Proteomic approach for the detection of biomarkers ofexposure in mussels exposed to PCB

In the current study, a preliminary proteomic approach has been used in Mytilus galloprovincialis as a screening of changes in protein expression caused by a mixture of polychlorinated biphenyls (PCBs), in order to characterize the effects of PCBs on the protein profile and to develop new molecular biomarkers, after identifying the proteins more drastically altered. Methods:Mussels were exposed for three weeks to three polychlorinated biphenyls under controlled conditions. The edible parts were homogenized and lyophilized. Extracted proteins were quantified and separated by two-dimensional electrophoresis (2-DE) in IPG strips (pH 3–10). The protein spots in gels were visualized by Coomassie Brilliant Blue staining. Gel images were obtained using a Image Scanner. Image analysis included spot detection, quantification and matching. The volume of each spot from each gel was normalized to the total gel spot volume in order to correct it for differences in gel staining. More than 500 spots were resolved and altered expression was qualitatively detected. Results and conclusions of the study: Our results showed a well conserved protein pattern regardless of the treatments, demonstrating that the exposition to the PCB mixture did not impair the normal physiological function of the mussels. However, the levels of a restricted number of proteins were clearly and reproducibly affected by the treatment; therefore, these polypeptides were considered promising biomarker candidates. In conclusion, even if further studies are needed to validate these findings, our data demonstrated that proteomic approach represents a valuable tool for identifying biomarkers of exposure to environmental contaminants.