In vivo identification of potential uranium protein targets in zebrafish ovaries after chronic waterborne exposure

Y. Eb-Levadoux (1) , S. Frelon (1) , O. Simon (1) , Carine Arnaudguilhem (2) , Ryszard Lobinski (2) , Sandra Mounicou (2)

1 IRSN/PRP-ENV/SERIS/LECO - Laboratoire d'écotoxicologie des radionucléides
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

Ecotoxicological studies have indicated the reprotoxicity of uranium (U) in zebrafish, but its molecular mechanisms remain unclear. Due to the non-covalent nature of U-protein complexes, canonical proteomics approaches are often not relevant as they usually use denaturating reagents or solvents. In this study, non-denaturating (ND) methods were used to obtain insight into the nature of U potential targets in ovaries of reproduced and non-reproduced zebrafish after 20 days of exposure to an environmentally relevant U concentration (20 μg L(-1)). After the ND sample preparation, 1-dimensional (SEC) and 2-dimensional (OGE × SEC) separations followed by ICP-sector-field MS measurements (U, P, Fe, Cu, and Zn) enabled the determination of chemical characteristics (MW, pI) of the metal-protein complexes. Phosphorus and U coelution confirmed the affinity of U for P-containing proteins. In addition, 2D separation allowed the discrimination of Fe-metalloproteins as potential U targets. Finally, 20 protein candidates for U complexation were identified after tryptic digestion conditions by LC-ESI FT MS and a database search. Potential U targets were mainly involved in three biological processes: oxidative stress regulation (SOD, GST), cytoskeleton structure (actin) and embryo early development (vtg, initiation factor).

Domaines: Chimie

Y. Eb-Levadoux, S. Frelon, O. Simon, Carine Arnaudguilhem, Ryszard Lobinski, et al.. In vivo identification of potential uranium protein targets in zebrafish ovaries after chronic waterborne exposure. Metallomics, 2017, 9, pp.525-534. ⟨10.1039/C6MT00291A⟩. ⟨hal-01499130⟩