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Johnson L, Aglas L, Punz B, Dang HH, Christ C, Pointner L, Wenger M, Hofstaetter N, Hofer S, Geppert M, Andosch A, Ferreira F, Horejs-Hoeck J, Duschl A, Himly M. Mechanistic insights into silica nanoparticle-allergen interactions on antigen presenting cell function in the context of allergic reactions. Nanoscale 2023; 15:2262-2275. [PMID: 36630186 PMCID: PMC9893438 DOI: 10.1039/d2nr05181h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
The incorporation of nanomaterials into consumer products has substantially increased in recent years, raising concerns about their safety. The inherent physicochemical properties of nanoparticles allow them to cross epithelial barriers and gain access to immunocompetent cells. Nanoparticles in cosmetic products can potentially interact with environmental allergens, forming a protein corona, and together penetrate through damaged skin. Allergen-nanoparticle interactions may influence the immune response, eventually resulting in an adverse or beneficial outcome in terms of allergic reactivity. This study determines the impact of silica nanoparticle-allergen interactions on allergic sensitization by studying the major molecular mechanisms affecting allergic responses. The major birch pollen allergen Bet v 1 was chosen as a model allergen and the birch pollen extract as a comparator. Key events in immunotoxicity including allergen uptake, processing, presentation, expression of costimulatory molecules and cytokine release were studied in human monocyte-derived dendritic cells. Using an in vivo sensitization model, murine Bet v 1-specific IgG and IgE levels were monitored. Upon the interaction of allergens with silica nanoparticles, we observed an enhanced uptake of the allergen by macropinocytosis, improved proteolytic processing, and presentation concomitant with a propensity to increase allergen-specific IgG2a and decrease IgE antibody levels. Together, these events suggest that upon nanoparticle interactions the immune response is biased towards a type 1 inflammatory profile, characterized by the upregulation of T helper 1 (Th1) cells. In conclusion, the interaction of the birch pollen allergen with silica nanoparticles will not worsen allergic sensitization, a state of type 2-inflammation, but rather seems to decrease it by skewing towards a Th1-dominated immune response.
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Affiliation(s)
- Litty Johnson
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Lorenz Aglas
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Benjamin Punz
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Hieu-Hoa Dang
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Constantin Christ
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Lisa Pointner
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Mario Wenger
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Norbert Hofstaetter
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Sabine Hofer
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Mark Geppert
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Ancuela Andosch
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Fatima Ferreira
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Jutta Horejs-Hoeck
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Albert Duschl
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
| | - Martin Himly
- Department of Biosciences and Medical Biology, University of Salzburg, 5020 Salzburg, Austria.
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Punz B, Johnson L, Geppert M, Dang HH, Horejs-Hoeck J, Duschl A, Himly M. Surface Functionalization of Silica Nanoparticles: Strategies to Optimize the Immune-Activating Profile of Carrier Platforms. Pharmaceutics 2022; 14:pharmaceutics14051103. [PMID: 35631689 PMCID: PMC9146724 DOI: 10.3390/pharmaceutics14051103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
Silica nanoparticles (SiNPs) are generally regarded as safe and may represent an attractive carrier platform for nanomedical applications when loaded with biopharmaceuticals. Surface functionalization by different chemistries may help to optimize protein loading and may further impact uptake into the targeted tissues or cells, however, it may also alter the immunologic profile of the carrier system. In order to circumvent side effects, novel carrier candidates need to be tested thoroughly, early in their development stage within the pharmaceutical innovation pipeline, for their potential to activate or modify the immune response. Previous studies have identified surface functionalization by different chemistries as providing a plethora of modifications for optimizing efficacy of biopharmaceutical (nano)carrier platforms while maintaining an acceptable safety profile. In this study, we synthesized SiNPs and chemically functionalized them to obtain different surface characteristics to allow their application as a carrier system for allergen-specific immunotherapy. In the present study, crude natural allergen extracts are used in combination with alum instead of well-defined active pharmaceutical ingredients (APIs), such as recombinant allergen, loaded onto (nano)carrier systems with immunologically inert and stable properties in suspension. This study was motivated by the hypothesis that comparing different charge states could allow tailoring of the binding capacity of the particulate carrier system, and hence the optimization of biopharmaceutical uptake while maintaining an acceptable safety profile, which was investigated by determining the maturation of human antigen-presenting cells (APCs). The functionalized nanoparticles were characterized for primary and hydrodynamic size, polydispersity index, zeta potential, endotoxin contamination. As potential candidates for allergen-specific immunotherapy, the differently functionalized SiNPs were non-covalently coupled with a highly purified, endotoxin-free recombinant preparation of the major birch pollen allergen Bet v 1 that functioned for further immunological testing. Binding efficiencies of allergen to SiNPs was controlled to determine uptake of API. For efficacy and safety assessment, we employed human monocyte-derived dendritic cells as model for APCs to detect possible differences in the particles’ APC maturation potential. Functionalization of SiNP did not affect the viability of APCs, however, the amount of API physisorbed onto the nanocarrier system, which induced enhanced uptake, mainly by macropinocytosis. We found slight differences in the maturation state of APCs for the differently functionalized SiNP–API conjugates qualifying surface functionalization as an effective instrument for optimizing the immune response towards SiNPs. This study further suggests that surface-functionalized SiNPs could be a suitable, immunologically inert vehicle for the efficient delivery of biopharmaceutical products, as evidenced here for allergen-specific immunotherapy.
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Mills-Goodlet R, Johnson L, Hoppe IJ, Regl C, Geppert M, Schenck M, Huber S, Hauser M, Ferreira F, Hüsing N, Huber CG, Brandstetter H, Duschl A, Himly M. The nanotopography of SiO 2 particles impacts the selectivity and 3D fold of bound allergens. Nanoscale 2021; 13:20508-20520. [PMID: 34854455 PMCID: PMC8675021 DOI: 10.1039/d1nr05958k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
A detailed description of the changes that occur during the formation of protein corona represents a fundamental question in nanoscience, given that it not only impacts the behaviour of nanoparticles but also affects the bound proteins. Relevant questions include whether proteins selectively bind particles, whether a specific orientation is preferred for binding, and whether particle binding leads to a modulation of their 3D fold. For allergens, it is important to answer these questions given that all these effects can modify the allergenic response of atopic individuals. These potential impacts on the bound allergen are closely related to the specific properties of the involved nanoparticles. One important property influencing the formation of protein corona is the nanotopography of the particles. Herein, we studied the effect of nanoparticle porosity on allergen binding using mesoporous and non-porous SiO2 NPs. We investigated (i) the selectivity of allergen binding from a mixture such as crude pollen extract, (ii) whether allergen binding results in a preferred orientation, (iii) the influence of binding on the conformation of the allergen, and (iv) how the binding affects the allergenic response. Nanotopography was found to play a major role in the formation of protein corona, impacting the physicochemical and biological properties of the NP-bound allergen. The porosity of the surface of the SiO2 nanoparticles resulted in a higher binding capacity with pronounced selectivity for (preferentially) binding the major birch pollen allergen Bet v 1. Furthermore, the binding of Bet v 1 to the mesoporous rather than the non-porous SiO2 nanoparticles influenced the 3D fold of the protein, resulting in at least partial unfolding. Consequently, this conformational change influenced the allergenic response, as observed by mediator release assays employing the sera of patients and immune effector cells. For an in-depth understanding of the bio-nano interactions, the properties of the particles need to be considered not only regarding the identity and morphology of the material, but also their nanotopography, given that porosity may greatly influence the structure, and hence the biological behaviour of the bound proteins. Thus, thorough structural investigations upon the formation of protein corona are important when considering immunological outcomes, as particle binding can influence the allergenic response elicited by the bound allergen.
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Affiliation(s)
| | - Litty Johnson
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Isabel J Hoppe
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, Paris Lodron University of Salzburg, Austria
| | - Christof Regl
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Mark Geppert
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Milena Schenck
- Dept. Chemistry and Physics of Materials, Paris Lodron University of Salzburg, Austria
| | - Sara Huber
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Michael Hauser
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Fátima Ferreira
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Nicola Hüsing
- Dept. Chemistry and Physics of Materials, Paris Lodron University of Salzburg, Austria
| | - Christian G Huber
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, Paris Lodron University of Salzburg, Austria
| | - Hans Brandstetter
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
- Christian Doppler Laboratory for Innovative Tools for Biosimilar Characterization, Paris Lodron University of Salzburg, Austria
| | - Albert Duschl
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
| | - Martin Himly
- Dept. Biosciences, Paris Lodron University of Salzburg, Austria.
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Johnson L, Aglas L, Soh WT, Geppert M, Hofer S, Hofstätter N, Briza P, Ferreira F, Weiss R, Brandstetter H, Duschl A, Himly M. Structural Alterations of Antigens at the Material Interface: An Early Decision Toolbox Facilitating Safe-by-Design Nanovaccine Development. Int J Mol Sci 2021; 22:10895. [PMID: 34639235 PMCID: PMC8509464 DOI: 10.3390/ijms221910895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 12/18/2022] Open
Abstract
Nanomaterials have found extensive interest in the development of novel vaccines, as adjuvants and/or carriers in vaccination platforms. Conjugation of protein antigens at the particle surface by non-covalent adsorption is the most widely used approach in licensed particulate vaccines. Hence, it is essential to understand proteins' structural integrity at the material interface in order to develop safe-by-design nanovaccines. In this study, we utilized two model proteins, the wild-type allergen Bet v 1 and its hypoallergenic fold variant (BM4), to compare SiO2 nanoparticles with Alhydrogel® as particulate systems. A set of biophysical and functional assays including circular dichroism spectroscopy and proteolytic degradation was used to examine the antigens' structural integrity at the material interface. Conjugation of both biomolecules to the particulate systems decreased their proteolytic stability. However, we observed qualitative and quantitative differences in antigen processing concomitant with differences in their fold stability. These changes further led to an alteration in IgE epitope recognition. Here, we propose a toolbox of biophysical and functional in vitro assays for the suitability assessment of nanomaterials in the early stages of vaccine development. These tools will aid in safe-by-design innovations and allow fine-tuning the properties of nanoparticle candidates to shape a specific immune response.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Martin Himly
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria; (L.J.); (L.A.); (W.T.S.); (M.G.); (S.H.); (N.H.); (P.B.); (F.F.); (R.W.); (H.B.); (A.D.)
