In vivo experiments for the evaluation of protein expression profiles in Zebra mussels (Dreissena polymorpha) exposed to benzo[α]pyrene

It is recently established that the use of proteomic techniques can be an useful tool in the biomonitoring programs to assess the water quality since these methodologies could be applied to obtain protein expression signatures of the pollutant exposure that could be further used for the validation of new biomarkers. Despite the fact that the mussel Dreissena polymorpha is considered a reference model for freshwater ecosystems, the investigation of proteomic approach in this organism has not been deeply investigated. To this end, several zebra mussel specimens were exposed for 7 days to two different concentrations (0, 1 and 2 μg L−1) of benzo[α]pyrene (B[α]P) which is well known in inducing DNA damage and alteration in antioxidant defenses. Changes in protein expression profiles were investigated in cytosolic fractions of gills from control/exposed male and female mussels by 2-DE electrophoresis. We evaluated an overall change in expression profile of 25 proteins in exposed mussels, 13 and 12 of which were respectively over and under expressed. Spots of interest were manually excised and analyzed by a MALDI-TOF/TOF mass spectrometer. The most significant identified altered proteins are related to oxidative stress, signal transduction, cellular structure and generic metabolism. This preliminary study shows the utility of proteomic approach also in ecotoxicological studies, even if mussels are poorly represented in sequence databases. Further studies on the identified proteins are however needed in order to provide crucial information and to understand possible mechanisms of action of B[α]P in this biological model.