Abstract: Objective To screen for the differential expression proteins in brain tissues of SD rat after diffuse axonal injury （DAI） by isobaric tag for relative and absolute quantification-liquid chromatograph-mass spectrometer/mass spectrometer （iTRAQ-LC-MS/MS）, and to explore potential biomarkers available for the diagnosis of DAI. Methods Animal models of DAI were established with the Marmarou method as reference, and the subjects were divided into blank control group （n=4）, sham strike group （n=4） and fatal strike group （n=4）, respectively. The proteins in rat brain tissues were detected by iTRAQ-LC-MS/MS, and bioinformatics analysis and verification were performed on the results and screened for the differential expression proteins. Results A total of 2 016 proteins were identified and quantified. The bioinformatics analysis revealed that the proteins had wide distribution and function, and participated in different biological processes. There were 16 proteins showed differential expression in fatal strike group, including one up-regulated expression protein and 15 down-regulated expression proteins. The results of iTRAQ-LC-MS/MS were confirmed by Western blotting method. Conclusion Multiple differential expression proteins in rat brain tissues after DAI can be screened by iTRAQ-LC-MS/MS. This not only indicates a research direction for exploring the pathogenesis of DAI, but also provides potential biomarkers available for the diagnosis of DAI.

Key words: forensic pathology, proteomics, diffuse axonal injury, isobaric labeling, tandem mass spectrometry, chromatography, reverse-phase, rats