Disease relevance of Gpx1

• CONCLUSION: Animals with lead-induced hypertension exhibited oxidative stress which was associated with mild up-regulation of superoxide-generating enzyme, NAD(P)H oxidase, with no evidence of quantitative SOD, CAT or GPX deficiencies [1].
• These results suggest that the enhanced oxidative metabolism and decreased glutathione peroxidase in hyperthyroidism result in an increase in lipid peroxidation and, in slow oxidative and heart muscle, possible organ damage [2].
• Prompted by this, we have generated herpes simplex virus-1 amplicon vectors over-expressing the genes for the antioxidant enzymes catalase (CAT) or glutathione peroxidase (GPX), both of which catalyze the degradation of hydrogen peroxide [3].
• In contrast, no significant increased survival of (6-OHDA)-treated dopaminergic cells was observed when they were infected with an adenovirus expressing the H(2) O(2) -scavenging glutathione peroxidase (GPx) enzyme [4].
• Relative to levels in injured, normothermic animals, hypothermia treatment not only suppressed NGF levels, but also attenuated CAT and GPx activity, and increased SOD activity [5].

Psychiatry related information on Gpx1

• There were no differences between NWR and SHR in stereotyped behavior or in striatal glutathione peroxidase activity [6].
• In this study we investigated the effects of prolonged (5-11 days) sleep deprivation on the activities of SOD and GPx as well as the metabolic activity of the mitochondria (using alamar blue) in several brain regions (cortex, hippocampus, hypothalamus, brainstem and cerebellum) [7].
• Electroconvulsive shock in rats: changes in superoxide dismutase and glutathione peroxidase activity [8].
• From these results, we suggest that the protective effect of crocetin on AFB1 hepatotoxicity in rats might be due to the hepatic tissues' defense mechanisms that elevated the cytosol GSH and the activities of GST and GSH-Px [9].

High impact information on Gpx1

• Selenocysteine is incorporated cotranslationally at UGA codons, normally read as stop codons, in several bacterial proteins and in the mammalian proteins glutathione peroxidase (GPX), selenoprotein P and Type I iodothyronine 5' deiodinase (5'DI) [10].
• Defective microbicidal activity in glutathione peroxidase-deficient neutrophils of selenium-deficient rats [11].
• This decline in MnSOD activity occurred without a change in the lung activity of copper-zinc SOD, catalase, or glutathione peroxidase [12].
• Mitochondrial oxygen uptake in state 3 and respiratory control as well as the activities of superoxide dismutase, catalase, and glutathione peroxidase and the level of nonenzymatic antioxidants (evaluated by the hydroperoxide-initiated chemiluminescence) were decreased [13].
• The enzyme study demonstrated that low dietary methionine decreased the nutritional biopotency of selenomethionine in restoring glutathione peroxidase activity but not that of selenite [14].

Chemical compound and disease context of Gpx1

• In conclusion, the results obtained indicate that the activity of SOD, GPX, and GR in renal and cardiac tissues is decreased in hyperthyroidism and that antioxidant treatment with tempol ameliorates T4-induced hypertension [15].
• Using the epilepsy model obtained by systemic administration of pilocarpine (PILO) in rats, we investigated the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities as well as the hydroperoxide (HPx) concentration in the hippocampus of rats during status epilepticus (SE), silent and chronic periods [16].
• To test the postulate that increased activity of the glutathione peroxidase system is required for the increased tolerance to oxygen toxicity that develops after several days of prior exposure to 85% oxygen we searched for a combination of increased tolerance but normal activity of the glutathione system [17].
• RESULTS: One week after exposure in the UVB group, lens opacities were observed and CAT, SOD, and GSHPx activities, and GSH level were lower than control and MDA level was higher than control (p < 0.05) [18].
• Gene expression of glutathione peroxidase, catalase, cuprozinc superoxide dismutase, and manganese superoxide dismutase were not reduced in experimental diabetic neuropathy at either 3 or 12 months [19].

Biological context of Gpx1

• This is because GPx1 mRNA is degraded by the surveillance pathway called nonsense-mediated mRNA decay (NMD) when the selenocysteine codon is recognized as nonsense [20].
• Thus, overexpression of Cat and Gpx, alone or in combination with SOD, by use of molecular biology techniques can protect insulin-producing cells against oxidative damage [21].
• We measured MDA concentrations, as an index of oxygen-derived free radical-mediated lipid peroxidation, and the activities of two main antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GPx), as an index of antioxidant defenses, after CLP [22].
• Furthermore, SAC prevented the GM-induced oxidative stress (protein carbonyl groups) and the decrease in manganese superoxide dismutase (Mn-SOD), GPx, and glutathione reductase (GR) activities in renal cortex [23].
• Gene expression of Cu-ZnSOD, MnSOD, GPx, and CAT was evaluated by real-time RT-PCR [24].