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Opršal J, Knotek P, Zickler GA, Sigg L, Schirmer K, Pouzar M, Geppert M. Cytotoxicity, Accumulation and Translocation of Silver and Silver Sulfide Nanoparticles in contact with Rainbow Trout Intestinal Cells. Aquat Toxicol 2021; 237:105869. [PMID: 34082272 DOI: 10.1016/j.aquatox.2021.105869] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/26/2021] [Accepted: 05/11/2021] [Indexed: 06/12/2023]
Abstract
Silver nanoparticles (Ag NPs) are widely used in consumer products especially because of their antimicrobial properties. However, this wide usage of Ag NPs is accompanied by their release into the environment where they will be rapidly transformed to other silver species - especially silver sulfide (Ag2S). In the present study, we synthesized Ag NPs and sulfidized them to obtain a core-shell system Ag@Ag2S NPs. Both types of particles form stable dispersions with hydrodynamic diameters of less than 100 nm when diluted in water, but tend to form micrometer-sized agglomerates in biological exposure media. Application of Ag and Ag@Ag2S NPs to rainbow trout intestinal cells (RTgutGC) resulted in a concentration-dependent cytotoxicity for both types of particles, as assessed by a three-endpoint assay for metabolic activity, membrane integrity and lysosomal integrity. The Ag NPs were shown to be slightly more toxic than the Ag@Ag2S NPs. Adding Ag or Ag@Ag2S NPs to RTgutGC cells, grown on a permeable membrane to mimic the intestinal barrier, revealed considerable accumulation of silver for both types of particles. Indeed, the cells significantly attenuated the NP translocation, allowing only a fraction of the metal to translocate across the intestinal epithelium. These findings support the notion that the intestine constitutes an important sink for Ag NPs and that, despite the reduced cytotoxicity of a sulfidized NP form, the particles can enter fish where they may constitute a long-term source for silver ion release and cytotoxicity.
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Affiliation(s)
- Jakub Opršal
- University of Pardubice, Faculty of Chemical Technology, Institute of Environmental and Chemical Engineering, 53210 Pardubice, Czech Republic; Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Petr Knotek
- University of Pardubice, Faculty of Chemical Technology, Department of General and Inorganic Chemistry, 53210 Pardubice, Czech Republic
| | - Gregor A Zickler
- University of Salzburg, Department of Chemistry and Physics of Materials, 5020 Salzburg, Austria
| | - Laura Sigg
- Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Kristin Schirmer
- Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; EPF Lausanne, School of Architecture, Civil and Environmental Engineering, 1015 Lausanne, Switzerland
| | - Miloslav Pouzar
- University of Pardubice, Faculty of Chemical Technology, Institute of Environmental and Chemical Engineering, 53210 Pardubice, Czech Republic; Center of Materials and Nanotechnologies, Faculty of Chemical Technology, University of Pardubice, 53002 Pardubice, Czech Republic
| | - Mark Geppert
- Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; University of Salzburg, Department of Biosciences, 5020 Salzburg, Austria.
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Marcoulaki E, López de Ipiña JM, Vercauteren S, Bouillard J, Himly M, Lynch I, Witters H, Shandilya N, van Duuren-Stuurman B, Kunz V, Unger WES, Hodoroaba VD, Bard D, Evans G, Jensen KA, Pilou M, Viitanen AK, Bochon A, Duschl A, Geppert M, Persson K, Cotgreave I, Niga P, Gini M, Eleftheriadis K, Scalbi S, Caillard B, Arevalillo A, Frejafon E, Aguerre-Chariol O, Dulio V. Blueprint for a self-sustained European Centre for service provision in safe and sustainable innovation for nanotechnology. NanoImpact 2021; 23:100337. [PMID: 35559838 DOI: 10.1016/j.impact.2021.100337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/05/2021] [Accepted: 06/17/2021] [Indexed: 06/15/2023]
Abstract
The coming years are expected to bring rapid changes in the nanotechnology regulatory landscape, with the establishment of a new framework for nano-risk governance, in silico approaches for characterisation and risk assessment of nanomaterials, and novel procedures for the early identification and management of nanomaterial risks. In this context, Safe(r)-by-Design (SbD) emerges as a powerful preventive approach to support the development of safe and sustainable (SSbD) nanotechnology-based products and processes throughout the life cycle. This paper summarises the work undertaken to develop a blueprint for the deployment and operation of a permanent European Centre of collaborating laboratories and research organisations supporting safe innovation in nanotechnologies. The proposed entity, referred to as "the Centre", will establish a 'one-stop shop' for nanosafety-related services and a central contact point for addressing stakeholder questions about nanosafety. Its operation will rely on significant business, legal and market knowledge, as well as other tools developed and acquired through the EU-funded EC4SafeNano project and subsequent ongoing activities. The proposed blueprint adopts a demand-driven service update scheme to allow the necessary vigilance and flexibility to identify opportunities and adjust its activities and services in the rapidly evolving regulatory and nano risk governance landscape. The proposed Centre will play a major role as a conduit to transfer scientific knowledge between the research and commercial laboratories or consultants able to provide high quality nanosafety services, and the end-users of such services (e.g., industry, SMEs, consultancy firms, and regulatory authorities). The Centre will harmonise service provision, and bring novel risk assessment and management approaches, e.g. in silico methodologies, closer to practice, notably through SbD/SSbD, and decisively support safe and sustainable innovation of industrial production in the nanotechnology industry according to the European Chemicals Strategy for Sustainability.
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Affiliation(s)
- Effie Marcoulaki
- National Centre for Scientific Research "Demokritos", PO Box 60037, 15310 Agia Paraskevi, Greece.
| | - Jesús M López de Ipiña
- TECNALIA, Basque Research and Technology Alliance (BRTA), Parque Tecnológico de Alava, 01510 Miñano, Spain.
| | | | - Jacques Bouillard
- Institut national de l'environnement industriel et des risques (INERIS), Rue Jacques Taffanel, Parc technologique ALATA, Verneuil-en-Halatte, 60550, France.
| | - Martin Himly
- Paris Lodron University of Salzburg, Kapitelgasse 4/6, 5020 Salzburg, Austria.
| | - Iseult Lynch
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT Birmingham, UK.
| | - Hilda Witters
- VITO NV, Health Unit, Boeretang 200, 2400 Mol, Belgium.
| | - Neeraj Shandilya
- TNO, Research group Risk Analysis for Products in Development (RAPID), Princetonlaan 6, 3584 CB Utrecht, Netherlands.
| | - Birgit van Duuren-Stuurman
- TNO, Research group Risk Analysis for Products in Development (RAPID), Princetonlaan 6, 3584 CB Utrecht, Netherlands.
| | - Valentin Kunz
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany
| | - Wolfgang E S Unger
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany
| | - Vasile-Dan Hodoroaba
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany.
| | - Delphine Bard
- Health & Safety Executive Science and Research Centre, Harpur Hill, Buxton, Derbyshire SK17 9JN, UK.
| | - Gareth Evans
- Health & Safety Executive Science and Research Centre, Harpur Hill, Buxton, Derbyshire SK17 9JN, UK.
| | - Keld Alstrup Jensen
- National Research Center for the Work Environment (NRCWE), Lersø Parkallé 105, 2100 København, Denmark.
| | - Marika Pilou
- National Centre for Scientific Research "Demokritos", PO Box 60037, 15310 Agia Paraskevi, Greece.
| | - Anna-Kaisa Viitanen
- Finnish Institute of Occupational Health (FIOH), P.O. Box 40, FI-00032 Työterveyslaitos, Finland.
| | - Anthony Bochon
- JurisLab, Centre de droit privé, Université Libre de Bruxelles, Avenue F. Roosevelt 50, CP 137, 1050 Bruxelles, Belgium.
| | - Albert Duschl
- Paris Lodron University of Salzburg, Kapitelgasse 4/6, 5020 Salzburg, Austria.
| | - Mark Geppert
- Paris Lodron University of Salzburg, Kapitelgasse 4/6, 5020 Salzburg, Austria.
| | - Karin Persson
- RISE Surface, Process and Formulation, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Ian Cotgreave
- RISE Surface, Process and Formulation, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Petru Niga
- RISE Surface, Process and Formulation, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Maria Gini
- National Centre for Scientific Research "Demokritos", PO Box 60037, 15310 Agia Paraskevi, Greece.
| | | | - Simona Scalbi
- ENEA, Agenzia Nazionale per le nuove tecnologie, l'energia e lo sviluppo sostenibile, SSPT-USER-RISE, Via martiri di monte sole 4, 40129 Bologna, Italy.
| | - Bastien Caillard
- European Risk Management Institute (EU-VRi), Fangelsbachstr. 14, 70178 Stuttgart, Germany.
| | - Alfonso Arevalillo
- TECNALIA, Basque Research and Technology Alliance (BRTA), Area Anardi 5, 20730 Azpeitia, Spain.
| | - Emeric Frejafon
- BRGM, 3 av. Claude-Guillemin, BP 36009, 45100 Orléans Cedex 2, France.
| | - Olivier Aguerre-Chariol
- Institut national de l'environnement industriel et des risques (INERIS), Rue Jacques Taffanel, Parc technologique ALATA, Verneuil-en-Halatte, 60550, France.
| | - Valeria Dulio
- Institut national de l'environnement industriel et des risques (INERIS), Rue Jacques Taffanel, Parc technologique ALATA, Verneuil-en-Halatte, 60550, France.
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Abstract
Iron oxide nanoparticles (IONPs) bear big hopes in nanomedicine due to their (potential) applications in tumor therapy, drug delivery or bioimaging. However, as foreign entities, such particles may be recognized by the immune system and, thus, lead to inflammation, hypersensitivity or anaphylactic shock. In addition, an overload with iron is known to cause oxidative stress. In this short review, we summarize the biological effects of such particles with a major focus on IONP-formulations used for bioimaging purposes and their effects on the human immune system. We conclude that especially the characteristics of the particles (size, shape, surface charge, coating, etc.) as well as the presence of bystander substances, such as bacterial endotoxin are important factors determining the resulting biological and immunological effects of IONPs. Further studies are needed in order to establish clear structure-activity relationships.
