1-Cys peroxiredoxin overexpression protects cells against phospholipid peroxidation-mediated membrane damage
AUTOR(ES)
Manevich, Yefim
FONTE
The National Academy of Sciences
RESUMO
1-Cys peroxiredoxin (1-cysPrx) is a novel antioxidant enzyme able to reduce phospholipid hydroperoxides in vitro by using glutathione as a reductant. This enzyme is widely expressed and is enriched in lungs. A fusion protein of green fluorescent protein with 1-cysPrx was stably expressed in a lung-derived cell line (NCI-H441) lacking endogenous enzyme. Overexpressing cells (C17 or C48) degraded H2O2 and t-butylhydroperoxide more rapidly and showed decreased sensitivity to oxidant stress as measured by 51Cr release. On exposure to •OH generated by Cu2+-ascorbate (Asc), overexpressing cells compared with H441 showed less increase in thiobarbituric acid-reactive substance and phosphatidylcholine hydroperoxide content. This effect was reversed by depletion of cellular glutathione. Diphenyl-1-pyrenoylphosphonium fluorescence, used as a real-time probe of membrane phospholipid peroxidation, increased immediately on exposure to Cu2+-Asc and was abolished by preincubation of cells with Trolox (a soluble vitamin E) or Tempol (a radical scavenger). The rate of diphenyl-1-pyrenoylphosphonium fluorescence increase with Cu2+-Asc exposure was markedly attenuated in C17 and C48 cells as compared with H441. Annexin V-Cy3 was used to detect phosphatidylserine translocation from the inner to outer leaflet of the plasma membrane. Cu2+-Asc treatment induced phosphatidylserine translocation within 2 h in H441 cells but none was observed in C48 cells up to 24 h. These results indicate that 1-cysPrx can scavenge peroxides but in addition can reduce peroxidized membrane phospholipids. Thus, the enzyme can protect cells against oxidant-induced plasma membrane damage, thereby playing an important role in cellular defense against oxidant stress.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=129315Documentos Relacionados
- Activation of the antioxidant enzyme 1-CYS peroxiredoxin requires glutathionylation mediated by heterodimerization with πGST
- Isoprene Produced by Leaves Protects the Photosynthetic Apparatus against Ozone Damage, Quenches Ozone Products, and Reduces Lipid Peroxidation of Cellular Membranes1
- Overexpression of HO-1 Protects against TNF-α-Mediated Airway Inflammation by Down-Regulation of TNFR1-Dependent Oxidative Stress
- Lycopene Protects the Diabetic Rat Kidney Against Oxidative Stress-mediated Oxidative Damage Induced by Furan
- MEK1 protein kinase inhibition protects against damage resulting from focal cerebral ischemia