I-TRAQ proteomic approach to understand low concentration citrate capped gold nanoparticle stress in the marine bivalve Ruditapes philippinarum

Trabajo presentado en el 6th Congress of the Spanish Proteomic Society, celebrado en Cádiz del 15 al 18 de noviembre de 2016.Over the last decades engineered gold nanoparticles (AuNPs) have been developed for and introduced into a growing number of commercial and industrial products. Up to date limited information is available on the ecotoxicological responses in non-target organisms, in par-ticular under environmental relevant concentrations. Notwithstanding their promising applica-tions, increased understanding of their behaviour and effects is required to manage potential risk for non-target organisms.We studied differential protein expression in response to citrate capped AuNPs (21.5 ± 2.9 nm) in the digestive gland of the bivalve Ruditapes philippinarum after 1 and 7 days of expo-sure at an environmental relevant concentration (750 ng L-1), using a 2nd-generation (iTRAQ-8plex) proteomic approach.2200 proteins were identified to be simultaneously expressed in control and treatment and a regularized regression approach (Elastic Net) identified 105 of those to be expressed dif-ferentially. Homology-based functional annotation could be successfully performed for 77% of all sequences and 75% of the differentially expressed sequences and subsequent analysis identified potential enrichment in various stress and injury related functions. Identified pro-teins may be useful as biomarkers of environmental nanoparticle pollution and provide insight about the mode of action of engineered gold nanoparticles.N