TY - JOUR A1 - Meyer, S. A1 - Raber, G. A1 - Ebert, Franziska A1 - Leffers, L. A1 - Müller, Sandra Marie A1 - Taleshi, M. S. A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites JF - Toxicology research N2 - Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMAV, DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at μM concentrations. DMAV causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMAV in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids. Y1 - 2015 U6 - https://doi.org/10.1039/c5tx00122f SN - 2045-4538 VL - 5 IS - 4 SP - 1289 EP - 1296 PB - Royal Society of Chemistry CY - Cambridge ER - TY - GEN A1 - Meyer, S. A1 - Raber, G. A1 - Ebert, Franziska A1 - Leffers, L. A1 - Müller, Sandra Marie A1 - Taleshi, M. S. A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites N2 - Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMAV, DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at μM concentrations. DMAV causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMAV in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 199 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-82008 ER - TY - JOUR A1 - Zhou, Suqiong A1 - Pan, Yuanwei A1 - Zhang, Jianguang A1 - Li, Yan A1 - Neumann, Falko A1 - Schwerdtle, Tanja A1 - Li, Wenzhong A1 - Haag, Rainer T1 - Dendritic polyglycerol-conjugated gold nanostars with different densities of functional groups to regulate osteogenesis in human mesenchymal stem cells JF - Nanoscale N2 - Nanomaterials play an important role in mimicking the biochemical and biophysical cues of the extracellular matrix in human mesenchymal stem cells (MSCs). Increasing studies have demonstrated the crucial impact of functional groups on MSCs, while limited research is available on how the functional group's density on nanoparticles regulates MSC behavior. Herein, the effects of dendritic polyglycerol (dPG)-conjugated gold nanostars (GNSs) with different densities of functional groups on the osteogenesis of MSCs are systematically investigated. dPG@GNS nanocomposites have good biocompatibility and the uptake by MSCs is in a functional group density-dependent manner. The osteogenic differentiation of MSCs is promoted by all dPG@GNS nanocomposites, in terms of alkaline phosphatase activity, calcium deposition, and expression of osteogenic protein and genes. Interestingly, the dPGOH@GNSs exhibit a slight upregulation in the expression of osteogenic markers, while the different charged densities of sulfate and amino groups show more efficacy in the promotion of osteogenesis. Meanwhile, the sulfated nanostars dPGS20@GNSs show the highest enhancement. Furthermore, various dPG@GNS nanocomposites exerted their effects by regulating the activation of Yes-associated protein (YAP) to affect osteogenic differentiation. These results indicate that dPG@GNS nanocomposites have functional group density-dependent influence on the osteogenesis of MSCs, which may provide a new insight into regulating stem cell fate. Y1 - 2020 U6 - https://doi.org/10.1039/d0nr06570f SN - 2040-3364 SN - 2040-3372 VL - 12 IS - 47 SP - 24006 EP - 24019 PB - Royal Society of Chemistry CY - Cambridge ER - TY - GEN A1 - Müller, Sandra A1 - Dawczynski, Christine A1 - Wiest, Johanna A1 - Lorkowski, Stefan A1 - Kipp, Anna Patricia A1 - Schwerdtle, Tanja T1 - Functional Biomarkers for the Selenium Status in a Human Nutritional Intervention Study T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Soils in Germany are commonly low in selenium; consequently, a sufficient dietary supply is not always ensured. The extent of such provision adequacy is estimated by the optimal effect range of biomarkers, which often reflects the physiological requirement. Preceding epidemiological studies indicate that low selenium serum concentrations could be related to cardiovascular diseases. Inter alia, risk factors for cardiovascular diseases are physical inactivity, overweight, as well as disadvantageous eating habits. In order to assess whether these risk factors can be modulated, a cardio-protective diet comprising fixed menu plans combined with physical exercise was applied in the German MoKaRi (modulation of cardiovascular risk factors) intervention study. We analyzed serum samples of the MoKaRi cohort (51 participants) for total selenium, GPx activity, and selenoprotein P at different timepoints of the study (0, 10, 20, 40 weeks) to explore the suitability of these selenium-associated markers as indicators of selenium status. Overall, the time-dependent fluctuations in serum selenium concentration suggest a successful change in nutritional and lifestyle behavior. Compared to baseline, a pronounced increase in GPx activity and selenoprotein P was observed, while serum selenium decreased in participants with initially adequate serum selenium content. SELENOP concentration showed a moderate positive monotonic correlation (r = 0.467, p < 0.0001) to total Se concentration, while only a weak linear relationship was observed for GPx activity versus total Se concentration (r = 0.186, p = 0.021). Evidently, other factors apart from the available Se pool must have an impact on the GPx activity, leading to the conclusion that, without having identified these factors, GPx activity should not be used as a status marker for Se T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 878 KW - Se KW - selenoprotein P KW - GPx activity KW - cardiovascular disease KW - status markers Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460115 SN - 1866-8372 IS - 878 ER - TY - GEN A1 - Witt, Barbara A1 - Schaumlöffel, Dirk A1 - Schaumlöffel, Dirk A1 - Schwerdtle, Tanja T1 - Subcellular Localization of Copper BT - Cellular Bioimaging with Focus on Neurological Disorders T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - As an essential trace element, copper plays a pivotal role in physiological body functions. In fact, dysregulated copper homeostasis has been clearly linked to neurological disorders including Wilson and Alzheimer’s disease. Such neurodegenerative diseases are associated with progressive loss of neurons and thus impaired brain functions. However, the underlying mechanisms are not fully understood. Characterization of the element species and their subcellular localization is of great importance to uncover cellular mechanisms. Recent research activities focus on the question of how copper contributes to the pathological findings. Cellular bioimaging of copper is an essential key to accomplish this objective. Besides information on the spatial distribution and chemical properties of copper, other essential trace elements can be localized in parallel. Highly sensitive and high spatial resolution techniques such as LA-ICP-MS, TEM-EDS, S-XRF and NanoSIMS are required for elemental mapping on subcellular level. This review summarizes state-of-the-art techniques in the field of bioimaging. Their strengths and limitations will be discussed with particular focus on potential applications for the elucidation of copper-related diseases. Based on such investigations, further information on cellular processes and mechanisms can be derived under physiological and pathological conditions. Bioimaging studies might enable the clarification of the role of copper in the context of neurodegenerative diseases and provide an important basis to develop therapeutic strategies for reduction or even prevention of copper-related disorders and their pathological consequences. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 862 KW - copper KW - cellular bioimaging KW - neurodegenerative diseases KW - copper-related disorders KW - SIMS techniques KW - TEM KW - S-XRF Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459544 SN - 1866-8372 IS - 862 ER - TY - GEN A1 - Maares, Maria A1 - Keil, Claudia A1 - Koza, Jenny A1 - Straubing, Sophia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - In Vitro Studies on Zinc Binding and Buffering by Intestinal Mucins T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The investigation of luminal factors influencing zinc availability and accessibility in the intestine is of great interest when analyzing parameters regulating intestinal zinc resorption. Of note, intestinal mucins were suggested to play a beneficial role in the luminal availability of zinc. Their exact zinc binding properties, however, remain unknown and the impact of these glycoproteins on human intestinal zinc resorption has not been investigated in detail. Thus, the aim of this study is to elucidate the impact of intestinal mucins on luminal uptake of zinc into enterocytes and its transfer into the blood. In the present study, in vitro zinc binding properties of mucins were analyzed using commercially available porcine mucins and secreted mucins of the goblet cell line HT-29-MTX. The molecular zinc binding capacity and average zinc binding affinity of these glycoproteins demonstrates that mucins contain multiple zinc-binding sites with biologically relevant affinity within one mucin molecule. Zinc uptake into the enterocyte cell line Caco-2 was impaired by zinc-depleted mucins. Yet this does not represent their form in the intestinal lumen in vivo under zinc adequate conditions. In fact, zinc-uptake studies into enterocytes in the presence of mucins with differing degree of zinc saturation revealed zinc buffering by these glycoproteins, indicating that mucin-bound zinc is still available for the cells. Finally, the impact of mucins on zinc resorption using three-dimensional cultures was studied comparing the zinc transfer of a Caco-2/HT-29-MTX co-culture and conventional Caco-2 monoculture. Here, the mucin secreting co-cultures yielded higher fractional zinc resorption and elevated zinc transport rates, suggesting that intestinal mucins facilitate the zinc uptake into enterocytes and act as a zinc delivery system for the intestinal epithelium. