on motor facilitation and recovery in stroke patients with mild arm paresis receiving the Arm Ability training. METHODS Thirty-one stroke patients with mild arm paresis were randomly assigned to either (a.) receiving placebo or (b.) d-amphetamine twice a week 2 hours before Arm Ability training sessions for three weeks. MAIN OUTCOME MEASURE time needed to perform TEMPA tasks, a measure of upper extremity performance reflecting everyday life tasks. Secondary measures: aimed movements, tapping, and a 10 m walkway as well as motor performance during training sessions. RESULTS The interim efficacy analysis of 26 stroke patients who completed the study intervention showed overall arm motor recovery both from pre to post test after 3 weeks of training and from pre test to follow-up 1 year later. No superior effect of d-amphetamine over placebo could be substantiated for either motor facilitation during training or motor recovery (post training or long-term). D-amphetamine exerted mild effects on blood pressure. Serious adverse events were not observed. CONCLUSIONS d-Amphetamine failed to facilitate motor performance during training sessions, to promote skill acquisition with training tasks, and most importantly to enhance motor recovery among patients with mild arm paresis after stroke.
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Affiliation(s)
- T Platz
- Klinik Berlin, Department of Neurological Rehabilitation, Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Germany.
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Lee H, Engel U, Rusch J, Scherrer S, Sheard K, Van Vactor D. The microtubule plus end tracking protein Orbit/MAST/CLASP acts downstream of the tyrosine kinase Abl in mediating axon guidance. Neuron 2004; 42:913-26. [PMID: 15207236 DOI: 10.1016/j.neuron.2004.05.020] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [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] [Received: 02/25/2004] [Revised: 04/16/2004] [Accepted: 05/05/2004] [Indexed: 11/25/2022]
Abstract
Axon guidance requires coordinated remodeling of actin and microtubule polymers. Using a genetic screen, we identified the microtubule-associated protein Orbit/MAST as a partner of the Abelson (Abl) tyrosine kinase. We find identical axon guidance phenotypes in orbit/MAST and Abl mutants at the midline, where the repellent Slit restricts axon crossing. Genetic interaction and epistasis assays indicate that Orbit/MAST mediates the action of Slit and its receptors, acting downstream of Abl. We find that Orbit/MAST protein localizes to Drosophila growth cones. Higher-resolution imaging of the Orbit/MAST ortholog CLASP in Xenopus growth cones suggests that this family of microtubule plus end tracking proteins identifies a subset of microtubules that probe the actin-rich peripheral growth cone domain, where guidance signals exert their initial influence on cytoskeletal organization. These and other data suggest a model where Abl acts as a central signaling node to coordinate actin and microtubule dynamics downstream of guidance receptors.
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Affiliation(s)
- Haeryun Lee
- Department of Cell Biology, Program in Neuroscience, Dana Farber Cancer Institute/Harvard Cancer Center and Harvard Center of Neurodegeneration and Repair, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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