Peroxiredoxin-2 up-regulation in inflammatory bowel disease: Friend or foe?

Inflammatory bowel diseases (IBD) are chronic multi-factorial inflammatory disorders. Accumulating investigations have provided compelling evidence that describe the interplay of a complex genetic landscape and inappropriate inflammatory response to intestinal microbes in disease etiopathogenesis but still pose challenges in diagnostic practices.

In this study, comparative proteomic analysis was conducted to identify disease specific proteins underlying IBD pathogenetic mechanisms. Total blood proteins of the IBD patients and healthy subjects were analyzed with one-dimensional electrophoresis; differentially expressed bands were excised and subjected to matrix-assisted laser desorption ionization-time of flight mass spectrometry along with nanoflow liquid chromatography electrospray ionization-tandem mass spectrometry analysis. Presence of glycosylation, hydroxylation, and phosphorylation post-translational modifications was further investigated by immunoprecipitation.

Peroxiredoxin-2 (PRDX2) and hemoglobin-subunits proteins, which are closely involved in the response to oxidative stress, were identified. PRDX2 was selected for further validation using western blot and reverse transcription-polymerase chain reaction. PRDX2 overexpression was restricted to the protein level within the membrane fraction. Immunoprecipitation identified PRDX2 to be post-translationally glycosylated and phosphorylated.

Our findings demonstrate the implication of PRDX2 in IBD. Future studies are required to establish its functional role and to determine the clinical utility.