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Riehle E, Beach DG, Multrus S, Parmar TP, Martin-Creuzburg D, Dietrich DR. Fate of Planktothrix-derived toxins in aquatic food webs: A case study in Lake Mindelsee (Germany). Ecotoxicol Environ Saf 2024; 273:116154. [PMID: 38422789 DOI: 10.1016/j.ecoenv.2024.116154] [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: 10/11/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/02/2024]
Abstract
Blooms of the red, filamentous cyanobacterium Planktothrix rubescens occur frequently in pre-alpine lakes in Europe, often with concomitant toxic microcystin (MC) production. Trophic transfer of MCs has been observed in bivalves, fish, and zooplankton species, while uptake of MCs into Diptera species could facilitate distribution of MCs into terrestrial food webs and habitats. In this study, we characterized a Planktothrix bloom in summer 2019 in Lake Mindelsee and tracked possible trophic transfer and/or bioaccumulation of MCs via analysis of phytoplankton, zooplankton (Daphnia) and emergent aquatic insects (Chaoborus, Chironomidae and Trichoptera). Using 16 S rRNA gene amplicon sequencing, we found that five sequence variants of Planktothrix spp. were responsible for bloom formation in September and October of 2019, and these MC-producing variants, provisionally identified as P. isothrix and/or P. serta, occurred exclusively in Lake Mindelsee (Germany), while other variants were also detected in nearby Lake Constance. The remaining cyanobacterial community was dominated by Cyanobiaceae species with high species overlap with Lake Constance, suggesting a well-established exchange of cyanobacteria species between the adjacent lakes. With targeted LC-HRMS/MS we identified two MC-congeners, MC-LR and [Asp3]MC-RR with maximum concentrations of 45 ng [Asp3]MC-RR/L in lake water in September. Both MC congeners displayed different predominance patterns, suggesting that two different MC-producing species occurred in a time-dependent manner, whereby [Asp3]MC-RR was clearly associated with the Planktothrix spp. bloom. We demonstrate an exclusive transfer of MC-LR, but not [Asp3]MC-RR, from phytoplankton into zooplankton reaching a 10-fold bioconcentration, yet complete absence of these MC congeners or their conjugates in aquatic insects. The latter demonstrated a limited trophic transfer of MCs from zooplankton to zooplanktivorous insect larvae (e.g., Chaoborus), or direct transfer into other aquatic insects (e.g. Chironomidae and Trichoptera), whether due to avoidance or limited uptake and/or rapid excretion of MCs by higher trophic emergent aquatic insects.
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Affiliation(s)
- Eva Riehle
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany.
| | - Daniel G Beach
- National Research Council Canada, Biotoxin Metrology, 1411 Oxford St., Halifax, Nova Scotia B3H 3Z1, Canada
| | - Selina Multrus
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany
| | - Tarn Preet Parmar
- Brandenburg Technical University (BTU), Cottbus-Senftenberg, Department of Aquatic Ecology, Seestrasse 45, Bad Saarow 15526, Germany
| | - Dominik Martin-Creuzburg
- Brandenburg Technical University (BTU), Cottbus-Senftenberg, Department of Aquatic Ecology, Seestrasse 45, Bad Saarow 15526, Germany
| | - Daniel R Dietrich
- University of Konstanz, Human and Environmental Toxicology Research Group, Universitaetsstrasse 10, Konstanz 78464, Germany.
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Schlichenmaier N, Zielinski A, Beneke S, Dietrich DR. PODO/TERT256 - A promising human immortalized podocyte cell line and its potential use for in vitro research at different oxygen levels. Chem Biol Interact 2024; 387:110813. [PMID: 38006960 DOI: 10.1016/j.cbi.2023.110813] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/27/2023]
Abstract
Podocytes are of key interest for the prediction of nephrotoxicity as they are especially sensitive to toxic insults due to their central role in the glomerular filtration apparatus. However, currently, prediction of nephrotoxicity in humans remains insufficiently reliable, thus highlighting the need for advanced in vitro model systems using human cells with improved prediction capacity. Recent approaches for refining in vitro model systems focus on closely replicating physiological conditions as observed under the in vivo situation typical of the respective nephron section of interest. PODO/TERT256, a human immortalized podocyte cell line, were employed in a semi-static transwell system to evaluate its potential use as a human podocyte in vitro system for modelling potential human glomerular toxicity. Furthermore, the impact of routinely employed excessive oxygen tension (21 % - AtmOx), when compared to the physiological oxygen tensions (10 % - PhysOx) observed in vivo, was analyzed. Generally, cultured PODO/TERT256 formed a stable, contact-inhibited monolayer with typical podocyte morphology (large cell body, apical microvilli, finger-like cytoplasmic projections (reminiscent of foot processes), and interdigitating cell-cell junctions) and developed a size-selective filtration barrier. PhysOx, however, induced a more pronounced in vivo like phenotype, comprised of significantly larger cell bodies, significantly enhanced filtration barrier size-selectivity, and a remarkable re-localization of nephrin to the cell membrane, thus suggesting an improved in vitro replication of in vivo characteristics. Preliminary toxicity characterization with the known glomerulotoxin doxorubicin (DOX) suggested an increasing change in filtration permeability, already at the lowest DOX concentrations tested (0.01 μM) under PhysOx, whereas obvious changes under AtmOx were observed as of 0.16 μM and higher with a near all or nothing effect. The latter findings suggested that PODO/TERT256 could serve as an in vitro human podocyte model for studying glomerulotoxicity, whereby culturing at PhyOx tension appeared critical for an improved in vivo-like phenotype and functionality. Moreover, PODO/TERT256 could be incorporated into advanced human glomerulus systems in vitro, recapitulating microfluidic conditions and multiple cell types (endothelial and mesenchymal cells) that can even better predict human glomerular toxicity.
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Affiliation(s)
- Nadja Schlichenmaier
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany.
| | - Alexander Zielinski
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany.
| | - Sascha Beneke
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany.
| | - Daniel R Dietrich
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany.
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Gori GB, Aschner M, Borgert CJ, Cohen SM, Dietrich DR, Galli CL, Greim H, Heslop-Harrison JS, Kacew S, Kaminski NE, Klaunig JE, Marquardt HWJ, Pelkonen O, Roberts R, Savolainen KM, Tsatsakis A, Yamazaki H. US regulations to curb alleged cancer causes are ineffectual and compromised by scientific, constitutional and ethical violations. Arch Toxicol 2023; 97:1813-1822. [PMID: 37029818 PMCID: PMC10182921 DOI: 10.1007/s00204-022-03429-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 04/09/2023]
Abstract
The 1958 Delaney amendment to the Federal Food Drug and Cosmetics Act prohibited food additives causing cancer in animals by appropriate tests. Regulators responded by adopting chronic lifetime cancer tests in rodents, soon challenged as inappropriate, for they led to very inconsistent results depending on the subjective choice of animals, test design and conduct, and interpretive assumptions. Presently, decades of discussions and trials have come to conclude it is impossible to translate chronic animal data into verifiable prospects of cancer hazards and risks in humans. Such conclusion poses an existential crisis for official agencies in the US and abroad, which for some 65 years have used animal tests to justify massive regulations of alleged human cancer hazards, with aggregated costs of $trillions and without provable evidence of public health advantages. This article addresses suitable remedies for the US and potentially worldwide, by critically exploring the practices of regulatory agencies vis-á-vis essential criteria for validating scientific evidence. According to this analysis, regulations of alleged cancer hazards and risks have been and continue to be structured around arbitrary default assumptions at odds with basic scientific and legal tests of reliable evidence. Such practices raise a manifold ethical predicament for being incompatible with basic premises of the US Constitution, and with the ensuing public expectations of testable truth and transparency from government agencies. Potential remedies in the US include amendments to the US Administrative Procedures Act, preferably requiring agencies to justify regulations compliant with the Daubert opinion of the Daubert ruling of the US Supreme Court, which codifies the criteria defining reliable scientific evidence. International reverberations are bound to follow what remedial actions may be taken in the US, the origin of current world regulatory procedures to control alleged cancer causing agents.
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Affiliation(s)
- Gio B Gori
- Emeritus Director, The Health Policy Center, Bethesda, Maryland, USA.
- Formerly Deputy Director, Division of Cancer Cause and Prevention, National Cancer Institute, Bethesda, Maryland, USA.
