Hyperoxidized peroxiredoxins in peripheral blood mononuclear cells of asthma patients is associated with asthma severity

Aims: Oxidative stress is involved in the pathogenesis of asthma, and peroxiredoxins (PRDX) may be critical in controlling intracellular oxidative stress. The aim of this study was to evaluate expressions of PRDX and their hyperoxidized forms in asthmatic individuals. Main methods: The levels of expression of PRDX1, PRDX2, PRDX3, and PRDX6 and their hyperoxidized forms (PRDX-SO3) were measured in PBMCs from asthma patients and control subjects. In addition, cells from these subjects were treated with hydrogen peroxide (H2O2) and their intracellular concentrations of reactive oxygen species (ROS) were measured. Key findings: The ratios of hyperoxidized to total PRDX (PRDX-SO3/PRDX) in PBMCs were significantly higher in asthma patients than in normal subjects and were correlated with disease severity, with the highest ratio seen in patients with severe asthma. Furthermore, H2O2 treatment of PBMCs, particularly lymphocytes, increased intracellular ROS concentrations with greater and more persistent increases observed in cells from asthmatic than from control subjects. Significance: Hyperoxidation of PRDX may serve as a biomarker of asthma severity and may predict enhanced susceptibility to oxidative stress load in PBMCs of asthmatics. (C) 2012 Elsevier inc. All rights reserved.