Proteomic Analysis Of Brain And Liver In Zebrafish (Danio Rerio)Exposed To Dechlorane Plus

Dechlorane Plus (DP), a chlorinated flame retardant recently identified as a high production volume (HPV) chemical, has been observed persistent in the environment contaminant, bioaccumulative in organisms and susceptible to long-range atmospheric transport. Toxicity data for DP are very limited till now. Further studies on DP toxicity should be carried out for revealing the subtle toxicological effects and mechanisms of DP. In this study, the possible mechanisms of biological response in zebrafish brain and liver to DP were analyzed at proteomic level. Results obtained in this study will surely provide some evidences for toxicity evaluation of DP to aquatic animals.Adult zebrafish were oral exposed to DP at the doses of7.5mg/g bw (body weight) per day for7,14and28days, respectively. Livers and brains from three biological replicates were dissected and the protein expression profiling were analyzed, using two-dimensional electrophoresis (2D-PAGE). Totally, twenty-four proteins in brain and twenty-five proteins in liver were found differentially expressed with significant difference (p<0.05). Ninteen of them, ten in brain and nine in liver, were selected for MALDI-TOF/TOF mass spectrometry. Six proteins were identified preliminary, four up-regulated and two down-regulated. The four up-regulated proteins are60S acidic ribosomal protein PO,60S acidic ribosomal protein P2, c-type lectin and F-actin capping protein. The two down-regulated proteins are Apolipoprotein A1/A4/E domain and14-3-3protein. Bioinformation analysis indicates these proteins are related to cell structure, immune response and protein synthesis, etc.According to the published studies on toxicities of DP and results obtained in this study, we presumed the possible mechanisms of DP in zebrafish as follows:DP may cause accumulation of reactive oxygen species (ROS) in cells and thus leads to the defence of organism against the oxidative stress; apoptosis could be induced if the antioxidant defenses cannot scavenge the extra ROS caused by DP; DP may destroy cellular structure and the disregulation of cytoskeleton may lead to cell death; DP may also affect the carbohydrates, lipids, nucleotides, and energy metabolism and signal transduction pathway in liver; moreover, DP may induce tumor by affect the process of cytoskeleton assembly or signal transduction pathways.