@misc{WinkelbeinerWandtEbertetal.2020, author = {Winkelbeiner, Nicola Lisa and Wandt, Viktoria Klara Veronika and Ebert, Franziska and Lossow, Kristina and Bankoglu, Ezgi E. and Martin, Maximilian and Mangerich, Aswin and Stopper, Helga and Bornhorst, Julia and Kipp, Anna Patricia and Schwerdtle, Tanja}, title = {A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1021}, issn = {1866-8372}, doi = {10.25932/publishup-48483}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-484831}, pages = {21}, year = {2020}, abstract = {Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2'-deoxyguanosine (8-oxodG), 5-hydroxy-2'-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.}, language = {en} } @article{BornhorstEbertMeyeretal.2020, author = {Bornhorst, Julia and Ebert, Franziska and Meyer, S{\"o}ren and Ziemann, Vanessa and Xiong, Chan and Guttenberger, Nikolaus and Raab, Andrea and Baesler, Jessica and Aschner, Michael and Feldmann, J{\"o}rg and Francesconi, Kevin and Raber, Georg and Schwerdtle, Tanja}, title = {Toxicity of three types of arsenolipids}, series = {Metallomics}, volume = {12}, journal = {Metallomics}, number = {5}, publisher = {Oxford University Press}, address = {Cambridge}, issn = {1756-591X}, doi = {https://doi.org/10.1039/d0mt00039f}, pages = {794 -- 798}, year = {2020}, abstract = {Although fish and seafood are well known for their nutritional benefits, they contain contaminants that might affect human health. Organic lipid-soluble arsenic species, so called arsenolipids, belong to the emerging contaminants in these food items; their toxicity has yet to be systematically studied. Here, we apply the in vivo model Caenorhabditis elegans to assess the effects of two arsenic-containing hydrocarbons (AsHC), a saturated arsenic-containing fatty acid (AsFA), and an arsenic-containing triacylglyceride (AsTAG) in a whole organism. Although all arsenolipids were highly bioavailable in Caenorhabditis elegans, only the AsHCs were substantially metabolized to thioxylated or shortened metabolic products and induced significant toxicity, affecting both survival and development. Furthermore, the AsHCs were several fold more potent as compared to the toxic reference arsenite. This study clearly indicates the need for a full hazard identification of subclasses of arsenolipids to assess whether they pose a risk to human health.}, language = {en} } @article{WinkelbeinerWandtEbertetal.2020, author = {Winkelbeiner, Nicola Lisa and Wandt, Viktoria Klara Veronika and Ebert, Franziska and Lossow, Kristina and Bankoglu, Ezgi E. and Martin, Maximilian and Mangerich, Aswin and Stopper, Helga and Bornhorst, Julia and Kipp, Anna Patricia and Schwerdtle, Tanja}, title = {A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {18}, publisher = {Molecular Diversity Preservation International}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms21186600}, pages = {19}, year = {2020}, abstract = {Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2'-deoxyguanosine (8-oxodG), 5-hydroxy-2'-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.}, language = {en} } @article{WittStibollerRaschkeetal.2021, author = {Witt, Barbara and Stiboller, Michael and Raschke, Stefanie and Friese, Sharleen and Ebert, Franziska and Schwerdtle, Tanja}, title = {Characterizing effects of excess copper levels in a human astrocytic cell line with focus on oxidative stress markers}, series = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS}, volume = {65}, journal = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS}, publisher = {Elsevier}, address = {M{\"u}nchen}, issn = {1878-3252}, doi = {10.1016/j.jtemb.2021.126711}, pages = {9}, year = {2021}, abstract = {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.}, language = {en} } @inproceedings{WandtWinkelbeinerLossowetal.2021, author = {Wandt, Viktoria Klara Veronika and Winkelbeiner, Nicola and Loßow, Kristina and Kopp, Johannes and Simon, Luise and Ebert, Franziska and Kipp, Anna Patricia and Schwerdtle, Tanja}, title = {Trace elements, ageing, and sex. Impact on genome stability}, series = {Naunyn-Schmiedeberg's archives of pharmacology}, volume = {394}, booktitle = {Naunyn-Schmiedeberg's archives of pharmacology}, number = {Suppl. 