Polycyclic aromatic hydrocarbons (PAHs) represent a class of widely distributed environmental pollutants that have been primarily studied as genotoxic compounds. Their mutagenicity/genotoxicity largely depends on their oxidative metabolism leading to the production of dihydrodiol epoxide metabolites, as well as additional metabolites contributing to oxidative DNA damage, such as PAH quinones. However, both parental PAHs and their metabolites, including PAH quinones or hydroxylated PAHs, have been shown to produce various types of non-genotoxic effects. These include e.g., activation of the aryl hydrocarbon receptor and/or additional nuclear receptors, activation of membrane receptors, including tyrosine kinases and G-protein coupled receptors, or activation of intracellular signaling pathways, such as mitogen-activated protein kinases, Akt kinase and Ca2+-dependent signaling. These pathways may, together with the cellular DNA damage responses, modulate cell proliferation, cell survival or cell-to-cell communication, thus contributing to the known carcinogenic effects of PAHs. In the present review, we summarize some of the known non-genotoxic effects of PAHs, focusing primarily on those that have also been shown to be modulated by PAH metabolites. Despite the limitations of the available data, it seems evident that more attention should be paid to the discrimination between the potential non-genotoxic effects of parental PAHs and those of their metabolites. This may provide further insight into the mechanisms of toxicity of this large and diverse group of environmental pollutants.

• MeSH
• látky znečišťující životní prostředí farmakokinetika   toxicita   MeSH
• lidé MeSH
• metabolická aktivace MeSH
• mutageny farmakokinetika   toxicita   MeSH
• oxidační stres MeSH
• polycyklické aromatické uhlovodíky farmakokinetika   toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.

• MeSH
• benzopyren toxicita   MeSH
• embryo nesavčí účinky léků   embryologie   metabolismus   MeSH
• embryonální vývoj účinky léků   genetika   MeSH
• etoposid toxicita   MeSH
• fragmentace DNA účinky léků   MeSH
• kamptothecin toxicita   MeSH
• kometový test MeSH
• mutageny toxicita   MeSH
• oprava DNA * MeSH
• poškození DNA * MeSH
• ryby embryologie   genetika   MeSH
• testy genotoxicity metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Following advancements in the field of genotoxicology, it has become widely accepted that 3D models are not only more physiologically relevant but also have the capacity to elucidate more complex biological processes that standard 2D monocultures are unable to. Whilst 3D liver models have been developed to evaluate the short-term genotoxicity of chemicals, the aim of this study was to develop a 3D model that could be used with the regulatory accepted in vitro micronucleus (MN) following low-dose, longer-term (5 days) exposure to engineered nanomaterials (ENMs). A comparison study was carried out between advanced models generated from two commonly used liver cell lines, namely HepaRG and HepG2, in spheroid format. While both spheroid systems displayed good liver functionality and viability over 14 days, the HepaRG spheroids lacked the capacity to actively proliferate and, therefore, were considered unsuitable for use with the MN assay. This study further demonstrated the efficacy of the in vitro 3D HepG2 model to be used for short-term (24 h) exposures to genotoxic chemicals, aflatoxin B1 (AFB1) and methyl-methanesulfonate (MMS). The 3D HepG2 liver spheroids were shown to be more sensitive to DNA damage induced by AFB1 and MMS when compared to the HepG2 2D monoculture. This 3D model was further developed to allow for longer-term (5 day) ENM exposure. Four days after seeding, HepG2 spheroids were exposed to Zinc Oxide ENM (0-2 µg/ml) for 5 days and assessed using both the cytokinesis-block MN (CBMN) version of the MN assay and the mononuclear MN assay. Following a 5-day exposure, differences in MN frequency were observed between the CBMN and mononuclear MN assay, demonstrating that DNA damage induced within the first few cell cycles is distributed across the mononucleated cell population. Together, this study demonstrates the necessity to adapt the MN assay accordingly, to allow for the accurate assessment of genotoxicity following longer-term, low-dose ENM exposure.