| | - Michael Aschner
- Professor of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Christopher J Borgert
- Applied Pharmacology and Toxicology, Inc., Department of Physiological Sciences, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Samuel M Cohen
- Havlik Wall Professor of Oncology, Department of Pathology and Microbiology and Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | - Daniel R Dietrich
- Professor of Human and Environmental Toxicology, Dean of Studies, Faculty of Biology, Konstanz University, Konstanz, Germany
| | - Corrado L Galli
- Professor of Toxicology and Risk Assessment, Department of Pharmacological and Biomolecular Sciences, University of Milan, 20133, Milan, Italy
| | - Helmut Greim
- Professor emeritus of Toxicology and Environmental Health Technical, University of Munich, Munich, Germany
| | | | - Sam Kacew
- McLauglin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, K1N6N5, Canada
| | - Norbert E Kaminski
- Pharmacology & Toxicology, Director, Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - James E Klaunig
- Professor of Environmental Health, Indiana University, Bloomington, Indiana, 47408, USA
| | - Hans W J Marquardt
- Department of Experimental & Clinical Toxicology, University Hamburg Medical School (Retired), Hamburg, Germany
| | - Olavi Pelkonen
- Professor of Pharmacology (Retired), Research Unit of Biomedical Sciences/Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Ruth Roberts
- Apconix Ltd. Chair and Director of Drug Discovery, University of Birmingham, Birmingham, UK
| | | | - Aristidis Tsatsakis
- Chairman of Toxicology and Forensics Departments, University of Crete Medical School, Heraklion, Crete, Greece
| | - Hiroshi Yamazaki
- Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, 194-8543, Japan
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Piossek F, Beneke S, Schlichenmaier N, Mucic G, Drewitz S, Dietrich DR. Physiological oxygen and co-culture with human fibroblasts facilitate in vivo-like properties in human renal proximal tubular epithelial cells. Chem Biol Interact 2022; 361:109959. [DOI: 10.1016/j.cbi.2022.109959] [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] [Received: 11/24/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/28/2022]
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Jaeger-Honz S, Nitschke J, Altaner S, Klein K, Dietrich DR, Schreiber F. Investigation of microcystin conformation and binding towards PPP1 by molecular dynamics simulation. Chem Biol Interact 2022; 351:109766. [PMID: 34861245 DOI: 10.1016/j.cbi.2021.109766] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 11/30/2022]
Abstract
Microcystins (MC) are a group of structurally similar cyanotoxins with currently 279 described structural variants. Human exposure is frequent by consumption of contaminated water, food or food supplements. MC can result in serious intoxications, commensurate with ensuing pathology in various organs or in rare cases even mortality. The current WHO risk assessment primarily considers MC-LR, while all other structural variants are treated as equivalent to MC-LR, despite that current data strongly suggest that MC-LR is not the most toxic MC, and toxicity can be very different for MC congeners. To investigate and analyse binding and conformation of different MC congeners, we applied for the first time Molecular Dynamics (MD) simulation to four MC congeners (MC-LR, MC-LF, [Enantio-Adda5]MC-LF, [β-D-Asp3,Dhb7]MC-RR). We could show that ser/thr protein phosphatase 1 is stable in all MD simulations and that MC-LR backbone adopts to a second conformation in solvent MD simulation, which was previously unknown. We could also show that MC congeners can adopt to different backbone conformation when simulated in solvent or in complex with ser/thr protein phosphatase 1 and differ in their binding behaviour. Our findings suggest that MD Simulation of different MC congeners aid in understanding structural differences and binding of this group of structurally similar cyanotoxins.
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Affiliation(s)
- Sabrina Jaeger-Honz
- Department of Computer and Information Science, University of Konstanz, Germany
| | - Jahn Nitschke
- Department of Biology, University of Konstanz, Germany
| | | | - Karsten Klein
- Department of Computer and Information Science, University of Konstanz, Germany
| | | | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz, Germany; Faculty of Information Technology, Monash University, Australia.
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Fournier C, Riehle E, Dietrich DR, Schleheck D. Is Toxin-Producing Planktothrix sp. an Emerging Species in Lake Constance? Toxins (Basel) 2021; 13:toxins13090666. [PMID: 34564670 PMCID: PMC8472890 DOI: 10.3390/toxins13090666] [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] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 01/04/2023] Open
Abstract
Recurring blooms of filamentous, red-pigmented and toxin-producing cyanobacteria Planktothrix rubescens have been reported in numerous deep and stratified prealpine lakes, with the exception of Lake Constance. In a 2019 and 2020 Lake Constance field campaign, we collected samples from a distinct red-pigmented biomass maximum below the chlorophyll-a maximum, which was determined using fluorescence probe measurements at depths between 18 and 20 m. Here, we report the characterization of these deep water red pigment maxima (DRM) as cyanobacterial blooms. Using 16S rRNA gene-amplicon sequencing, we found evidence that the blooms were, indeed, contributed by Planktothrix spp., although phycoerythrin-rich Synechococcus taxa constituted most of the biomass (>96% relative read abundance) of the cyanobacterial DRM community. Through UPLC-MS/MS, we also detected toxic microcystins (MCs) in the DRM in the individual sampling days at concentrations of ≤1.5 ng/L. Subsequently, we reevaluated the fluorescence probe measurements collected over the past decade and found that, in the summer, DRM have been present in Lake Constance, at least since 2009. Our study highlights the need for a continuous monitoring program also targeting the cyanobacterial DRM in Lake Constance, and for future studies on the competition of the different cyanobacterial taxa. Future studies will address the potential community composition changes in response to the climate change driven physiochemical and biological parameters of the lake.
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Affiliation(s)
- Corentin Fournier
- Microbial Ecology and Limnic Microbiology, University of Konstanz, 78457 Konstanz, Germany;
| | - Eva Riehle
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany;
| | - Daniel R. Dietrich
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany;
- Correspondence: (D.R.D.); (D.S.)
| | - David Schleheck
- Microbial Ecology and Limnic Microbiology, University of Konstanz, 78457 Konstanz, Germany;
- Limnological Institute, University of Konstanz, 78457 Konstanz, Germany
- Correspondence: (D.R.D.); (D.S.)
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7
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Wood SA, Puddick J, Hawes I, Steiner K, Dietrich DR, Hamilton DP. Variability in microcystin quotas during a Microcystis bloom in a eutrophic lake. PLoS One 2021; 16:e0254967. [PMID: 34288957 PMCID: PMC8294494 DOI: 10.1371/journal.pone.0254967] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 07/08/2021] [Indexed: 11/18/2022] Open
Abstract
Microcystis is a bloom-forming genus of cyanobacteria with some genotypes that produce highly toxic microcystin hepatotoxins. In waterbodies where biological and physical factors are relatively homogenous, toxin quotas (the average amount of toxin per cell), at a single point in time, are expected to be relatively constant. In this study we challenged this assumption by investigating the spatial distribution of microcystin quotas at a single point in time on two separate occasions in a lake with a major Microcystis bloom. Microcystis cell concentrations varied widely across the lake on both sampling occasions (730- and 137-fold) together with microcystin quotas (148- and 362-fold). Cell concentrations and microcystin quotas were strongly positively correlated (R2 = 0.89, P < 0.001, n = 28; R2 = 0.67, P < 0.001, n = 25). Analysis of Microcystis strains using high-throughput sequencing of the 16S-23S rRNA intergenic spacer region showed no relationship between microcystin quota and the relative abundance of specific sequences. Collectively, the results of this study indicate an association between microcystin production and cell density that magnifies the potential for bloom toxicity at elevated cell concentrations.
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Affiliation(s)
| | | | - Ian Hawes
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
| | | | | | - David P. Hamilton
- Australian Rivers Institute, Griffith University, Brisbane, Australia
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Monteleone A, Schary W, Wenzel F, Langhals H, Dietrich DR. Label-free identification and differentiation of different microplastics using phasor analysis of fluorescence lifetime imaging microscopy (FLIM)-generated data. Chem Biol Interact 2021; 342:109466. [PMID: 33865829 DOI: 10.1016/j.cbi.2021.109466] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 11/17/2022]
Abstract
As plastic pollution is becoming an increasing worldwide problem, a variety of different techniques for the detection and in-depth characterization of plastics, including spectroscopy and chromatography methods, were introduced to the public. Recently we presented fluorescence lifetime imaging microscopy (FLIM) a new approach for the identification and characterization of microplastics using their fluorescence lifetime (τ) for differentiation. A very powerful extension of the recently established FLIM could be phasor analysis, which allows data representation in an interactive 2D graphical phasor plot thereby enabling a global view of the fluorescence decay in each pixel of the measured image. Microplastic particles generated from six different types of plastics were subjected to excitation wavelengths of 440 nm, upon which specific fluorescence lifetimes as well as the photon yield were determined using FLIM and phasor analysis. We could show that phasor analysis for FLIM with a laser pulse repetition frequency of 40 MHz was able to generate specific locations in the phasor plot for the plastics for fast differentiation, e.g. resulting in well-defined phasor plot positions for ABS at 3.019 ns, PPE at 6.239 ns, PET bottle from Germany at 2.703 ns and PET bottle from USA at 2.711 ns. Phasor analysis for FLIM proves to be a fast, label-free, and sensitive method for the identification and differentiation of plastics also with the aid of visualization variation enabling techniques such as heat treatment of plastics.
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Affiliation(s)
- Adrian Monteleone
- Faculty of Medical and Life Sciences, Hochschule Furtwangen, Villingen-Schwenningen, Germany; Human and Environmental Toxicology, University Konstanz, Constance, Germany
| | - Weronika Schary
- Faculty of Medical and Life Sciences, Hochschule Furtwangen, Villingen-Schwenningen, Germany
| | - Folker Wenzel
- Faculty of Medical and Life Sciences, Hochschule Furtwangen, Villingen-Schwenningen, Germany.
| | - Heinz Langhals
- Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University Konstanz, Constance, Germany.
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Weisbrod B, Riehle E, Helmer M, Martin-Creuzburg D, Dietrich DR. Can toxin warfare against fungal parasitism influence short-term Dolichospermum bloom dynamics? - A field observation. Harmful Algae 2020; 99:101915. [PMID: 33218440 DOI: 10.1016/j.hal.2020.101915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/20/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacterial blooms often consist of numerous co-existing cyanobacterial species, with predominant taxa dynamically varying intra-annually. Parasitism by fungi (chytrids) has come into focus as an important factor driving short-term bloom dynamics. Using microscopic analysis, Illumina sequencing and cyanobacterial toxin analyses, we monitored the seasonal succession of Dolichospermum blooms in a reservoir along with environmental parameters. We identified two consecutive Dolichospermum blooms that were characterized by a straight and a coiled morphotype, separated by a complete bloom collapse. Phylotyping provided evidence for three putative Dolichospermum amplicon sequence variants (ASVs); i.e. Dolichospermum1 & 2 in the first bloom (straight filaments) and Dolichospermum3 in the second bloom (coiled filaments). Morphotype succession as well as total filament concentration did not correlate with any of the measured environmental parameters. Fungal parasitism by the chytrid Rhizosiphon crassum occurred in straight Dolichospermum filaments only. Coiled filaments showed no infection despite ambient presence of chytrids, deduced from fungal ASVs, throughout the entire observation period. Toxin concentrations (microcystins (MCs) and anabaenopeptins) correlated significantly with the abundance of the straight Dolichospermum morphotype. Enhanced cyanotoxin biosynthesis in the straight Dolichospermum morphotype, interpreted as a defensive reaction to fungal parasitism, appeared to come at the expense of lowered competitiveness with the co-occurring coiled morphotype. Our findings support the hypothesis that selective parasitism by chytrids is an important factor driving short-term morphotype and toxin dynamics within cyanobacterial blooms.
