Different uranium distribution patterns in cytosolic protein pool of zebrafish gills after chronic and acute waterborne exposures

作者：Bucher Guillaume; Mounicou Sandra; Simon Olivier; Floriani Magali; Lobinski Ryszard; Frelon Sandrine^*

来源：Chemosphere, 2014, 111: 412-417.

DOI：10.1016/j.chemosphere.2014.03.110

• Zebrafish
• Gills
• Uranium speciation
• SEC-ICP-SFMS
• Cytosolic distribution

The toxicity of uranium (U) to aquatic organisms depends notably on its compartmentalization in organs, tissues, cells as well as on its distribution among biomolecules. In order to contribute to the understanding of U accumulation and associated toxicity mechanisms in case of waterborne exposure, this study focused on U fate in the gills epithelia, uptake pathway, of the fish model Danio rerio (zebrafish). U distribution among cytosolic biomolecules was investigated after no addition (0 mu g L-1 (c(0)) for 3 and 30 d), chronic (20 mu g L-1 (c(20)) for 30 d) and acute (20 mu g L-1 (c(20)) and 250 mu g L-1 (c(250)) for 3 d) exposures to depleted U. Cytosolic U accounted for an average of 24-32% of gills burden for c(20) and c(250), respectively. Size Exclusion Chromatography (SEC) coupled with Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) allowed identification of ecotoxicologically relevant U-containing fractions among cytosolic biomolecules as a function of exposure conditions. In c(0) and c(20) samples, most U (ca. 80%) was found in the Low Molecular Weight fraction (LMW, <18 kDa), often considered as a detoxifying fraction. In c(250) exposed fish, U was equally distributed between LMW (40%) and High Molecular Weight (HMW, 150-670 kDa; 40%) fractions, the latter including sensitive metalloproteins. Uranium-biomolecules were co-eluted with endogenous essential metal (Fe, Cu and Zn) species, however, no major influence on their cytosolic concentration and distribution pattern among cytosolic proteins was found.

• 出版日期2014-9