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Affiliation(s)
- Mark Geppert
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
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Korotchenko E, Schießl V, Scheiblhofer S, Schubert M, Dall E, Joubert IA, Strandt H, Neuper T, Sarajlic M, Bauer R, Geppert M, Joedicke D, Wildner S, Schaller S, Winkler S, Gadermaier G, Horejs‐Hoeck J, Weiss R. Laser-facilitated epicutaneous immunotherapy with hypoallergenic beta-glucan neoglycoconjugates suppresses lung inflammation and avoids local side effects in a mouse model of allergic asthma. Allergy 2021; 76:210-222. [PMID: 32621318 PMCID: PMC7818228 DOI: 10.1111/all.14481] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 01/20/2020] [Revised: 05/28/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022]
Abstract
Background Allergen‐specific immunotherapy via the skin targets a tissue rich in antigen‐presenting cells, but can be associated with local and systemic side effects. Allergen‐polysaccharide neoglycogonjugates increase immunization efficacy by targeting and activating dendritic cells via C‐type lectin receptors and reduce side effects. Objective We investigated the immunogenicity, allergenicity, and therapeutic efficacy of laminarin‐ovalbumin neoglycoconjugates (LamOVA). Methods The biological activity of LamOVA was characterized in vitro using bone marrow‐derived dendritic cells. Immunogenicity and therapeutic efficacy were analyzed in BALB/c mice. Epicutaneous immunotherapy (EPIT) was performed using fractional infrared laser ablation to generate micropores in the skin, and the effects of LamOVA on blocking IgG, IgE, cellular composition of BAL, lung, and spleen, lung function, and T‐cell polarization were assessed. Results Conjugation of laminarin to ovalbumin reduced its IgE binding capacity fivefold and increased its immunogenicity threefold in terms of IgG generation. EPIT with LamOVA induced significantly higher IgG levels than OVA, matching the levels induced by s.c. injection of OVA/alum (SCIT). EPIT was equally effective as SCIT in terms of blocking IgG induction and suppression of lung inflammation and airway hyperresponsiveness, but SCIT was associated with higher levels of therapy‐induced IgE and TH2 cytokines. EPIT with LamOVA induced significantly lower local skin reactions during therapy compared to unconjugated OVA. Conclusion Conjugation of ovalbumin to laminarin increased its immunogenicity while at the same time reducing local side effects. LamOVA EPIT via laser‐generated micropores is safe and equally effective compared to SCIT with alum, without the need for adjuvant.
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Affiliation(s)
| | - Viktoria Schießl
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Mario Schubert
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Elfriede Dall
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Helen Strandt
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Theresa Neuper
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Muamera Sarajlic
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Renate Bauer
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Mark Geppert
- Department of Biosciences University of Salzburg Salzburg Austria
| | - David Joedicke
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | - Sabrina Wildner
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Susanne Schaller
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | - Stephan Winkler
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | | | | | - Richard Weiss
- Department of Biosciences University of Salzburg Salzburg Austria
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Joubert AI, Geppert M, Johnson L, Mills-Goodlet R, Michelini S, Korotchenko E, Duschl A, Weiss R, Horejs-Höck J, Himly M. Mechanisms of Particles in Sensitization, Effector Function and Therapy of Allergic Disease. Front Immunol 2020; 11:1334. [PMID: 32714326 PMCID: PMC7344151 DOI: 10.3389/fimmu.2020.01334] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/26/2020] [Indexed: 12/15/2022] Open
Abstract
Humans have always been in contact with natural airborne particles from many sources including biologic particulate matter (PM) which can exhibit allergenic properties. With industrialization, anthropogenic and combustion-derived particles have become a major fraction. Currently, an ever-growing number of diverse and innovative materials containing engineered nanoparticles (NPs) are being developed with great expectations in technology and medicine. Nanomaterials have entered everyday products including cosmetics, textiles, electronics, sports equipment, as well as food, and food packaging. As part of natural evolution humans have adapted to the exposure to particulate matter, aiming to protect the individual's integrity and health. At the respiratory barrier, complications can arise, when allergic sensitization and pulmonary diseases occur in response to particle exposure. Particulate matter in the form of plant pollen, dust mites feces, animal dander, but also aerosols arising from industrial processes in occupational settings including diverse mixtures thereof can exert such effects. This review article gives an overview of the allergic immune response and addresses specifically the mechanisms of particulates in the context of allergic sensitization, effector function and therapy. In regard of the first theme (i), an overview on exposure to particulates and the functionalities of the relevant immune cells involved in allergic sensitization as well as their interactions in innate and adaptive responses are described. As relevant for human disease, we aim to outline (ii) the potential effector mechanisms that lead to the aggravation of an ongoing immune deviation (such as asthma, chronic obstructive pulmonary disease, etc.) by inhaled particulates, including NPs. Even though adverse effects can be exerted by (nano)particles, leading to allergic sensitization, and the exacerbation of allergic symptoms, promising potential has been shown for their use in (iii) therapeutic approaches of allergic disease, for example as adjuvants. Hence, allergen-specific immunotherapy (AIT) is introduced and the role of adjuvants such as alum as well as the current understanding of their mechanisms of action is reviewed. Finally, future prospects of nanomedicines in allergy treatment are described, which involve modern platform technologies combining immunomodulatory effects at several (immuno-)functional levels.
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Affiliation(s)
- Anna I Joubert
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Mark Geppert
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Litty Johnson
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Robert Mills-Goodlet
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Sara Michelini
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Evgeniia Korotchenko
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Albert Duschl
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Richard Weiss
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Jutta Horejs-Höck
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Martin Himly
- Division of Allergy and Immunology, Department of Biosciences, University of Salzburg, Salzburg, Austria
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Himly M, Geppert M, Hofer S, Hofstätter N, Horejs-Höck J, Duschl A. When Would Immunologists Consider a Nanomaterial to be Safe? Recommendations for Planning Studies on Nanosafety. Small 2020; 16:e1907483. [PMID: 32239645 DOI: 10.1002/smll.201907483] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
The immune system is professional in recognizing and responding to non-self, including nanomaterials. Immune responses by professional and nonprofessional immune cells are thus nearly inevitable upon exposure of cells and organisms to such materials. The state of research into taking the immune system into account in nanosafety studies is reviewed and three aspects in which further improvements are desirable are identified: 1) Due to technical limitations, more stringent testing for endotoxin contamination should be made. 2) Since under overdose conditions immunity shows unphysiological responses, all doses used should be justified by being equivalent to tissue-delivered doses. 3) When markers of acute inflammation or cell stress are observed, functional assays are necessary to distinguish between homeostatic fluctuation and genuine defensive or tolerogenic responses. Since immune activation can also indicate that the immune system considers a stimulus to be harmless and induces tolerance, activation markers by themselves do not necessarily imply a danger to the body. Guidelines such as these are necessary to approach the point where specific nanomaterials are classified as safe based on reliable testing strategies.
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Affiliation(s)
- Martin Himly
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
| | - Mark Geppert
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
| | - Sabine Hofer
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
| | - Norbert Hofstätter
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
| | - Jutta Horejs-Höck
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
| | - Albert Duschl
- Department for Biosciences & Allergy Cancer BioNano Research Centre, University of Salzburg, Hellbrunner Strasse 34, Salzburg, 5020, Austria
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11
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Geppert M, Schwarz A, Stangassinger LM, Wenger S, Wienerroither LM, Ess S, Duschl A, Himly M. Interactions of TiO 2 Nanoparticles with Ingredients from Modern Lifestyle Products and Their Effects on Human Skin Cells. Chem Res Toxicol 2020; 33:1215-1225. [PMID: 32088960 PMCID: PMC7238409 DOI: 10.1021/acs.chemrestox.9b00428] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 12/23/2022]
Abstract
![]()
The
number of consumer products containing nanoparticles (NPs)
experienced a rapid increase during the past decades. However, most
studies of nanosafety have been conducted using only pure NPs produced
in the laboratory, while the interactions with other ingredients in
consumer products have rarely been considered so far. In the present
study, we investigated such interactions—with a special focus
on modern lifestyle products (MLPs) used by adolescents. An extensive
survey was undertaken at different high schools all over Austria to
identify MLPs that either contain NPs or that could come easily in
contact with NPs from other consumer products (such as TiO2 from sunscreens). Based on the results from a survey among secondary
schools students, we focused on ingredients from Henna tattoos (2-hydroxy-1,4-naphtoquinone,
HNQ, and p-phenylenediamine, PPD), fragrances (butylphenyl
methylpropional, known as Lilial), cosmetics and skin-care products
(four different parabens). As a cellular model, we decided to use
neonatal normal human dermal fibroblasts (nNHDF), since skin contact
is the main route of exposure for these compounds. TiO2 NPs interacted with these compounds as evidenced by alterations
in their hydrodynamic diameter observed by nanoparticle tracking analysis.
Combinations of TiO2 NPs with the different MLP components
did not show altered cytotoxicity profiles compared to MLP components
without TiO2 NPs. Nevertheless, altered cellular glutathione
contents were detected after incubation of the cells with Lilial.
This effect was independent of the presence of TiO2 NPs.
Testing mixtures of NPs with other compounds from consumer products
is an important approach to achieve a more reliable safety assessment.