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Affiliation(s)
- B Weisbrod
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78464 Konstanz, Germany.
| | - E Riehle
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78464 Konstanz, Germany
| | - M Helmer
- Limnological Institute, University of Konstanz, Mainaustrasse 252, 78464 Konstanz, Germany
| | - D Martin-Creuzburg
- Limnological Institute, University of Konstanz, Mainaustrasse 252, 78464 Konstanz, Germany
| | - D R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78464 Konstanz, Germany
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Klima S, Suciu I, Hoelting L, Gutbier S, Waldmann T, Dietrich DR, Leist M. Examination of microcystin neurotoxicity using central and peripheral human neurons. ALTEX 2020; 38:73-81. [PMID: 32591837 DOI: 10.14573/altex.2003182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/09/2020] [Indexed: 11/23/2022]
Abstract
Microcystins (MC) are a group of cyanobacterial toxins that comprises MC-LF and other cyclic heptapeptides, best known as potent hepatotoxicants. Cell culture and epidemiological studies suggest that MC might also affect the nervous system when there is systemic exposure, e.g., via drinking water or food. We asked whether in vitro studies with human neurons could provide estimates on the neurotoxicity hazard of MC-LF. First, we used LUHMES neurons, a well-established test system for neurotoxicants and neuropathological processes. These central nervous system cells express OATP1A2, a presumed carrier of MC-LF, and we observed selective neurite toxicity in the μM range (EC20 = 3.3 μM ≈ 3.3 μg/mL). Transcriptome changes pointed towards attenuated cell maintenance and biosynthetic processes. Prolonged exposure for up to four days did not increase toxicity. As a second model, we used human dorsal root ganglia-like neurons. These peripheral nervous system cells represent parts of the nervous system not protected by the blood-brain barrier in humans. Toxicity was observed in a similar concentration range (EC20 = 7.4 μM). We conclude that MC-LF poses a potential neurotoxic hazard in humans. The adverse effect concentrations observed here were orders of magnitude higher than those presumed to be encountered after normal nutritional or environmental exposure. However, the low μM concentrations found to be toxic are close to levels that may be reached after very excessive algae supplement intake.
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Affiliation(s)
- Stefanie Klima
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Cooperative doctorate college InViTe, University of Konstanz, Konstanz, Germany
| | - Ilinca Suciu
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany
| | - Lisa Hoelting
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Simon Gutbier
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Tanja Waldmann
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Daniel R Dietrich
- Cooperative doctorate college InViTe, University of Konstanz, Konstanz, Germany.,Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Marcel Leist
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,CAAT-Europe, University of Konstanz, Konstanz, Germany.
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11
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Rovida C, Barton-Maclaren T, Benfenati E, Caloni F, Chandrasekera PC, Chesné C, Cronin MTD, De Knecht J, Dietrich DR, Escher SE, Fitzpatrick S, Flannery B, Herzler M, Hougaard Bennekou S, Hubesch B, Kamp H, Kisitu J, Kleinstreuer N, Kovarich S, Leist M, Maertens A, Nugent K, Pallocca G, Pastor M, Patlewicz G, Pavan M, Presgrave O, Smirnova L, Schwarz M, Yamada T, Hartung T. Internationalization of read-across as a validated new approach method (NAM) for regulatory toxicology. ALTEX 2020; 37:579-606. [PMID: 32369604 PMCID: PMC9201788 DOI: 10.14573/altex.1912181] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/28/2020] [Indexed: 11/23/2022]
Abstract
Read-across (RAx) translates available information from well-characterized chemicals to a substance for which there is a toxicological data gap. The OECD is working on case studies to probe general applicability of RAx, and several regulations (e.g., EU-REACH) already allow this procedure to be used to waive new in vivo tests. The decision to prepare a review on the state of the art of RAx as a tool for risk assessment for regulatory purposes was taken during a workshop with international experts in Ranco, Italy in July 2018. Three major issues were identified that need optimization to allow a higher regulatory acceptance rate of the RAx procedure: (i) the definition of similarity of source and target, (ii) the translation of biological/toxicological activity of source to target in the RAx procedure, and (iii) how to deal with issues of ADME that may differ between source and target. The use of new approach methodologies (NAM) was discussed as one of the most important innovations to improve the acceptability of RAx. At present, NAM data may be used to confirm chemical and toxicological similarity. In the future, the use of NAM may be broadened to fully characterize the hazard and toxicokinetic properties of RAx compounds. Concerning available guidance, documents on Good Read-Across Practice (GRAP) and on best practices to perform and evaluate the RAx process were identified. Here, in particular, the RAx guidance, being worked out by the European Commission’s H2020 project EU-ToxRisk together with many external partners with regulatory experience, is given.
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Affiliation(s)
- Costanza Rovida
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany
| | | | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Francesca Caloni
- Università degli Studi di Milano, Department of Veterinary Medicine (DIMEVET) Milan, Italy
| | | | | | - Mark T D Cronin
- Liverpool John Moores University, School of Pharmacy and Biomolecular Sciences, Liverpool, UK
| | - Joop De Knecht
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Sylvia E Escher
- Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Hannover, Germany
| | - Suzanne Fitzpatrick
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, MD, USA
| | - Brenna Flannery
- US Food and Drug Administration, Center for Food Safety and Applied Nutrition, MD, USA
| | - Matthias Herzler
- German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Susanne Hougaard Bennekou
- Danish Environmental Protection Agency, Copenhagen, Denmark / Danish Technical University, FOOD, Lyngby, Denmark
| | - Bruno Hubesch
- European Chemical Industry Council (Cefic), Brussels, Belgium
| | - Hennicke Kamp
- Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Jaffar Kisitu
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Nicole Kleinstreuer
- NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | | | - Marcel Leist
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany.,In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Alexandra Maertens
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | - Kerry Nugent
- Australian Government Department of Health, Canberra, Australia
| | - Giorgia Pallocca
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Manuel Pastor
- Research Programme on Biomedical Informatics (GRIB), Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Dept. of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Grace Patlewicz
- Center for Computational Toxicology & Exposure (CCTE), U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | - Octavio Presgrave
- Departamento de Farmacologia e Toxicologia, Instituto Nacional de Controle da Qualidade em Saúde, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Lena Smirnova
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | | | | | - Thomas Hartung
- Center for Alternatives to Animal Testing, CAAT-Europe, University of Konstanz, Konstanz, Germany.,Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
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12
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Krebs A, Waldmann T, Wilks MF, Van Vugt-Lussenburg BMA, Van der Burg B, Terron A, Steger-Hartmann T, Ruegg J, Rovida C, Pedersen E, Pallocca G, Luijten M, Leite SB, Kustermann S, Kamp H, Hoeng J, Hewitt P, Herzler M, Hengstler JG, Heinonen T, Hartung T, Hardy B, Gantner F, Fritsche E, Fant K, Ezendam J, Exner T, Dunkern T, Dietrich DR, Coecke S, Busquet F, Braeuning A, Bondarenko O, Bennekou SH, Beilmann M, Leist M. Template for the description of cell-based toxicological test methods to allow evaluation and regulatory use of the data. ALTEX 2020; 36:682-699. [PMID: 31658359 DOI: 10.14573/altex.1909271] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/23/2022]
Abstract
Only few cell-based test methods are described by Organisation for Economic Co-operation and Development (OECD) test guidelines or other regulatory references (e.g., the European Pharmacopoeia). The majority of toxicity tests still falls into the category of non-guideline methods. Data from these tests may nevertheless be used to support regulatory decisions or to guide strategies to assess compounds (e.g., drugs, agrochemicals) during research and development if they fulfill basic requirements concerning their relevance, reproducibility and predictivity. Only a method description of sufficient clarity and detail allows interpretation and use of the data. To guide regulators faced with increasing amounts of data from non-guideline studies, the OECD formulated Guidance Document 211 (GD211) on method documentation for the purpose of safety assessment. As GD211 is targeted mainly at regulators, it leaves scientists less familiar with regulation uncertain as to what level of detail is required and how individual questions should be answered. Moreover, little attention was given to the description of the test system (i.e., cell culture) and the steps leading to it being established in the guidance. To address these issues, an annotated toxicity test method template (ToxTemp) was developed (i) to fulfill all requirements of GD211, (ii) to guide the user concerning the types of answers and detail of information required, (iii) to include acceptance criteria for test elements, and (iv) to define the cells sufficiently and transparently. The fully annotated ToxTemp is provided here, together with reference to a database containing exemplary descriptions of more than 20 cell-based tests.