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1079 KW - intestinal zinc resorption KW - zinc binding KW - mucus layer KW - intestinal mucins KW - in vitro intestinal model KW - goblet cells KW - Caco-2/HT-29-MTX-model Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-469078 SN - 1866-8372 IS - 1079 ER - TY - GEN A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes F. A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1081 KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472873 SN - 1866-8372 IS - 1081 ER - TY - GEN A1 - Alker, Wiebke A1 - Schwerdtle, Tanja A1 - Schomburg, Lutz A1 - Haase, Hajo T1 - A Zinpyr-1-based fluorimetric microassay for free zinc in human serum T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual’s zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body’s zinc status, and its suitability as a future biomarker for an individual’s zinc status. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1086 KW - zinc KW - free zinc KW - serum KW - biomarker KW - fluorescent probe KW - Zinypr-1 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472833 SN - 1866-8372 IS - 1086 ER - TY - JOUR A1 - Taylor, Vivien A1 - Goodale, Britton A1 - Raab, Andrea A1 - Schwerdtle, Tanja A1 - Reimer, Ken A1 - Conklin, Sean A1 - Karagas, Margaret R. A1 - Francesconi, Kevin A. T1 - Human exposure to organic arsenic species from seafood JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Seafood, including finfish, shellfish, and seaweed, is the largest contributor to arsenic (As) exposure in many human populations. In contrast to the predominance of inorganic As in water and many terrestrial foods, As in marine-derived foods is present primarily in the form of organic compounds. To date, human exposure and toxicological assessments have focused on inorganic As, while organic As has generally been considered to be nontoxic. However, the high concentrations of organic As in seafood, as well as the often complex As speciation, can lead to complications in assessing As exposure from diet. In this report, we evaluate the presence and distribution of organic As species in seafood, and combined with consumption data, address the current capabilities and needs for determining human exposure to these compounds. The analytical approaches and shortcomings for assessing these compounds are reviewed, with a focus on the best practices for characterization and quantitation. Metabolic pathways and toxicology of two important classes of organic arsenicals, arsenolipids and arsenosugars, are examined, as well as individual variability in absorption of these compounds. Although determining health outcomes or assessing a need for regulatory policies for organic As exposure is premature, the extensive consumption of seafood globally, along with the preliminary toxicological profiles of these compounds and their confounding effect on assessing exposure to inorganic As, suggests further investigations and process-level studies on organic As are needed to fill the current gaps in knowledge. KW - Organic arsenic KW - Seafood KW - Arsenosugar KW - Arsenolipid Y1 - 2017 U6 - https://doi.org/10.1016/j.scitotenv.2016.12.113 SN - 0048-9697 SN - 1879-1026 VL - 580 SP - 266 EP - 282 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ebert, Franziska A1 - Ziemann, Vanessa A1 - Wandt, Viktoria Klara Veronika A1 - Witt, Barbara A1 - Müller, Sandra Marie A1 - Guttenberger, Nikolaus A1 - Bankoglu, Ezgi Eyluel A1 - Stopper, Helga A1 - Raber, Georg A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Cellular toxicological characterization of a thioxolated arsenic-containing hydrocarbon JF - Journal of trace elements in medicine and biology N2 - Arsenolipids, especially arsenic-containing hydrocarbons (AsHC), are an emerging class of seafood originating contaminants. Here we toxicologically characterize a recently identified oxo-AsHC 332 metabolite, thioxo-AsHC 348 in cultured human liver (HepG2) cells. Compared to results of previous studies of the parent compound oxo-AsHC 332, thioxo-AsHC 348 substantially affected cell viability in the same concentration range but exerted about 10-fold lower cellular bioavailability. Similar to oxo-AsHC 332, thioxo-AsHC 348 did not substantially induce oxidative stress nor DNA damage. Moreover, in contrast to oxo-AsHC 332 mitochondria seem not to be a primary subcellular toxicity target for thioxo-AsHC 348. This study indicates that thioxo-AsHC 348 is at least as toxic as its parent compound oxo-AsHC 332 but very likely acts via a different mode of toxic action, which still needs to be identified. Y1 - 2017 U6 - https://doi.org/10.1016/j.jtemb.2020.126563 VL - 61 PB - Elsevier CY - München ER - TY - JOUR A1 - Maares, Maria A1 - Duman, Ayse A1 - Keil, Claudia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - The impact of apical and basolateral albumin on intestinal zinc resorption in the Caco-2/HT-29-MTX co-culture model JF - Metallomics : integrated biometal science N2 - The molecular mechanisms of intestinal zinc resorption and its regulation are still topics of ongoing research. To this end, the application of suitable in vitro intestinal models, optimized with regard to their cellular composition and medium constituents, is of crucial importance. As one vital aspect, the impact of cell culture media or buffer compounds, respectively, on the speciation and cellular availability of zinc has to be considered when investigating zinc resorption. Thus, the present study aims to investigate the impact of serum, and in particular its main constituent serum albumin, on zinc uptake and toxicity in the intestinal cell line Caco-2. Furthermore, the impact of serum albumin on zinc resorption is analyzed using a co-culture of Caco-2 cells and the mucin-producing goblet cell line HT-29-MTX. Apically added albumin significantly impaired zinc uptake into enterocytes and buffered its cytotoxicity. Yet, undigested albumin does not occur in the intestinal lumen in vivo and impairment of zinc uptake was abrogated by digestion of albumin. Interestingly, zinc uptake, as well as gene expression studies of mt1a and selected intestinal zinc transporters after zinc incubation for 24 h, did not show significant differences between 0 and 10% serum. Importantly, the basolateral application of serum in a transport study significantly enhanced fractional apical zinc resorption, suggesting that the occurrence of a zinc acceptor in the plasma considerably affects intestinal zinc resorption. This study demonstrates that the apical and basolateral medium composition is crucial when investigating zinc, particularly its intestinal resorption, using in vitro cell culture. Y1 - 2018 U6 - https://doi.org/10.1039/c8mt00064f SN - 1756-5901 SN - 1756-591X VL - 10 IS - 7 SP - 979 EP - 991 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Duydu, Yalcin A1 - Basaran, Nursen A1 - Ustundag, Aylin A1 - Aydin, Sevtap A1 - Yalcin, Can Ozgur A1 - Anlar, Hatice Gul A1 - Bacanli, Merve A1 - Aydos, Kaan A1 - Atabekoglu, Cem Somer A1 - Golka, Klaus A1 - Ickstadt, Katja A1 - Schwerdtle, Tanja A1 - Werner, Matthias A1 - Meyer, Sören A1 - Bolt, Hermann M. T1 - Birth weights of newborns and pregnancy outcomes of environmentally boron-exposed females in Turkey JF - Archives of toxicology : official journal of EUROTOX N2 - Boric acid and sodium borates are currently classified as being toxic to reproduction under "Category 1B" with the hazard statement of "H360 FD" in the European CLP regulation. This has prompted studies on boron-mediated reprotoxic effects in male workers in boron mining areas and boric acid production plants. By contrast, studies on boron-mediated developmental effects in females are scarce. The present study was designed to fill this gap. Hundred and ninety nine females residing in Bandirma and Bigadic participated in this study investigating pregnancy outcomes. The participants constituted a study group covering blood boron from low (< 100 ng B/g blood, n = 143) to high (> 150 ng B/g blood, n = 27) concentrations. The mean blood boron concentration and the mean estimated daily boron exposure of the high exposure group was 274.58 (151.81-975.66) ng B/g blood and 24.67 (10.47-57.86) mg B/day, respectively. In spite of the high level of daily boron exposure, boron-mediated adverse effects on induced abortion, spontaneous abortion (miscarriage), stillbirth, infant death, neonatal death, early neonatal death, preterm birth, congenital anomalies, sex ratio and birth weight of newborns were not observed. KW - Boric acid KW - Boron exposure KW - Biological monitoring KW - Developmental toxicity KW - Pregnancy outcomes Y1 - 2018 U6 - https://doi.org/10.1007/s00204-018-2238-4 SN - 0340-5761 SN - 1432-0738 VL - 92 IS - 8 SP - 2475 EP - 2485 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Turrini, Nikolaus G. A1 - Kroepfl, Nina A1 - Jensen, Kenneth Bendix A1 - Reiter, Tamara C. A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja A1 - Kroutil, Wolfgang A1 - Kuehnelt, Doris T1 - Biosynthesis and isolation of selenoneine from genetically modified fission yeast JF - Metallomics : integrated biometal science N2 - Selenoneine, a naturally occurring form of selenium, is the selenium analogue of ergothioneine, a sulfur species with health relevance not only as a purported antioxidant but likely also beyond. Selenoneine has been speculated to exhibit similar effects. To study selenoneine's health properties as well as its metabolic transformation, the pure compound is required. Chemical synthesis of selenoneine, however, is challenging and biosynthetic approaches have been sought. We herein report the biosynthesis and isolation of selenoneine from genetically modified fission yeast Schizosaccharomyces pombe grown in a medium containing sodium selenate. After cell lysis and extraction with methanol, selenoneine was purified by three consecutive preparative reversed-phase HPLC steps. The product obtained at the mg level was characterised by high resolution mass spectrometry, NMR and HPLC/ICPMS. Biosynthesis was found to be a promising alternative to chemical synthesis, and should be suitable for upscaling to produce higher amounts of this important selenium species in the future. Y1 - 2018 U6 - https://doi.org/10.1039/c8mt00200b SN - 1756-5901 SN - 1756-591X VL - 10 IS - 10 SP - 1532 EP - 1538 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kopp, Johannes