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Affiliation(s)
- Mark Geppert
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Alexandra Schwarz
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Lea Maria Stangassinger
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Susanna Wenger
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Lisa Maria Wienerroither
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Stefanie Ess
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Albert Duschl
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
| | - Martin Himly
- Department of Biosciences and Allergy Cancer Bio Nano Research Centre, University of Salzburg, 5020 Salzburg, Austria
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12
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Pinto D, Plieschnegger W, Schneider NI, Geppert M, Bordel H, Höss GM, Eherer A, Wolf EM, Vieth M, Langner C. Carditis: a relevant marker of gastroesophageal reflux disease. Data from a prospective central European multicenter study on histological and endoscopic diagnosis of esophagitis (histoGERD trial). Dis Esophagus 2019; 32:5078141. [PMID: 30137321 DOI: 10.1093/dote/doy073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The columnar-lined mucosa at the gastroesophageal junction may contain an inflammatory infiltrate, commonly referred to as carditis (or cardia gastritis). The etiology of carditis is not entirely clear since published data are conflicting. Some authors believe it to be secondary to gastroesophageal reflux disease (GERD) and others to Helicobacter pylori gastritis. This prospective study aims at clarifying the relationship between carditis and the histological, clinical, and endoscopic findings of GERD, in a large cohort of individuals negative for H. pylori infection. Eight hundred and seventy-three individuals (477 females and 396 males, median age 53 years) participated in this study. Biopsy material was systematically sampled from above and below the gastroesophageal junction. Reflux-associated changes of the esophageal squamous epithelium were assessed according to the Esohisto consensus guidelines. Grading of carditis was performed according to the Updated Sydney System, known from the histological evaluation of gastritis. In total, 590 individuals (67.5%) had chronic carditis. Of these, 468 (53.6%) had mild chronic inflammation, with 321 individuals (68.6%) showing no or minimal changes on endoscopic examination (Los Angeles Categories N and M). The presence of chronic carditis was associated with several GERD-related parameters of the esophageal squamous epithelium (P < 0.0001), and data retained statistical significance even when analysis was restricted to individuals with mild chronic carditis and/or endoscopically normal mucosa. Chronic carditis was also associated with the presence of intestinal metaplasia (P < 0.0001). In addition, chronic carditis had a statistically significant association with patients' symptoms of GERD (P = 0.0107). This observation remained valid for mild chronic carditis in all patients (P = 0.0038) and in those with mild chronic carditis and normal endoscopic mucosa (P = 0.0217). In conclusion, chronic carditis appears to be the immediate consequence of GERD, correlating with patients' symptoms and endoscopic diagnosis. These results are valid in individuals with nonerosive reflux disease, which indicates a higher sensitivity of histological diagnosis. Our findings may impact the routine assessment of reflux patients.
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Affiliation(s)
- D Pinto
- Centro Hospitalar de Lisboa Ocidental, EPE, Lisboa, Portugal.,Diagnostic & Research Centre for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, Graz, Austria
| | - W Plieschnegger
- Department of Internal Medicine, Krankenhaus der Barmherzigen Brüder, St. Veit/Glan, Austria
| | - N I Schneider
- Diagnostic & Research Centre for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, Graz, Austria
| | - M Geppert
- Private Practice of Gastroenterology, Bayreuth, Germany
| | - H Bordel
- Private Practice of Gastroenterology, Osnabrück, Germany
| | - G M Höss
- Department of Surgery, Division of General Surgery, Medical University of Graz, Graz, Austria
| | - A Eherer
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - E-M Wolf
- Diagnostic & Research Centre for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, Graz, Austria
| | - M Vieth
- Institute of Pathology, Klinikum Bayreuth, Bayreuth, Germany
| | - C Langner
- Diagnostic & Research Centre for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, Graz, Austria
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Mills-Goodlet R, Geppert M, Himly M, Duschl A. Disease-modifying effects of allergen-nanoparticle conjugates – A study in human alveolar co-culture models mimicking the type 2 pre-inflamed state. Toxicol Lett 2017. [DOI: 10.1016/j.toxlet.2017.07.631] [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: 10/18/2022]
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14
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Verstraerlen S, Frijns E, Stoehr LC, Van Laer J, Jacobs A, Peters J, Tirez K, Boyles MSP, Geppert M, Madl P, Nelissen I, Duschl A, Himly M. A novel exposure system termed NAVETTA for in vitro laminar flow electrodeposition of nanoaerosol and evaluation of immune effects in human lung reporter cells. Toxicol Lett 2017. [DOI: 10.1016/j.toxlet.2017.08.043] [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: 11/29/2022]
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15
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Frijns E, Verstraelen S, Stoehr LC, Van Laer J, Jacobs A, Peters J, Tirez K, Boyles MSP, Geppert M, Madl P, Nelissen I, Duschl A, Himly M. A Novel Exposure System Termed NAVETTA for In Vitro Laminar Flow Electrodeposition of Nanoaerosol and Evaluation of Immune Effects in Human Lung Reporter Cells. Environ Sci Technol 2017; 51:5259-5269. [PMID: 28339192 DOI: 10.1021/acs.est.7b00493] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A new prototype air-liquid interface (ALI) exposure system, a flatbed aerosol exposure chamber termed NAVETTA, was developed to investigate deposition of engineered nanoparticles (NPs) on cultured human lung A549 cells directly from the gas phase. This device mimics human lung cell exposure to NPs due to a low horizontal gas flow combined with cells exposed at the ALI. Electrostatic field assistance is applied to improve NP deposition efficiency. As proof-of-principle, cell viability and immune responses after short-term exposure to nanocopper oxide (CuO)-aerosol were determined. We found that, due to the laminar aerosol flow and a specific orientation of inverted transwells, much higher deposition rates were obtained compared to the normal ALI setup. Cellular responses were monitored with postexposure incubation in submerged conditions, revealing CuO dissolution in a concentration-dependent manner. Cytotoxicity was the result of ionic and nonionic Cu fractions. Using the optimized inverted ALI/postincubation procedure, pro-inflammatory immune responses, in terms of interleukin (IL)-8 promoter and nuclear factor kappa B (NFκB) activity, were observed within short time, i.e. One hour exposure to ALI-deposited CuO-NPs and 2.5 h postincubation. NAVETTA is a novel option for mimicking human lung cell exposure to NPs, complementing existing ALI systems.
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Affiliation(s)
- Evelien Frijns
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Sandra Verstraelen
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Linda Corinna Stoehr
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Jo Van Laer
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - An Jacobs
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Jan Peters
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Kristof Tirez
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Matthew Samuel Powys Boyles
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Mark Geppert
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Pierre Madl
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Inge Nelissen
- Flemish Institute for Technological Research (VITO NV) , Boeretang 200, 2400 Mol, Belgium
| | - Albert Duschl
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
| | - Martin Himly
- Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria
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16
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Himly M, Mills-Goodlet R, Geppert M, Duschl A. Nanomaterials in the Context of Type 2 Immune Responses-Fears and Potentials. Front Immunol 2017; 8:471. [PMID: 28487697 PMCID: PMC5403887 DOI: 10.3389/fimmu.2017.00471] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 04/05/2017] [Indexed: 01/07/2023] Open
Abstract
The type 2 immune response is an adaptive immune program involved in defense against parasites, detoxification, and wound healing, but is predominantly known for its pathophysiological effects, manifesting as allergic disease. Engineered nanoparticles (NPs) are non-self entities that, to our knowledge, do not stimulate detrimental type 2 responses directly, but have the potential to modulate ongoing reactions in various ways, including the delivery of substances aiming at providing a therapeutic benefit. We review, here, the state of knowledge concerning the interaction of NPs with type 2 immune responses and highlight their potential as a multifunctional platform for therapeutic intervention.
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Affiliation(s)
- Martin Himly
- Division of Allergy and Immunology, Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Robert Mills-Goodlet
- Division of Allergy and Immunology, Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Mark Geppert
- Division of Allergy and Immunology, Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Albert Duschl
- Division of Allergy and Immunology, Department of Molecular Biology, University of Salzburg, Salzburg, Austria
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18
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Jemec A, Kahru A, Potthoff A, Drobne D, Heinlaan M, Böhme S, Geppert M, Novak S, Schirmer K, Rekulapally R, Singh S, Aruoja V, Sihtmäe M, Juganson K, Käkinen A, Kühnel D. An interlaboratory comparison of nanosilver characterisation and hazard identification: Harmonising techniques for high quality data. Environ Int 2016; 87:20-32. [PMID: 26638016 DOI: 10.1016/j.envint.2015.10.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 05/02/2023]
Abstract
Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions. Altogether ten different toxicity assays with a range of environmentally relevant test species from different trophic levels were conducted in parallel to AgNP characterisation in the respective test media. The paper presents a comprehensive dataset of toxicity values and AgNP characteristics like hydrodynamic sizes of AgNP agglomerates and the share (%) of Ag(+)-species (the concentration of Ag(+)-species in relation to the total measured concentration of Ag). The studied AgNP preparation (20.4±6.8 nm primary size, mean total Ag concentration 41.14 mg/L, 46-68% of soluble Ag(+)-species in stock, 123.8±12.2 nm mean z-average value in dH2O) showed extreme toxicity to crustaceans Daphnia magna, algae Pseudokirchneriella subcapitata and zebrafish Danio rerio embryos (EC50<0.01 mg total Ag/L), was very toxic in the in vitro assay with rainbow trout Oncorhynchus mykiss gut cells (EC50: 0.01-1 mg total Ag/L); toxic to bacteria Vibrio fischeri, protozoa Tetrahymena thermophila (EC50: 1-10 mg total Ag/L) and harmful to marine crustaceans Artemia franciscana (EC50: 10-100 mg total Ag/L). Along with AgNPs, also the toxicity of AgNO3 was analyzed. The toxicity data revealed the same hazard ranking for AgNPs and AgNO3 (i.e. the EC50 values were in the same order of magnitude) proving the importance of soluble Ag(+)-species analysis for predicting the hazard of AgNPs. The study clearly points to the need for harmonised procedures for the characterisation of NMs. Harmonised procedures should consider: (i) measuring the AgNP properties like hydrodynamic size and metal ions species in each toxicity test medium at a range of concentrations, and (ii) including soluble metal salt control both in toxicity testing as well as in Ag(+)-species measurements. The present study is among the first nanomaterial interlaboratory comparison studies with the aim to improve the hazard identification testing protocols.
