Proteomic and biochemical alterations in mussel gills after exposure to the organophoosphate flame retardant TDCPP

Abstract

The organophosphate flame retardants (OPFRs) are a diverse group of substances used as flame retardants, plasticizer and anti-foaming agents in several consumer and industrial products including plastics. Like other additives, they are not chemically bound to the substrate material, and therefore they are released into the medium throughout the useful life of the products. This has resulted in the detection of the presence of OPFRs in air, soil, sediments and surface waters. Harmful effects of OPFRs have been detected in animals and humans. In the aquatic environment, the effects of the OPFRs reported are mainly in freshwater species. The aim of this study is to evaluate the effects of the OPFR tris (1, 3-dichloro-2-propyl) phosphate (TDCPP) on the gill proteome of the mussel Mytilus galloprovincialis, a sentinel species in marine pollution monitoring, as well as to assess the effects on molecular biomarkers, including a neurotoxic response as acetylcholinesterase (AChE) and a Phase II detoxification enzyme: glutathione Stransferase (GST). For that, mussels from a pristine area were exposed to the flame retardant TDCPP during 28 days, at a concentration of 10 μg/L. Gills proteomic analysis was performed by LC-MS/MS using “tandem mass tags” (TMTs) isobaric labelling. Stability of TDCPP in water and its bioaccumulation in M. galloprovincialis in tissues was also studied. Water analysis showed that TDCPP was stable in water during the course of the experiment and mussels bioaccumulated TDCPP rapidly, the bioconcentration factor being 150 L/Kg. Differentially expressed proteins upon exposure to TDCPP at both 7 and 28 days of exposure will be presented and discussed with the aim of gaining insight on the toxicological action of TDCPP and the cellular detoxification processes activated in mussels. Also, differential expression of AChE and GST proteins will be compared with the results of biochemical analysis of their activities