The Proteome of Enchytraeus crypticus-Exposure to CuO Nanomaterial and CuCl2 -in Pursue of a Mechanistic Interpretation

Abstract

The transcriptome of the ecotoxicological model Enchytraeus crypticus (known as potworm) is well studied, but the downstream changes at the protein level remained a gap. Changes in the protein regulation following exposure to CuO nanomaterial (NM) and Cu salt (CuCl₂ ) are investigated. HPLC-MS/MS using tandem mass tags is used. CuO NM elicits higher number of differentially expressed proteins (DEPs) compared to CuCl₂ with little to no overlap of proteins. CuO NM causes more stress response mechanisms, with good agreement between DEPs, genes, and metabolites. CuCl₂ causes higher impact in shorter time periods, but organisms have conserved mechanisms (constitutive genes) that allow Cu handling and detoxification. CuO NM causes higher impact after a longer exposure period, inducing regulation of facultative genes with a whole differentiated paradigm and cascade. This could be due to different issues: 1) the cell uptake route is different for Cu NM and Cu ions, 2) internalized Cu NM can result in a "Trojan-horse" effect, 3) the cascade of events occurs in a different time order, and 4) the organism uptake is different between life stages, i.e., cocoons thickened surface protects the entry of NM and juveniles have facilitated entry via tegument. The data have been deposited to the ProteomeXchange with identifier PXD010647.

Keywords: Enchytraeids; metallic nanomaterials; protein profiling; tandem mass tags.