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Affiliation(s)
- Anita Jemec
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, Slovenia.
| | - Anne Kahru
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Annegret Potthoff
- Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstrasse 28, 01277 Dresden, Germany
| | - Damjana Drobne
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Margit Heinlaan
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Steffi Böhme
- Helmholtz-Centre for Environmental Research - UFZ, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
| | - Mark Geppert
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133 Postfach 611, 8600 Dübendorf, Switzerland
| | - Sara Novak
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Kristin Schirmer
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133 Postfach 611, 8600 Dübendorf, Switzerland
| | - Rohit Rekulapally
- Centre for Cellular & Molecular Biology, Habsiguda, Hyderabad, Telangana 500007, India
| | - Shashi Singh
- Centre for Cellular & Molecular Biology, Habsiguda, Hyderabad, Telangana 500007, India
| | - Villem Aruoja
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Mariliis Sihtmäe
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Katre Juganson
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Aleksandr Käkinen
- National Institute of Chemical Physics and Biophysics, Laboratory of Environmental Toxicology, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Dana Kühnel
- Helmholtz-Centre for Environmental Research - UFZ, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
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Geppert M, Ayub Q, Xue Y, Santos S, Ribeiro-dos-Santos Â, Baeta M, Núñez C, Martínez-Jarreta B, Tyler-Smith C, Roewer L. Identification of new SNPs in native South American populations by resequencing the Y chromosome. Forensic Sci Int Genet 2015; 15:111-4. [DOI: 10.1016/j.fsigen.2014.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 09/16/2014] [Indexed: 12/21/2022]
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Filser J, Arndt D, Baumann J, Geppert M, Hackmann S, Luther EM, Pade C, Prenzel K, Wigger H, Arning J, Hohnholt MC, Köser J, Kück A, Lesnikov E, Neumann J, Schütrumpf S, Warrelmann J, Bäumer M, Dringen R, von Gleich A, Swiderek P, Thöming J. Intrinsically green iron oxide nanoparticles? From synthesis via (eco-)toxicology to scenario modelling. Nanoscale 2013; 5:1034-1046. [PMID: 23255050 DOI: 10.1039/c2nr31652h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Iron oxide nanoparticles (IONP) are currently being studied as green magnet resonance imaging (MRI) contrast agents. They are also used in huge quantities for environmental remediation and water treatment purposes, although very little is known on the consequences of such applications for organisms and ecosystems. In order to address these questions, we synthesised polyvinylpyrrolidone-coated IONP, characterised the particle dispersion in various media and investigated the consequences of an IONP exposure using an array of biochemical and biological assays. Several theoretical approaches complemented the measurements. In aqueous dispersion IONP had an average hydrodynamic diameter of 25 nm and were stable over six days in most test media, which could also be predicted by stability modelling. The particles were tested in concentrations of up to 100 mg Fe per L. The activity of the enzymes glutathione reductase and acetylcholine esterase was not affected, nor were proliferation, morphology or vitality of mammalian OLN-93 cells although exposure of the cells to 100 mg Fe per L increased the cellular iron content substantially. Only at this concentration, acute toxicity tests with the freshwater flea Daphnia magna revealed slightly, yet insignificantly increased mortality. Two fundamentally different bacterial assays, anaerobic activated sludge bacteria inhibition and a modified sediment contact test with Arthrobacter globiformis, both rendered results contrary to the other assays: at the lowest test concentration (1 mg Fe per L), IONP caused a pronounced inhibition whereas higher concentrations were not effective or even stimulating. Preliminary and prospective risk assessment was exemplified by comparing the application of IONP with gadolinium-based nanoparticles as MRI contrast agents. Predicted environmental concentrations were modelled in two different scenarios, showing that IONP could reduce the environmental exposure of toxic Gd-based particles by more than 50%. Application of the Swiss "Precautionary Matrix for Synthetic Nanomaterials" rendered a low precautionary need for using our IONP as MRI agents and a higher one when using them for remediation or water treatment. Since IONP and (considerably more reactive) zerovalent iron nanoparticles are being used in huge quantities for environmental remediation purposes, it has to be ascertained that these particles pose no risk to either human health or to the environment.
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Geppert M, Hohnholt MC, Nürnberger S, Dringen R. Ferritin up-regulation and transient ROS production in cultured brain astrocytes after loading with iron oxide nanoparticles. Acta Biomater 2012; 8:3832-9. [PMID: 22750736 DOI: 10.1016/j.actbio.2012.06.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 05/15/2012] [Accepted: 06/20/2012] [Indexed: 12/15/2022]
Abstract
To investigate the cellular consequences of a prolonged cellular presence of large amounts of iron oxide nanoparticles (IONPs) as well as the fate of such particles in brain cells, cultured primary astrocytes were loaded for 4h with dimercaptosuccinate-coated IONPs. Subsequently, the IONP-treated cells were incubated for up to 7 days in IONP-free medium and the cell viability, metabolic parameters and iron metabolism of the cells were investigated. Despite an up to 100-fold elevated specific cellular iron content, IONP-loaded cells remained viable throughout the 7 day main incubation and did not show any substantial alteration in glucose and glutathione metabolism. During the incubation, the high cellular iron content of IONP-loaded astrocytes remained almost constant. Electron microscopy revealed that after 7 days of incubation most of the cellular iron was still present in IONP-filled vesicles. However, the transient appearance of reactive oxygen species (ROS) as well as a strong increase in cellular levels of the iron storage protein ferritin suggest that at least some low-molecular-weight iron was liberated from the accumulated IONPs. These results demonstrate that even the prolonged presence of large amounts of accumulated IONPs does not harm astrocytes and that these cells store IONP-derived iron in ferritin.
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Affiliation(s)
- Mark Geppert
- Centre for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
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Purps J, Geppert M, Nagy M, Roewer L. Evaluation of the IrisPlex eye colour prediction tool in a German population sample. Forensic Science International: Genetics Supplement Series 2011. [DOI: 10.1016/j.fsigss.2011.08.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Lamkowsky MC, Geppert M, Schmidt MM, Dringen R. Magnetic field-induced acceleration of the accumulation of magnetic iron oxide nanoparticles by cultured brain astrocytes. J Biomed Mater Res A 2011; 100:323-34. [DOI: 10.1002/jbm.a.33263] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/05/2011] [Accepted: 08/26/2011] [Indexed: 12/31/2022]
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Hohnholt MC, Geppert M, Dringen R. Treatment with iron oxide nanoparticles induces ferritin synthesis but not oxidative stress in oligodendroglial cells. Acta Biomater 2011; 7:3946-54. [PMID: 21763792 DOI: 10.1016/j.actbio.2011.06.052] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [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: 03/11/2011] [Revised: 06/23/2011] [Accepted: 06/29/2011] [Indexed: 11/18/2022]
Abstract
Magnetic iron oxide nanoparticles (IONPs) have been used for a variety of neurobiological applications, although little is yet known as to the fate of such particles in brain cells. To address these questions, we have exposed oligodendroglial OLN-93 cells to dimercaptosuccinate-coated IONPs. Treatment of the cells strongly increased the specific cellular iron content proportional to the IONP concentrations applied (0-1000 μM total iron as IONPs) up to 300-fold, but did not cause any acute cytotoxicity or induce oxidative stress. To investigate the potential of OLN-93 cells to liberate iron from the accumulated IONPs, we have studied the upregulation of the iron storage protein ferritin and the cell proliferation as cellular processes that depend on the availability of low-molecular-weight iron. The presence of IONPs caused a concentration-dependent increase in the amount of cellular ferritin and partially bypassed the inhibition of cell proliferation by the iron chelator deferoxamine. These data demonstrate that viable OLN-93 cells efficiently take up IONPs and suggest that these cells are able to use iron liberated from accumulated IONPs for their metabolism.
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Affiliation(s)
- Michaela C Hohnholt
- Centre for Biomolecular Interactions Bremen, University of Bremen, D-28334 Bremen, Germany
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Geppert M, Hohnholt MC, Thiel K, Nürnberger S, Grunwald I, Rezwan K, Dringen R. Uptake of dimercaptosuccinate-coated magnetic iron oxide nanoparticles by cultured brain astrocytes. Nanotechnology 2011; 22:145101. [PMID: 21346306 DOI: 10.1088/0957-4484/22/14/145101] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [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
Magnetic iron oxide nanoparticles (Fe-NP) are currently considered for various diagnostic and therapeutic applications in the brain. However, little is known on the accumulation and biocompatibility of such particles in brain cells. We have synthesized and characterized dimercaptosuccinic acid (DMSA) coated Fe-NP and have investigated their uptake by cultured brain astrocytes. DMSA-coated Fe-NP that were dispersed in physiological medium had an average hydrodynamic diameter of about 60 nm. Incubation of cultured astrocytes with these Fe-NP caused a time- and concentration-dependent accumulation of cellular iron, but did not lead within 6 h to any cell toxicity. After 4 h of incubation with 100-4000 µM iron supplied as Fe-NP, the cellular iron content reached levels between 200 and 2000 nmol mg⁻¹ protein. The cellular iron content after exposure of astrocytes to Fe-NP at 4 °C was drastically lowered compared to cells that had been incubated at 37 °C. Electron microscopy revealed the presence of Fe-NP-containing vesicles in cells that were incubated with Fe-NP at 37 °C, but not in cells exposed to the nanoparticles at 4 °C. These data demonstrate that cultured astrocytes efficiently take up DMSA-coated Fe-NP in a process that appears to be saturable and strongly depends on the incubation temperature.
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Affiliation(s)
- Mark Geppert
- Center for Biomolecular Interactions Bremen, University of Bremen, PO Box 330440, D-28334 Bremen, Germany
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Baeta M, Núñez C, González-Andrade F, Sosa C, Casalod Y, Bolea M, Zweynert S, Vacas Cruz O, González-Solorzano J, Geppert M, Roewer L, Martínez-Jarreta B. Mitochondrial analysis revealed high homogeneity in the Waorani population—The last nomadic group of hunter-gatherers from Ecuador. Forensic Science International: Genetics Supplement Series 2009. [DOI: 10.1016/j.fsigss.2009.08.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Geppert M, Hohnholt M, Gaetjen L, Grunwald I, Bäumer M, Dringen R. Accumulation of Iron Oxide Nanoparticles by Cultured Brain Astrocytes. J Biomed Nanotechnol 2009; 5:285-93. [DOI: 10.1166/jbn.2009.1033] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Erckenbrecht J, Geppert M. Definition und Symptome, Epidemiologie, Diagnostik und Therapie - Obstipation - ein tägliches Problem. ACTA ACUST UNITED AC 2004. [DOI: 10.1055/s-2004-831034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Schlüter OM, Fornai F, Alessandrí MG, Takamori S, Geppert M, Jahn R, Südhof TC. Role of alpha-synuclein in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonism in mice. Neuroscience 2003; 118:985-1002. [PMID: 12732244 DOI: 10.1016/s0306-4522(03)00036-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In humans, mutations in the alpha-synuclein gene or exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produce Parkinson's disease with loss of dopaminergic neurons and depletion of nigrostriatal dopamine. alpha-Synuclein is a vertebrate-specific component of presynaptic nerve terminals that may function in modulating synaptic transmission. To test whether MPTP toxicity involves alpha-synuclein, we generated alpha-synuclein-deficient mice by homologous recombination, and analyzed the effect of deleting alpha-synuclein on MPTP toxicity using these knockout mice. In addition, we examined commercially available mice that contain a spontaneous loss of the alpha-synuclein gene. As described previously, deletion of alpha-synuclein had no significant effects on brain structure or composition. In particular, the levels of synaptic proteins were not altered, and the concentrations of dopamine, dopamine metabolites, and dopaminergic proteins were unchanged. Upon acute MPTP challenge, alpha-synuclein knockout mice were partly protected from chronic depletion of nigrostriatal dopamine when compared with littermates of the same genetic background, whereas mice carrying the spontaneous deletion of the alpha-synuclein gene exhibited no protection. Furthermore, alpha-synuclein knockout mice but not the mice with the alpha-synuclein gene deletion were slightly more sensitive to methamphetamine than littermate control mice. These results demonstrate that alpha-synuclein is not obligatorily coupled to MPTP sensitivity, but can influence MPTP toxicity on some genetic backgrounds, and illustrate the need for extensive controls in studies aimed at describing the effects of mouse knockouts on MPTP sensitivity.
