TY - JOUR A1 - Ghanawi, Hanaa A1 - Hennlein, Luisa A1 - Zare, Abdolhossein A1 - Bader, Jakob A1 - Salehi, Saeede A1 - Hornburg, Daniel A1 - Ji, Changhe A1 - Sivadasan, Rajeeve A1 - Drepper, Carsten A1 - Meissner, Felix A1 - Mann, Matthias A1 - Jablonka, Sibylle A1 - Briese, Michael A1 - Sendtner, Michael T1 - Loss of full-length hnRNP R isoform impairs DNA damage response in motoneurons by inhibiting Yb1 recruitment to chromatin JF - Nucleic Acids Research N2 - Neurons critically rely on the functions of RNA-binding proteins to maintain their polarity and resistance to neurotoxic stress. HnRNP R has a diverse range of post-transcriptional regulatory functions and is important for neuronal development by regulating axon growth. Hnrnpr pre-mRNA undergoes alternative splicing giving rise to a full-length protein and a shorter isoform lacking its N-terminal acidic domain. To investigate functions selectively associated with the full-length hnRNP R isoform, we generated a Hnrnpr knockout mouse (Hnrnpr\(^{tm1a/tm1a}\)) in which expression of full-length hnRNP R was abolished while production of the truncated hnRNP R isoform was retained. Motoneurons cultured from Hnrnpr\(^{tm1a/tm1a}\) mice did not show any axonal growth defects but exhibited enhanced accumulation of double-strand breaks and an impaired DNA damage response upon exposure to genotoxic agents. Proteomic analysis of the hnRNP R interactome revealed the multifunctional protein Yb1 as a top interactor. Yb1-depleted motoneurons were defective in DNA damage repair. We show that Yb1 is recruited to chromatin upon DNA damage where it interacts with gamma-H2AX, a mechanism that is dependent on full-length hnRNP R. Our findings thus suggest a novel role of hnRNP R in maintaining genomic integrity and highlight the function of its N-terminal acidic domain in this context. KW - nuclear ribonucleoprotein-R KW - determining gene-product KW - actin messenger RNA KW - comet assay KW - genome wide KW - spinal cord KW - YB-1 KW - SMN KW - interacts KW - enrichment Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265687 VL - 49 IS - 21 ER - TY - JOUR A1 - Bankoglu, Ezgi Eyluel A1 - Stipp, Franzisca A1 - Gerber, Johanna A1 - Seyfried, Florian A1 - Heidland, August A1 - Bahner, Udo A1 - Stopper, Helga T1 - Effect of cryopreservation on DNA damage and DNA repair activity in human blood samples in the comet assay JF - Archives of Toxicology N2 - The comet assay is a commonly used method to determine DNA damage and repair activity in many types of samples. In recent years, the use of the comet assay in human biomonitoring became highly attractive due to its various modified versions, which may be useful to determine individual susceptibility in blood samples. However, in human biomonitoring studies, working with large sample numbers that are acquired over an extended time period requires some additional considerations. One of the most important issues is the storage of samples and its effect on the outcome of the comet assay. Another important question is the suitability of different blood preparations. In this study, we analysed the effect of cryopreservation on DNA damage and repair activity in human blood samples. In addition, we investigated the suitability of different blood preparations. The alkaline and FPG as well as two different types of repair comet assay and an in vitro hydrogen peroxide challenge were applied. Our results confirmed that cryopreserved blood preparations are suitable for investigating DNA damage in the alkaline and FPG comet assay in whole blood, buffy coat and PBMCs. Ex vivo hydrogen peroxide challenge yielded its optimal effect in isolated PBMCs. The utilised repair comet assay with either UVC or hydrogen peroxide-induced lesions and an aphidicolin block worked well in fresh PBMCs. Cryopreserved PBMCs could not be used immediately after thawing. However, a 16-h recovery with or without mitotic stimulation enabled the application