Florian A1 - Müller, Sandra Marie A1 - Pohl, Gabriele A1 - Lossow, Kristina A1 - Kipp, Anna Patricia A1 - Schwerdtle, Tanja T1 - A quick and simple method for the determination of six trace elements in mammalian serum samples using ICP-MS/MS JF - Journal of trace elements in medicine and biology N2 - In order to assess the individual trace element status of humans for either medical or scientific purposes, amongst others, blood serum levels are determined. Furthermore, animal models are used to study interactions of trace elements. Most published methods require larger amounts (500-1000 mu L) of serum to achieve a reliable determination of multiple trace elements. However, oftentimes, these amounts of serum cannot be dedicated to a single analysis and the amount available for TE-determination is much lower. Therefore, a published ICP-MS/MS method for trace element determination in serum was miniaturized, optimized and validated for the measurement of Mn, Fe, Cu Zn, I and Se in as little as 50 mu L of human and murine serum and is presented in this work. For validation, recoveries of multiple LOTs and levels from commercially available human reference serum samples were determined, infra- and inter-day variations were assessed and limits of detection and quantification determined. It is shown, that the method is capable of giving accurate and reproducible results for all six elements within the relevant concentration ranges for samples from humans living in central Europe as well as from laboratory mice. As a highlight, the achieved limits of detection and quantification for Mn were found to be at 0.02 mu g/L serum and 0.05 mu g/L serum, respectively, while using an alkaline diluent for the parallel determination of iodine. Y1 - 2019 U6 - https://doi.org/10.1016/j.jtemb.2019.04.015 SN - 0946-672X VL - 54 SP - 221 EP - 225 PB - Elsevier CY - München ER - TY - JOUR A1 - Basaran, Nursen A1 - Duydu, Yalcin A1 - Ustundag, Aylin A1 - Taner, Gokce A1 - Aydin, Sevtap A1 - Anlar, Hatice Gul A1 - Yalcin, Can Özgür A1 - Bacanli, Merve A1 - Aydos, Kaan A1 - Atabekoglu, Cem Somer A1 - Golka, Klaus A1 - Ickstadt, Katja A1 - Schwerdtle, Tanja A1 - Werner, Matthias A1 - Meyer, Sören A1 - Bolt, Hermann M. T1 - Evaluation of the DNA damage in lymphocytes, sperm and buccal cells of workers under environmental and occupational boron exposure conditions JF - Mutation Research/Genetic Toxicology and Environmental Mutagenesis N2 - Industrial production and use of boron compounds have increased during the last decades, especially for the manufacture of borosilicate glass, fiberglass, metal alloys and flame retardants. This study was conducted in two districts of Balikesir; Bandirma and Bigadic, which geographically belong to the Marmara Region of Turkey. Bandirma is the production and exportation zone for the produced boric acid and some borates and Bigadic has the largest B deposits in Turkey. 102 male workers who were occupationally exposed to boron from Bandirma and 110 workers who were occupationally and environmentally exposed to boron from Bigadic participated to our study. In this study the DNA damage in the sperm, blood and buccal cells of 212 males was evaluated by comet and micronucleus assays. No significant increase in the DNA damage in blood, sperm and buccal cells was observed in the residents exposed to boron both occupationally and environmentally (p = 0.861) for Comet test in the sperm samples, p = 0.116 for Comet test in the lymphocyte samples, p = 0.042 for micronucleus (MN) test, p = 0.955 for binucleated cells (BN), p = 1.486 for condensed chromatin (CC), p = 0.455 for karyorrhectic cells (KHC), p = 0.541 for karyolitic cells (KLY), p = 1.057 for pyknotic cells (PHC), p = 0.331 for nuclear bud (NBUD)). No correlations were seen between blood boron levels and tail intensity values of the sperm samples, lymphocyte samples, frequencies of MN, BN, KHC, KYL, PHC and NBUD. The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions. KW - Boric acid KW - Boron exposure KW - DNA damage KW - Comet assay Y1 - 2019 U6 - https://doi.org/10.1016/j.mrgentox.2018.12.013 SN - 1383-5718 SN - 1879-3592 VL - 843 SP - 33 EP - 39 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Li, Mingjun A1 - Schlaich, Christoph A1 - Kulka, Michael Willem A1 - Donskyi, Ievgen S. A1 - Schwerdtle, Tanja A1 - Unger, Wolfgang E. S. A1 - Haag, Rainer T1 - Mussel-inspired coatings with tunable wettability, for enhanced antibacterial efficiency and reduced bacterial adhesion JF - Journal of materials chemistry : B, Materials for biology and medicine N2 - Over the last few decades, there has been a tremendous increase in research on antibacterial surface coatings as an alternative strategy against bacterial infections. Although there are several examples of effective strategies to prevent bacterial adhesion, the effect of the wetting properties on the coating was rarely considered as a crucial factor. Here we report an in-depth study on the effect of extreme wettability on the antibacterial efficiency of a silver nanoparticles ( AgNPs)-based coating. By controlling surface polymerization of mussel-inspired dendritic polyglycerol ( MI-dPG) and post-functionalization, surfaces with wetting properties ranging from superhydrophilic to superhydrophobic were fabricated. Subsequently, AgNPs were embedded into the coatings by applying in situ reduction using the free catechols-moieties present in the MI-dPG coating. The resulting polymer coatings exhibited excellent antibacterial ability against planktonic Escherichia coli ( E. coli) DH5a and Staphylococcus aureus ( S. aureus) SH1000. The antibacterial efficiency of the coatings was analyzed by using inductively coupled plasma mass spectrometry ( ICP-MS) and bacterial viability tests. Furthermore, the antifouling properties of the coatings in relation to the antibacterial properties were evaluated. Y1 - 2019 U6 - https://doi.org/10.1039/c9tb00534j SN - 2050-750X SN - 2050-7518 VL - 7 IS - 21 SP - 3438 EP - 3445 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Meyer, Sören A1 - Lopez-Serrano, Aniceto A1 - Mitze, Hanna A1 - Jakubowski, Norbert A1 - Schwerdtle, Tanja T1 - Single-cell analysis by ICP-MS/MS as a fast tool for cellular bioavailability studies of arsenite JF - Metallomics : integrated biometal science N2 - Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has become a powerful and fast tool to evaluate the elemental composition at a single-cell level. In this study, the cellular bioavailability of arsenite (incubation of 25 and 50 mu M for 0-48 h) has been successfully assessed by SC-ICP-MS/MS for the first time directly after re-suspending the cells in water. This procedure avoids the normally arising cell membrane permeabilization caused by cell fixation methods (e.g. methanol fixation). The reliability and feasibility of this SC-ICP-MS/MS approach with a limit of detection of 0.35 fg per cell was validated by conventional bulk ICP-MS/MS analysis after cell digestion and parallel measurement of sulfur and phosphorus. Y1 - 2017 U6 - https://doi.org/10.1039/c7mt00285h SN - 1756-5901 SN - 1756-591X VL - 10 IS - 1 SP - 73 EP - 76 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kröpfl, Nina A1 - Marschall, Talke A. A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja A1 - Kuehnelt, Doris T1 - Quantitative determination of the sulfur-containing antioxidant ergothioneine by HPLC/ICP- QQQ-MS JF - Journal of Analytical Atomic Spectrometry N2 - Interest in the sulfur-containing antioxidant ergothioneine calls for reliable analytical methods for its quantification. In this work, a method based on reversed-phase high performance liquid chromatography (RP-HPLC) coupled with elemental mass spectrometry detection in mass shift mode (inductively coupled plasma triple quadrupole mass spectrometry, ICP-QQQ-MS) using oxygen as the reaction gas was developed for the element-selective determination of ergothioneine in complex biological matrices. Application of an instrumental setup using a 6-port-valve and the introduction of a methanol gradient allowed the time-efficient analysis of samples containing strongly retained sulfur species besides ergothioneine without compromising ICPMS detection. In aqueous solution, limits of detection and quantification (LOD and LOQ) of the optimized method for m/z 32 -> 48 (SO+) were 0.23 mu g S per L and 0.80 mu g S per L, respectively; measurements in a complex matrix (human hepatocyte carcinoma cells, HepG2) resulted in an LOD of 0.6 mu g S per L and an LOQ of 2.3 mu g S per L. Recoveries of ergothioneine from cell pellets spiked with the analyte before cell lysis (97 +/- 3%) matched those obtained for cell culture medium spiked before syringe filtration (96 +/- 9%) demonstrating that sample preparation did not impair the quantitative determination of ergothioneine. When HepG2 cells were exposed to ergothioneine via the culture medium, they showed low absorption; approximately 3% of the added ergothioneine was found in cell lysates, while most of it (>= 85%) remained in the cell culture medium. The method is capable of separating ergothioneine from other biologically relevant sulfur-containing species and is expected to be of broad future use. Furthermore, the potential use for the simultaneous separation of selenium species, thereby extending the scope of possible applications, was demonstrated by applying it to water extracts of oyster mushrooms. Y1 - 2017 U6 - https://doi.org/10.1039/c7ja00030h SN - 0267-9477 SN - 1364-5544 VL - 32 SP - 1571 EP - 1581 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Meyer, Sören A1 - Markova, Mariya A1 - Pohl, Gabriele A1 - Marschall, Talke Anu A1 - Pivovarova, Olga A1 - Pfeiffer, Andreas F. H. A1 - Schwerdtle, Tanja T1 - Development, validation and application of an ICP-MS/MS method to quantify minerals and (ultra-)trace elements in human serum JF - Journal of trace elements in medicine and biology N2 - Multi-element determination in human samples is very challenging. Especially in human intervention studies sample volumes are often limited to a few microliters and due to the high