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Affiliation(s)
- O M Schlüter
- Center for Basic Neuroscience, Department of Molecular Genetics, and The Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA.
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Voets T, Moser T, Lund PE, Chow RH, Geppert M, Südhof TC, Neher E. Intracellular calcium dependence of large dense-core vesicle exocytosis in the absence of synaptotagmin I. Proc Natl Acad Sci U S A 2001; 98:11680-5. [PMID: 11562488 PMCID: PMC58789 DOI: 10.1073/pnas.201398798] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Synaptotagmin I is a synaptic vesicle-associated protein essential for synchronous neurotransmission. We investigated its impact on the intracellular Ca(2+)-dependence of large dense-core vesicle (LDCV) exocytosis by combining Ca(2+)-uncaging and membrane capacitance measurements in adrenal slices from mouse synaptotagmin I null mutants. Synaptotagmin I-deficient chromaffin cells displayed prolonged exocytic delays and slow, yet Ca(2+)-dependent fusion rates, resulting in strongly reduced LDCV release in response to short depolarizations. Vesicle recruitment, the shape of individual amperometric events, and endocytosis appeared unaffected. These findings demonstrate that synaptotagmin I is required for rapid, highly Ca(2+)-sensitive LDCV exocytosis and indicate that it regulates the equilibrium between a slowly releasable and a readily releasable state of the fusion machinery. Alternatively, synaptotagmin I could function as calcium sensor for the readily releasable pool, leading to the destabilization of the pool in its absence.
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Affiliation(s)
- T Voets
- Department of Membrane Biophysics, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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Prosser HM, Gill CH, Hirst WD, Grau E, Robbins M, Calver A, Soffin EM, Farmer CE, Lanneau C, Gray J, Schenck E, Warmerdam BS, Clapham C, Reavill C, Rogers DC, Stean T, Upton N, Humphreys K, Randall A, Geppert M, Davies CH, Pangalos MN. Epileptogenesis and enhanced prepulse inhibition in GABA(B1)-deficient mice. Mol Cell Neurosci 2001; 17:1059-70. [PMID: 11414794 DOI: 10.1006/mcne.2001.0995] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The recent cloning of two GABA(B) receptor subunits, GABA(B1) and GABA(B2), has raised the possibility that differences in GABA(B) receptor subunit composition may give rise to pharmacologically or functionally distinct receptors. If present, such molecular diversity could permit the selective targeting of GABA(B) receptor subtypes specifically involved in pathologies such as drug addiction, spasticity, pain, and epilepsy. To address these issues we have developed a GABA(B1) subunit knockout mouse using gene targeting techniques. In the brains of GABA(B1) null mice, all pre- and postsynaptic GABA(B) receptor function was absent demonstrating that the GABA(B1) subunit is essential for all GABA(B) receptor-mediated mechanisms. Despite this, GABA(B1) null mice appeared normal at birth, although by postnatal week four their growth was retarded and they developed a generalized epilepsy that resulted in premature death. In addition, GABA(B1) heterozygote animals showed enhanced prepulse inhibition responses compared to littermate controls, suggesting that GABA(B1) deficient mice exhibit increased sensorimotor gating mechanisms. These data suggest that GABA(B) receptor antagonists may be of benefit in the treatment of psychiatric and neurological disorders in which attentional processing is impaired.
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MESH Headings
- Action Potentials/drug effects
- Action Potentials/physiology
- Animals
- Baclofen/pharmacology
- Behavior, Animal/physiology
- Central Nervous System/abnormalities
- Central Nervous System/metabolism
- Central Nervous System/physiopathology
- Down-Regulation/genetics
- Epilepsy/congenital
- Epilepsy/genetics
- Epilepsy/physiopathology
- GABA Agonists/pharmacology
- Gene Targeting/methods
- Heterozygote
- Mice
- Mice, Knockout/abnormalities
- Mice, Knockout/anatomy & histology
- Mice, Knockout/metabolism
- Neural Inhibition/genetics
- Neurons/cytology
- Neurons/metabolism
- Phenotype
- RNA, Messenger/metabolism
- Radioligand Assay
- Receptors, GABA-B/deficiency
- Receptors, GABA-B/genetics
- Receptors, GABA-B/metabolism
- Reflex, Startle/drug effects
- Reflex, Startle/physiology
- Seizures/congenital
- Seizures/genetics
- Seizures/physiopathology
- Synapses/drug effects
- Synapses/metabolism
- Synapses/ultrastructure
- Synaptic Transmission/drug effects
- Synaptic Transmission/genetics
- gamma-Aminobutyric Acid/metabolism
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Affiliation(s)
- H M Prosser
- Genetics Research, Safety Assessment, Laboratory Animal Sciences, Neurology Centre of Excellence for Drug Discovery, Psychiatry Centre of Excellence for Drug Discovery, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, United Kingdom
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32
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Fersis N, Relakis K, Krainick U, Geppert M, Ruck P, Wallwiener D. Riesenfibroadenom (Phyllodes-Tumor) der weiblichen Brust - Klinische Merkmale, histologische Kriterien und Therapieoptionen einer seltenen Brusterkrankung -. Geburtshilfe Frauenheilkd 2001. [DOI: 10.1055/s-2001-11162] [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: 10/17/2022] Open
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33
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Müller-Schimpfle M, Noack F, Oettling G, Haug G, Kienzler D, Geppert M, Dietz K, Claussen CD. [Influence of histopathological factors on dynamic MR mammography]. ROFO-FORTSCHR RONTG 2000; 172:894-900. [PMID: 11142121 DOI: 10.1055/s-2000-8366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 10/17/2022]
Abstract
AIM To assess the histopathological background of enhancement mechanisms in dynamic MR mammography studies. METHODS The dynamic MR mammography (MRM) examinations were done with a 1.5 T MR imager (Magnetom Vision, Siemens) using a double breast coil and a coronal FLASH-3D sequence. Enhancement data were acquired during 9 minutes post contrast medium injection (Gd-DTPA 0.2 mmol/kg). Acquisition time was 87 sec/slab. Early enhancement at the first post contrast measurement (E1) and slope of wash-out (SE2-L) were calculated. In immunohistology, proliferation was assessed by the monoclonal antibody Ki 67, capillaries were stained by a CD 31 antibody. Of a total of 48 operated patients, 58 lesions and 46 surrounding tissues were evaluated. RESULTS Cellularity, capillary density and proliferation showed statistically significant correlations with E1 (p < 0.01). In multiple regression analysis, E1 was significantly associated only with high cellularity (p = 0.002) and the combination of high cellularity and high microvessel density (p = 0.002); a negative slope of wash out was significantly associated only with malignant histology (p = 0.027). CONCLUSIONS Our findings indicate a direct influence of cellularity and microvessel density on early enhancement. The expression of the proliferation marker Ki 67 was not an independent predictor for contrast enhancement.
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Bartsch C, Szadowska A, Karasek M, Bartsch H, Geppert M, Mecke D. Serial transplants of DMBA-induced mammary tumors in fischer rats as model system for human breast cancer: V. Myoepithelial-mesenchymal conversion during passaging as possible cause for modulation of pineal-tumor interaction. Exp Toxicol Pathol 2000; 52:93-101. [PMID: 10965982 DOI: 10.1016/s0940-2993(00)80091-3] [Citation(s) in RCA: 9] [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: 11/29/2022]
Abstract
An elevation of melatonin secretion parallel to an enhanced production of macrophage-derived biopterin was observed in female F344 Fischer rats bearing passage 2 serial transplants derived from a malignant mammary tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA). As opposed to that both parameters were depressed at passage 12. These results indicate the presence of divergent immunoneuroendocrine interactions during different phases of tumor growth. Since these biochemical events must have their common origin in changes taking place within these tumor transplants the current histopathological study was initiated. The primary tumor used for serial transplantation was a moderately differentiated adenocarcinoma of the mammary gland showing cytokeratin-positive epithelial components located in the inner epithelial tubule layer. In addition, bland-looking round or elongated actin-positive myoepithelial cells were detected which apart from epithelial cells are known to constitute the main cellular components of the mammary ductal system which resemble smooth muscle cells both morphologically and functionally. The tumor of passage 1 showed glandular tubules, lined by an inner epithelial layer, and many nests of clear, bland-looking actin-positive myoepithelial cells lying around tubules as well as in the stroma between actin-negative epithelial elements. The tumor of passage 2 used for transplantation consisted of a chaotic mixture of epithelial carcinomatous cells, forming a few irregular small tubules or solid nests, and, predominantly, of elongated plump or spindle-shaped, "myoid" atypical myoepithelial cells with a strong actin-positive reaction and some of these cells showed a focal vimentin expression. The tumor was characterized as a carcinosarcoma. At passage 12 epithelial cells were not identified. The tumor displayed features of a pleomorphic sarcoma consisting mainly of giant cells with bizarre nuclei being cytokeratin- and desmin-negative, weakly vimentin-positive but strongly actin-positive. These results indicate that DMBA-induced mammary tumor cells in female F344 Fischer rats undergo dramatic morphological changes during serial transplantation characterized by a total loss of malignant epithelial (carcinomatous) cells and the emergence and subsequent predominance of malignant (sarcomatous) mesenchymal cells. It appears that these sarcomatous cells develop out of myoepithelial cells since atypical myoepithelial cells with a strong actin-positive reaction showed a focal vimentin expression at passage 2 indicating myofibroblastic differentiation as part of mesenchymal transition. The loss of epithelial cell elements as well as a parallel transition of myoepithelial to mesenchymal cell elements during passaging could lead to a lack of immunological recognition of these tumor transplants and to depression of melatonin. Possible mechanisms involved in these phenomena as well as the relevance of these findings for a better understanding of the role of melatonin in human mammary cancer are discussed.
