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Paradoxical Response of Endothelial ROS production in Peroxiredoxin 6 null mice to Ischemia
Author(s) -
Chatterjee Shampa,
Feinstein Sheldon I.,
Hong Nankang,
DeBolt Kristine
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1201-b
Subject(s) - reactive oxygen species , tbars , nadph oxidase , oxidative stress , ischemia , peroxiredoxin , chemistry , glutathione peroxidase , nad(p)h oxidase , peroxidase , microbiology and biotechnology , biochemistry , biology , lipid peroxidation , catalase , medicine , enzyme
Peroxiredoxin 6 (Prdx6), a glutathione peroxidase finds its highest expression in the lung and functions as a major lung antioxidant enzyme. We have previously observed that in isolated perfused lungs, abrupt cessation of perfusate flow results in activation of endothelial cell NADPH oxidase leading to the generation of reactive oxygen species (ROS). We hypothesized that in mice with deletion of Prdx6 by gene targeting, oxidative stress with ischemia would be significantly increased. We used amplex red, a dye that measures extracellular H 2 O 2 for monitoring ROS generation in the lung endothelium by fluorescence microscopy. Isolated perfused lungs were preperfusedwith 20 μM of amplex red and horseradish peroxidase before start of ischemia. Quantification of the images showed a 100% increase of endothelial ROS after 1 min of ischemia in wild type lungs while in Prdx6 −/− lungs the increase was a modest 15%. Overall ROS generation in Prdx6 −/− lungs after 1 min of ischemia was 46 ±5% lower than in wild type lungs. Oxidative damage measured by thiobarbituric acid reactive substances (TBARS) revealed that TBARS were 71± 5 pmol/mg protein in control, 120 ± 8 at 1h ischemia in wild type and 68 ± 3 in Prdx6 −/− lungs. As the lung ischemia model of injury involves ROS generation through NADPH oxidase activation, the abrogation of ROS with ischemia in Prdx6 −/− is compatible with the involvement of Prdx6 in NADPH oxidase activation.