Temporal changes in glutaredoxin 1 and protein s-glutathionylation in allergic airway inflammation

Asthma is a chronic inflammatory disorder of the airways, involving oxidative stress. Upon oxidative stress, glutathione covalently binds to protein thiols to protect them against irreversible oxidation. This posttranslational modification, known as protein S-glutathionylation, can be reversed by glutaredoxin 1 (Glrx1) under physiological condition. Glrx1 is known to increase in the lung tissues of a murine model of allergic airway inflammation. However, the temporal relationship between levels of Glrx1, protein S-glutathionylation, and glutathione in the lungs with allergic airway inflammation is not clearly understood.

BALB/c mice received 3 aerosol challenges with ovalbumin (OVA) following sensitization to OVA. They were sacrificed at 6, 24, 48, or 72 h, or 8 days (5 mice per group), and the levels of Glrx1, protein S-glutathionylation, glutathione, and 25 cytokines/chemokines were evaluated in bronchoalveolar lavage fluid (BALF) and/or lung tissue.

Levels of Glrx1 in BALF were significantly elevated in the OVA 6 h (final challenge) group compared to those in the control, with concurrent increases in protein S-glutathionylation levels in the lungs, as well as total glutathione (reduced and oxidized) and oxidized glutathione in BALF. Protein S-glutathionylation levels were attenuated at 24 h, with significant increases in Glrx1 levels in lung tissues at 48 and 72 h. Glrx1 in alveolar macrophages was induced after 6 h. Glrx1 levels concomitantly increased with Th2/NF-κB-related cytokines and chemokines in BALF.

The temporal relationships of Glrx1 with protein S-glutathionylation, glutathione, and cytokines/chemokines were observed as dynamic changes in lungs with allergic airway inflammation, suggesting that Glrx1 and protein-SSG redox status may play important roles in the development of allergic airway inflammation.