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Affiliation(s)
- C Bartsch
- Department of Gynecology, University of Tübingen, Germany.
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35
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Giger RJ, Cloutier JF, Sahay A, Prinjha RK, Levengood DV, Moore SE, Pickering S, Simmons D, Rastan S, Walsh FS, Kolodkin AL, Ginty DD, Geppert M. Neuropilin-2 is required in vivo for selective axon guidance responses to secreted semaphorins. Neuron 2000; 25:29-41. [PMID: 10707970 DOI: 10.1016/s0896-6273(00)80869-7] [Citation(s) in RCA: 353] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neuropilins are receptors for class 3 secreted semaphorins, most of which can function as potent repulsive axon guidance cues. We have generated mice with a targeted deletion in the neuropilin-2 (Npn-2) locus. Many Npn-2 mutant mice are viable into adulthood, allowing us to assess the role of Npn-2 in axon guidance events throughout neural development. Npn-2 is required for the organization and fasciculation of several cranial nerves and spinal nerves. In addition, several major fiber tracts in the brains of adult mutant mice are either severely disorganized or missing. Our results show that Npn-2 is a selective receptor for class 3 semaphorins in vivo and that Npn-1 and Npn-2 are required for development of an overlapping but distinct set of CNS and PNS projections.
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Affiliation(s)
- R J Giger
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Abstract
SV2 proteins are abundant synaptic vesicle proteins expressed in two major (SV2A and SV2B) and one minor isoform (SV2C) that resemble transporter proteins. We now show that SV2B knockout mice are phenotypically normal while SV2A- and SV2A/SV2B double knockout mice exhibit severe seizures and die postnatally. In electrophysiological recordings from cultured hippocampal neurons, SV2A- or SV2B-deficient cells exhibited no detectable abnormalities. Neurons lacking both SV2 isoforms, however, experienced sustained increases in Ca2+-dependent synaptic transmission when two or more action potentials were triggered in succession. These increases could be reversed by EGTA-AM. Our data suggest that without SV2 proteins, presynaptic Ca2+ accumulation during consecutive action potentials causes abnormal increases in neurotransmitter release that destabilize synaptic circuits and induce epilepsy.
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Affiliation(s)
- R Janz
- Howard Hughes Medical Institute, Center for Basic Neuroscience and Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas 75235, USA
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37
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Mayer R, Mielke G, Oettling G, Geppert M, Stoll P, Wallwiener D. Sonographisch gesteuerte Hochgeschwindigkeitsstanzbiopsien der Mamma. Eine Gegenüberstellung von Histologie, Hormonrezeptorfärbung sowie Expression von Ki-67 an Stanzbiopsien und Operationspräparaten. Geburtshilfe Frauenheilkd 1999. [DOI: 10.1055/s-1999-5983] [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: 10/17/2022] Open
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38
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Schlüter OM, Schnell E, Verhage M, Tzonopoulos T, Nicoll RA, Janz R, Malenka RC, Geppert M, Südhof TC. Rabphilin knock-out mice reveal that rabphilin is not required for rab3 function in regulating neurotransmitter release. J Neurosci 1999; 19:5834-46. [PMID: 10407024 PMCID: PMC6783077] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/1999] [Revised: 04/27/1999] [Accepted: 04/27/1999] [Indexed: 02/13/2023] Open
Abstract
Rab3A and rab3C are GTP-binding proteins of synaptic vesicles that regulate vesicle exocytosis. Rabphilin is a candidate rab3 effector at the synapse because it binds to rab3s in a GTP-dependent manner, it is co-localized with rab3s on synaptic vesicles, and it dissociates with rab3s from the vesicles during exocytosis. Rabphilin contains two C(2) domains, which could function as Ca(2+) sensors in exocytosis and is phosphorylated as a function of stimulation. However, it is unknown what essential function, if any, rabphilin performs. One controversial question regards the respective roles of rab3s and rabphilin in localizing each other to synaptic vesicles: although rabphilin is mislocalized in rab3A knock-out mice, purified synaptic vesicles were shown to require rabphilin for binding of rab3A but not rab3A for binding of rabphilin. To test whether rabphilin is involved in localizing rab3s to synaptic vesicles and to explore the functions of rabphilin in regulating exocytosis, we have now analyzed knock-out mice for rabphilin. Mice that lack rabphilin are viable and fertile without obvious physiological impairments. In rabphilin-deficient mice, rab3A is targeted to synaptic vesicles normally, whereas in rab3A-deficient mice, rabphilin transport to synapses is impaired. These results show that rabphilin binds to vesicles via rab3s, consistent with an effector function of rabphilin for a synaptic rab3-signal. Surprisingly, however, no abnormalities in synaptic transmission or plasticity were observed in rabphilin-deficient mice; synaptic properties that are impaired in rab3A knock-out mice were unchanged in rabphilin knock-out mice. Our data thus demonstrate that rabphilin is endowed with the properties of a rab3 effector but is not essential for the regulatory functions of rab3 in synaptic transmission.
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Affiliation(s)
- O M Schlüter
- Abteilung Molekulare Neurobiologie, Max-Planck-Institut für Experimentelle Medizin, 37075 Goettingen, Germany
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Abstract
Synaptic vesicle exocytosis occurs in consecutive steps: docking, which specifically attaches vesicles to the active zone; priming, which makes the vesicles competent for Ca(2+)-triggered release and may involve a partial fusion reaction; and the final Ca(2+)-regulated step that completes fusion. Recent evidence suggests that the critical regulation of the last step in the reaction is mediated by two proteins with opposite actions: synaptotagmin, a Ca(2+)-binding protein that is essential for Ca(2+)-triggered release and probably serves as the Ca(2+)-sensor in fusion, and rab3, which limits the number of vesicles that can be fused as a function of Ca2+ in order to allow a temporally limited, repeatable signal.
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Affiliation(s)
- M Geppert
- Abteilung Molekulare Neurobiologie, Max-Planck-Institut für experimentelle Medizin, Göttingen, Germany
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Geppert M, Khvotchev M, Krasnoperov V, Goda Y, Missler M, Hammer RE, Ichtchenko K, Petrenko AG, Südhof TC. Neurexin I alpha is a major alpha-latrotoxin receptor that cooperates in alpha-latrotoxin action. J Biol Chem 1998; 273:1705-10. [PMID: 9430716 DOI: 10.1074/jbc.273.3.1705] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
alpha-Latrotoxin is a potent neurotoxin from black widow spider venom that binds to presynaptic receptors and causes massive neurotransmitter release. A surprising finding was the biochemical description of two distinct cell surface proteins that bind alpha-latrotoxin with nanomolar affinities; Neurexin I alpha binds alpha-latrotoxin in a Ca(2+)-dependent manner, and CIRL/latrophilin binds in a Ca(2+)-independent manner. We have now generated and analyzed mice that lack neurexin I alpha to test its importance in alpha-latrotoxin action. alpha-Latrotoxin binding to brain membranes from mutant mice was decreased by almost 50% compared with wild type membranes; the decrease was almost entirely due to a loss of Ca(2+)-dependent alpha-latrotoxin binding sites. In cultured hippocampal neurons, alpha-latrotoxin was still capable of activating neurotransmission in the absence of neurexin I alpha. Direct measurements of [3H]glutamate release from synaptosomes, however, showed a major decrease in the amount of release triggered by alpha-latrotoxin in the presence of Ca2+. Thus neurexin I alpha is not essential for alpha-latrotoxin action but contributes to alpha-latrotoxin action when Ca2+ is present. Viewed as a whole, our results show that mice contain two distinct types of alpha-latrotoxin receptors with similar affinities and abundance but different properties and functions. The action of alpha-latrotoxin may therefore be mediated by independent parallel pathways, of which the CIRL/latrophilin pathway is sufficient for neurotransmitter release, whereas the neurexin I alpha pathway contributes to the Ca(2+)-dependent action of alpha-latrotoxin.
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Affiliation(s)
- M Geppert
- Max-Planck-Institut für Experimentelle Medizin, Göttingen, Germany
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41
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Abstract
The Rab family of low-molecular-mass GTP-binding proteins are thought to guide membrane fusion between a transport vesicle and the target membrane, and to determine the specificity of docking. The docking and fusion of vesicles is, however, a complex multistep reaction, and the precise point at which Rab proteins act in these sequential processes is unknown. In brain, the Rab protein Rab3A is specific to synaptic vesicles, whose exocytosis can be monitored with submillisecond resolution by following synaptic transmission. We have now determined the precise point at which Rab3A acts in the sequence of synaptic vesicle docking and fusion by using electrophysiological analysis of neurotransmitter release in Rab3A-deficient mice. Unexpectedly, the size of the readily releasable pool of vesicles is normal, whereas Ca2+-triggered fusion is altered in the absence of Rab3A in that a more-than-usual number of exocytic events occur within a brief time after arrival of the nerve impulse.
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Affiliation(s)
- M Geppert
- Max Planck Institute for Experimental Medicine, Gottingen, Germany
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42
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Smyczek-Gargya B, Volz B, Geppert M, Dietl J. A multivariate analysis of clinical and morphological prognostic factors in squamous cell carcinoma of the vulva. Gynecol Obstet Invest 1997; 43:261-7. [PMID: 9194626 DOI: 10.1159/000291869] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Clinical and histological data of 168 patients with squamous cell carcinoma of the vulva were analyzed with respect to survival. 151 patients underwent surgery, 12 patients were treated with primary radiation and in 5 patients no treatment was performed. Follow-up lasted from at least 2 up to 22 years' posttreatment. In univariate analysis, the following factors were highly significant: presurgery lymph node status, tumor infiltration beyond the vulva, tumor grading, histological inguinal lymph node status, pre- and postsurgery tumor stage, depth of invasion and tumor diameter. In the multivariate analysis (Cox regression), the most powerful factors were shown to be histological inguinal lymph node status, tumor diameter and tumor grading. The multivariate logistic regression analysis worked out as main prognostic factors for metastases of inguinal lymph nodes: presurgery inguinal lymph node status, tumor size, depth of invasion and tumor grading. Based on these results, tumor biology seems to be the decisive factor concerning recurrence and survival. Therefore, we suggest a more conservative treatment of vulvar carcinoma. Patients with confined carcinoma to the vulva, with a tumor diameter up to 3 cm and without clinical suspected lymph nodes, should be treated by wide excision/partial vulvectomy with ipsilateral lymphadenectomy.
