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Oxidative stress induced translocation of Prdx6 to the plasma membrane in lung epithelial cells A549
Author(s) -
KAZI ALTAF S,
CHOWDHURY IBRUL,
DODIA CHANDRA,
FEINSTEIN SHELDON,
FISHER ARON
Publication year - 2009
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.23.1_supplement.617.15
Subject(s) - tbars , chemistry , oxidative stress , lipid peroxidation , phospholipid , a549 cell , biochemistry , substrate (aquarium) , membrane , microbiology and biotechnology , in vitro , biology , ecology
Peroxiredoxin 6 (Prdx6), a bifunctional 25‐kDa protein with both peroxidase and phospholipase A 2 (PLA 2 ) activities, is expressed in all major organs with particularly high levels in the lung. Prdx6 can reduce phosphatidylcholine hydroperoxides with a high rate constant similar to H 2 O 2 (~10 6 M −1 s −1 ). In vitro, recombinant Prdx6 binds only to oxidized phospholipid substrate at pH 7.0 but not to reduced substrate. Consistent with its antioxidant functions and preferential binding to oxidized phospholipids we hypothesized that Prdx6 can repair oxidized membrane without hydrolyzing reduced phospholipids. Plasma membranes (PM) preparations from A549 cells treated with either H 2 O 2 (400μM) or t‐butyl hydroperoxide (800μM) for 6 hr showed translocation of Prdx6 as compared to PMs from control untreated cells. H 2 O 2 treated A549 cells showed a 3.8 and 3.6 fold increase in DPPP fluorescence and TBARS, respectively, indicating lipid peroxidation. H 2 O 2 induced enrichment of Prdx6 in PM, DPPP fluorescence, and TBARS values returned to basal levels when cells were either allowed to recover for 6 hr post H 2 O 2 treatment or pretreated with catalase (100U/ml). In conclusion, using intact lung epithelial cells, we establish a mechanism by which Prdx6 mediates reduction of oxidized phospholipids such as those present in the plasma membrane of cells exposed to oxidative stress.