• MeSH
• aflatoxin B1 toxicita   MeSH
• biologické modely MeSH
• buněčné kultury metody   MeSH
• buněčné linie MeSH
• buněčné sféroidy * MeSH
• buňky Hep G2 MeSH
• hepatocyty účinky léků   MeSH
• játra účinky léků   MeSH
• lidé MeSH
• methylmethansulfonát toxicita   MeSH
• mikrojaderné testy metody   MeSH
• mutageny toxicita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Replication factor C (RFC), a heteropentamer of RFC1-5, loads PCNA onto DNA during replication and repair. Once DNA synthesis has ceased, PCNA must be unloaded. Recent findings assign the uloader role primarily to an RFC-like (RLC) complex, in which the largest RFC subunit, RFC1, has been replaced with ATAD5 (ELG1 in Saccharomyces cerevisiae). ATAD5-RLC appears to be indispensable, given that Atad5 knock-out leads to embryonic lethality. In order to learn how the retention of PCNA on DNA might interfere with normal DNA metabolism, we studied the response of ATAD5-depleted cells to several genotoxic agents. We show that ATAD5 deficiency leads to hypersensitivity to methyl methanesulphonate (MMS), camptothecin (CPT) and mitomycin C (MMC), agents that hinder the progression of replication forks. We further show that ATAD5-depleted cells are sensitive to poly(ADP)ribose polymerase (PARP) inhibitors and that the processing of spontaneous oxidative DNA damage contributes towards this sensitivity. We posit that PCNA molecules trapped on DNA interfere with the correct metabolism of arrested replication forks, phenotype reminiscent of defective homologous recombination (HR). As Atad5 heterozygous mice are cancer-prone and as ATAD5 mutations have been identified in breast and endometrial cancers, our finding may open a path towards the therapy of these tumours.

• MeSH
• antitumorózní látky farmakologie   MeSH
• ATPázy spojené s různými buněčnými aktivitami genetika   metabolismus   MeSH
• buněčné linie MeSH
• chromatin enzymologie   MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• DNA metabolismus   MeSH
• ftalaziny farmakologie   MeSH
• kur domácí MeSH
• mutageny toxicita   MeSH
• nádorové buněčné linie MeSH
• nestabilita genomu MeSH
• PARP inhibitory farmakologie   MeSH
• piperaziny farmakologie   MeSH
• poly-ADP-ribóza-polymeráza 1 metabolismus   MeSH
• poškození DNA * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aryl hydrocarbon receptor (AhR) transcription factor is activated by polycyclic aromatic hydrocarbons (PAH) and other ligands. Activated AhR binds to dioxin responsive elements (DRE) and initiates transcription of target genes, including the gene encoding prostaglandin endoperoxide synthase 2 (PTGS-2), which is also activated by the transcription factor NF-ĸB. PTGS-2 catalyzes the conversion of arachidonic acid (AA) into prostaglandins, thromboxanes or isoprostanes. 15-F2t-Isoprostane (IsoP), regarded as a universal marker of lipid peroxidation, is also induced by PAH exposure. We investigated the processes associated with lipid peroxidation in human alveolar basal epithelial cells (A549) exposed for 4 h or 24 h to model PAH (benzo[a]pyrene, BaP; 3-nitrobenzanthrone, 3-NBA) and organic extracts from ambient air particulate matter (EOM), collected in two seasons in a polluted locality. Both EOM induced the expression of CYP1A1 and CYP1B1; 24 h treatment significantly reduced PTGS-2 expression. IsoP levels decreased after both exposure periods, while the concentration of AA was not affected. The effects induced by BaP were similar to EOM except for increased IsoP levels after 4 h exposure and elevated AA concentration after 24 h treatment. In contrast, 3-NBA treatment did not induce CYP expression, had a weak effect on PTGS-2 expression, and, similar to BaP, induced IsoP levels after 4 h exposure and AA levels after 24 h treatment. All tested compounds induced the activity of NF-ĸB after the longer exposure period. In summary, our data suggest that EOM, and partly BaP, reduce lipid peroxidation by a mechanism that involves AhR-dependent inhibition of PTGS-2 expression. The effect of 3-NBA on IsoP levels is probably mediated by a different mechanism independent of AhR activation.

