Binding of estrogenic compounds to recombinant estrogen receptor-alpha: application to environmental analysis.

Arnaud Pillon (1, 2) , Anne-Marie Boussioux (1) , Aurélie Escande (1) , Sélim Aït-Aïssa (2) , Elena Gomez (3) , Hélène Fenet (3) , Marc Ruff (4) , Dino Moras (4) , Françoise Vignon (1) , Marie-Josèphe Duchesne (1) , Claude Casellas (3) , Jean-Claude Nicolas (1) , Patrick Balaguer (1)

1 Endocrinologie moléculaire et cellulaire des cancers
2 INERIS - Institut National de l'Environnement Industriel et des Risques
3 HSM - Hydrosciences Montpellier
4 IGBMC - Institut de génétique et biologie moléculaire et cellulaire

Estrogenic activity in environmental samples could be mediated through a wide variety of compounds and by various mechanisms. High-affinity compounds for estrogen receptors (ERs), such as natural or synthetic estrogens, as well as low-affinity compounds such as alkylphenols, phthalates, and polychlorinated biphenyls are present in water and sediment samples. Furthermore, compounds such as polycyclic aromatic hydrocarbons, which do not bind ERs, modulate estrogen activity by means of the aryl hydrocarbon receptor (AhR). In order to characterize compounds that mediate estrogenic activity in river water and sediment samples, we developed a tool based on the ER-alphaligand-binding domain, which permitted us to estimate contaminating estrogenic compound affinities. We designed a simple transactivation assay in which compounds of high affinity were captured by limited amounts of recombinant ER-alpha and whose capture led to a selective inhibition of transactivation. This approach allowed us to bring to light that water samples contain estrogenic compounds that display a high affinity for ERs but are present at low concentrations. In sediment samples, on the contrary, we showed that estrogenic compounds possess a low affinity and are present at high concentration. Finally, we used immobilized recombinant ER-alpha to separate ligands for ER and AhR that are present in river sediments. Immobilized ER-alpha, which does not retain dioxin-like compounds, enabled us to isolate and concentrate ER ligands to facilitate their further analysis.

Domaines: Biologie moléculaire

Arnaud Pillon, Anne-Marie Boussioux, Aurélie Escande, Sélim Aït-Aïssa, Elena Gomez, et al.. Binding of estrogenic compounds to recombinant estrogen receptor-alpha: application to environmental analysis.. Environmental Health Perspectives, 2005, 113 (3), pp.278-84. ⟨10.1289/ehp.7522⟩. ⟨hal-00187720⟩