Preliminary proteomic analysis of circulating polymorphonuclear neutrophils from rabbits experiencing scald injury and Staphylococcus aureus sepsis

Background The aim of this study is to identify the differentially expressed proteins in circulating polymorphonuclear neutrophils (PMN) from scalded bacteremia rabbits infected with Staphylococcus aureus to provide a basis to reveal the pathogenesis of burns and sepsis. Methods Rabbits were subjected to sham burn (A), A + bacterial challenge (B), 30% scald injury (C), or C + bacterial challenge (D). Bacterial challenge was inflicted as an injection of 2.0 × 10⁸ cfu S. aureus 18 h after burn procedure. Animals were sacrificed 24 h after burn. PMN were isolated, and the differential proteins in the PMN from these animals were identified by two-dimensional electrophoresis coupled with MALDI-TOF-MS; two proteins were confirmed by Western blotting. Results Twenty-one differential protein spots were found, and seven differential proteins were identified. Among the identified proteins, the expression levels of protein disulfide-isomerase and thiol-specific antioxidant protein were down-regulated in groups C and D, and two protein spots of annexin I were identified, one of which was down-regulated and another up-regulated in groups C and D. Conclusions Preliminary proteome changes in PMN from rabbits experiencing scald injury and S. aureus sepsis were revealed, which possibly play an important role in the inflammation and pathogenesis of sepsis after scald injury.