This study was to determine if cellular glutathione peroxidase (GPX1) protects against acute oxidative stress induced by diquat. Lethality and hepatic biochemical indicators in GPX1 knockout mice [GPX1 (-/-)] were compared with those of wild-type mice (WT) after an intraperitoneal injection of diquat at 6,12,24, or 48 mg/kg of body weight. Although the WT survived all the doses, the GPX1(-/-) survived only 6 mg diquat/kg and were killed by 12, 24, and 48 mg diquat/kg at 52, 4.4 and 3.9 hr, respectively. Compared with those of surviving mice that were sacrificed on Day 7, the dead GPX1(-/-) had diquat dose-dependent increases (P < 0.05) in plasma alanine aminotransferase (ALT) activities. The GPX1(-/-) also had higher (P < 0.05) liver carbonyl contents than those of the WT, but the differences were irrespective of diquat doses. Whereas hepatic total GPX and phospholipid hydroperoxide glutathione peroxidase activities or hepatic GPX1 protein was not significantly affected by the diquat treatment, liver thioredoxin reductase and catalase activities were lower (P < 0.05) in the GPX1(-/-) injected with 12 mg diquat/kg than those of other groups. In conclusion, normal GPX1 expression is necessary to protect mice against the lethality, hepatic protein oxidation, and elevation of plasma ALT activity induced by 12–48 mg diquat/kg.
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References
1.
EvansMD, GriffithsHR, LunecJ.Reactive oxygen species and their cytotoxic mechanisms. Adv Mol Cell Biol20: 25–73, 1997.
RotruckJT, PopeAL, GantherHE, SwansonAB, HafemanDG, HoekstraWG. Selenium: Biochemical role as a component of glutathione peroxidase. Science179: 588–590, 1973.
4.
ChengW-H, HoYS, RossDA, ValentineBA, CombsGFJr.., LeiXG. Cellular glutathione peroxidase knockout mice express normal levels of selenium-dependent plasma and phospholipid hydroperoxide glutathione peroxidase in various tissues. J Nutr127: 1445–1450, 1997.
5.
BehneD, WoltersW.Distribution of selenium and glutathione peroxidase in the rat. J Nutr113: 456–461, 1983.
6.
HoekstraWG. Biochemical function of selenium and its relation to vitamin EFed Proc34: 2083–2089, 1975.
7.
HoYS, MagnenatJL, BronsonRT, CaoJ, GarganoM, SugawaraM, FunkCD. Mice deficient in cellular glutathione peroxidase develop normally and show no increased sensitivity to hyperoxia. J Biol Chem272: 16644–16651, 1997.
8.
ChengW-H, HoYS, ValentineBA, RossDA, CombsGFJr.., LeiXG. Cellular glutathione peroxidase is the mediator of the body selenium to protect against paraquat lethality in transgenic mice. J Nutr128: 1070–1076, 1998.
9.
de HaanJB, BladierC, GriffithsP, KelnerM, O'SheaRD, CheungNS, BronsonRT, SilvestroMJ, WildS, ZhengSS, BeartPM, HertzogPJ, KolaI.Mice with a homozygous null mutation for the most abundant glutathione peroxidase, GPX1, show increased susceptibility to the oxidative stress-inducing agents paraquat and hydrogen peroxide. J Biol Chem273: 22528–22536, 1998.
10.
SpectorA, YangY, HoYS, MagnenatJL, WangRR, MaW, LiWC. Variation in cellular glutathione peroxidase activity in lens epithelial cells, transgenic, and knockouts does not significantly change the response to H2O2 stress. Exp Eye Res62: 521–540, 1996.
11.
BurkRF, LawrenceRA, LaneJM. Liver necrosis and lipid peroxidation in the rat as the result of paraquat and diquat administration. J Clin Invest65: 1024–1031, 1980.
12.
