Proteomic analysis and biochemical alterations in marine mussel gills after exposure to the organophosphate flame retardant TDCPP

• Published in: Aquatic toxicology 2021-01, Vol.230, p.105688, Article 105688
• Main Authors: Sánchez-Marín, Paula, Vidal-Liñán, Leticia, Fernández-González, Laura Emilia, Montes, Rosa, Rodil, Rosario, Quintana, José Benito, Carrera, Mónica, Mateos, Jesús, Diz, Angel P., Beiras, Ricardo
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase - metabolism; Animals; Bioaccumulation - drug effects; Biomarkers; Biomarkers - metabolism; Dose-Response Relationship, Drug; Flame retardants; Flame Retardants - metabolism; Flame Retardants - toxicity; Gills - drug effects; Gills - metabolism; Glutathione Transferase - metabolism; Isobaric labelling; Kinetics; Marine mussels; Models, Biological; Mytilus - drug effects; Mytilus - metabolism; Organophosphorus Compounds - metabolism; Organophosphorus Compounds - toxicity; Proteomics; Tandem mass tag (TMT); Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2020.105688

•TDCPP was quickly bioaccumulated and eliminated by mussels soft tissues.•TDCPP inhibited AChE activity and caused differential regulation of few gill proteins.•Gill proteome was more responsive to time than to chemical exposure itself. Organophosphate flame retardants (OPFRs) are (re-)emergent environmental pollutants increasingly being used because of the restriction of other flame retardants. The chlorinated OPFR, tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is among those of highest environmental concern, but its potential effects in the marine environment have rarely been investigated. We exposed a widely used sentinel marine mussel species, Mytilus galloprovincialis, to 10 μg L−1 of TDCPP during 28 days and studied: (i) the kinetics of bioaccumulation and elimination of the compound, (ii) the effect on two molecular biomarkers, glutathione S-transferase (GST) and acetylcholinesterase (AChE) activities, and (iii) proteomic alterations in the gills, following an isobaric labeling quantitative shotgun proteomic approach, at two exposure times (7 and 28 days). Uptake and elimination of TDCPP by mussels were very fast, and the bioconcentration factor of this compound in mussels was 147 L kgww-1, confirming that this compound is not very bioaccumulative, as predicted by its chemical properties. GST activity was not affected by TDCPP exposure, but AChE activity was inhibited by TDCPP at both 7 and 28 days of exposure. Proteomic analysis revealed subtle effects of TDCPP in mussel gills, since few proteins (less than 2 % of the analysed proteome) were significantly affected by TDCPP, and effect sizes were low. The most relevant effects detected were the up-regulation of epimerase family protein SDR39U1, an enzyme that could be involved in detoxification processes, at both exposure times, and the down-regulation of receptor-type tyrosine-protein phosphatase N2-like (PTPRN2) after 7 days of exposure, which is involved in neurotransmitter secretion and might be related to the neurotoxicity described for this compound. Exposure time rather than TDCPP exposure was the most important driver of protein abundance changes, with 33 % of the proteome being affected by this factor, suggesting that stress caused by laboratory conditions could be an important confounding factor that needs to be controlled in similar ecotoxicology studies. Proteomic data are available via ProteomeXchange with identifier PXD019720.