Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differentiation-arrested monolayer lung cell cultures were developed from day 18, 20, and 22 rat fetuses and 3-day-old neonatal rats. These cultures were examined for antioxidant enzyme activity, and the values obtained were compared with previously reported in vivo activity. All cultures were catalase deficient, and activity could be restored by the addition of 0.25 microM Fe(NO3)3 X 9H2O to the culture medium. The other measured antioxidant enzymes--copper-zinc and manganese superoxide dismutase, glutathione peroxidase, and glucose 6-phosphate dehydrogenase-demonstrate gestation-dependent increases of activity in vivo that were not evident in vitro, supporting the concept of a circulating "maturation factor" during fetal life. When cultures from fetal days 20 and 22 and from neonatal day 3 lungs were challenged with 50% oxygen in the presence of serum, antioxidant enzyme activities were unchanged, and there was no evidence of cell damage as assessed by release of lactate dehydrogenase. In the absence of serum, however, fetal day 20 (but not fetal day 22 or neonatal day 3) lung cells showed evidence of cell damage and increased antioxidant enzyme activities. It is concluded that cultured immature fetal cells are more susceptible to oxygen toxicity than those derived from mature fetal or neonatal animals. This increased susceptibility cannot be explained on the basis of the reduced antioxidant enzyme activity observed in vivo.
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PMID:Differentiation-arrested rat fetal lung in primary monolayer cell culture. III. Antioxidant enzyme activity. 674 12

Because hyperoxia induces early injury to lung endothelial cells and since tolerance to hyperoxia is correlated with increased lung antioxidant enzyme activity, we measured superoxide dismutase, catalase and glutathione peroxidase in both fresh isolates and primary cultures of endothelial cells from pig pulmonary artery and aorta. Cultured endothelial cells were studied at confluency and up to 5 days thereafter under control or hyperoxic conditions. In both types of confluent cell, total and cyanide-insensitive superoxide dismutase increased when compared to fresh cells. The most conspicuous postconfluency change in both types of endothelial cell was a marked decrease in glutathione peroxidase, which could be prevented by the addition of selenomethionine to culture media. A 5-day exposure to hyperoxia resulted in a 2-fold increase in cyanide-insensitive superoxide dismutase in both aortic and pulmonary artery endothelial cells. In view of a similar decrease in DNA in both types of cells despite some differences in enzyme levels, oxygen cytotoxicity could not be related to a particular antioxidant enzyme profile.
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PMID:Effects of culture conditions and hyperoxia on antioxidant enzymes in pig pulmonary artery and aortic endothelium. 711 52

To examine the dose-response relationships of oxygen-induced lung changes, newborn rats were exposed to various patterns of concentrations of hyperoxia (0.4, 0.8, and greater than 0.95 FiO2) for up to 12 days. Prominent findings included microscopic evidence of lung injury and retarded alveolar development (secondary septal development delayed by as much as 88%), lower whole lung DNA (50% of control), lung-to-body-weight ratios (by as much as 18%), and significantly less compliance in the lungs afer exposures of 6 or 12 day duration to all concentrations of hyperoxia. Significant increases in the activities of the lung protective enzymes superoxide dismutase (129 to 160% of control), catalase (112 to 274% of control), and glutathione peroxidase (118 to 256% of control) were noted when activity was expressed on a DNA basis after 12 day exposures to the various patterns of hyperoxia. Lung changes noted after a 7-day recovery period in air included interstitial thickening (117% of control), persistance of the microscopic injury, and retarded alveolar development seen immediately after initial 6-day hyperoxic exposures. At the conclusion of a second wk of recovery in air, the lungs of hyperoxic exposed animals resembled controls in most respects, but a significantly altered compliance was exhibited by the lungs of animals initially exposed to 6 days of 0.4 or greater than 0.95 FiO2. The dose dependency of oxygen-induced lung injury is complex. Straightforward, stepwise dose-response adequately describes the evolution of microscopic injury and slowing of alveolar development in hyperoxia, but the dose dependency is not as clearly identified in the oxygen-induced retardation of lung growth including DNA content and in changes in antioxidant enzyme activities. Changes in lung compliance clearly do not follow expected dose response relationships.
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PMID:The development of the newborn rat lung in hyperoxia: a dose-response study of lung growth, maturation, and changes in antioxidant enzyme activities. 725 58

