Nutzung der induzierbaren Genexpression des NematodenCaenorhabditis elegans als Biomonitor

Menzel, Ralph; Reichert, Kerstin; Achazi, R.K.

doi:10.1007/bf03038654

Cited by 3 publications

(2 citation statements)

References 25 publications

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“…Our ongoing interest is to further characterize the CYP specific genetic response and thereby not only provide new insights regarding the nematode's reaction to man-made chemical stress, but also exploit CYP as a biomarker for common environmental stressors. C. elegans has proven useful in classical in vivo toxicity testing (lethality, reproduction, growth or developmental toxicity) [12][13][14] as well as in more recently developed molecular biological approaches like differential display [15,16], and DNA microarray analyses [17,18]; or systems with transgenic animals [19][20][21][22]. This latter system is based on heat shock promoter elements inducible by various kinds of natural and man-made stress.…”

Section: Introductionmentioning

confidence: 99%

CYP35: Xenobiotically induced gene expression in the nematode Caenorhabditis elegans

Menzel

Rödel

Kulas

et al. 2005

Archives of Biochemistry and Biophysics

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Abstract:Although over 80 cytochrome P450 (CYP) encoding genes have been identified in the genome of the nematode Caenorhabditis elegans very little is known about their involvement in biotransformation. This paper demonstrates a concentration dependent relationship of C. elegans CYP35A1, A2, A5, and C1 gene expression in response to four organic xenobiotics, namely atrazine, PCB52, fluoranthene, and lansoprazole. The toxicity of these xenobiotics was determined using a reproduction assay. CYP-specific messenger RNA expression was analyzed by semi-quantitative RT-PCR resulting in a strongly increasing, concentration-dependent induction well below the EC 50 for reproduction. For PCB52, approximately 0.5 % of the EC 50 induces a two-fold increase of CYP35 gene expression. Using a double mutant and multiple RNAi of CYP35A/C it was possible to diminish the reproduction decline caused by PCB52 and fluoranthene.

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Section: Introductionmentioning

confidence: 99%

CYP35: Xenobiotically induced gene expression in the nematode Caenorhabditis elegans

Menzel

Rödel

Kulas

et al. 2005

Archives of Biochemistry and Biophysics

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100

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“…2002). Therein,Menzel et al (2002) reported on a LOEC 0.1 µg β-NF / L for cyp-35A3 induction. In comparison, an EC50 (8−24 h) of 72−79 µg/L β-NF was determined in this thesis.…”

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Ecotoxicological characterization of micropollutants and wastewater samples from conventional biological and advanced wastewater treatment

Abbas¹

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Clean water is fundamental to human health and ecosystem integrity. However, water quality deteriorates due to novel anthropogenic pollutants present at microgram per liter concentrations in urban water cycles (termed micropollutants). Wastewater treatment plants (WWTP) have been identified as major point sources for aquatic (micro-)pollutants. Chemical and ecotoxicological analyses have shown that conventional biological WWTPs do not fully remove micropollutants and associated toxicities, which is often because of mobile, polar and/or recalcitrant compounds and transformation products (TPs). To minimize possible environmental risks, advanced wastewater treatment (AWWT) technologies could be a promising mitigation measure. Multiple processes are therefore being developed and evaluated such as ozonation and ozonation followed by granulated activated carbon (GAC) or biological filtration. Assessing the performance of these combined AWWTs was the focus the TransRisk project. Within this project, this thesis accomplished four major goals. Firstly, the preparation of (waste)water samples was optimised for in vitro bioassays. Acidification, filtration and solid phase extraction (SPE) were tested for their impact on environmentally relevant in vitro endocrine activities, mutagenicity, genotoxicity and cytotoxicity. Significantly different outcomes of these assays were detected comparing neutral and acidified samples. Sample filtration had a lesser impact, but in some cases retention of particle-bound compounds could have caused significant toxicity losses. Out of three SPE sorbents the Telos C18/ENV at sample pH 2.5 extracted highest toxicity, some undetected in aqueous samples. These results indicate that sample preparation needs to be optimised for specific sample matrices and bioassays to avoid false-positive or -negative detects in effect-based analyses. Secondly, the above listed in vitro toxicities were monitored in a protected region for drinking water production in South-West Germany (2012-2015). Out of 30 sampling sites surface water and groundwater were the least polluted. Nonetheless, a few groundwater samples induced high anti-estrogenic activity that prompted further monitoring. The latter included a waterworks in which no toxicity was detected. Hospital wastewater also had elevated in vitro toxicities and hospitals are, thus, relevant intervention points for source control. The biological WWTPs were effective in removing most of the detected toxicity, and the selected bioassays proved to be pertinent tools for water quality assessment and prioritisation of pollution hotspots. Thirdly, the in vivo bioassay ISO10872 based on Caenorhabditis elegans (C. elegans) was adapted for this thesis. Using this model, a median effect concentration (EC50) for reproductive toxicity of the polycyclic aromatic hydrocarbon β-naphthoflavone (β- NF) of 114 µg/L was computed which is slightly lower than reported in the scientific literature. β-NF induced cyp-35A3::GFP (a biomarker in transgenic animals) in a time and concentration dependent manner (≤ 21.3–24 fold above controls). β-NF spiked wastewater samples supported earlier hypotheses on particle-bound pollutants. Reproductive toxicity (96 h) and cyp-35A3 induction (24 h) of biologically treated and/or ozonated wastewater extracts and growth promoting effects of GAC/biologically filtered ozonated wastewater extracts were observed. This suggested the presence of residual bioactive/toxic chemicals not included in the targeted chemical analysis. It also highlighted the importance of integrating multiple (apical and molecular) endpoints in wastewater assessments. Fourthly, five in vitro and the adapted C. elegans bioassay were integrated into a wastewater quality evaluation (developed within TransRisk). Out of the five AWWT options, ozonation (at 1 g O3,applied/g DOC, HRT ~ 18 min) combined with nonaerated GAC filtration was rated most effective for toxicity removal. All five AWWTs largely removed estrogenic and (anti-)androgenic activities, but not anti-estrogenic activity and mutagenicity, which even increased during ozonation. This has been observed in related studies and points towards toxic TPs. These results also emphasized the need for implementing an effective post-treatment for ozonation. The results from a parallel in vivo study with Lumbriculus variegatus and Potamopyrgus antipodarum conducted on site at the WWTP (using flow through systems) were in accordance with the C. elegans results. In this context, it is suggested to further implement C. elegans as sensitive, feasible and ecologically relevant model. In conclusion, this thesis shows how optimised sample preparation, long-term (in vitro) environmental monitoring, sensitive and ecologically relevant (in vivo) bioassays as well as innovative evaluation concepts, are pivotal in improving the removal of micropollutants and their toxicities with AWWTs. Future research should further develop and evaluate measures at sewer systems, conventional biological, tertiary and other advanced treatment technologies, as well as sociopolitical strategies (e.g., source control or natural conservation) and restoration projects. The effect-based tools optimised in this thesis will support assessing their success.

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Invertebrates in risk assessment development of a test battery and of short term biotests for ecological risk assessment of soil

Achazi

2002

J Soils & Sediments

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Nutzung der induzierbaren Genexpression des NematodenCaenorhabditis elegans als Biomonitor

Cited by 3 publications

References 25 publications

CYP35: Xenobiotically induced gene expression in the nematode Caenorhabditis elegans

CYP35: Xenobiotically induced gene expression in the nematode Caenorhabditis elegans

Ecotoxicological characterization of micropollutants and wastewater samples from conventional biological and advanced wastewater treatment

Invertebrates in risk assessment development of a test battery and of short term biotests for ecological risk assessment of soil

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