• MeSH
• benz(a)anthraceny toxicita   MeSH
• benzopyren toxicita   MeSH
• buňky A549 MeSH
• cyklooxygenasa 1 metabolismus   MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• lidé MeSH
• mutageny toxicita   MeSH
• nádorové buněčné linie MeSH
• NF-kappa B metabolismus   MeSH
• peroxidace lipidů účinky léků   MeSH
• pevné částice toxicita   MeSH
• pneumocyty účinky léků   MeSH
• polycyklické aromatické uhlovodíky toxicita   MeSH
• receptory aromatických uhlovodíků metabolismus   MeSH
• transkripční faktory bHLH metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are a group of environmental pollutants found in complex mixtures together with PAHs. In contrast to the extensively studied PAHs, which have been established to have mutagenic and carcinogenic properties, much less is known about the effects of oxy-PAHs. The present work aimed to investigate the genotoxic potency of a set of environmentally relevant oxy-PAHs along with environmental soil samples in human bronchial epithelial cells (HBEC). We found that all oxy-PAHs tested induced DNA strand breaks in a dose-dependent manner and some of the oxy-PAHs further induced micronuclei formation. Our results showed weak effects in response to the oxy-PAH containing subfraction of the soil sample. The genotoxic potency was confirmed in both HBEC and HepG2 cells following exposure to oxy-PAHs by an increased level of phospho-Chk1, a biomarker used to estimate the carcinogenic potency of PAHs in vitro. We further exposed zebrafish embryos to single oxy-PAHs or a binary mixture with PAH benzo[a]pyrene (B[a]P) and found the mixture to induce comparable or greater effects on the induction of DNA strand breaks compared to the sum of that induced by B[a]P and oxy-PAHs alone. In conclusion, oxy-PAHs were found to elicit genotoxic effects at similar or higher levels to that of B[a]P which indicates that oxy-PAHs may contribute significantly to the total carcinogenic potency of environmental PAH mixtures. This emphasizes further investigations of these compounds as well as the need to include oxy-PAHs in environmental monitoring programs in order to improve health risk assessment.

• MeSH
• buněčné kultury MeSH
• buňky Hep G2 MeSH
• dánio pruhované embryologie   MeSH
• embryonální vývoj účinky léků   genetika   MeSH
• epitelové buňky účinky léků   patologie   MeSH
• kometový test MeSH
• kyslík chemie   MeSH
• lidé MeSH
• monitorování životního prostředí metody   MeSH
• mutageny analýza   toxicita   MeSH
• polycyklické aromatické uhlovodíky analýza   toxicita   MeSH
• poškození DNA * MeSH
• viabilita buněk účinky léků   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Exposure to aristolochic acid (AA) is associated with human nephropathy and urothelial cancer. The tumour suppressor TP53 is a critical gene in carcinogenesis and frequently mutated in AA-induced urothelial tumours. We investigated the impact of p53 on AAI-induced nephrotoxicity and DNA damage in vivo by treating Trp53(+/+), Trp53(+/-) and Trp53(-/-) mice with 3.5 mg/kg body weight (bw) AAI daily for 2 or 6 days. Renal histopathology showed a gradient of intensity in proximal tubular injury from Trp53(+/+) to Trp53(-/-) mice, especially after 6 days. The observed renal injury was supported by nuclear magnetic resonance (NMR)-based metabonomic measurements, where a consistent Trp53 genotype-dependent trend was observed for urinary metabolites that indicate aminoaciduria (i.e. alanine), lactic aciduria (i.e. lactate) and glycosuria (i.e. glucose). However, Trp53 genotype had no impact on AAI-DNA adduct levels, as measured by 32P-postlabelling, in either target (kidney and bladder) or non-target (liver) tissues, indicating that the underlying mechanisms of p53-related AAI-induced nephrotoxicity cannot be explained by differences in AAI genotoxicity. Performing gas chromatography-mass spectrometry (GC-MS) on kidney tissues showed metabolic pathways affected by AAI treatment, but again Trp53 status did not clearly impact on such metabolic profiles. We also cultured primary mouse embryonic fibroblasts (MEFs) derived from Trp53(+/+), Trp53(+/-) and Trp53(-/-) mice and exposed them to AAI in vitro (50 µM for up to 48 h). We found that Trp53 genotype impacted on the expression of NAD(P)H:quinone oxidoreductase (Nqo1), a key enzyme involved in AAI bioactivation. Nqo1 induction was highest in Trp53(+/+) MEFs and lowest in Trp53(-/-) MEFs; and it correlated with AAI-DNA adduct formation, with lowest adduct levels being observed in AAI-exposed Trp53(-/-) MEFs. Overall, our results clearly demonstrate that p53 status impacts on AAI-induced renal injury, but the underlying mechanism(s) involved remain to be further explored. Despite the impact of p53 on AAI bioactivation and DNA damage in vitro, such effects were not observed in vivo.

• MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• exprese genu účinky léků   MeSH
• fibroblasty účinky léků   metabolismus   patologie   MeSH
• kultivované buňky MeSH
• kyseliny aristolochové metabolismus   toxicita   MeSH
• mutageny metabolismus   toxicita   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• NAD(P)H dehydrogenasa (chinon) genetika   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• poškození DNA * MeSH
• proximální tubuly ledvin účinky léků   metabolismus   patologie   MeSH
• vyšetření funkce ledvin MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

DNA damage is a ubiquitous threat endangering DNA integrity in all living organisms. Responses to DNA damage include, among others, induction of DNA repair and blocking of cell cycle progression in order to prevent transmission of damaged DNA to daughter cells. Here, we tested the effect of the antibiotic zeocin, inducing double stranded DNA breaks, on the cell cycle of synchronized cultures of the green alga Chlamydomonas reinhardtii. After zeocin application, DNA replication partially occurred but nuclear and cellular divisions were completely blocked. Application of zeocin combined with caffeine, known to alleviate DNA checkpoints, decreased cell viability significantly. This was probably caused by a partial overcoming of the cell cycle progression block in such cells, leading to aberrant cell divisions. The cell cycle block was accompanied by high steady state levels of mitotic cyclin-dependent kinase activity. The data indicate that DNA damage response in C. reinhardtii is connected to the cell cycle block, accompanied by increased and stabilized mitotic cyclin-dependent kinase activity.