Surfactant liposomes, encapsulating CuZn-superoxide dismutase (SOD) and catalase, increase alveolar type II cell antioxidant activity and protect cells against oxidant stress. We examined whether intratracheal instillation of antioxidant-surfactant liposomes increases lung antioxidant activity in premature rabbits. Pregnant New Zealand White rabbits were delivered by cesarean section on day 28 or 29 of gestation or allowed to deliver spontaneously. After premature birth or at 2 days of age in the term rabbits, the pups from each litter were divided into four groups. One group received 0.1 ml/15 g birth wt of antioxidant-surfactant liposomes by intratracheal injection and was then exposed to hyperoxia (> 95% oxygen) for 24 h and killed. The second group received an equal amount of surfactant liposomes without antioxidant enzymes and was exposed to hyperoxia for 24 h. The third group received air placebo and was exposed to hyperoxia for 24 h, and the fourth group was killed after birth if premature or at 2 days of age if term. After the pups were killed, lung homogenates were investigated for total SOD and catalase activity and DNA content. Each treatment group consisted of 12-15 rabbit pups. Lung antioxidant enzyme activity increased with advancing maturity. Among the premature rabbits, total lung SOD and catalase activity were lowest in the pups killed before hyperoxia and the air placebo controls exposed to hyperoxia, intermediate in the pups treated with liposomes without antioxidant enzymes and hyperoxia, and highest in the pups that received antioxidant-surfactant liposomes and hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antioxidant-surfactant liposomes mitigate hyperoxic lung injury in premature rabbits. 749 79

Light and oxygen are necessary for the function of the eye. However, when present in excess or in uncontrolled circumstances, they appear to be related, probably causally, to the development of cataract. Compromises of function of the lens and retina with aging are exacerbated by depleted or diminished primary antioxidant reserves, antioxidant enzyme capabilities, and diminished secondary defenses such as proteases. Smoking appears to provide an additional oxidative challenge associated with depletion of antioxidants as well as with enhanced risk for cataract formation. Poor education and lower socioeconomic status are associated with poorer nutriture and are also significantly related to increased risk for these debilities. Optimizing nutriture, including diets rich in fruit and vegetables, may provide the least costly and most practicable means to delay cataract.
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PMID:Relations among aging, antioxidant status, and cataract. 749 45

Three different molecular masses (24, 22, and 20 kDa) of antioxidant proteins were purified in Escherichia coli. These proteins exhibited the preventive effects against the inactivation of glutamine synthetase activity and the cleavage of DNA by a metal-catalyzed oxidation system capable of generating reactive oxygen species. Their antioxidant activities were supported by a thiol-reducing equivalent such as dithiothreitol. Analysis of the amino-terminal amino acid sequences and the immunoblots between 24- and 22-kDa proteins indicates that the 24-kDa protein is an intact form of the 22-kDa protein that was previously identified 22-kDa subunit (AhpC) of E. coli alkyl hydroperoxide reductase (AhpC/AhpF). We isolated and sequenced an E. coli genomic DNA fragment that encodes 20-kDa protein. Comparison of the deduced amino acid sequence of the 20-kDa protein with that of AhpC revealed no sequence homology. A search of a data bank showed that the 20-kDa protein is a new type of antioxidant enzyme. The synthesis of this novel 20-kDa protein was increased in response to oxygen stress during growth. The 20-kDa protein resides mainly in the periplasmic space of E. coli, whereas the 24-kDa AhpC resides mainly in the matrix. The 20-kDa protein was functionally linked to the thioredoxin as an in vivo thiol-regenerating system and exerted a peroxidase activity. This 20-kDa protein is thus named "thiol peroxidase," which could act as an antioxidant enzyme removing peroxides or H2O2 within the catalase- and peroxidase-deficient periplasmic space of E. coli.
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PMID:Thioredoxin-linked "thiol peroxidase" from periplasmic space of Escherichia coli. 749 81

Studies have implicated active oxygen species (AOS) in the pathogenesis of various lung diseases. Many chemical and physical agents in the environment are potent generators of AOS, including ozone, hyperoxia, mineral dusts, paraquat, etc. These agents produce AOS by different mechanisms, but frequently the lung is the primary target of toxicity, and exposure results in damage to lung tissue to varying degrees. The lung has developed defenses to AOS-mediated damage, which include antioxidant enzymes, the superoxide dismutases [copper-zinc (CuZnSOD) and manganese-containing (MnSOD)], catalase, and glutathione peroxidase (GPX). In this review, antioxidant defenses to environmental stresses in the lung as well as in isolated pulmonary cells following exposure to a number of different oxidants, are summarized. Each oxidant appears to induce a different pattern of antioxidant enzyme response in the lung, although some common trends, i.e., induction of MnSOD following oxidants inducing inflammation or pulmonary fibrosis, in responses to oxidants occur. Responses may vary between the different cell types in the lung as a function of cell-cycle or other factors. Increases in MnSOD mRNA or immunoreactive protein in response to certain oxidants may serve as a biomarker of AOS-mediated damage in the lung.
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PMID:Regulation of antioxidant enzymes in lung after oxidant injury. 752 4