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Affiliation(s)
- B Smyczek-Gargya
- Department of Obstetrics and Gynecology, University of Tbingen, Germany
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43
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Nandy A, Geppert M, Waldschütz R, Lehle G. The anti-Dextran response of scid mice transgenic for the heavy chain of a Dextran specific IgM antibody. Cell Immunol 1996; 170:168-77. [PMID: 8660815 DOI: 10.1006/cimm.1996.0149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mice homozygous for the scid mutation bear a severe defect in their ability to rearrange V(D)J gene segments to yield active genes for immunoglobulin and T cell receptor molecules. In older animals few clones of B and T cells can arise at random, a phenomenon called leakyness of the scid mutation. We established scid mice carrying as a transgene the rearranged heavy chain of the IgM/lambda1 antibody MOPC 104E with specificity for the alpha(1,3) glucosidic linkages in Dextran. Despite the scid defect one-third of these mice immunized with the thymus independent antigen Dextran at 2 weeks of age, and all of those immunized at 6 weeks responded with anti-Dextran antibodies bearing the lambda light chain. This indicates that despite the scid mutation these animals had at least once successfully rearranged their endogenous lambda1 light chain gene segments and harbor Dextran specific B cells. These mice thus provided for the first time the opportunity to study the immune response of B cells of a single specificity in an environment that should, as we shall argue, be devoid of regulatory B and T cells able to recognize the idiotype of the responding cells. One week after immunization the anti-Dextran response of 5- to 6-week-old mu-transgenic scid mice amounted to 30% of the response of mu-transgenic non-scid mice but in essence both responses followed the same kinetics, reaching antibody concentrations indistinguishable from each other 8 weeks after a single dose of Dextran. Furthermore, the ready response of young mu-transgenic scid mice to this antigen by employment of endogenously rearranged lambda1 light chains allowed experiments to be done to compare the frequency of lambda1 light chain rearrangements in mu-transgenic scid mice to that in mu-transgenic non-scid mice. This was done in limiting dilution assays counting B cell precursors responsive to mitogen and differentiating in vitro to produce antibodies toward Dextran. Specific precursors were reduced to about 1% in the spleen of mu-transgenic scid mice when compared to the spleen of mu-transgenic non-scid mice; those in the peritoneal cavity lymphocyte population were reduced to about 12%.
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Affiliation(s)
- A Nandy
- Fakultät für Biologie, Universität Konstanz, Germany
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44
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Abstract
143 cases of serous ovarian cystadenocarcinoma were studied to establish the prognostic relevance of specific macroscopic and microscopic criteria. Significant differences in the survival rate were found depending on TNM classification, age, residual tumor mass, ascites, and degree of invasion. The prognosis was significantly better for normotypical or predominantly cystic tumors as well as for those with mononuclear infiltration, little histological atypia, or limited invasion. No prognostic relevance was found, however, for cytologic criteria such as Broder's grading and rate of mitosis.
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Affiliation(s)
- M Geppert
- Department of Obstetrics and Gynecology, University of Tübingen, Germany
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45
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Abstract
At least four forms of synaptotagmin are expressed in neurons. Of these, synaptotagmin I has an essential function in mediating Ca(2+)-triggered neurotransmitter release at hippocampal synapses, but the functional implications of multiple synaptotagmins are unknown. Synaptotagmins I-III exhibit a strikingly differential distribution between synapses, with most neurons coexpressing either synaptotagmins I or II with III. Synaptotagmin IV is present uniformly throughout the brain at low levels. Synaptotagmins III and IV are both coexpressed with synaptotagmin I in hippocampal synapses, suggesting that these synaptotagmins are not functionally redundant. The first C2 domains of synaptotagmins I-III exhibit similar Ca2+ affinities in phospholipid-binding assays, whereas that of synaptotagmin IV is unable to bind Ca2+. All synaptotagmins tested bind the clathrin-adaptor protein AP-2 with high affinity. Our results suggest that different synaptotagmins serve distinct but overlapping functions in neuronal membrane traffic, with synaptotagmins I and II representing alternative Ca2+ sensors in exocytosis and all synaptotagmins functioning as AP-2 receptors in endocytosis.
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Affiliation(s)
- B Ullrich
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235
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46
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Abstract
Mice carrying a mutation in the synaptotagmin I gene were generated by homologous recombination. Mutant mice are phenotypically normal as heterozygotes, but die within 48 hr after birth as homozygotes. Studies of hippocampal neurons cultured from homozygous mutant mice reveal that synaptic transmission is severely impaired. The synchronous, fast component of Ca(2+)-dependent neurotransmitter release is decreased, whereas asynchronous release processes, including spontaneous synaptic activity (miniature excitatory postsynaptic current frequency) and release triggered by hypertonic solution or alpha-latrotoxin, are unaffected. Our findings demonstrate that synaptotagmin I function is required for Ca2+ triggering of synchronous neurotransmitter release, but is not essential for asynchronous or Ca(2+)-independent release. We propose that synaptotagmin I is the major low affinity Ca2+ sensor mediating Ca2+ regulation of synchronous neurotransmitter release in hippocampal neurons.
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Affiliation(s)
- M Geppert
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235
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47
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Li C, Takei K, Geppert M, Daniell L, Stenius K, Chapman ER, Jahn R, De Camilli P, Südhof TC. Synaptic targeting of rabphilin-3A, a synaptic vesicle Ca2+/phospholipid-binding protein, depends on rab3A/3C. Neuron 1994; 13:885-98. [PMID: 7946335 DOI: 10.1016/0896-6273(94)90254-2] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
rab3A, a low molecular weight GTP-binding protein of synaptic vesicles with a putative function in synaptic vesicle docking, interacts in a GTP-dependent manner with rabphilin-3A, a peripheral membrane protein that binds Ca2+ and phospholipids. We now show that rabphilin-3A is an evolutionarily conserved synaptic vesicle protein that is attached to synaptic vesicle membranes via its N terminus and exhibits a heterogeneous distribution among synapses. In rab3A-deficient mice, rabphilin-3A is decreased in synapses belonging to neurons that primarily express rab3A and accumulates in the perikarya of these neurons. In contrast, neurons expressing significant levels of rab3C still contain normal levels of rabphilin-3A in a synaptic pattern, and rabphilin-3A binds rab3C in vitro. These results suggest that analogous to the membrane recruitment of raf by ras, rab3A and rab3C may function in recruiting rabphilin-3A to the synaptic vesicle membrane in a GTP-dependent manner.
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Affiliation(s)
- C Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235
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48
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Geppert M, Ullrich B, Green DG, Takei K, Daniels L, De Camilli P, Südhof TC, Hammer RE. Synaptic targeting domains of synapsin I revealed by transgenic expression in photoreceptor cells. EMBO J 1994; 13:3720-7. [PMID: 8070400 PMCID: PMC395282 DOI: 10.1002/j.1460-2075.1994.tb06681.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Synapsins are abundant nerve terminal proteins present at all synapses except for ribbon synapses, e.g. photoreceptor cell synapses. Multiple functions have been proposed for synapsins, including clustering of synaptic vesicles and regulation of synaptic vesicle exocytosis. To investigate the physiological functions of synapsin and to ascertain which domains of synapsin are involved in synaptic targeting in vivo, we expressed synapsin Ib and its N- and C-terminal domains in the photoreceptor cells of transgenic mice. In these cells synapsin Ib is targeted efficiently to synaptic vesicles but has no significant effect on the development, structure or physiology of the synapses. This suggests that synapsin I does not have dominant physiological or morphoregulatory functions at these synapses. Full-length synapsin Ib and the N-terminal domains of synapsin Ib but not its C-terminal domains are transported to synapses, revealing that the molecular apparatus for synaptic targeting of synapsins is also present in cells which form ribbon synapses that normally lack synapsins. This apparatus appears to utilize the conserved N-terminal domains that are shared between all synapsins.
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Affiliation(s)
- M Geppert
- Department of Molecular Genetics, University of Texas Southwestern Medical School, Dallas 75235
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49
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Geppert M, Smyczek-Gargya B, Blum S, Schrage R, Menton M. [The value of colposcopy and portio biopsy in preventive examination]. Geburtshilfe Frauenheilkd 1994; 54:394-6. [PMID: 7926570 DOI: 10.1055/s-2007-1022864] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
133 patients attending the colposcopy-laser outpatient consultations were examined simultaneously by cytology, colposcopy and punch biopsy. A cone biopsy was taken 25 patients and one patient was hysterectomised later. A comparison between cytology and histology revealed 17.1% false negative smear results. Cytology and histology showed the same result in 84.6%. The highest percentage of high-grade dysplasia was found in colposcopy with signs of punctation and/or mosaicism. A similar diagnosis was achieved in 92.3% of cases comparing punch with cone biopsy. Simultaneous use of cytology, colposcopy and punch biopsy enables reliable diagnosis and follow-up of dysplastic lesions of the cervix. Besides, one can use punch biopsy as basic histology for local destructive manoeuvres such as laser vaporisation.
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50
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Abstract
The small GTP-binding protein Rab3A is a Rab family member that is abundant in brain synaptic vesicles. Here we show that mice in which the rab3A gene has been mutated by homologous recombination do not express Rab3A but are viable and fertile. Electrophysiological recordings in hippocampal CA1 pyramidal cells indicate that most of their synaptic parameters are also normal, although synaptic depression after short trains of repetitive stimuli (15-30 stimuli at 14 Hz) is significantly increased. Levels of the Rab3A-binding protein rabphilin are decreased by 70%, but expression of more than 20 other synaptic proteins is unchanged. No compensatory changes were detected in other GTP-binding proteins or in proteins that interact with Rab3. Rab3A thus appears not to be essential for synaptic vesicle exocytosis but to play a role in the recruitment of synaptic vesicles for exocytosis during repetitive stimulation.
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Affiliation(s)
- M Geppert
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235
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