• MeSH
• bleomycin toxicita   MeSH
• Chlamydomonas reinhardtii účinky léků   genetika   MeSH
• cyklin-dependentní kinasy metabolismus   MeSH
• cytostatické látky toxicita   MeSH
• DNA rostlinná účinky léků   MeSH
• dvouřetězcové zlomy DNA MeSH
• kofein farmakologie   MeSH
• kontrolní body buněčného cyklu MeSH
• mutageny toxicita   MeSH
• replikace DNA MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Gulf of Follonica (Italy) is impacted by the chemical pollution from ancient mining activity and present industrial processes. This study was aimed to determine the bioavailability of dioxin-like compounds (DLCs) in coastal marine environment and to assess the genotoxic potential of waste waters entering the sea from an industrial canal. Moderately high levels of DCLs compounds (∑ PCDDs + PCDFs 2.18–29.00 pg/g dry wt) were detected in Mytilus galloprovincialis transplanted near the waste waters canal and their corresponding Toxic Equivalents (TEQs) calculated. In situ exposed mussels did not show any genotoxic effect (by Comet and Micronucleus assay). Otherwise, laboratory exposure to canal waters exhibited a reduced genomic template stability (by RAPD-PCR assay) but not DNA or chromosomal damage. Our data reveal the need to focus on the levels and distribution of DLCs in edible species from the study area considering their potential transfer to humans through the consumption of sea food.

• MeSH
• biologická dostupnost MeSH
• chemické látky znečišťující vodu analýza   toxicita   MeSH
• dioxiny analýza   toxicita   MeSH
• lidé MeSH
• monitorování životního prostředí metody   MeSH
• mutageny analýza   chemie   toxicita   MeSH
• Mytilus účinky léků   genetika   MeSH
• technika náhodné amplifikace polymorfní DNA MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Itálie MeSH

The exceptionally high cellular uptake of gold nanorods (GNRs) bearing cationic surfactants makes them a promising tool for biomedical applications. Given the known specific toxic and stress effects of some preparations of cationic nanoparticles, the purpose of this study was to evaluate, in an in vitro and in vivo in mouse, the potential harmful effects of GNRs coated with (16-mercaptohexadecyl)trimethylammonium bromide (MTABGNRs). Interestingly, even after cellular accumulation of high amounts of MTABGNRs sufficient for induction of photothermal effect, no genotoxicity (even after longer-term accumulation), induction of autophagy, destabilization of lysosomes (dominant organelles of their cellular destination), alterations of actin cytoskeleton, or in cell migration could be detected in vitro. In vivo, after intravenous administration, the majority of GNRs accumulated in mouse spleen followed by lungs and liver. Microscopic examination of the blood and spleen showed that GNRs interacted with white blood cells (mononuclear and polymorphonuclear leukocytes) and thrombocytes, and were delivered to the spleen red pulp mainly as GNR-thrombocyte complexes. Importantly, no acute toxic effects of MTABGNRs administered as 10 or 50 μg of gold per mice, as well as no pathological changes after their high accumulation in the spleen were observed, indicating good tolerance of MTABGNRs by living systems.

• MeSH
• autofagie účinky léků   MeSH
• kvartérní amoniové sloučeniny metabolismus   MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• mezenchymální kmenové buňky cytologie   účinky léků   MeSH
• mikrofilamenta účinky léků   metabolismus   MeSH
• mutageny toxicita   MeSH
• myši inbrední C57BL MeSH
• nádorové buněčné linie MeSH
• nanotrubičky chemie   toxicita   ultrastruktura   MeSH
• podocyty účinky léků   metabolismus   MeSH
• pohyb buněk účinky léků   MeSH
• poškození DNA MeSH
• slezina účinky léků   patologie   MeSH
• sulfhydrylové sloučeniny metabolismus   MeSH
• tkáňová distribuce MeSH
• trombocyty účinky léků   patologie   ultrastruktura   MeSH
• zlato metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH