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(129) Cellular receptor-reporter systems as fundamental instruments for environmental toxicity assessments: case studies for pollutants in aquatic and terrestrial ecosystems. De Coen , W.1, Vlaeminck, A.1, Willems, K.1,2, Blust, R.1, 1 2 ABSTRACT- Toxicological receptor mediated responses are widely used to assess the presence and potency of agonists or antagonists for a given receptor or target. Due to the limitations of these in vitro interactions, more and more cellular assays with specific reporter systems are being applied to study the effects of receptor-ligand interactions of environmental pollutants at the (post)transcriptional level. Recent advances in drug discovery have opened the opportunity to apply specific cellular tools in environmental toxicity assessments. In the present study we demonstrate the potential of specific bacterial and eukaryotic receptor-reporter assays for environmental risk assessments of chemicals. A first example will be discussed where urban air samples were evaluated on their toxicological impact using a battery of 13 bacterial cell constructs. These constructs cover toxic interactions ranging from the DNA to the membrane level. Specific oxidative stress and genotoxic effects were detected in urban air samples. By applying the toxic equivalent approach a limited fraction of the observed effects could be attributed to the chemicals measured. A second example will be discussed on the potential use of a battery of recepter-reporter systems in order to evaluate specific modes of action of a perfluorinated chemicals, a new class of environmental pollutants. These products have recently been identified as being highly persistent and globally distributed. However, little insights have been generated on their toxicological mode of action. Using cellular receptor-reporter constructs we were able to pinpoint the membrane-mediated impact of chemicals such as perfluoro-octane sulfonic acid (PFOS). Both studies will be used to evaluate the advantages and weaknesses of cellular reporter systems in general. Key words: Cell bioassays, Genotoxicity, Air pollution, Polyfluorinated chemicals |