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Affiliation(s)
- Alice Krebs
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany
| | - Tanja Waldmann
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Martin F Wilks
- Swiss Centre for Applied Human Toxicology, University of Basel, Basel, Switzerland
| | | | | | | | - Thomas Steger-Hartmann
- Investigational Toxicology, Drug Discovery, Pharmaceuticals, Bayer AG, Wuppertal, Germany
| | - Joelle Ruegg
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | | | - Emma Pedersen
- RISE Research Institutes of Sweden, Göteborg, Sweden
| | - Giorgia Pallocca
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Sofia B Leite
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Stefan Kustermann
- F. Hoffmann - La Roche, Pharma Research and Early Development, Pharmaceutical Sciences - Roche Innovation Center, Basel, Switzerland
| | - Hennicke Kamp
- Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Julia Hoeng
- Philip Morris International R&D, Neuchâtel, Switzerland
| | | | - Matthias Herzler
- German Federal Institute for Risk Assessment, Dept. Chemical Safety, Berlin, Germany
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Technical University of Dortmund, Dortmund, Germany
| | - Tuula Heinonen
- FICAM, Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland
| | - Thomas Hartung
- CAAT-Europe, University of Konstanz, Konstanz, Germany.,Johns Hopkins University, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
| | - Barry Hardy
- Edelweiss Connect GmbH, Technology Park Basel, Basel, Switzerland
| | - Florian Gantner
- Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Kristina Fant
- RISE Research Institutes of Sweden, Göteborg, Sweden
| | - Janine Ezendam
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Thomas Exner
- Edelweiss Connect GmbH, Technology Park Basel, Basel, Switzerland
| | | | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Francois Busquet
- CAAT-Europe, University of Konstanz, Konstanz, Germany.,ALTERTOX SPRL, Ixelles, Bruxelles, Belgium
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Dept. Food Safety, Berlin, Germany
| | - Olesja Bondarenko
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Susanne H Bennekou
- The National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Mario Beilmann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Nonclinical Drug Safety, Biberach, Germany
| | - Marcel Leist
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany.,CAAT-Europe, University of Konstanz, Konstanz, Germany
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13
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Altaner S, Jaeger S, Fotler R, Zemskov I, Wittmann V, Schreiber F, Dietrich DR. Erratum to Machine learning prediction of cyanobacterial toxin (microcystin) toxicodynamics in humans. ALTEX 2020; 37:337-338. [PMID: 32242643 DOI: 10.14573/altex.1904031e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 11/23/2022]
Abstract
In this manuscript, which appeared in ALTEX (2020), 37(1), 24-36, doi:10.14573/altex.1904031 , there were errors in Tables 1 and 3.
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Affiliation(s)
- Stefan Altaner
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Sabrina Jaeger
- Life Science Informatics, University of Konstanz, Konstanz, Germany
| | - Regina Fotler
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Ivan Zemskov
- Organic and Bioorganic Chemistry, University of Konstanz, Konstanz, Germany
| | - Valentin Wittmann
- Organic and Bioorganic Chemistry, University of Konstanz, Konstanz, Germany
| | - Falk Schreiber
- Life Science Informatics, University of Konstanz, Konstanz, Germany.,Faculty of IT, Monash University, Melbourne, Australia
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
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14
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Krebs A, Waldmann T, Wilks MF, Van Vugt-Lussenburg BMA, Van der Burg B, Terron A, Steger-Hartmann T, Ruegg J, Rovida C, Pedersen E, Pallocca G, Luijten M, Leite SB, Kustermann S, Kamp H, Hoeng J, Hewitt P, Herzler M, Hengstler JG, Heinonen T, Hartung T, Hardy B, Gantner F, Fritsche E, Fant K, Ezendam J, Exner T, Dunkern T, Dietrich DR, Coecke S, Busquet F, Braeuning A, Bondarenko O, Bennekou SH, Beilmann M, Leist M. Erratum to Template for the description of cell-based toxicological test methods to allow evaluation and regulatory use of the data. ALTEX 2020; 37:164. [PMID: 31960940 DOI: 10.14573/altex.1909271e] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this manuscript, which appeared in ALTEX (2019), 36(4), 682- 699, doi:10.14573/altex.1909271 , the affiliation of Hennicke Kamp should be Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany. Further, the reference to an article by Bal-Price et al. (2015) should have the following doi:10.1007/s00204-015-1464-2 .
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Affiliation(s)
- Alice Krebs
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany
| | - Tanja Waldmann
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany
| | - Martin F Wilks
- Swiss Centre for Applied Human Toxicology, University of Basel, Basel, Switzerland
| | | | | | | | - Thomas Steger-Hartmann
- Investigational Toxicology, Drug Discovery, Pharmaceuticals, Bayer AG, Wuppertal, Germany
| | - Joelle Ruegg
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | | | - Emma Pedersen
- RISE Research Institutes of Sweden, Göteborg, Sweden
| | - Giorgia Pallocca
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Sofia B Leite
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Stefan Kustermann
- F. Hoffmann - La Roche, Pharma Research and Early Development, Pharmaceutical Sciences - Roche Innovation Center, Basel, Switzerland
| | - Hennicke Kamp
- Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
| | - Julia Hoeng
- Philip Morris International R&D, Neuchâtel, Switzerland
| | | | - Matthias Herzler
- German Federal Institute for Risk Assessment, Dept. Chemical Safety, Berlin, Germany
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Technical University of Dortmund, Dortmund, Germany
| | - Tuula Heinonen
- FICAM, Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland
| | - Thomas Hartung
- CAAT-Europe, University of Konstanz, Konstanz, Germany.,Johns Hopkins University, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
| | - Barry Hardy
- Edelweiss Connect GmbH, Technology Park Basel, Basel, Switzerland
| | - Florian Gantner
- Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Kristina Fant
- RISE Research Institutes of Sweden, Göteborg, Sweden
| | - Janine Ezendam
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Thomas Exner
- Edelweiss Connect GmbH, Technology Park Basel, Basel, Switzerland
| | | | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Francois Busquet
- CAAT-Europe, University of Konstanz, Konstanz, Germany.,ALTERTOX SPRL, Ixelles, Bruxelles, Belgium
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Dept. Food Safety, Berlin, Germany
| | - Olesja Bondarenko
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Susanne H Bennekou
- The National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Mario Beilmann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Nonclinical Drug Safety, Biberach, Germany
| | - Marcel Leist
- In vitro Toxicology and Biomedicine, Dept inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Konstanz, Germany.,CAAT-Europe, University of Konstanz, Konstanz, Germany
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15
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Altaner S, Jaeger S, Fotler R, Zemskov I, Wittmann V, Schreiber F, Dietrich DR. Machine learning prediction of cyanobacterial toxin (microcystin) toxicodynamics in humans. ALTEX 2019; 37:24-36. [PMID: 31280325 DOI: 10.14573/altex.1904031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/27/2019] [Indexed: 11/23/2022]
Abstract
Microcystins (MC) represent a family of cyclic peptides with approx. 250 congeners presumed harmful to human health due to their ability to inhibit ser/thr-proteinphosphatases (PPP), albeit all hazard and risk assessments (RA) are based on data of one MC-congener (MC-LR) only. MC congener structural diversity is a challenge for the risk assessment of these toxins, especially as several different PPPs have to be included in the RA. Consequently, the inhibition of PPP1, PPP2A and PPP5 was determined with 18 structurally different MC and demonstrated MC congener dependent inhibition activity and a lower susceptibility of PPP5 to inhibition than PPP1 and PPP2A. The latter data were employed to train a machine learning algorithm that should allow prediction of PPP inhibition (toxicity) based on MCs 2D chemical structure. IC50 values were classified in toxicity classes and three machine learning models were used to predict the toxicity class, resulting in 80-90% correct predictions.
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Affiliation(s)
- Stefan Altaner
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Sabrina Jaeger
- Life Science Informatics, University of Konstanz, Germany
| | - Regina Fotler
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Ivan Zemskov
- Organic and Bioorganic Chemistry, University of Konstanz, Germany
| | | | - Falk Schreiber
- Life Science Informatics, University of Konstanz, Germany.,Faculty of IT, Monash University, Melbourne, Australia
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
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16
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Bastek H, Zubel T, Stemmer K, Mangerich A, Beneke S, Dietrich DR. Comparison of Aristolochic acid I derived DNA adduct levels in human renal toxicity models. Toxicology 2019; 420:29-38. [DOI: 10.1016/j.tox.2019.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/22/2019] [Accepted: 03/28/2019] [Indexed: 01/28/2023]
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17
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Secker PF, Beneke S, Schlichenmaier N, Delp J, Gutbier S, Leist M, Dietrich DR. Canagliflozin mediated dual inhibition of mitochondrial glutamate dehydrogenase and complex I: an off-target adverse effect. Cell Death Dis 2018; 9:226. [PMID: 29445145 PMCID: PMC5833677 DOI: 10.1038/s41419-018-0273-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [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: 08/15/2017] [Revised: 12/20/2017] [Accepted: 12/27/2017] [Indexed: 12/23/2022]
Abstract
Recent FDA Drug Safety Communications report an increased risk for acute kidney injury in patients treated with the gliflozin class of sodium/glucose co-transport inhibitors indicated for treatment of type 2 diabetes mellitus. To identify a potential rationale for the latter, we used an in vitro human renal proximal tubule epithelial cell model system (RPTEC/TERT1), physiologically representing human renal proximal tubule function. A targeted metabolomics approach, contrasting gliflozins to inhibitors of central carbon metabolism and mitochondrial function, revealed a double mode of action for canagliflozin, but not for its analogs dapagliflozin and empagliflozin. Canagliflozin inhibited the glutamate dehydrogenase (GDH) and mitochondrial electron transport chain (ETC) complex I at clinically relevant concentrations. This dual inhibition specifically prevented replenishment of tricarboxylic acid cycle metabolites by glutamine (anaplerosis) and thus altered amino acid pools by increasing compensatory transamination reactions. Consequently, canagliflozin caused a characteristic intracellular accumulation of glutamine, glutamate and alanine in confluent, quiescent RPTEC/TERT1. Canagliflozin, but none of the classical ETC inhibitors, induced cytotoxicity at particularly low concentrations in proliferating RPTEC/TERT1, serving as model for proximal tubule regeneration in situ. This finding is testimony of the strong dependence of proliferating cells on glutamine anaplerosis via GDH. Our discovery of canagliflozin-mediated simultaneous inhibition of GDH and ETC complex I in renal cells at clinically relevant concentrations, and their particular susceptibility to necrotic cell death during proliferation, provides a mechanistic rationale for the adverse effects observed especially in patients with preexisting chronic kidney disease or previous kidney injury characterized by sustained regenerative tubular epithelial cell proliferation.
