Oxidative stress plays a critical role in the pathogenesis of chronic obstructive airway diseases (COAD) such as asthma and COPD. Peroxiredoxin-6 (PRDX6) is highly expressed in lung and regulation of its antioxidative function could affect the development and progression of COAD. Recently, post-translational modification such as phosphorylation and acetylation of peroxiredoxins has been suggested to alter their function. The objective of this study was to investigate distinct post-translational modifications of PRDX6 in asthma and COPD.
Proteome analysis of peripheral blood mononuclear cells (PBMCs) from 5 healthy controls and 80 COAD patients (asthma, COPD, and overlap syndrome) was done with 2D-PAGE and post-translational modifications such as mono/di-oxidation, acetylation, and phosphorylation were studied.
Asthma patients showed significantly higher expression of either phosphorylated or acetylated PRDX6 in PBMCs compared to COPD patients. Interestingly, acetylated PRDX6 was highly expressed in PBMCs of severe asthma patients. The post-translational modification patterns were confirmed by immunoprecipitation with anti-PRDX6 antibody and mass spectrometry analysis of the separated modified proteins from 2D PAGE gel.
Post-translational modification profile of PRDX6 showed distinct patterns between COPD and asthma, especially severe asthma. Further analysis of the post-translational modification profiles of PRDX6 could lead to a novel diagnostic/prognostic biomarker of COAD.