Reactive oxygen species have been implicated as mediators of tissue injury in glomerular inflammation. The expression of the antioxidant enzyme, manganese superoxide dismutase (MnSOD), was examined in primary cultures of rat glomerular epithelial cells (GEC) in response to inflammatory mediators. The results demonstrate that GEC respond to interleukin-1 (IL-1) and bacterial lipopolysaccharride (LPS) with an increase in MnSOD steady-state mRNA levels. The IL-1 alpha-mediated induction of MnSOD mRNA levels was both time- and dose-dependent. Maximal levels approximately 40-fold above controls, were observed at 12 hours with 2 ng/ml of IL-1 alpha. MnSOD protein levels were also markedly elevated by IL-1 alpha. The induction of MnSOD mRNA by IL-1 alpha required de novo transcription as well as some degree of protein synthesis. To elucidate the potential intracellular signal that mediates IL-1 alpha-dependent MnSOD expression, three classical signaling pathways were examined. We found no evidence that MnSOD induction by IL-1 alpha is mediated by either the cyclooxygenase or lipoxygenase pathway or via activation of protein kinase C. Based on the presence of IL-1 alpha in several forms of glomerular inflammation, the observed increase in MnSOD expression by this immunoregulatory cytokine must have an important role in the antioxidant defense of glomerular epithelial cells.
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PMID:Regulation of manganese superoxide dismutase in glomerular epithelial cells: mechanisms for interleukin 1 induction. 756 2

In this study, we have used the rat model of hyperoxia to examine the molecular responses to oxidative stress in lung. We show that in addition to the antioxidant enzyme manganese superoxide dismutase, expression of a variety of stress-responsive genes including heme oxygenase-1, c-fos, c-jun, CAAT-enhancer binding protein (C/EBP)-beta, and C/EBP-delta were increased after hyperoxia. Increased c-fos, c-jun, C/EBP-beta, and C/EBP-delta mRNA expression was correlated with increased DNA binding activity of the transcription factor complexes activator protein 1 and C/EBP in tissue lysates. Because oxidative damage plays an important role in the aging process and little is known about the susceptibility of aged rats to hyperoxia, we also examined the relative tolerance of old rats to hyperoxia. Surprisingly, we observed that aged rats exhibit greater tolerance to hyperoxic stress than young rats. Old rats exhibited decreased arterial oxygen tension when compared to young rats after hyperoxia exposure. This increased tolerance coincided with decreased albumin levels in bronchoalveolar lavage and the delayed onset of activation of transcription factors and expression of oxidative stress-inducible genes in old rats. Transcription factor and stress-response gene activation may serve as useful molecular markers for oxidant lung injury.
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PMID:Molecular responses to hyperoxia in vivo: relationship to increased tolerance in aged rats. 759 40

The effects of oxygen inhalation for 48 h on the antioxidant capacity of lungs, livers, and brains in normal and vitamin E-deficient rats at various ages were examined. The activity levels of catalase, glutathione peroxidase, and superoxide dismutase, and the level of vitamin E in tissue homogenates were assayed as the indices of antioxidant capacity. Oxygen inhalation mostly decreased antioxidant enzyme activity in lungs. In particular, the catalase activity was much decreased. The glutathione peroxidase activity tended to be decreased. The superoxide dismutase activity was decreased in 32-month-old rats. Vitamin E deficiency did not augment oxidative damage due to oxygen inhalation. There appears to be no age effect on the oxygen-induced decrease in the antioxidant enzyme activities of lungs, except the superoxide dismutase activity in very old rats. Oxygen inhalation had some effects on the antioxidant capacity of livers and brains. For example, oxygen inhalation decreased the vitamin E concentration of livers in 32-month-old, normal rats. These results suggest that the antioxidant capacity of lungs is directly damaged by oxygen inhalation and that the antioxidant capacity of livers and brains is indirectly affected through lung damage. Antioxidant capacity may be maintained without large variation during young and middle ages, but its redundancy for emergency use may be diminished in old age.
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PMID:Effects of oxygen inhalation on the antioxidant capacity of lungs, livers, and brains in normal and vitamin E-deficient rats at various ages. 761 20


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