BurkRF, HillKE, AwadJA, MorrowJD, KatoT, CockellKA, LyonsPR. Pathogenesis of diquat-induced liver necrosis in selenium-deficient rat: Assessment of the role of lipid peroxidation and selenoprotein P. Hepatology21: 561–569, 1995.
13.
FarringtonJA, EbertM, LandEJ, FletcherK.Bipyridylium quaternary salts and related compounds. V. Pulse radiolysis studies of the reaction of paraquat radical with oxygen. Implication for the mode of action of bipyridyl herbicides. Biochim Biophys Acta314: 372–381, 1973.
14.
AwadJA, BurkRF, RobertsLJ. Effect of selenium deficiency and glutathione-modulating agents on diquat toxicity and lipid peroxidation in rats. J Pharmacol Exp Ther270: 858–864, 1994.
ReznickAZ, PackerL.Oxidative damages to protein: Spectrophotometric method for carbonyl assay. Meth Enzymol233: 357–363, 1994.
17.
LawrenceRA, SundeRA, SchwartzGL, HoekstraWG. Glutathione peroxidase activity in rat lens and other tissues in relation to dietary selenium intake. Exp Eye Res18: 563–569, 1974.
RoseMS, SmithLL. Tissue uptake of paraquat and diquat. Gen Pharmacol8: 173–176, 1977.
24.
RoseMS, LockEA, SmithLL, WyattI.Paraquat accumulation: Tissue and species specificity. Biochem Pharmacol25: 419–423, 1976.
25.
ChengW-H, FuYX, PorresJM, RossDA, LeiXG. Selenium-dependent cellular glutathione peroxidase protects mice against a pro-oxidant-induced oxidation of NADPH, NADH, lipids, and protein. FASEB J13: 1467–1475, 1999.
26.
ShacterE, WilliamsJA, LimM, LevineRL. Differential susceptibility of plasma proteins to oxidative modification: Examination by western blot immunoassay. Free Radic Biol Med17: 429–437, 1994.
27.
BarbaraSB, StadtmanER. Protein oxidation in aging, disease, and oxidative stress. J Biol Chem272: 20313–20316, 1997.
28.
StadtmanER. Oxidation of free amino acids and amino acid residues in proteins by radiolysis and by metal-catalyzed reactions. Annu Rev Biochem62: 797–821, 1993.
29.
UchidaK, StadtmanER. Modification of histidine residues in proteins by reaction with 4-hydroxynonenal. Proc Natl Acad Sci U S A89: 4544–4548, 1992.
30.
LeeY, ShacterE.Role of carbohydrates in oxidative modification of fibrinogen and other plasma proteins. Arch Biochem Biophys321: 175–181, 1995.
31.
GarbergP, ThullbergM.Decreased glutathione peroxidase activity in mice in response to nafenopin is caused by changes in selenium metabolism. Chem Biol Interact99: 165–177, 1996.
32.
GladyshevVN, JeangKT, StadtmanTC. Selenocysteine, identified as the penultimate C-terminal residue in human T-cell thioredoxin reductase, corresponds to TGA in the human placental gene. Proc Natl Acad Sci U S A93: 6146–6151, 1996.
33.
GladyshevVN, FactorVM, HousseauF, HatfieldDL. Contrasting patterns of regulation of the antioxidant selenoproteins, thioredoxin reductase, and glutathione peroxidase, in cancer cells. Biochem Biophys Res Commun251: 488–493, 1998.
34.
BjörnstedtM, HambergM, KumarS, XueJ, HolmgrenA.Human thioredoxin reductase directly reduces lipid hydroperoxides by NADPH, and selenocystine strongly stimulates the reaction via catalytically generated selenols. J Biol Chem270: 11761–11764, 1995.
35.
MakinoN, MochizukiY, BannaiS, SugitaY.Kinetic studies on the removal of extracellular hydrogen peroxide by cultured fibroblasts. J Biol Chem269: 1020–1025, 1994.