number of samples a high-throughput is indispensable. Here, we present a state-of-the-art ICP-MS/MS-based method for the analysis of essential (trace) elements, namely Mg, Ca, Fe, Cu, Zn, Mo, Se and I, as well as food-relevant toxic elements such as As and Cd. The developed method was validated regarding linearity of the calibration curves, method LODs and LOQs, selectivity and trueness as well as precision. The established reliable method was applied to quantify the element serum concentrations of participants of a human intervention study (LeguAN). The participants received isocaloric diets, either rich in plant protein or in animal protein. While the serum concentrations of Mg and Mo increased in participants receiving the plant protein-based diet (above all legumes), the Se concentration in serum decreased. In contrast, the animal protein-based diet, rich in meat and dairy products, resulted in an increased Se concentration in serum. KW - ICP-MS KW - Elemental blood serum concentration KW - Human nutritional intervention Y1 - 2018 U6 - https://doi.org/10.1016/j.jtemb.2018.05.012 SN - 0946-672X VL - 49 SP - 157 EP - 163 PB - Elsevier GMBH CY - München ER - TY - JOUR A1 - Duydu, Yalcin A1 - Basaran, Nursen A1 - Yalcin, Can Özgür A1 - Ustundag, Aylin A1 - Aydin, Sevtap A1 - Anlar, Hatice Gul A1 - Bacanli, Merve A1 - Aydos, Kaan A1 - Atabekoglu, Cem Somer A1 - Golka, Klaus A1 - Ickstadt, Katja A1 - Schwerdtle, Tanja A1 - Werner, Matthias A1 - Bolt, Hermann M. T1 - Boron-exposed male workers in Turkey BT - no change in sperm Y:X chromosome ratio and in offspring's sex ratio JF - Archives of toxicology : official journal of EUROTOX N2 - Boron-associated shifts in sex ratios at birth were suggested earlier and attributed to a decrease in Y- vs. X-bearing sperm cells. As the matter is pivotal in the discussion of reproductive toxicity of boron/borates, re-investigation in a highly borate-exposed population was required. In the present study, 304 male workers in Bandirma and Bigadic (Turkey) with different degrees of occupational and environmental exposure to boron were investigated. Boron was quantified in blood, urine and semen, and the persons were allocated to exposure groups along B blood levels. In the highest ("extreme") exposure group (n = 69), calculated mean daily boron exposures, semen boron and blood boron concentrations were 44.91 +/- 18.32 mg B/day, 1643.23 +/- 965.44 ng B/g semen and 553.83 +/- 149.52 ng B/g blood, respectively. Overall, an association between boron exposure and Y:X sperm ratios in semen was not statistically significant (p > 0.05). Also, the mean Y:X sperm ratios in semen samples of workers allocated to the different exposure groups were statistically not different in pairwise comparisons (p > 0.05). Additionally, a boron-associated shift in sex ratio at birth towards female offspring was not visible. In essence, the present results do not support an association between boron exposure and decreased Y:X sperm ratio in males, even under extreme boron exposure conditions. KW - Paternal exposure KW - Boron exposure KW - Y:X chromosome ratio KW - Sex ratio at birth Y1 - 2019 U6 - https://doi.org/10.1007/s00204-019-02391-z SN - 0340-5761 SN - 1432-0738 VL - 93 IS - 3 SP - 743 EP - 751 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Kroepfl, Nina A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja A1 - Kuehnelt, Doris T1 - Selenoneine and ergothioneine in human blood cells determined simultaneously by HPLC/ICP-QQQ-MS JF - Journal of Analytical Atomic Spectrometry N2 - The possible relevance to human health of selenoneine and its sulfur-analogue ergothioneine has generated interest in their quantitative determination in biological samples. To gain more insight into the similarities and differences of these two species, a method for their simultaneous quantitative determination in human blood cells using reversed-phase high performance liquid chromatography (RP-HPLC) coupled to inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ-MS) is presented. Spectral interferences hampering the determination of sulfur and selenium by ICPMS are overcome by introducing oxygen to the reaction cell. To access selenoneine and ergothioneine in the complex blood matrix, lysis of the cells with cold water followed by cut-off filtration (3000 Da) is performed. Recoveries based on blood cells spiked with selenoneine and ergothioneine were between 80% and 85%. The standard deviation of the method was around 0.10 mg S per L for ergothioneine (corresponding to relative standard deviations (RSD) between 10-1% for ergothioneine concentrations of 1-10 mg S per L) and 0.25 g Se per L for selenoneine (RSDs of 25-2% for concentrations of 1-10 g Se per L). The method was applied to blood cell samples from three volunteers which showed selenoneine and ergothioneine concentrations in the range of 3.25 to 7.35 g Se per L and 0.86 to 6.44 mg S per L, respectively. The method is expected to be of wide use in future studies investigating the dietary uptake of selenoneine and ergothioneine and their relevance in human health. Y1 - 2018 U6 - https://doi.org/10.1039/c8ja00276b SN - 0267-9477 SN - 1364-5544 VL - 34 IS - 1 SP - 127 EP - 134 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Başaran, Nurşen A1 - Duydu, Yalçın A1 - Üstündağ, Aylin A1 - Taner, Gökçe A1 - Aydin Dilsiz, Sevtap A1 - Anlar, Hatice Gül A1 - Yalçin, Can Özgür A1 - Bacanli, Merve A1 - Golka, Klaus A1 - Schwerdtle, Tanja A1 - Bolt, Hermann M. T1 - Environmental boron exposure does not induce DNA damage in lymphocytes and buccal cells of females DNA damage in lymphocytes and buccal cells of boron exposed females JF - Journal of trace elements in medicine and biology N2 - Boron (B) compounds are essential for plants and animals and beneficial for humans in nutritional amounts. I animals and humans increasing evidence have shown beneficial effects on B compounds on nutrition and on antioxidant status. The genotoxic effects of environmental B exposure in women living in boron-rich and boronpoor areas was examined in this study. For this purpose, the DNA damage in the lymphocytes and buccal cells of females were assessed by Comet and micronucleus (MN) assays respectively. No significant difference was observed in the DNA damage of the lymphocytes of B exposed groups of female volunteers in Comet assay. Even buccal micronucleus (MN) frequency observed in the high exposure group was significantly lower than the low exposure group (p < 0.05). The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions. KW - Boric acid KW - Boron exposure KW - DNA damage Y1 - 2019 U6 - https://doi.org/10.1016/j.jtemb.2019.03.004 SN - 0946-672X VL - 53 SP - 150 EP - 153 PB - Elsevier B.V. CY - München ER - TY - JOUR A1 - Kotthoff, Lisa A1 - O'Callaghan, Sarah-Louise A1 - Lisec, Jan A1 - Schwerdtle, Tanja A1 - Koch, Matthias T1 - Structural annotation of electro- and photochemically generated transformation products of moxidectin using high-resolution mass spectrometry JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica N2 - Moxidectin (MOX) is a widely used anthelmintic drug for the treatment of internal and external parasites in food-producing and companion animals. Transformation products (TPs) of MOX, formed through metabolic degradation or acid hydrolysis, may pose a potential environmental risk, but only few were identified so far. In this study, we therefore systematically characterized electro- and photochemically generated MOX TPs using high-resolution mass spectrometry (HRMS). Oxidative electrochemical (EC) TPs were generated in an electrochemical reactor and photochemical (PC) TPs by irradiation with UV-C light. Subsequent HRMS measurements were performed to identify accurate masses and deduce occurring modification reactions of derived TPs in a suspected target analysis. In total, 26 EC TPs and 59 PC TPs were found. The main modification reactions were hydroxylation, (de-)hydration, and derivative formation with methanol for EC experiments and isomeric changes, (de-)hydration, and changes at the methoxime moiety for PC experiments. In addition, several combinations of different modification reactions were identified. For 17 TPs, we could predict chemical structures through interpretation of acquired MS/MS data. Most modifications could be linked to two specific regions of MOX. Some previously described metabolic reactions like hydroxylation or O-demethylation were confirmed in our EC and PC experiments as reaction type, but the corresponding TPs were not identical to known metabolites or degradation products. The obtained knowledge regarding novel TPs and reactions will aid to elucidate the degradation pathway of MOX which is currently unknown. KW - veterinary drug KW - moxidectin KW - transformation products KW - electrochemistry KW - photochemistry KW - LC KW - HRMS Y1 - 2020 U6 - https://doi.org/10.1007/s00216-020-02572-1 SN - 1618-2642 SN - 1618-2650 VL - 412 IS - 13 SP - 3141 EP - 3152 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Rausch, Ann-Kristin A1 - Brockmeyer, Robert A1 - Schwerdtle, Tanja T1 - Development and Validation of a QuEChERS-Based Liquid Chromatography Tandem Mass Spectrometry Multi-Method for the Determination of 38 Native and Modified Mycotoxins in Cereals JF - Journal of Agricultural and Food Chemistry N2 - Here, a reliable and sensitive method for the determination of 38 (modified) mycotoxins was developed. Using a QuEChERS-based extraction method [acetonitrile/water/formic acid (75:20:5, v/v/v)], followed by two runs of high performance liquid chromatography tandem mass spectrometry with different conditions, relevant mycotoxins in cereals were analyzed. The method was validated according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002. Limits of quantification ranged from 0.05 to 150 μg/kg. Good linearity (R2 > 0.99), recovery (61–120%), repeatability (RSDr < 15%), and reproducibility (RSDR < 20%) were obtained for most mycotoxins. However, validation results for Alternaria toxins and fumonisins were unsatisfying. Matrix effects (−69 to +59%) were compensated for using standard