Analysis of earthworm Eisenia fetida proteomes during cadmium exposure: An ecotoxicoproteomics approach

Identification of differential proteomic responses to cadmium (Cd) would provide a means for better understanding the survival mechanisms of the earthworm, Eisenia fetida, living in a Cd-polluted environment, and the stress responses can be assessed by ecotoxiptoromics approaches. Extracts of whole earthworm collected at days 7, 14, 21, and 28 after Cd exposure were analyzed by 2-DE and quantitative image analysis. In total, 143 proteins demonstrated significant regulation in at least at one time point, and 56 proteins were identified by MALDI-TOF/TOF-MS and database searching. Compared with control samples, 28 protein spots were up-regulated and 28 were down-regulated during at least one time point. The identified proteins, including chaperonine protein HSP60, caspase-8, calcium ion-binding protein, zinc ion-binding protein, actin-binding protein, proteolysis, fibrinolytic protease, glutamate dehydrogenase, gelsolin-like protein, lombricine kinase, coelomic cytolytic factor 1, manganous superoxide dismutase, extracellular globin-4, lysenin, intermediate filament protein, and tubulin, are involved in several processes, including transcription, translation, the tricarboxylic acid cycle, the cellular amino acid metabolic process, protein amino acid phosphorylation, glycolysis, and the glucose metabolic process. Thus, our study provides a functional profile of the Cd-responsive proteins in earthworms.