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Affiliation(s)
- Philipp F Secker
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany
| | - Sascha Beneke
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany
| | - Nadja Schlichenmaier
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany
| | - Johannes Delp
- In-vitro Toxicology and Biomedicine, University of Konstanz, 78457, Konstanz, Germany
| | - Simon Gutbier
- In-vitro Toxicology and Biomedicine, University of Konstanz, 78457, Konstanz, Germany
| | - Marcel Leist
- In-vitro Toxicology and Biomedicine, University of Konstanz, 78457, Konstanz, Germany
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, 78457, Konstanz, Germany.
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18
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Kleinteich J, Hildebrand F, Bahram M, Voigt AY, Wood SA, Jungblut AD, Küpper FC, Quesada A, Camacho A, Pearce DA, Convey P, Vincent WF, Zarfl C, Bork P, Dietrich DR. Pole-to-Pole Connections: Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00137] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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19
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Bond GG, Dietrich DR. Further thoughts on limitations, uncertainties and competing interpretations regarding chemical exposures and diabetes. J Epidemiol Community Health 2017; 71:943. [PMID: 28689177 PMCID: PMC5561354 DOI: 10.1136/jech-2017-209451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 05/20/2017] [Indexed: 11/04/2022]
Affiliation(s)
| | - Daniel R Dietrich
- Department of Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
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20
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Bond GG, Dietrich DR. Human cost burden of exposure to endocrine disrupting chemicals. A critical review. Arch Toxicol 2017; 91:2745-2762. [PMID: 28528477 DOI: 10.1007/s00204-017-1985-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/08/2017] [Indexed: 01/01/2023]
Abstract
Recently published papers have alleged that exposures to endocrine disrupting chemicals (EDCs) are causing substantial disease burdens in the EU and US and are consequently costing society hundreds of billions of dollars annually. To date, these cost estimates have not undergone adequate scientific scrutiny, but nevertheless are being used aggressively in advocacy campaigns in an attempt to fundamentally change how chemicals are tested, evaluated and regulated. Consequently, we critically evaluated the underlying methodology and assumptions employed by the chief architects of the disease burden cost estimates. Since the vast majority of their assigned disease burden costs are driven by the assumption that "loss of IQ" and "increased prevalence of intellectual disability" are caused by exposures to organophosphate pesticides (OPPs) and brominated flame retardants (PBDEs), we have taken special care in describing and evaluating the underlying toxicology and epidemiology evidence that was relied upon. Unfortunately, our review uncovered substantial flaws in the approach taken and the conclusions that were drawn. Indeed, the authors of these papers assumed causal relationships between putative exposures to EDCs and selected diseases, i.e., "loss of IQ" and "increased prevalence of intellectual disability", despite not having established them via a thorough evaluation of the strengths and weaknesses of the underlying animal toxicology and human epidemiology evidence. Consequently, the assigned disease burden costs are highly speculative and should not be considered in the weight of evidence approach underlying any serious policy discussions serving to protect the public and regulate chemicals considered as EDCs.
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Affiliation(s)
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Constance, Germany
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21
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Altaner S, Puddick J, Wood SA, Dietrich DR. Adsorption of Ten Microcystin Congeners to Common Laboratory-Ware Is Solvent and Surface Dependent. Toxins (Basel) 2017; 9:toxins9040129. [PMID: 28383495 PMCID: PMC5408203 DOI: 10.3390/toxins9040129] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/23/2017] [Accepted: 03/31/2017] [Indexed: 11/21/2022] Open
Abstract
Cyanobacteria can produce heptapetides called microcystins (MC) which are harmful to humans due to their ability to inhibit cellular protein phosphatases. Quantitation of these toxins can be hampered by their adsorption to common laboratory-ware during sample processing and analysis. Because of their structural diversity (>100 congeners) and different physico-chemical properties, they vary in their adsorption to surfaces. In this study, the adsorption of ten different MC congeners (encompassing non-arginated to doubly-arginated congeners) to common laboratory-ware was assessed using different solvent combinations. Sample handling steps were mimicked with glass and polypropylene pipettes and vials with increasing methanol concentrations at two pH levels, before analysis by liquid chromatography-tandem mass spectrometry. We demonstrated that MC adsorb to polypropylene surfaces irrespective of pH. After eight successive pipet actions using polypropylene tips ca. 20% of the MC were lost to the surface material, which increased to 25%–40% when solutions were acidified. The observed loss was alleviated by changing the methanol (MeOH) concentration in the final solvent. The required MeOH concentration varied depending on which congener was present. Microcystins only adsorbed to glass pipettes (loss up to 30% after eight pipet actions) when in acidified aqueous solutions. The latter appeared largely dependent on the presence of ionizable groups, such as arginine residues.
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Affiliation(s)
- Stefan Altaner
- Human and Environmental Toxicology, University of Konstanz, P.O. Box 662, 78457 Konstanz, Germany.
| | | | - Susanna A Wood
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, P.O. Box 662, 78457 Konstanz, Germany.
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22
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Klaus V, Bastek H, Damme K, Collins LB, Frötschl R, Benda N, Lutter D, Ellinger-Ziegelbauer H, Swenberg JA, Dietrich DR, Stemmer K. Time-matched analysis of DNA adduct formation and early gene expression as predictive tool for renal carcinogenesis in methylazoxymethanol acetate treated Eker rats. Arch Toxicol 2017; 91:3427-3438. [PMID: 28349193 DOI: 10.1007/s00204-017-1953-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 03/01/2017] [Indexed: 11/28/2022]
Abstract
Genotoxic carcinogens pose great hazard to human health. Uncertainty of current risk assessment strategies and long latency periods between first carcinogen exposure and diagnosis of tumors have raised interest in predictive biomarkers. Initial DNA adduct formation is a necessary step for genotoxin induced carcinogenesis. However, as DNA adducts not always translate into tumorigenesis, their predictive value is limited. Here we hypothesize that the combined analysis of pro-mutagenic DNA adducts along with time-matched gene expression changes could serve as a superior prediction tool for genotoxic carcinogenesis. Eker rats, heterozygous for the tuberous sclerosis (Tsc2) tumor suppressor gene and thus highly susceptible towards genotoxic renal carcinogens, were continuously treated with the DNA alkylating carcinogen methylazoxymethanol acetate (MAMAc). Two weeks of MAMAc treatment resulted in a time-dependent increase of O6-methylguanine and N7-methylguanine adducts in the kidney cortex, which was however not reflected by significant expression changes of cyto-protective genes involved in DNA repair, cell cycle arrest or apoptosis. Instead, we found a transcriptional regulation of genes involved in the tumor-related MAPK, FoxO and TGF-beta pathways. Continuous MAMAc treatment for up to 6 months resulted in a mild but significant increase of cancerous lesions. In summary, the combined analysis of DNA adducts and early gene expression changes could serve as a suitable predictive tool for genotoxicant-induced carcinogenesis.
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Affiliation(s)
- Valentina Klaus
- Computational Discovery Research, Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany
| | - Heinke Bastek
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Katja Damme
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Leonard B Collins
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Roland Frötschl
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - Norbert Benda
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - Dominik Lutter
- Computational Discovery Research, Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany
| | | | - James A Swenberg
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Kerstin Stemmer
- Metabolism and Cancer, Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany.
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Abstract
Microcystins (MCs) are highly toxic natural products which are produced by cyanobacteria. They can be released to the water during harmful algal blooms and are a serious threat to animals and humans. Described is the total synthesis of the cyanotoxin microcystin-LF (MC-LF, 1a) and two derivatives thereof. Deuterated derivative 1b is of interest as an internal standard during MC quantification in biological samples by mass spectrometry and alkyne-labeled 1c can be employed for toxin derivatization by click chemistry with an azide-containing reporter molecule or as an activity-based probe to identify interaction partners. Application of tert-butyl ester protecting groups for erythro-β-d-methylaspartic acid and γ-d-glutamic acid were key for an isomerization-free synthesis. The analytical data of synthetic MC-LF were identical to those of an authentic sample of the natural product. All derivatives 1a-c were determined to be potent inhibitors of protein phosphatase-1 with similar activity.
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Affiliation(s)
- Ivan Zemskov
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz , 78457 Konstanz, Germany
| | - Stefan Altaner
- Department of Biology and Graduate School Biological Sciences (GBS), University of Konstanz , 78457 Konstanz, Germany
| | - Daniel R Dietrich
- Department of Biology and Graduate School Biological Sciences (GBS), University of Konstanz , 78457 Konstanz, Germany
| | - Valentin Wittmann
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz , 78457 Konstanz, Germany
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24
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Affiliation(s)
- Daniel R Dietrich
- Human and Environmental Toxicology, Faculty of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Constance, Germany.
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
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25
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Bond GG, Dietrich DR. Limitations, uncertainties and competing interpretations regarding chemical exposures and diabetes. J Epidemiol Community Health 2017; 71:941. [PMID: 28264881 PMCID: PMC5561358 DOI: 10.1136/jech-2016-208711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 11/17/2022]
Affiliation(s)
| | - Daniel R Dietrich
- University of Konstanz-Human and Environmental Toxicology, Konstanz, Germany
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26
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Wood SA, Maier MY, Puddick J, Pochon X, Zaiko A, Dietrich DR, Hamilton DP. Trophic state and geographic gradients influence planktonic cyanobacterial diversity and distribution in New Zealand lakes. FEMS Microbiol Ecol 2016; 93:fiw234. [PMID: 27856621 DOI: 10.1093/femsec/fiw234] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/01/2016] [Accepted: 11/16/2016] [Indexed: 11/14/2022] Open
Abstract
Cyanobacteria are commonly associated with eutrophic lakes, where they often form blooms and produce toxins. However, they are a ubiquitous component of phytoplankton in lakes of widely varying trophic status. We hypothesised that cyanobacterial diversity would vary among lakes of differing trophic status, but that the relative importance of geographical and hydromorphological characteristics driving these patterns would differ across trophic groups. DNA from 143 New Zealand lakes that spanned a range of geographic, hydromorphological and trophic gradients was analysed using automated rRNA intergenic spacer analysis and screened for genes involved in cyanotoxin production. Statistical analysis revealed significant delineation among cyanobacterial communities from different trophic classes. Multivariate regression indicated that geographical features (latitude, longitude and altitude) were significant in driving cyanobacterial community structure; however, partitioning of their effects varied among trophic categories. High-throughput sequencing was undertaken on selected samples to investigate their taxonomic composition. The most abundant and diverse (71 operational taxonomic units) taxon across all lake types was the picocyanobacteria genus Synechococcus Cyanotoxins (microcystins n = 23, anatoxins n = 1) were only detected in eutrophic lowland lakes. Collectively, these data infer that increasing eutrophication of lakes will have broad-scale impacts on planktonic cyanobacteria diversity and the prevalence of cyanotoxins.