addition. Application on reference materials gave correct results while analysis of samples from local retailers revealed contamination, especially with deoxynivalenol, deoxynivalenol-3-glucoside, fumonisins, and zearalenone, in concentrations up to 369, 58, 1002, and 21 μg/kg, respectively. KW - multi-mycotoxin analysis KW - modified mycotoxins KW - QuEChERS KW - LC−MS/MS KW - cereals KW - validation Y1 - 2020 U6 - https://doi.org/10.1021/acs.jafc.9b07491 SN - 0021-8561 VL - 68 IS - 16 SP - 4657 EP - 4669 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Rausch, Ann-Kristin A1 - Brockmeyer, Robert A1 - Schwerdtle, Tanja T1 - Development and validation of a liquid chromatography tandem mass spectrometry multi-method for the determination of 41 free and modified mycotoxins in beer JF - Food chemistry N2 - A fast high performance liquid chromatography tandem mass spectrometry multi-method based on an ACN-precipitation extraction was developed for the analysis of 41 (modified) mycotoxins in beer. Validation according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002 revealed good linearity (R2 > 0.99), repeatability (RSDr < 15%), reproducibility (RSDR < 15%), and recovery (79–100%). Limits of quantification ranging from 0.04 to 75 µg/L were obtained. Matrix effects varied from −67 to +319% and were compensated for using standard addition. In total, 87 beer samples, produced worldwide, were analyzed for the presence of mycotoxins with a focus on modified mycotoxins, whereof 76% of the samples were contaminated with at least one mycotoxin. The most prevalent mycotoxins were deoxynivalenol-3-glucoside (63%), HT-2 toxin (15%), and tenuazonic acid (13%). Exposure estimates of deoxynivalenol and its metabolites for German beer revealed no significant contribution to intake of deoxynivalenol. KW - Multi-mycotoxin analysis KW - Modified mycotoxins KW - LC–MS/MS KW - Beer KW - Validation Y1 - 2020 U6 - https://doi.org/10.1016/j.foodchem.2020.127801 SN - 1873-7072 SN - 0308-8146 VL - 338 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Rausch, Ann-Kristin A1 - Brockmeyer, Robert A1 - Schwerdtle, Tanja T1 - Development, validation, and application of a multi-method for the determination of mycotoxins, plant growth regulators, tropane alkaloids, and pesticides in cereals by two-dimensional liquid chromatography tandem mass spectrometry JF - Analytical & bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica N2 - Mycotoxins and pesticides regularly co-occur in agricultural products worldwide. Thus, humans can be exposed to both toxic contaminants and pesticides simultaneously, and multi-methods assessing the occurrence of various food contaminants and residues in a single method are necessary. A two-dimensional high performance liquid chromatography tandem mass spectrometry method for the analysis of 40 (modified) mycotoxins, two plant growth regulators, two tropane alkaloids, and 334 pesticides in cereals was developed. After an acetonitrile/water/formic acid (79:20:1, v/v/v) multi-analyte extraction procedure, extracts were injected into the two-dimensional setup, and an online clean-up was performed. The method was validated according to Commission Decision (EC) no. 657/2002 and document N° SANTE/12682/2019. Good linearity (R2 > 0.96), recovery data between 70-120%, repeatability and reproducibility values < 20%, and expanded measurement uncertainties < 50% were obtained for a wide range of analytes, including very polar substances like deoxynivalenol-3-glucoside and methamidophos. However, results for fumonisins, zearalenone-14,16-disulfate, acid-labile pesticides, and carbamates were unsatisfying. Limits of quantification meeting maximum (residue) limits were achieved for most analytes. Matrix effects varied highly (−85 to +1574%) and were mainly observed for analytes eluting in the first dimension and early-eluting analytes in the second dimension. The application of the method demonstrated the co-occurrence of different types of cereals with 28 toxins and pesticides. Overall, 86% of the samples showed positive findings with at least one mycotoxin, plant growth regulator, or pesticide. KW - 2D-LC-MS/MS KW - Multi-method KW - Mycotoxins KW - Modified mycotoxins KW - Pesticides KW - Cereals Y1 - 2021 U6 - https://doi.org/10.1007/s00216-021-03239-1 SN - 1618-2650 SN - 1618-2642 VL - 413 IS - 11 SP - 3041 EP - 3054 PB - Springer CY - Berlin ER - TY - JOUR A1 - Dünkelberg, Sophie A1 - Maywald, Martina A1 - Schmitt, Anne Kristina A1 - Schwerdtle, Tanja A1 - Meyer, Sören A1 - Rink, Lothar T1 - The interaction of sodium and zinc in the priming of T cell subpopulations regarding Th17 and Treg cells JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - Scope: Nutrition is a critical determinant of a functional immune system. The aim of this study is to investigate the molecular mechanisms by which immune cells are influenced by zinc and sodium. Methods and Results: Mixed lymphocyte cultures and Jurkat cells are generated and incubated with zinc, sodium, or a combination of both for further tests. Zinc induces the number of regulatory T cells (Treg) and decreases T helper 17 cells (Th17), and sodium has the opposite effect. The transforming growth factor beta receptor signaling pathway is also enhanced by zinc and reduced by sodium as indicated by contrary phosphoSmad 2/3 induction. Antagonistic effects can also be seen on zinc transporter and metallothionein-1 (MT-1) mRNA expression: zinc declines Zip10 mRNA expression while sodium induces it, whereas MT-1 mRNA expression is induced by zinc while it is reduced by sodium. Conclusion: This data indicate that zinc and sodium display opposite effects regarding Treg and Th17 induction in MLC, respectively, resulting in a contrary effect on the immune system. Additionally, it reveals a direct interaction of zinc and sodium in the priming of T cell subpopulations and shows that Zip10 and MT-1 play a significant role in those differentiation pathways. KW - Foxp3 KW - regulatory T cells KW - sodium KW - T helper 17 cells KW - zinc Y1 - 2020 U6 - https://doi.org/10.1002/mnfr.201900245 SN - 1613-4133 VL - 64 IS - 2 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes Florian A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper JF - Nutrients N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2019 U6 - https://doi.org/10.3390/nu11092112 SN - 2072-6643 VL - 11 IS - 9 PB - MDPI CY - Basel ER - TY - JOUR A1 - Hackethal, Christin A1 - Kopp, Johannes Florian A1 - Sarvan, Irmela A1 - Schwerdtle, Tanja A1 - Lindtner, Oliver T1 - Total arsenic and water-soluble arsenic species in foods of the first German total diet study (BfR MEAL Study) JF - Food chemistry N2 - Arsenic can occur in foods as inorganic and organic forms. Inorganic arsenic is more toxic than most watersoluble organic arsenic compounds such as arsenobetaine, which is presumed to be harmless for humans. Within the first German total diet study, total arsenic, inorganic arsenic, arsenobetaine, dimethylarsinic acid and monomethylarsonic acid were analyzed in various foods. Highest levels of total arsenic were found in fish, fish products and seafood (mean: 1.43 mg kg(-1); n = 39; min-max: 0.01-6.15 mg kg(-1)), with arsenobetaine confirmed as the predominant arsenic species (1.233 mg kg 1; n = 39; min-max: 0.01-6.23 mg kg (1)). In contrast, inorganic arsenic was determined as prevalent arsenic species in terrestrial foods (0.02 mg kg (1); n = 38; min-max: 0-0.11 mg kg (1)). However, the toxicity of arsenic species varies and measurements are necessary to gain information about the composition and changes of arsenic species in foods due to household processing of foods. KW - Occurrence data KW - Food KW - Total arsenic KW - Arsenic speciation KW - Inductively KW - coupled plasma mass spectrometry Y1 - 2021 U6 - https://doi.org/10.1016/j.foodchem.2020.128913 SN - 0308-8146 SN - 1873-7072 VL - 346 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Finke, Hannah A1 - Wandt, Viktoria Klara Veronika A1 - Ebert, Franziska A1 - Guttenberger, Nikolaus A1 - Glabonjat, Ronald A. A1 - Stiboller, Michael A1 - Francesconi, Kevin A. A1 - Raber, Georg A1 - Schwerdtle, Tanja T1 - Toxicological assessment of arsenic-containing phosphatidylcholines in HepG2 cells N2 - Arsenolipids include a wide range of organic arsenic species that occur naturally in seafood and thereby contribute to human arsenic exposure. Recently arsenic-containing phosphatidylcholines (AsPCs) were identified in caviar, fish, and algae. In this first toxicological assessment of AsPCs, we investigated the stability of both the oxo- and thioxo-form of an AsPC under experimental conditions, and analyzed cell viability, indicators of genotoxicity and biotransformation in human liver cancer cells (HepG2). Precise toxicity data could not be obtained owing to the low solubility in the cell culture medium of the thioxo-form, and the ease of hydrolysis of the oxo-form, and to a lesser degree the thioxo-form. Hydrolysis resulted amongst others in the respective constituent arsenic-containing fatty acid (AsFA). Incubation of the cells with oxo-AsPC resulted in a toxicity similar to that determined for the hydrolysis product oxo-AsFA alone, and there were no indices for genotoxicity. Furthermore, the oxo-AsPC was readily taken up by the cells resulting in high cellular arsenic concentrations (50 μM incubation: 1112 ± 146 μM As cellular), whereas the thioxo-AsPC was substantially less bioavailable (50 μM incubation: 293 ± 115 μM As cellular). Speciation analysis revealed biotransformation of the AsPCs to a series of AsFAs in the culture medium, and, in the case of the oxo-AsPC, to as yet unidentified arsenic species in cell pellets. The results reveal the difficulty of toxicity studies of AsPCs in vitro, indicate that their toxicity might be largely governed by their arsenic fatty acid content and suggest a multifaceted human metabolism of food derived complex arsenolipids. KW - Biochemistry KW - Biological Sciences KW - Science and Mathematics KW - Books KW - Journals Y1 - 2020 U6 - https://doi.org/10.1039/d0mt00073f VL - 12 IS - 7 SP - 1159 EP - 1170 PB - Oxford University CY - Cambridge ER - TY - JOUR A1 - Finke, Hannah A1 - Winkelbeiner, Nicola Lisa A1 - Lossow, Kristina A1 - Hertel, Barbara A1 - Wandt, Viktoria Klara Veronika A1 - Schwarz, Maria A1 - Pohl, Gabriele A1 - Kopp, Johannes Florian A1 - Ebert, Franziska A1 - Kipp, Anna Patricia A1 - Schwerdtle, Tanja T1 - Effects of a Cumulative, Suboptimal Supply of Multiple Trace Elements in Mice BT - trace element status, genomic stability, inflammation, and epigenetics JF - Molecular nutrition & food research N2 - Scope: Trace element (TE) deficiencies often occur accumulated, as nutritional intake is inadequate for several TEs, concurrently. Therefore, the impact of a suboptimal supply of iron, zinc, copper, iodine, and selenium on the TE status, health parameters, epigenetics, and genomic stability in mice are studied. Methods and results: Male mice receive reduced or adequate amounts of TEs for 9 weeks. The TE status is analyzed mass‐spectrometrically in serum and different tissues. Furthermore, gene and protein expression of TE biomarkers are assessed with focus on liver. Iron concentrations are most sensitive toward a reduced supply indicated by increased serum transferrin levels and altered hepatic expression of iron‐related genes. Reduced TE supply results in smaller weight gain but higher spleen and heart weights. Additionally, inflammatory mediators in serum and liver are increased together with hepatic genomic instability. However, global DNA (hydroxy)methylation is unaffected by the TE modulation. Conclusion: Despite homeostatic regulation of most TEs in response to a low intake, this condition still has substantial effects on health parameters. It appears that the liver and immune system react particularly sensitive toward changes in TE intake. The reduced Fe status might be the primary driver for the observed effects. Y1 - 2020 U6 - https://doi.org/10.1002/mnfr.202000325 SN - 1613-4125 VL - 64 IS - 16 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Witt, Barbara A1 - Stiboller, Michael A1 - Raschke, Stefanie A1 - Friese, Sharleen A1 - Ebert, Franziska A1 - Schwerdtle, Tanja T1 - Characterizing effects of excess copper levels in a human astrocytic cell line with focus on oxidative stress markers JF - Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS N2 - Background: Being an essential trace element, copper is involved in diverse physiological processes. However, excess levels might lead to adverse effects. Disrupted copper homeostasis, particularly in the brain, has been associated with human diseases including the neurodegenerative disorders Wilson and Alzheimer?s disease. In this context, astrocytes play an important role in the regulation of the copper homeostasis in the brain and likely in the prevention against neuronal toxicity, consequently pointing them out as a potential target for the neurotoxicity of copper. Major toxic mechanisms are discussed to be directed against mitochondria probably via oxidative stress. However, the toxic potential and mode of action of copper in astrocytes is poorly understood, so far. Methods: In this study, excess copper levels affecting human astrocytic cell model and their involvement in the neurotoxic mode of action of copper, as well as, effects on the homeostasis of other trace elements (Mn, Fe, Ca and Mg) were investigated. Results: Copper induced substantial cytotoxic effects in the human astrocytic cell line following 48 h incubation (EC30: 250 ?M) and affected mitochondrial function, as observed via reduction of mitochondrial membrane potential and increased ROS production, likely originating from mitochondria. Moreover, cellular GSH metabolism was altered as well. Interestingly, not only cellular copper levels were affected, but also the homeostasis of other elements (Ca, Fe and Mn) were disrupted. Conclusion: One potential toxic mode of action of copper seems to be effects on the mitochondria along with induction of oxidative stress in the human astrocytic cell model. Moreover, excess copper levels seem to interact with the homeostasis of other essential elements such as Ca, Fe and Mn. Disrupted element homeostasis might also contribute to the induction of oxidative stress, likely involved in the onset and progression of neurodegenerative disorders. These insights in the toxic mechanisms will help to develop ideas and approaches for therapeutic strategies against copper-mediated diseases. KW - Copper KW - Astrocytes KW - Toxicity KW - Mitochondria KW - ROS KW - Trace elements Y1 - 2021 U6 - https://doi.org/10.1016/j.jtemb.2021.126711 SN - 1878-3252 VL - 65 PB - Elsevier CY - München ER - TY - JOUR A1 - Müller, Anke Katharina A1 - Helms, Ute A1 - Rohrer, Carsten A1 - Möhler, Monika A1 - Hellwig, Frank A1 - Glei, Michael A1 - Schwerdtle, Tanja A1 - Lorkowski, Stefan A1 - Dawczynski, Christine T1 - Nutrient composition of different hazelnut cultivars grown in Germany JF - Foods N2 - Hazelnuts are rarely cultivated in Germany, although they are a valuable source for macro- and micronutrients and can thus contribute to a healthy diet. Near the present, 15 varieties were cultivated in Thuringia, Germany, as a pilot study for further research. The aim of our study was to evaluate the micro- and macronutrient composition of representative, randomly mixed samples of the 15 different hazelnut cultivars. Protein, fat, and fiber contents were determined using established methods. Fatty acids, tocopherols, minerals, trace elements, and ultra-trace elements were analyzed using gas chromatography, high-performance liquid chromatography, and inductively coupled plasma triple quadrupole mass-spectrometry, respectively. We found that the different hazelnut varieties contained valuable amounts of fat, protein, dietary fiber, minerals, trace elements, and alpha-tocopherol, however, in different quantities. The variations in nutrient composition were independent of growth conditions, which were identical for all hazelnut varieties. Therefore, each hazelnut cultivar has its specific nutrient profile. KW - Corylus avellana L. KW - nutrient composition KW - hazelnut cultivars KW - minerals KW - tocopherols Y1 - 2020 U6 - https://doi.org/10.3390/foods9111596 SN - 2304-8158 VL - 9 IS - 11 PB - MDPI CY - Basel ER - TY - GEN A1 - Kotthoff, Lisa A1 - Lisec, Jan A1 - Schwerdtle, Tanja A1 - Koch, Matthias T1 - Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid+ chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1340 KW - transformation products KW - monensin KW - veterinary drugs KW - electrochemistry KW - hydrolysis KW - LC/HRMS Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-473262 SN - 1866-8372 IS - 1340 ER - TY - JOUR A1 - Kotthoff, Lisa A1 - Lisec, Jan A1 - Schwerdtle, Tanja A1 - Koch, Matthias T1 - Prediction of transformation products of monensin by electrochemistry compared to microsomal assay and hydrolysis JF - Molecules N2 - The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation. KW - transformation products KW - monensin KW - veterinary drugs KW - electrochemistry KW - hydrolysis KW - LC/HRMS Y1 - 2019 U6 - https://doi.org/10.3390/molecules24152732 SN - 1420-3049 VL - 24 IS - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Meyer, Sören A1 - Matissek, M. A1 - Mueller, S. M. A1 - Taleshi, M. S. A1 - Ebert, Franziska A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - In vitro toxicological characterisation of three arsenic-containing hydrocarbons JF - Metallomics : integrated biometal science N2 - Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk. Y1 - 2014 U6 - https://doi.org/10.1039/c4mt00061g SN - 1756-5901 SN - 1756-591X VL - 6 IS - 5 SP - 1023 EP - 1033 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Köhler, Yvonne A1 - Luther, Eva Maria A1 - Meyer, Sören A1 - Schwerdtle, Tanja A1 - Dringen, Ralf T1 - Uptake and toxicity of arsenite and arsenate in cultured brain astrocytes JF - Journal of trace elements in medicine and biology N2 - Inorganic arsenicals are environmental toxins that have been connected with neuropathies and impaired cognitive functions. To investigate whether such substances accumulate in brain astrocytes and affect their viability and glutathione metabolism, we have exposed cultured primary astrocytes to arsenite or arsenate. Both arsenicals compromised the cell viability of astrocytes in a time- and concentration-dependent manner. However, the early onset of cell toxicity in arsenite-treated astrocytes revealed the higher toxic potential of arsenite compared with arsenate. The concentrations of arsenite and arsenate that caused within 24 h half-maximal release of the cytosolic enzyme lactate dehydrogenase were around 0.3 mM and 10 mM, respectively. The cellular arsenic contents of astrocytes increased rapidly upon exposure to arsenite or arsenate and reached after 4 h of incubation almost constant steady state levels. These levels were about 3-times higher in astrocytes that had been exposed to a given concentration of arsenite compared with the respective arsenate condition. Analysis of the intracellular arsenic species revealed that almost exclusively arsenite was present in viable astrocytes that had been exposed to either arsenate or arsenite. The emerging toxicity of arsenite 4 h after exposure was accompanied by a loss in cellular total glutathione and by an increase in the cellular glutathione disulfide content. These data suggest that the high arsenite content of astrocytes that had been exposed to inorganic arsenicals causes an increase in the ratio of glutathione disulfide to glutathione which contributes to the toxic potential of these substances. KW - Arsenic KW - Astrocytes KW - GSH KW - Metabolism KW - Toxicity Y1 - 2014 U6 - https://doi.org/10.1016/j.jtemb.2014.04.007 SN - 0946-672X VL - 28 IS - 3 SP - 328 EP - 337 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Mayer, Lena S. A1 - Uciechowski, Peter A1 - Meyer, Sören A1 - Schwerdtle, Tanja A1 - Rink, Lothar A1 - Haase, Hajo T1 - Differential impact of zinc deficiency on phagocytosis, oxidative burst, and production of pro-inflammatory cytokines by human monocytes JF - Metallomics : integrated biometal science Y1 - 2014 U6 - https://doi.org/10.1039/c4mt00051j SN - 1756-5901 SN - 1756-591X VL - 6 IS - 7 SP - 1288 EP - 1295 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Draude, F. A1 - Pelster, A. A1 - Koersgen, M. A1 - Kassenboehmer, R. A1 - Schwerdtle, Tanja A1 - Muething, J. A1 - Arlinghaus, H. F. T1 - ToF-SIMS imaging of plasma membrane lipids with sub-micrometer resolution JF - Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films N2 - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used for label-free analyses of the molecular lateral distribution of two different epithelial cell membranes (PANC-1 and UROtsa). The goal of the research was to enhance the ion yield of specific membrane molecules for improving the membrane imaging capability of ToF-SIMS on the nanoscale lateral dimension. For this task, a special silicon wafer sandwich preparation technique was optimized using different wafer materials, spacers, and washing procedures. Under optimized preparation conditions, the yield could be significantly enhanced, allowing imaging of the inhomogeneous distribution of phosphocholine (common head group for phosphatidylcholine and sphingomyelin) of a PANC-1 cell membrane's outer lipid layer with a lateral resolution of less than 200nm. Copyright (c) 2014 John Wiley & Sons, Ltd. KW - ToF-SIMS KW - high-resolution imaging KW - membrane analysis KW - lipid analysis KW - yield enhancement KW - sample preparation Y1 - 2014 U6 - https://doi.org/10.1002/sia.5576 SN - 0142-2421 SN - 1096-9918 VL - 46 SP - 127 EP - 130 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Unterberg, Marlies A1 - Leffers, Larissa A1 - Huebner, Florian A1 - Humpf, Hans-Ulrich A1 - Lepikhov, Konstantin A1 - Walter, Joern A1 - Ebert, Franziska A1 - Schwerdtle, Tanja T1 - Toxicity of arsenite and thio-DMA(V) after long-term (21 days) incubation of human urothelial cells: cytotoxicity, genotoxicity and epigenetics JF - Toxicology research N2 - This study aims to further mechanistically understand toxic modes of action after chronic inorganic arsenic exposure. Therefore long-term incubation studies in cultured cells were carried out, to display chronically attained changes, which cannot be observed in the generally applied in vitro short-term incubation studies. Particularly, the cytotoxic, genotoxic and epigenetic effects of an up to 21 days incubation of human urothelial (UROtsa) cells with pico- to nanomolar concentrations of iAs(III) and its metabolite thio-DMA(V) were compared. After 21 days of incubation, cytotoxic effects were strongly enhanced in the case of iAs(III) and might partly be due to glutathione depletion and genotoxic effects on the chromosomal level. These results are in strong contrast to cells exposed to thio-DMA(V). Thus, cells seemed to be able to adapt to this arsenical, as indicated among others by an increase in the cellular glutathione level. Most interestingly, picomolar concentrations of both iAs(III) and thio-DMA(V) caused global DNA hypomethylation in UROtsa cells, which was quantified in parallel by 5-medC immunostaining and a newly established, reliable, high resolution mass spectrometry (HRMS)-based test system. This is the first time that epigenetic effects are reported for thio-DMA(V); iAs(III) induced epigenetic effects occur in at least 8000 fold lower concentrations as reported in vitro before. The fact that both arsenicals cause DNA hypomethylation at really low, exposure-relevant concentrations in human urothelial cells suggests that this epigenetic effect might contribute to inorganic arsenic induced carcinogenicity, which for sure has to be further investigated in future studies. Y1 - 2014 U6 - https://doi.org/10.1039/c4tx00036f SN - 2045-452X SN - 2045-4538 VL - 3 IS - 6 SP - 456 EP - 464 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Meyer, Sören A1 - Schulz, J. A1 - Jeibmann, A. A1 - Taleshi, M. S. A1 - Ebert, Franziska A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster JF - Metallomics : integrated biometal science N2 - Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood. Y1 - 2014 U6 - https://doi.org/10.1039/c4mt00249k SN - 1756-5901 SN - 1756-591X VL - 6 IS - 11 SP - 2010 EP - 2014 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Pieper, Christian A1 - Marek, Jasmin Jacqueline A1 - Unterberg, Marlies A1 - Schwerdtle, Tanja A1 - Galla, Hans-Joachim T1 - Brain capillary pericytes contribute to the immune defense in response to cytokines or LPS in vitro JF - Brain research : an international multidisciplinary journal devoted to fundamental research in the brain sciences N2 - The prevention of an inflammation in the brain is one of the most important goals the body has to achieve. As pericytes are located on the abluminal side of the capillaries in the brain, their role in fighting against invading pathogens has been investigated in some points, mostly in their ability to behave like macrophages. Here we studied the potential of pericytes to react as immune cells under inflammatory conditions, especially regarding the expression of the inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), major histocompatibility complex II (MHC II) molecules, CD68, as well as the generation of reactive oxygen and nitrogen species (RONS), and their ability in phagocytosis. Quantitative real time PCR and western blot analysis showed that pericytes are able to increase the expression of typical inflammatory marker proteins after the stimulation with tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1 beta), interferon-gamma (IFN-gamma), or lipopolysaccharides (LPS). Depending on the different specific pro-inflammatory factors pericytes changed the expression of alpha smooth muscle actin (alpha SMA), the most predominant pericyte marker. We conclude that the role of the pericytes within the immune system is regulated and fine-tuned by different cytokines strongly depending on the time when the cytokines are released and their concentration. The present results will help to understand the pericyte mediated defense mechanisms in the brain. KW - Pericytes KW - Cytokines KW - Inflammation KW - LPS KW - Macrophage-like phenotype Y1 - 2014 U6 - https://doi.org/10.1016/j.brainres.2014.01.004 SN - 0006-8993 SN - 1872-6240 VL - 1550 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Taleshi, Mojtaba S. A1 - Seidler-Egdal, Rune K. A1 - Jensen, Kenneth Bendix A1 - Schwerdtle, Tanja A1 - Francesconi, Kevin A. T1 - Synthesis and Characterization of Arsenolipids: Naturally Occurring Arsenic Compounds in Fish and Algae JF - Organometallics N2 - Arsenic-containing lipids (arsenolipids) are natural products present in fish and algae. Because these compounds occur in foods, there is considerable interest in their human toxicology. We report the synthesis and characterization of seven arsenic-containing lipids, including six natural products. The compounds comprise dimethylarsinyl groups attached to saturated long-chain hydrocarbons (three compounds), saturated long-chain fatty acids (two compounds), and monounsaturated long chain fatty acids (two compounds). The arsenic group was introduced through sodium dimethylarsenide or bis(dimethylarsenic) oxide. The latter route provided higher and more reproducible yields, and consequently, this pathway was followed to synthesize six of the seven compounds. Mass spectral properties are described to assist in the identification of these compounds in natural samples. The pure synthesized arsenolipids will be used for in vitro experiments with human cells to test their uptake, biotransformation, and possible toxic effects. Y1 - 2014 U6 - https://doi.org/10.1021/om4011092 SN - 0276-7333 SN - 1520-6041 VL - 33 IS - 6 SP - 1397 EP - 1403 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Wehe, Christoph A. A1 - Pieper, Imke A1 - Holtkamp, Michael A1 - Thyssen, Georgina M. A1 - Sperling, Michael A1 - Schwerdtle, Tanja A1 - Karst, Uwe T1 - On-line species-unspecific isotope dilution analysis in the picomolar range reveals the time- and species-depending mercury uptake in human astrocytes JF - Analytical & bioanalytical chemistry N2 - In order to reveal the time-depending mercury species uptake by human astrocytes, a novel approach for total mercury analysis is presented, which uses an accelerated sample introduction system combined on-line with an inductively coupled plasma mass spectrometer equipped with a collision/reaction cell. Human astrocyte samples were incubated with inorganic mercury (HgCl2), methylmercury chloride (MeHgCl), and thimerosal. After 1-h incubation with Hg2+, cellular concentrations of 3 mu M were obtained, whereas for organic species, concentrations of 14-18 mu M could be found. After 24 h, a cellular accumulation factor of 0.3 was observed for the cells incubated with Hg2+, whereas the organic species both showed values of about 5. Due to the obtained steady-state signals, reliable results with relative standard deviations of well below 5 % and limits of detection in the concentration range of 1 ng L-1 were obtained using external calibration and species-unspecific isotope dilution analysis approaches. The results were further validated using atomic fluorescence spectrometry. KW - Mercury KW - Thimerosal KW - Astrocytes KW - ICP-MS KW - Isotope dilution analysis KW - Automation Y1 - 2014 U6 - https://doi.org/10.1007/s00216-013-7608-4 SN - 1618-2642 SN - 1618-2650 VL - 406 IS - 7 SP - 1909 EP - 1916 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Niehoff, Ann-Christin A1 - Bauer, Oliver Bolle A1 - Kröger, Sabrina A1 - Fingerhut, Stefanie A1 - Schulz, Jacqueline A1 - Meyer, Sören A1 - Sperling, Michael A1 - Jeibmann, Astrid A1 - Schwerdtle, Tanja A1 - Karst, Uwe T1 - Quantitative Bioimaging to Investigate the Uptake of Mercury Species in Drosophila melanogaster JF - Analytical chemistry N2 - The uptake of mercury species in the model organism Drosophila melanogaster was investigated by elemental bioimaging using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS). The mercury distribution in Drosophila melanogaster was analyzed for the three species