Anatomical context of Gpx1

• In situ hybridisation and immunohistochemistry confirmed micro-anatomical location of Gpx1 within lymphatic tissue and the lamina propria, sub-mucosa, muscularis and serosa, but not the lumenal epithelium [25].
• These results support the potential for Gpx1 and Gpx2 redundancy in lymphatic tissue, but not in epithelial cells of the colon crypt or in the lamina propria, sub-mucosa, muscularis or serosa [25].
• In the pancreas, only glutathione peroxidase activity was affected, and it was reduced in both the BHA and BHT treatment groups [26].
• Previous studies of mRNA for classical glutathione peroxidase 1 (GPx1) demonstrated that hepatocytes of rats fed a selenium-deficient diet have less cytoplasmic GPx1 mRNA than hepatocytes of rats fed a selenium-adequate diet [20].
• In contrast to MnSOD, expression of CAT, CuZnSOD, GPX, and MT was uniform within the bronchial epithelium, and the distribution of expression was the same in control and smoke-exposed animals at all time points [27].

Associations of Gpx1 with chemical compounds

• O2 plus endotoxin increased the concentration and stability of MnSOD, catalase, and GP mRNAs [28].
• Glutathione peroxidase activities and reduced glutathione concentrations in rats, iron-loaded by either method, were not significantly different from those of control animals [29].
• Superoxide dismutase activity, glutathione peroxidase activity, and reduced glutathione concentrations, together with malondialdehyde production, were measured in the livers of rats chronically iron-overloaded by (a) parenteral iron (primarily Kupffer cell iron deposition) and (b) dietary carbonyl iron (mainly parenchymal iron deposition) [29].
• In the nonfailure stage, there was a marginal increase in superoxide dismutase, glutathione peroxidase, and catalase activities as well as vitamin E levels [30].
• Nonsense-mediated decay of mRNA for the selenoprotein phospholipid hydroperoxide glutathione peroxidase is detectable in cultured cells but masked or inhibited in rat tissues [20].

Physical interactions of Gpx1

• Incubations in the presence of either N-acetylcysteine, glutathione, catalase or glutathione-peroxidase decreased binding to DNA while superoxide dismutase had no effect [31].
• 2. GPx activity was measured by a spectrophotometric method in which its activity was coupled to the oxidation of NADPH by glutathione reductase [32].

Enzymatic interactions of Gpx1

• The caudate-putamen, a catecholamine rich area, may produce H2O2 via MAO and would require glutathione reductase to recycle glutathione oxidized by glutathione peroxidase [33].

Regulatory relationships of Gpx1

• Catalase was inhibited with aminotriazole while glutathione peroxidase activity was blocked by eliminating reduced glutathione after addition of either iodoacetamide diethylmaleate or phorone [34].
• Rosiglitazone did not revert the reduced glutathione peroxidase activity but enhanced significantly (P<0.01) the decreased xanthine oxidase and superoxide dismutase activities in gastric mucosa of ischemic rats [35].
• Selenoprotein P concentration was proportional to dietary selenium level up to 0.1 mg/kg and was a greater percentage of control values than was glutathione peroxidase activity [36].
• Aminoguanidine (AG) treatment of diabetic rats returned the testis PHGPx activity (136.5 +/- 24.9) to the control level but did not change the value of GPx activity (69.2 +/- 17.4) compared with diabetic group [37].
• Involvement of superoxide dismutase and glutathione peroxidase in attenuation of radiation-induced hyperthermia by interleukin-1 alpha in rats [38].

Other interactions of Gpx1

• This study reports evidence of both common sites of Gpx1 and Gpx2 expression in rat colon and sites that are exclusive to each isoform [25].
• In conclusion, the protective effect of SnCl2 on K2Cr2O7-induced nephrotoxicity is associated with HO-1 induction and not with other antioxidant enzymes (Cu,Zn-SOD, Mn-SOD, GPx, GR, and CAT) and SnCl2 has a preventive and not a therapeutic effect on renal damage induced by K2Cr2O7 [39].

Analytical, diagnostic and therapeutic context of Gpx1

• Semi-quantitative PCR performed previously demonstrated RNA expression of Gpx1 and Gpx2 in proximal, transverse and distal colon [25].
• In rats treated with GM (70 mg/kg/12 h/4 days/s.c.), ARF was evident by the: (i) decrease in creatinine clearance and increase in blood urea nitrogen, (ii) decrease in blood glutathione peroxidase (GPx) activity and increase in urinary excretion of N-acetyl-beta-D-glucosaminidase and total protein, and (iii) necrosis of proximal tubular cells [23].
• Activities of GPx, SOD and CAT were higher in groups receiving DOX and/or DOX plus melatonin than in control groups [40].
• Western blot analysis of cytoplasm for GPX and CuZn SOD showed a significant decrease in GPX and CuZn SOD proteins [41].
• Endotracheal bleomycin administration alone caused significant reductions in catalase activity at 2 days and 2 weeks after treatment, whereas glutathione peroxidase activity increased above control untreated animals at 2 and 4 weeks, respectively [42].

References