of the repair comet assay, albeit only in a surviving cell fraction. KW - human biomonitoring KW - DNA damage KW - DNA repair KW - comet assay KW - blood samples Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265326 VL - 95 IS - 5 ER - TY - JOUR A1 - Milić, Mirta A1 - Ceppi, Marcello A1 - Bruzzone, Marco A1 - Azqueta, Amaya A1 - Brunborg, Gunnar A1 - Godschalk, Roger A1 - Koppen, Gudrun A1 - Langie, Sabine A1 - Møller, Peter A1 - Teixeira, João Paulo A1 - Alija, Avdulla A1 - Anderson, Diana A1 - Andrade, Vanessa A1 - Andreoli, Cristina A1 - Asllani, Fisnik A1 - Bangkoglu, Ezgi Eyluel A1 - Barančoková, Magdalena A1 - Basaran, Nursen A1 - Boutet-Robinet, Elisa A1 - Buschini, Annamaria A1 - Cavallo, Delia A1 - Costa Pereira, Cristiana A1 - Costa, Carla A1 - Costa, Solange A1 - Da Silva, Juliana A1 - Del Boˊ, Cristian A1 - Dimitrijević Srećković, Vesna A1 - Djelić, Ninoslav A1 - Dobrzyńska, Malgorzata A1 - Duračková, Zdenka A1 - Dvořáková, Monika A1 - Gajski, Goran A1 - Galati, Serena A1 - García Lima, Omar A1 - Giovannelli, Lisa A1 - Goroshinskaya, Irina A. A1 - Grindel, Annemarie A1 - Gutzkow, Kristine B. A1 - Hernández, Alba A1 - Hernández, Carlos A1 - Holven, Kirsten B. A1 - Ibero-Baraibar, Idoia A1 - Ottestad, Inger A1 - Kadioglu, Ela A1 - Kažimirová, Alena A1 - Kuznetsova, Elena A1 - Ladeira, Carina A1 - Laffon, Blanca A1 - Lamonaca, Palma A1 - Lebailly, Pierre A1 - Louro, Henriqueta A1 - Mandina Cardoso, Tania A1 - Marcon, Francesca A1 - Marcos, Ricard A1 - Moretti, Massimo A1 - Moretti, Silvia A1 - Najafzadeh, Mojgan A1 - Nemeth, Zsuzsanna A1 - Neri, Monica A1 - Novotna, Bozena A1 - Orlow, Irene A1 - Paduchova, Zuzana A1 - Pastor, Susana A1 - Perdry, Hervé A1 - Spremo-Potparević, Biljana A1 - Ramadhani, Dwi A1 - Riso, Patrizia A1 - Rohr, Paula A1 - Rojas, Emilio A1 - Rossner, Pavel A1 - Safar, Anna A1 - Sardas, Semra A1 - Silva, Maria João A1 - Sirota, Nikolay A1 - Smolkova, Bozena A1 - Staruchova, Marta A1 - Stetina, Rudolf A1 - Stopper, Helga A1 - Surikova, Ekaterina I. A1 - Ulven, Stine M. A1 - Ursini, Cinzia Lucia A1 - Valdiglesias, Vanessa A1 - Valverde, Mahara A1 - Vodicka, Pavel A1 - Volkovova, Katarina A1 - Wagner, Karl-Heinz A1 - Živković, Lada A1 - Dušinská, Maria A1 - Collins, Andrew R. A1 - Bonassi, Stefano T1 - The hCOMET project: International database comparison of results with the comet assay in human biomonitoring. Baseline frequency of DNA damage and effect of main confounders JF - Mutation Research/Reviews in Mutation Research N2 - The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations. KW - comet assay KW - DNA damage KW - pooled analysis KW - human biomonitoring KW - biomarkers Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-371614 VL - 787 ER - TY - JOUR A1 - Ilin, Alexander A1 - Kulmanov, Murat A1 - Nersesyan, Armen A1 - Stopper, Helga T1 - Genotoxic activity of the new pharmaceutical FS-1 in Salmonella/microsome test and mouse lymphoma L5178Y cells JF - Journal of BUON N2 - Purpose: The purpose of this study was to determine possible genotoxic effects of a new very promising antibacterial/ antiviral drug FS-1. Methods: The drug was tested in TA98, TA100, TA102, TA 1535 and TA1537 strains of Salmonella (Ames test) with and without metabolic activation, and also in mouse lymphoma L5178Y cells by means of micronucleus and comet assays. In microbes the drug was tested at concentrations up to 500 \(\mu\)g/plate and in mouse lymphoma cells up to 2,000 \(\mu\)g/ml. Results: In both test-systems in all experiments completely negative results were obtained although FS-1 was tested at maximum tolerated doses. Conclusions: The drug is not genotoxic. This is advantageous because many antibacterial/antiviral drugs possess such activity. KW - mutagenicity KW - antibacterial/antiviral drug KW - comet assay KW - mouse lymphoma L5178Y KW - Salmonella/microsome assay KW - micronucleus test Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143769 VL - 20 IS - 2 ER -