Proteomic study of sulfated polysaccharide from Enterobacter cloacae Z0206 against H2O2-induced oxidative damage in murine macrophages

The present study aimed to unveil potential protective mechanisms of SEPS-4, a novel sulfated derivative of exopolysaccharide produced by Enterobacter cloacae Z0206, against H2O2-induced oxidative damage in murine macrophages based on proteomic approaches. SEPS-4 pre-treatment was found to be capable of alleviating H2O2-induced reduction of RAW264.7 cell viability. Two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were used to evaluate proteins with significant expression alterations in H2O2-challenged RAW264.7 cells following pre-incubation with SEPS-4. Here 12 up-regulated proteins and 12 down-regulated proteins were successfully identified. Bio-informatic analysis was applied for further mechanistic studies. GO annotation and KEGG pathway enrichment analyses demonstrated that differentially expressed proteins were mainly clustered in stress-related biological processes, including metabolic process, stimulus to response, cell growth and death. Peroxiredoxin-2 and Eeflg were core modules of proteinprotein interaction network. Collectively, our data indicated that SEPS-4 may exert protective effects against H2O2-induced oxidative damage via the regulation of these functional proteins and related biological processes.