1}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0028-1298}, doi = {10.1007/s00210-021-02066-6}, pages = {S13 -- S13}, year = {2021}, language = {en} } @article{WandtWinkelbeinerBornhorstetal.2021, author = {Wandt, Viktoria Klara Veronika and Winkelbeiner, Nicola Lisa and Bornhorst, Julia and Witt, Barbara and Raschke, Stefanie and Simon, Luise and Ebert, Franziska and Kipp, Anna Patricia and Schwerdtle, Tanja}, title = {A matter of concern}, series = {Redox Biology}, volume = {41}, journal = {Redox Biology}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.redox.2021.101877}, pages = {13}, year = {2021}, abstract = {Neurons are post-mitotic cells in the brain and their integrity is of central importance to avoid neurodegeneration. Yet, the inability of self-replenishment of post-mitotic cells results in the need to withstand challenges from numerous stressors during life. Neurons are exposed to oxidative stress due to high oxygen consumption during metabolic activity in the brain. Accordingly, DNA damage can occur and accumulate, resulting in genome instability. In this context, imbalances in brain trace element homeostasis are a matter of concern, especially regarding iron, copper, manganese, zinc, and selenium. Although trace elements are essential for brain physiology, excess and deficient conditions are considered to impair neuronal maintenance. Besides increasing oxidative stress, DNA damage response and repair of oxidative DNA damage are affected by trace elements. Hence, a balanced trace element homeostasis is of particular importance to safeguard neuronal genome integrity and prevent neuronal loss. This review summarises the current state of knowledge on the impact of deficient, as well as excessive iron, copper, manganese, zinc, and selenium levels on neuronal genome stability}, language = {en} } @article{NicolaiWittFrieseetal.2022, author = {Nicolai, Merle Marie and Witt, Barbara and Friese, Sharleen and Michaelis, Vivien and H{\"o}lz-Armstrong, Lisa and Martin, Maximilian and Ebert, Franziska and Schwerdtle, Tanja and Bornhorst, Julia}, title = {Mechanistic studies on the adverse effects of manganese overexposure in differentiated LUHMES cells}, series = {Food and chemical toxicology}, volume = {161}, journal = {Food and chemical toxicology}, publisher = {Elsevier}, address = {Oxford}, issn = {0278-6915}, doi = {10.1016/j.fct.2022.112822}, pages = {10}, year = {2022}, abstract = {Manganese (Mn) is an essential trace element, but overexposure is associated with toxicity and neurological dysfunction. Accumulation of Mn can be observed in dopamine-rich regions of the brain in vivo and Mn-induced oxidative stress has been discussed extensively. Nevertheless, Mn-induced DNA damage, adverse effects of DNA repair, and possible resulting consequences for the neurite network are not yet characterized. For this, LUHMES cells were used, as they differentiate into dopaminergic-like neurons and form extensive neurite networks. Experiments were conducted to analyze Mn bioavailability and cytotoxicity of MnCl2, indicating a dose-dependent uptake and substantial cytotoxic effects. DNA damage, analyzed by means of 8-oxo-7,8-dihydro-2'-guanine (8oxodG) and single DNA strand break formation, showed significant dose- and time-dependent increase of DNA damage upon 48 h Mn exposure. Furthermore, the DNA damage response was increased which was assessed by analytical quantification of poly(ADP-ribosyl)ation (PARylation). Gene expression of the respective DNA repair genes was not significantly affected. Degradation of the neuronal network is significantly altered by 48 h Mn exposure. Altogether, this study contributes to the characterization of Mn-induced neurotoxicity, by analyzing the adverse effects of Mn on genome integrity in dopaminergic-like neurons and respective outcomes.}, language = {en} }