mercury(II) chloride, methylmercury chloride, and thimerosal after intoxication. A respective analytical method was developed and applied to the analysis of the entire Drosophila melanogaster first, before a particular focus was directed to the cerebral areas of larvae and adult flies. For quantification of mercury, matrix-matched standards based on gelatin were prepared. Challenges of spatially dissolved mercury determination, namely, strong evaporation issues of the analytes and an inhomogeneous distribution of mercury in the standards due to interactions with cysteine containing proteins of the gelatin were successfully addressed by complexation with meso-2,3-dimercaptosuccinic acid (DMSA). No mercury was detected in the cerebral region for mercury(II) chloride, whereas both organic species showed the ability to cross the blood brain barrier. Quantitatively, the mercury level in the brain exceeded the fed concentration indicating mercury enrichment, which was approximately 3 times higher for methylmercury chloride than for thimerosal. Y1 - 2015 U6 - https://doi.org/10.1021/acs.analchem.5b02500 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 20 SP - 10392 EP - 10396 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Meyer, Sören A1 - Raber, Georg A1 - Ebert, Franziska A1 - Taleshi, Mojtaba S. A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Arsenic-containing hydrocarbons and arsenic-containing fatty acids: Transfer across and presystemic metabolism in the Caco-2 intestinal barrier model JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - Scope: Arsenic-containing hydrocarbons (AsHCs) and arsenic-containing fatty acids (AsFAs) represent two classes of arsenolipids occurring naturally in marine food. Toxicological data are yet scarce and an assessment regarding the risk to human health has not been possible. Here, we investigated the transfer and presystemic metabolism of five arsenolipids in an intestinal barrier model. Methods and results: Three AsHCs and two AsFAs were applied to the Caco-2 intestinal barrier model. Thereby, the short-chain AsHCs reached up to 50% permeability. Transport is likely to occur via passive diffusion. The AsFAs showed lower intestinal bioavailability, but respective permeabilities were still two to five times higher as compared to arsenobetaine or arsenosugars. Interestingly, AsFAs were effectively biotransformed while passing the in vitro intestinal barrier, whereas AsHCs were transported to the blood-facing compartment essentially unchanged. Conclusion: AsFAs can be presystemically metabolised and the amount of transferred arsenic is lower than that for AsHCs. In contrast, AsHCs are likely to be highly intestinally bioavailable to humans. Since AsHCs exert strong toxicity in vitro and in vivo, toxicity studies with experimental animals as well as a human exposure assessment are needed to assess the risk to human health related to the presence of AsHCs in seafood. KW - Arsenolipids KW - Caco-2 intestinal barrier model KW - Presystemic metabolism KW - Toxicity Y1 - 2015 U6 - https://doi.org/10.1002/mnfr.201500286 SN - 1613-4125 SN - 1613-4133 VL - 59 IS - 10 SP - 2044 EP - 2056 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Draude, Felix A1 - Körsgen, Martin A1 - Pelster, Andreas A1 - Schwerdtle, Tanja A1 - Müthing, Johannes A1 - Arlinghaus, Heinrich F. T1 - Characterization of freeze-fractured epithelial plasma membranes on nanometer scale with ToF-SIMS JF - Analytical & bioanalytical chemistry N2 - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to characterize the freeze-fracturing process of human epithelial PANC-1 and UROtsa cells. For this purpose, phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, and phosphatidylserine standard samples were investigated to find specific signals with both high specificity and signal intensity. The results were used to investigate single cells of subconfluent cell layers prepared with a special silicon wafer sandwich preparation technique. This freeze-fracturing technique strips cell membranes off the cells, isolating them on opposing silicon wafer substrates. Criteria were found for defining regions with stripped off cell membranes and, on the opposing wafer, complementary regions with the remaining cells. Measured ethanolamine/choline and serine/choline ratios in these regions clearly showed that in the freeze-fracturing process, the lipid bilayer of the plasma membrane is split along its central zone. Accordingly, only the outer lipid monolayer is stripped off the cell, while the inner lipid monolayer remains attached to the cell on the opposing wafer, thus allowing detailed analysis of a single lipid monolayer. Furthermore, it could be shown that using different washing procedures did not influence the transmembrane lipid distribution. Under optimized preparation conditions, it became feasible to detect lipids with a lateral resolution of approximately 100 nm. The data indicate that ToF-SIMS would be a very useful technique to study with very high lateral resolution changes in lipid composition caused, for example, by lipid storage diseases or pharmaceuticals that interfere with the lipid metabolism. KW - ToF-SIMS imaging KW - Life science KW - Lipid KW - Freeze-fracturing KW - Membrane KW - Transmembrane asymmetry Y1 - 2015 U6 - https://doi.org/10.1007/s00216-014-8334-2 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 8 SP - 2203 EP - 2211 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Rosenkranz, Eva A1 - Maywald, Martina A1 - Hilgers, Ralf-Dieter A1 - Brieger, Anne A1 - Clarner, Tim A1 - Kipp, Markus A1 - Pluemaekers, Birgit A1 - Meyer, Sören A1 - Schwerdtle, Tanja A1 - Rink, Lothar T1 - Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration JF - The journal of nutritional biochemistry N2 - The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 mu g/day (0.3 mg/kg body weight) or 30 mu g/day (1.5 mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 ROR gamma T+ cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. (C) 2015 Elsevier Inc. All rights reserved. KW - Zinc KW - Regulatory T cells (Treg) KW - Foxp3 KW - Mixed lymphocyte culture (MLC) KW - Experimental autoimmune encephalomyelitis (EAE) KW - Th17 Y1 - 2016 U6 - https://doi.org/10.1016/j.jnutbio.2015.11.010 SN - 0955-2863 SN - 1873-4847 VL - 29 SP - 116 EP - 123 PB - Elsevier CY - New York ER - TY - JOUR A1 - Ebert, Franziska A1 - Meyer, Sören A1 - Leffers, Larissa A1 - Raber, Georg A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja T1 - Toxicological characterisation of a thio-arsenosugar-glycerol in human cells JF - Journal of trace elements in medicine and biology N2 - Arsenosugars are water-soluble arsenic species predominant in marine algae and other seafood including mussels and oysters. They typically occur at levels ranging from 2 to 50 mg arsenic/kg dry weight. Most of the arsenosugars contain arsenic as a dimethylarsinoyl group (Me2As(O)-), commonly referred to as the oxo forms, but thio analogues have also been identified in marine organisms and as metabolic products of oxo-arsenosugars. So far, no data regarding toxicity and toxicokinetics of thio-arsenosugars are available. This in vitro-based study indicates that thio-dimethylarsenosugar-glycerol exerts neither pronounced cytotoxicity nor genotoxicity even though this arsenical was bioavailable to human hepatic (HepG2) and urothelial (UROtsa) cells. Experiments with the Caco-2 intestinal barrier model mimicking human absorption indicate for the thio-arsenosugar-glycerol higher intestinal bioavailability as compared to the oxo-arsenosugars. Nevertheless, absorption estimates were much lower in comparison to other arsenicals including arsenite and arsenic-containing hydrocarbons. Arsenic speciation in cell lysates revealed that HepG2 cells are able to metabolise the thio-arsenosugar-glycerol to some extent to dimethylarsinic acid (DMA). These first in vitro data cannot fully exclude risks to human health related to the presence of thio-arsenosugars in food. (C) 2016 Elsevier GmbH. All rights reserved. KW - Arsenic KW - Thio-arsenosugar-glycerol KW - Toxicity KW - Toxicokinetics KW - Genotoxicity KW - Metabolism Y1 - 2016 U6 - https://doi.org/10.1016/j.jtemb.2016.04.013 SN - 0946-672X VL - 38 SP - 150 EP - 156 PB - Springer Publishing Company CY - Jena ER - TY - JOUR A1 - Ebert, Franziska A1 - Thomann, Marlies A1 - Witt, Barbara A1 - Müller, Sandra Marie A1 - Meyer, Sören A1 - Weber, Till A1 - Christmann, Markus A1 - Schwerdtle, Tanja T1 - Evaluating long-term cellular effects of the arsenic species thio-DMA(V): qPCR-based gene expression as screening tool JF - Journal of trace elements in medicine and biology N2 - Thio-dimethylarsinic acid (thio-DMA(V)) is a human urinary metabolite of the class 1 human carcinogen inorganic arsenic as well as of arsenosugars. Thio-DMA(V) exerts strong cellular toxicity, whereas its toxic modes of action are not fully understood. For the first time, this study characterises the impact of a long-term (21 days) in vitro incubation of thio-DMA(V) on the expression of selected genes related to cell death, stress response, epigenetics and DNA repair. The observed upregulation of DNMT1 might be a cellular compensation to counterregulate the in a very recent study observed massive global DNA hypomethylation after chronic thio-DMAv incubation. Moreover, our data suggest that chronic exposure towards subcytotoxic, pico- to nanomolar concentrations of thio-DMA(V) causes a stress response in human urothelial cells. The upregulation of genes encoding for proteins of DNA repair (Apex1,Lig1, XRCC1,DDB2, XPG, ATR) as well as damage response (GADD45A, GADD45G, Trp53) indicate a potential genotoxic risk emanating from thio-DMA(V) after long-term incubation. (C) 2016 Elsevier GmbH. All rights reserved. KW - Thio-dimethylarsinic acid KW - Long-term cellular toxicity KW - qPCR-based gene expression screening KW - GADD45A and GADD45G KW - DNMT1 KW - Cellular damage response Y1 - 2016 U6 - https://doi.org/10.1016/j.jtemb.2016.06.004 SN - 0946-672X VL - 37 SP - 78 EP - 84 PB - Yokohama Publishers CY - Jena ER -