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Affiliation(s)
- Susanna A Wood
- Cawthron Institute, Nelson 7010, New Zealand .,Environmental Research Institute, University of Waikato, Hamilton 3240, New Zealand
| | - Marcia Y Maier
- Cawthron Institute, Nelson 7010, New Zealand.,Faculty of Biology, University of Konstanz, Konstanz, D-78457, Germany
| | | | - Xavier Pochon
- Cawthron Institute, Nelson 7010, New Zealand.,Institute of Marine Science, University of Auckland, Auckland 1142, New Zealand
| | - Anastasija Zaiko
- Cawthron Institute, Nelson 7010, New Zealand.,Marine Science and Technology Center, Klaipeda University, Klaipeda LT-92294, Lithuania
| | - Daniel R Dietrich
- Faculty of Biology, University of Konstanz, Konstanz, D-78457, Germany
| | - David P Hamilton
- Environmental Research Institute, University of Waikato, Hamilton 3240, New Zealand
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27
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Dietrich DR, Dekant W, Greim H, Heslop-Harrison P, Berry SC, Boobis A, Hengstler J, Sharpe R. Allowing pseudoscience into EU risk assessment processes is eroding public trust in science experts and in science as a whole: The bigger picture. Chem Biol Interact 2016; 257:1-3. [DOI: 10.1016/j.cbi.2016.07.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Wolf JC, Dietrich DR, Friederich U, Caunter J, Brown AR. Qualitative and Quantitative Histomorphologic Assessment of Fathead Minnow Pimephales promelas Gonads as an Endpoint for Evaluating Endocrine-Active Compounds: A Pilot Methodology Study. Toxicol Pathol 2016; 32:600-12. [PMID: 15603544 DOI: 10.1080/01926230490515201] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Although histopathology is routinely employed as a tool for the detection and assessment of xenobiotic-mediated effects in mammals, it is less frequently applied to fish. In part, this is due to a lack of method standardization regarding study design, tissue preservation, tissue sectioning, histopathological evaluation, reporting, and statistical analysis. The objectives of the present study were: (1) to test and refine a method for the microsurgical excision of fathead minnow (FHM) Pimephales promelas gonads for the purpose of histopathologic examination; (2) to determine the optimal combination of fixation and embedding procedures for the histopathologic and morphometric analysis of FHM gonads following exposure to a known estrogenic compound, 17 β-estradiol (E2); and (3) to provide a method for the categorization and quantification of cell types in FHM gonads by manually counting cells in digitized images using image analysis software. The light microscopic evaluation of individual gametogenic cells was greatly facilitated by specimen preparation techniques that included the excision of gonads via microdissection and by optimized fixation and embedding procedures.
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29
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Luks L, Sacchi S, Pollegioni L, Dietrich DR. Novel insights into renal D-amino acid oxidase accumulation: propiverine changes DAAO localization and peroxisomal size in vivo. Arch Toxicol 2016; 91:427-437. [PMID: 26961980 DOI: 10.1007/s00204-016-1685-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/22/2016] [Indexed: 11/29/2022]
Abstract
Chronic exposure to propiverine, a frequently prescribed pharmaceutical for treatment of overactive bladder and incontinence, provokes massive protein accumulation in the cytosol and nucleus of renal proximal tubule epithelial cells in rats. Previously, the accumulating protein was identified as D-amino acid oxidase (DAAO), a peroxisomal flavoenzyme expressed in kidney, liver and brain. The cellular mechanism of propiverine-induced DAAO accumulation, however, remains unexplained and poorly characterized. Therefore, to further increase the understanding of DAAO accumulation in rat kidney, this study aimed to characterize DAAO accumulations using differential immunofluorescent staining of rat kidney sections as well as in vitro binding analyses and proteasomal activity studies. We demonstrated that propiverine is neither a ligand of DAAO nor an inhibitor of the proteasome in vitro. However, propiverine treatment resulted in a significant decrease of peroxisomal size in rat proximal tubule epithelial cells. Moreover, peroxisomal catalase also accumulated in the cytosol and nuclei of propiverine-treated rats concurrently with DAAO. Taken together, our study indicates that propiverine treatment affects the trafficking and/or degradation of peroxisomal proteins such as DAAO and catalase by a so far unique and unknown mechanism.
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Affiliation(s)
- Lisanne Luks
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457, Constance, Germany
| | - Silvia Sacchi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,The Protein Factory Research Center, Politecnico di Milano and University of Insubria, Milan, Varese, Italy
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy.,The Protein Factory Research Center, Politecnico di Milano and University of Insubria, Milan, Varese, Italy
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457, Constance, Germany.
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30
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Abstract
The scent of blood is potentially one of the most fundamental and survival-relevant olfactory cues in humans. This experiment tests the first human parameters of perceptual threshold and emotional ratings in men and women of an artificially simulated smell of fresh blood in contact with the skin. We hypothesize that this scent of blood, with its association with injury, danger, death, and nutrition will be a critical cue activating fundamental motivational systems relating to either predatory approach behavior or prey-like withdrawal behavior, or both. The results show that perceptual thresholds are unimodally distributed for both sexes, with women being more sensitive. Furthermore, both women and men’s emotional responses to simulated blood scent divide strongly into positive and negative valence ratings, with negative ratings in women having a strong arousal component. For women, this split is related to the phase of their menstrual cycle and oral contraception (OC). Future research will investigate whether this split in both genders is context-dependent or trait-like.
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Affiliation(s)
- James K. Moran
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
- * E-mail:
| | - Daniel R. Dietrich
- Department of Human and Environmental Toxicology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Thomas Elbert
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Bettina M. Pause
- Biological Psychology and Social Psychology, Heinrich-Heine University, Düsseldorf, North Rhine-Westphalia, Germany
| | - Lisa Kübler
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Roland Weierstall
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
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31
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Rogers S, Puddick J, Wood SA, Dietrich DR, Hamilton DP, Prinsep MR. The effect of cyanobacterial biomass enrichment by centrifugation and GF/C filtration on subsequent microcystin measurement. Toxins (Basel) 2015; 7:821-34. [PMID: 25763766 PMCID: PMC4379527 DOI: 10.3390/toxins7030821] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 02/10/2015] [Accepted: 03/02/2015] [Indexed: 11/26/2022] Open
Abstract
Microcystins are cyclic peptides produced by multiple cyanobacterial genera. After accumulation in the liver of animals they inhibit eukaryotic serine/threonine protein phosphatases, causing liver disease or death. Accurate detection/quantification of microcystins is essential to ensure safe water resources and to enable research on this toxin. Previous methodological comparisons have focused on detection and extraction techniques, but have not investigated the commonly used biomass enrichment steps. These enrichment steps could modulate toxin production as recent studies have demonstrated that high cyanobacterial cell densities cause increased microcystin levels. In this study, three microcystin-producing strains were processed using no cell enrichment steps (by direct freezing at three temperatures) and with biomass enrichment (by centrifugation or GF/C filtration). After extraction, microcystins were analyzed using liquid chromatography-tandem mass spectrometry. All processing methods tested, except GF/C filtration, resulted in comparable microcystin quotas for all strains. The low yields observed for the filtration samples were caused by adsorption of arginine-containing microcystins to the GF/C filters. Whilst biomass enrichment did not affect microcystin metabolism over the time-frame of normal sample processing, problems associated with GF/C filtration were identified. The most widely applicable processing method was direct freezing of samples as it could be utilized in both field and laboratory environments.
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Affiliation(s)
- Shelley Rogers
- Department of Chemistry, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | | | - Susanna A Wood
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
- Cawthron Institute, Private Bag 2, Nelson 7010, New Zealand.
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, P.O. Box 662, 78457 Konstanz, Germany.
| | - David P Hamilton
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Michele R Prinsep
- Department of Chemistry, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
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32
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van der Burg B, Wedebye EB, Dietrich DR, Jaworska J, Mangelsdorf I, Paune E, Schwarz M, Piersma AH, Kroese ED. The ChemScreen project to design a pragmatic alternative approach to predict reproductive toxicity of chemicals. Reprod Toxicol 2015; 55:114-23. [PMID: 25656794 DOI: 10.1016/j.reprotox.2015.01.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 12/29/2014] [Accepted: 01/22/2015] [Indexed: 01/28/2023]
Abstract
There is a great need for rapid testing strategies for reproductive toxicity testing, avoiding animal use. The EU Framework program 7 project ChemScreen aimed to fill this gap in a pragmatic manner preferably using validated existing tools and place them in an innovative alternative testing strategy. In our approach we combined knowledge on critical processes affected by reproductive toxicants with knowledge on the mechanistic basis of such effects. We used in silico methods for prescreening chemicals for relevant toxic effects aiming at reduced testing needs. For those chemicals that need testing we have set up an in vitro screening panel that includes mechanistic high throughput methods and lower throughput assays that measure more integrative endpoints. In silico pharmacokinetic modules were developed for rapid exposure predictions via diverse exposure routes. These modules to match in vitro and in vivo exposure levels greatly improved predictivity of the in vitro tests. As a further step, we have generated examples how to predict reproductive toxicity of chemicals using available data. We have executed formal validations of panel constituents and also used more innovative manners to validate the test panel using mechanistic approaches. We are actively engaged in promoting regulatory acceptance of the tools developed as an essential step towards practical application, including case studies for read-across purposes. With this approach, a significant saving in animal use and associated costs seems very feasible.
