TY  - GEN
A1  - Pieper, Imke
A1  - Wehe, Christoph A.
A1  - Bornhorst, Julia
A1  - Ebert, Franziska
A1  - Leffers, Larissa
A1  - Holtkamp, Michael
A1  - Höseler, Pia
A1  - Weber, Till
A1  - Mangerich, Aswin
A1  - Bürkle, Alexander
A1  - Karst, Uwe
A1  - Schwerdtle, Tanja
T1  - Mechanisms of Hg species induced toxicity in cultured human astrocytes
BT  - genotoxicity and DNA-damage response
N2  - The toxicologically most relevant mercury (Hg) species for human exposure is methylmercury (MeHg). Thiomersal is a common preservative used in some vaccine formulations. The aim of this study is to get further mechanistic insight into the yet not fully understood neurotoxic modes of action of organic Hg species. Mercury species investigated include MeHgCl and thiomersal. Additionally HgCl2 was studied, since in the brain mercuric Hg can be formed by dealkylation of the organic species. As a cellular system astrocytes were used. In vivo astrocytes provide the environment necessary for neuronal function. In the present study, cytotoxic effects of the respective mercuricals increased with rising alkylation level and correlated with their cellular bioavailability. Further experiments revealed for all species at subcytotoxic concentrations no induction of DNA strand breaks, whereas all species massively increased H2O2-induced DNA strand breaks. This co- genotoxic effect is likely due to a disturbance of the cellular DNA damage response. Thus, at nanomolar, sub-cytotoxic concentrations, all three mercury species strongly disturbed poly(ADP-ribosyl)ation, a signalling reaction induced by DNA strand breaks. Interestingly, the molecular mechanism behind this inhibition seems to be different for the species. Since chronic PARP-1 inhibition is also discussed to sacrifice neurogenesis and learning abilities, further experiments on neurons and in vivo studies could be helpful to clarify whether the inhibition of poly(ADP-ribosyl) ation contributes to organic Hg induced neurotoxicity.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 171 
KW  - adduct formation
KW  - cell-death
KW  - exposure
KW  - manganese
KW  - methylmercury
KW  - neurodegenerative diseases
KW  - neurotoxicity
KW  - poly(ADP-ribose) polymerase-1
KW  - repair
KW  - thimerosal
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-74379
SP  - 662
EP  - 671
ER  - 
TY  - GEN
A1  - Winkelbeiner, Nicola Lisa
A1  - Wandt, Viktoria Klara Veronika
A1  - Ebert, Franziska
A1  - Lossow, Kristina
A1  - Bankoglu, Ezgi E.
A1  - Martin, Maximilian
A1  - Mangerich, Aswin
A1  - Stopper, Helga
A1  - Bornhorst, Julia
A1  - Kipp, Anna Patricia
A1  - Schwerdtle, Tanja
T1  - A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice
BT  - Impact of Sex and Age
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1021 
KW  - maintenance of genomic integrity
KW  - ageing
KW  - sex
KW  - DNA damage
KW  - base excision repair (incision activity)
KW  - DNA damage response
KW  - poly(ADP-ribosyl)ation
KW  - liver
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-484831
SN  - 1866-8372
IS  - 1021
ER  -