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Affiliation(s)
| | | | | | | | | | | | | | - Aldert H Piersma
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands; Utrecht University, Utrecht, The Netherlands
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33
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Shams S, Capelli C, Cerasino L, Ballot A, Dietrich DR, Sivonen K, Salmaso N. Anatoxin-a producing Tychonema (Cyanobacteria) in European waterbodies. Water Res 2015; 69:68-79. [PMID: 25437339 DOI: 10.1016/j.watres.2014.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [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: 08/22/2014] [Revised: 10/14/2014] [Accepted: 11/07/2014] [Indexed: 06/04/2023]
Abstract
In order to identify the cyanobacterial species responsible of anatoxin-a (ATX) production in Lake Garda (Northern Italy), an intensive isolation and culturing of filamentous cyanobacteria were established since 2014 from environmental samples. In this work, we report a detailed account of the strategy adopted, which led to the discovery of a new unexpected producer of ATX, Tychonema bourrellyi. So far, this species is the first documented example of cultured Oscillatoriales able to produce ATX isolated from pelagic freshwater ecosystems. The isolated filaments were identified adopting a polyphasic approach, which included microscopic species identification, genetic characterisation and phylogenetic analyses based on 16S rRNA genes. The taxonomic identification was further confirmed by the high (>99%) rbcLX sequence similarities of the T. bourrellyi strains of Lake Garda with those deposited in DNA sequence databases. More than half of the isolates were shown to produce a significant amount of ATX, with cell quota ranging between 0.1 and 2.6 μg mm(-3), and 0.01 and 0.35 pg cell(-1). The toxic isolates were tested positive for anaC of the anatoxin-a synthetase (ana) gene cluster. These findings were confirmed with the discovery of one ATX producing T. bourrellyi strain isolated in Norway. This strain and a further non-ATX producing Norwegian Tychonema bornetii strain tested positive for the presence of the anaF gene of the ana gene cluster. Conversely, none of the Italian and Norwegian Tychonema strains were positive for microcystins (MCs), which was also confirmed by the absence of mcyE PCR products in all the samples analysed. This work suggests that the only reliable strategy to identify cyanotoxins producers should be based on the isolation of strains and their identification with a polyphasic approach associated to a concurrent metabolomic profiling.
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Affiliation(s)
- S Shams
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige - Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy; Human and Environmental Toxicology Group, Department of Biology, University of Konstanz, P.O. Box X-622, D-78457 Konstanz, Germany
| | - C Capelli
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige - Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy; Department of Biology, University of Florence, Via La Pira 4, 50121 Florence, Italy
| | - L Cerasino
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige - Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy
| | - A Ballot
- Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway
| | - D R Dietrich
- Human and Environmental Toxicology Group, Department of Biology, University of Konstanz, P.O. Box X-622, D-78457 Konstanz, Germany
| | - K Sivonen
- Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, P.O.Box 56, Biocenter 1 Viikki (Viikinkaari 9), FIN-00014, Helsinki University, Finland
| | - N Salmaso
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige - Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy.
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Heussner AH, Altaner S, Kamp L, Rubio F, Dietrich DR. Pitfalls in microcystin extraction and recovery from human blood serum. Chem Biol Interact 2014; 223:87-94. [DOI: 10.1016/j.cbi.2014.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 08/20/2014] [Accepted: 08/22/2014] [Indexed: 10/24/2022]
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35
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Steiner K, Hagenbuch B, Dietrich DR. Molecular cloning and functional characterization of a rainbow trout liver Oatp. Toxicol Appl Pharmacol 2014; 280:534-42. [PMID: 25218291 DOI: 10.1016/j.taap.2014.08.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 01/06/2023]
Abstract
Cyanobacterial blooms have an impact on the aquatic ecosystem due to the production of toxins (e.g. microcystins, MCs), which constrain fish health or even cause fish death. However the toxicokinetics of the most abundant toxin, microcystin-LR (MC-LR), are not yet fully understood. To investigate the uptake mechanism, the novel Oatp1d1 in rainbow trout (rtOatp1d1) was cloned, identified and characterized. The cDNA isolated from a clone library consisted of 2772bp containing a 2115bp open reading frame coding for a 705 aa protein with an approximate molecular mass of 80kDa. This fish specific transporter belongs to the OATP1 family and has most likely evolved from a common ancestor of OATP1C1. Real time PCR analysis showed that rtOatp1d1 is predominantly expressed in the liver, followed by the brain while expression in other organs was not detectable. Transient transfection in HEK293 cells was used for further characterization. Like its human homologues OATP1A1, OATP1B1 and OATP1B3, rtOatp1d1 displayed multi-specific transport including endogenous and xenobiotic substrates. Kinetic analyses revealed a Km value of 13.9μM and 13.4μM for estrone-3-sulfate and methotrexate, respectively and a rather low affinity for taurocholate with a Km value of 103μM. Furthermore, it was confirmed that rtOatp1d1 is a MC-LR transporter and therefore most likely plays a key role in the susceptibility of rainbow trout to MC intoxications.
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Affiliation(s)
- Konstanze Steiner
- University of Konstanz, Human- and Environmental Toxicology, 78464 Konstanz, Germany.
| | - Bruno Hagenbuch
- Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City 66160, KS, USA.
| | - Daniel R Dietrich
- University of Konstanz, Human- and Environmental Toxicology, 78464 Konstanz, Germany.
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Shams S, Cerasino L, Salmaso N, Dietrich DR. Experimental models of microcystin accumulation in Daphnia magna grazing on Planktothrix rubescens: implications for water management. Aquat Toxicol 2014; 148:9-15. [PMID: 24440453 DOI: 10.1016/j.aquatox.2013.12.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 09/10/2013] [Revised: 11/27/2013] [Accepted: 12/22/2013] [Indexed: 06/03/2023]
Abstract
In this study, we investigated the kinetic aspects of the microcystin (MC) transfer from Planktothrix rubescens to Daphnia magna by carrying out exposure experiments in small simple mesocosms. We hypothesized that higher fractions of toxic cyanobacteria in the diet of grazers would shift the balance towards a greater than linear, i.e. non-linear accumulation of MC in D. magna. This hypothesis was tested by exposing D. magna to varying initial densities of MC-producing P. rubescens. The evolving models of MC accumulation differed largely as a result of the duration of exposure and initial MC concentrations used. Within the first 24h of exposure, MC accumulation in D. magna was linear, irrespective of the initial densities of toxic P. rubescens and thus MC concentrations. After 48 h of exposure, MC accumulation in D. magna showed an exponential pattern, possibly due to a delayed digestion of P. rubescens and/or decreased MC detoxification capabilities when compared with higher ambient concentrations of MC. After 72 h toxin concentrations in Daphnia drop in all experiments as a consequence of the reduced cyanobacterial cells in the medium and the detoxification of MC within Daphnia. The results obtained suggest that in lakes with higher MC content and longer cyanobacterial bloom period MC accumulation in D. magna should be more pronounced than in mesotrophic lakes with lower MC content. The latter interpretation, however, should be verified investigating accumulation of MC both in larger mesocosms and in situ, in lakes of different trophic status.
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Affiliation(s)
- Shiva Shams
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige, Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy; Human and Environmental Toxicology Group, Department of Biology, University of Konstanz, P.O. Box X-918, D-78457 Konstanz, Germany.
| | - Leonardo Cerasino
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige, Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy
| | - Nico Salmaso
- IASMA Research and Innovation Centre, Istituto Agrario di S. Michele all'Adige, Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige (Trento), Italy
| | - Daniel R Dietrich
- Human and Environmental Toxicology Group, Department of Biology, University of Konstanz, P.O. Box X-918, D-78457 Konstanz, Germany
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Dietrich DR, von Aulock S, Marquardt H, Blaauboer B, Dekant W, Kehrer J, Hengstler J, Collier A, Gori GB, Pelkonen O, Lang F, Nijkamp FP, Stemmer K, Li A, Savolainen K, Hayes AW, Gooderham N, Harvey A, Barile FA. Scientifically unfounded precaution drives European Commission's recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. Toxicon 2013; 76:A1-A2. [PMID: 24409469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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Heussner AH, Dietrich DR. Primary porcine proximal tubular cells as an alternative to human primary renal cells in vitro: an initial characterization. BMC Cell Biol 2013; 14:55. [PMID: 24308307 PMCID: PMC4234457 DOI: 10.1186/1471-2121-14-55] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 11/28/2013] [Indexed: 02/07/2023] Open
Abstract
Background A good in vitro model should approximate an in vivo-like behavior as closely as possible in order to reflect most likely the in vivo situation. Regarding renal physiology of different species, humans are more closely related to pigs than to rodents, therefore primary porcine kidney cells (PKC) and their subsequent cell strain could be a valid alternative to primary human cells for renal in vitro toxicology. For this PKC must display inherent characteristics (e.g. structural organization) and functions (e.g. transepithelial transport) as observed under in vivo conditions within the respective part of the kidney. Results We carried out a comprehensive characterization of PKC and their subsequent cell strain, including morphology and growth as well as transporter expression and functionality. The data presented here demonstrate that PKC express various transporters including pMrp1 (abcc1), pMrp2 (abcc2), pOat1 (slc22a6) and pOat3 (slc22a8), whereas pMdr1 (abcb1) and pOatp1a2 (slco1a2) mRNA could not be detected in either the PKCs or in the porcine cortical tissue. Functionality of the transporters was demonstrated by determining the specific PAH transport kinetics. Conclusions On the basis of the presented results it can be concluded that PKC and to some extent their subsequent cell strain represent a valuable model for in vitro toxicology, which might be used as an alternative to human primary cells.
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Affiliation(s)
| | - Daniel R Dietrich
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany.
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Dietrich DR. Editorial (for "The billboard"). Chem Biol Interact 2013; 206:A1. [PMID: 24103855 DOI: 10.1016/j.cbi.2013.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Daniel R Dietrich
- University of Konstanz, Human and Environmental Toxicology, Jacob-Burckhardtstr. 25, 78457 Konstanz, Germany.
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Dietrich DR, von Aulock S, Marquardt H, Blaauboer B, Dekant W, Kehrer J, Hengstler J, Collier A, Batta Gori G, Pelkonen O, Lang F, Nijkamp FP, Stemmer K, Li A, Savolainen K, Wallace Hayes A, Gooderham N, Harvey A. Scientifically unfounded precaution drives European Commission's recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. ALTEX 2013; 30:381-5. [PMID: 23861084 DOI: 10.14573/altex.2013.3.381] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Foley JF, Dietrich DR, Swenberg JA, Maronpot RR. Detection and Evaluation of Proliferating Cell Nuclear Antigen (PCNA) in Rat Tissue by an Improved Immunohistochemical Procedure. J Histotechnol 2013. [DOI: 10.1179/his.1991.14.4.237] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Dietrich DR, von Aulock S, Marquardt H, Blaauboer B, Dekant W, Kehrer J, Hengstler J, Collier A, Gori GB, Pelkonen OP, Lang F, Nijkamp FP, Stemmer K, Li A, Savolainen K, Hayes AW, Gooderham N, Harvey A. Scientifically unfounded precaution drives European Commission's recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. Toxicol In Vitro 2013; 27:2110-4. [PMID: 23850741 DOI: 10.1016/j.tiv.2013.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dietrich DR, von Aulock S, Marquardt H, Blaauboer B, Dekant W, Kehrer J, Hengstler J, Collier A, Gori GB, Pelkonen O, Lang F, Nijkamp FP, Stemmer K, Li A, Savolainen K, Hayes AW, Gooderham N, Harvey A. Scientifically unfounded precaution drives European Commission's recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. Food Chem Toxicol 2013; 62:A1-4. [PMID: 23835284 DOI: 10.1016/j.fct.2013.07.005] [Citation(s) in RCA: 3] [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: 10/26/2022]
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Dietrich DR, Aulock SV, Marquardt H, Blaauboer B, Dekant W, Kehrer J, Hengstler J, Collier A, Gori GB, Pelkonen O, Lang F, Barile FA, Nijkamp FP, Stemmer K, Li A, Savolainen K, Hayes AW, Gooderham N, Harvey A. Scientifically unfounded precaution drives European Commission's recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. Chem Biol Interact 2013; 205:A1-5. [PMID: 23832050 DOI: 10.1016/j.cbi.2013.07.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gauggel-Lewandowski S, Heussner AH, Steinberg P, Pieterse B, van der Burg B, Dietrich DR. Bioavailability and potential carcinogenicity of polycyclic aromatic hydrocarbons from wood combustion particulate matter in vitro. Chem Biol Interact 2013; 206:411-22. [PMID: 23796820 DOI: 10.1016/j.cbi.2013.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/03/2013] [Accepted: 05/28/2013] [Indexed: 11/16/2022]
Abstract
Due to increasing energy demand and limited fossil fuels, renewable energy sources have gained in importance. Particulate matter (PM) in general, but also PM from the combustion of wood is known to exert adverse health effects in human. These are often related to specific toxic compounds adsorbed to the PM surface, such as polycyclic aromatic hydrocarbons (PAH), of which some are known human carcinogens. This study focused on the bioavailability of PAHs and on the tumor initiation potential of wood combustion PM, using the PAH CALUX® reporter gene assay and the BALB/c 3T3 cell transformation assay, respectively. For this, both cell assays were exposed to PM and their respective organic extracts from varying degrees of combustion. The PAH CALUX® experiments demonstrated a concentration-response relationship matching the PAHs detected in the samples. Contrary to expectations, PM samples from complete (CC) and incomplete combustion (IC) provided for a stronger and weaker response, respectively, suggesting that PAH were more readily bioavailable in PM from CC. These findings were corroborated via PAH spiking experiments indicating that IC PM contains organic components that strongly adsorb PAH thereby reducing their bioavailability. The results obtained with organic extracts in the cell transformation assay presented the highest potential for carcinogenicity in samples with high PAH contents, albeit PM from CC also demonstrated a carcinogenic potential. In conclusion, the in vitro assays employed emphasize that CC produces PM with low PAH content however with a general higher bioavailability and thus with a nearly similar carcinogenic potential than IC PM.
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Okle O, Rath L, Galizia CG, Dietrich DR. The cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) induces neuronal and behavioral changes in honeybees. Toxicol Appl Pharmacol 2013; 270:9-15. [PMID: 23591064 DOI: 10.1016/j.taap.2013.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/02/2013] [Accepted: 04/04/2013] [Indexed: 10/27/2022]
Abstract
The cyanobacterially produced neurotoxin beta-N-methylamino-l-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using (14)C-BMAA we demonstrated that BMAA is biologically available to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca(2+) homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA.
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Affiliation(s)
- Oliver Okle
- Human and Environmental Toxicology, University of Konstanz, Jacob-Burckhardt-Strasse 25, 78457 Konstanz, Germany.
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Heussner AH, Mazija L, Fastner J, Dietrich DR. Toxin content and cytotoxicity of algal dietary supplements. Toxicol Appl Pharmacol 2012; 265:263-71. [PMID: 23064102 DOI: 10.1016/j.taap.2012.10.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [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: 08/08/2012] [Revised: 09/27/2012] [Accepted: 10/06/2012] [Indexed: 11/19/2022]
Abstract
Blue-green algae (Spirulina sp., Aphanizomenon flos-aquae) and Chlorella sp. are commercially distributed as organic algae dietary supplements. Cyanobacterial dietary products in particular have raised serious concerns, as they appeared to be contaminated with toxins e.g. microcystins (MCs) and consumers repeatedly reported adverse health effects following consumption of these products. The aim of this study was to determine the toxin contamination and the in vitro cytotoxicity of algae dietary supplement products marketed in Germany. In thirteen products consisting of Aph. flos-aquae, Spirulina and Chlorella or mixtures thereof, MCs, nodularins, saxitoxins, anatoxin-a and cylindrospermopsin were analyzed. Five products tested in an earlier market study were re-analyzed for comparison. Product samples were extracted and analyzed for cytotoxicity in A549 cells as well as for toxin levels by (1) phosphatase inhibition assay (PPIA), (2) Adda-ELISA and (3) LC-MS/MS. In addition, all samples were analyzed by PCR for the presence of the mcyE gene, a part of the microcystin and nodularin synthetase gene cluster. Only Aph. flos-aquae products were tested positive for MCs as well as the presence of mcyE. The contamination levels of the MC-positive samples were ≤ 1 μg MC-LR equivalents g(-1) dw. None of the other toxins were found in any of the products. However, extracts from all products were cytotoxic. In light of the findings, the distribution and commercial sale of Aph. flos-aquae products, whether pure or mixed formulations, for human consumption appear highly questionable.
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Affiliation(s)
- A H Heussner
- Human and Environmental Toxicology, University of Konstanz, 78457 Konstanz, Germany
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Okle O, Stemmer K, Deschl U, Dietrich DR. L-BMAA Induced ER Stress and Enhanced Caspase 12 Cleavage in Human Neuroblastoma SH-SY5Y Cells at Low Nonexcitotoxic Concentrations. Toxicol Sci 2012; 131:217-24. [DOI: 10.1093/toxsci/kfs291] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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50
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Stemmer K, Perez-Tilve D, Ananthakrishnan G, Bort A, Seeley RJ, Tschöp MH, Dietrich DR, Pfluger PT. High-fat-diet-induced obesity causes an inflammatory and tumor-promoting microenvironment in the rat kidney. Dis Model Mech 2012; 5:627-35. [PMID: 22422828 PMCID: PMC3424460 DOI: 10.1242/dmm.009407] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Obesity and concomitant comorbidities have emerged as public health problems of the first order. For instance, obese individuals have an increased risk for kidney cancer. However, direct mechanisms linking obesity with kidney cancer remain elusive. We hypothesized that diet-induced obesity (DIO) promotes renal carcinogenesis by inducing an inflammatory and tumor-promoting microenvironment. We compared chow-fed lean Wistar rats with those that were sensitive (DIOsens) or partially resistant (DIOres) to DIO to investigate the impact of body adiposity versus dietary nutrient overload in the development of renal preneoplasia and activation of tumor-promoting signaling pathways. Our data clearly show a correlation between body adiposity, the severity of nephropathy, and the total number and incidence of preneoplastic renal lesions. However, similar plasma triglyceride, plasma free fatty acid and renal triglyceride levels were found in chow-fed, DIOres and DIOsens rats, suggesting that lipotoxicity is not a critical contributor to the renal pathology. Obesity-related nephropathy was further associated with regenerative cell proliferation, monocyte infiltration and higher renal expression of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-6, IL-6 receptor and leptin receptor. Accordingly, we observed increased signal transducer and activator of transcription 3 (STAT3) and mammalian target of rapamycin (mTOR) phosphorylation in tubules with preneoplastic phenotypes. In summary, our results demonstrate that high body adiposity induces an inflammatory and proliferative microenvironment in rat kidneys that promotes the development of preneoplastic lesions, potentially via activation of the STAT3 and mTOR signaling pathways.
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Affiliation(s)
- Kerstin Stemmer
- Department of Internal Medicine, Metabolic Diseases Institute, University of Cincinnati, Division of Endocrinology and Metabolism, 2170 East Galbraith Road, Building E, Cincinnati, OH 45237, USA.
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