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Query: UNIPROT:P04179 (
MnSOD
)
2,777
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Ubiquinone (Q) is an essential, lipid soluble, redox component of the mitochondrial respiratory chain. Much evidence suggests that ubiquinol (QH2) functions as an effective antioxidant in a number of membrane and biological systems by preventing peroxidative damage to lipids. It has been proposed that superoxide dismutase (SOD) may protect QH2 form autoxidation by acting either directly as a superoxide-semiquinone oxidoreductase or indirectly by scavenging superoxide. In this study, such an interaction between QH2 and SOD was tested by monitoring the fluorescence of cis-parinaric acid (cPN) incorporated phosphatidylcholine (PC) liposomes. Q6H2 was found to prevent both fluorescence decay and generation of lipid peroxides (LOOH) when peroxidation was initiated by the lipid-soluble azo initiator DAMP, dimethyl 2,2'-azobis (2-methylpropionate), while Q6 or SOD alone had no inhibitory effect. Addition of either SOD or
catalase
to Q6H2-containing liposomes had little effect on the rate of peroxidation even when incubated in 100% O2. Hence, the autoxidation of QH2 is a competing reaction that reduces the effectiveness of QH2 as an antioxidant and was not slowed by either SOD or
catalase
. The in vivo interaction of SOD and QH2 was also tested by employing yeast mutant strains harboring deletions in either CuZnSOD and/or
MnSOD
. The sod mutant yeast strains contained the same percent Q6H2 per cell as wild-type cells. These results indicate that the autoxidation of QH2 is independent of SOD.
...
PMID:Autoxidation of ubiquinol-6 is independent of superoxide dismutase. 863 7
Cu/Zn-superoxide dismutase (SOD)-accelerated oxidation of the benzene metabolite 1,4-hydroquinone (HQ) results in the enhanced formation of semiquinone anion radicals, electrophilic 1,4-benzoquinone (BQ), and H202. We selected bone marrow stromal cells and phiX-174 double stranded plasmid DNA as model systems to investigate the cytotoxicity and DNA cleaving activity of the Cu/Zn-SOD-mediated activation of HQ. The addition of either Cu/Zn-SOD or Min-SOD to the primary bone marrow stromal cell cultures significantly enhanced HQ-induced cytotoxicity, which could be completely prevented by adding reduced glutathione (GSH) or dithiothreitol but not be adding
catalase
. Incubation of the plasmid DNA with the HQ/Cu/Zn-SOD system resulted in the induction of single- as well as double-strand breaks, which could be inhibited by
catalase
and the Cu(I) chelators, bathocuproinedisulfonic acid (BCS) and GSH. Although
Mn-SOD
could enhance HQ-induced cytotoxicity to stromal cells, the activation of HQ by
Mn-SOD
did not contribute to the induction of DNA strand breaks. Similar to the HQ/Cu(II) and H202/Cu(II) systems, the DNA strand breaks mediated by HQ/Cu/Zn-SOD could not be effectively inhibited by the hydroxyl radical scavengers, including dimethylsulfoxide, mannitol, and 5,5-dimethyl-1-pyrroline N-oxide, but could be protected by sodium azide. Low-temperature electron spin resonance experiments showed that incubation of Cu/Znu-SOD with HQ resulted in the release of copper from the Cu/Zn-SOD, which could be prevented by
catalase
. Alpha-(4-Pyridyl-1-oxide)-N-tert-butylnitrone (POBN)/spin-trapping studies demonstrated that the interaction of HQ with Cu/Zn-SOD, but not with
Mn-SOD
, resulted in the significant formation of POBN-CH3 adduct in the presence of dimethylsulfoxide, suggesting the production of hydroxyl radical or its equivalent from this enzyme/xenobiotic interaction. The formation of the POBN-CH3 adduct from the HQ/Cu/Zn-SOD could be inhibited by
catalase
, BCS or GSH, indicating the important role for H202 and Cu(I) in the production of reactive oxygen species. Addition of human myeloperoxidase to the HQ/Cu/Zn-SOD synergistically enhanced the formation of BQ from HQ. This enhancement could be abolished by
catalase
. Taken together, these results demonstrate that activation of HQ by either Cu/Zn-SOD or
Mn-SOD
results in cytotoxicity to primary bone marrow stromal cells through the formation of electrophilic BQ. Interaction of HQ with Cu/Zn-SOD causes oxidative damage to Cu/Zn-SOD, leading to the release of copper from the enzyme. The further reaction between the released copper and H202 generates reactive oxygen species that participate in the induction of strand breaks in plasmid DNA. The H202 generated from the Cu/Zn-SOD-accelerated oxidation of HQ can also be utilized by myeloperoxidase resulting in additional conversion of HQ to BQ.
...
PMID:Role of Cu/Zn-superoxide dismutase in xenobiotic activation. II. Biological effects resulting from the Cu/Zn-superoxide dismutase-accelerated oxidation of the benzene metabolite 1,4-hydroquinone. 864 80
In this study, the activities of major enzymes participating in free radical metabolism (xanthine oxidase, XO; Cu,Zn and Mn superoxide dismutases, SOD; glutathione peroxidase, GSH-Px;
catalase
, CAT) were measured in kidney tissues from guinea pigs treated with gentamicin alone (200 mg/kg/day), gentamicin plus vitamin C (600 mg/kg/day), gentamicin plus vitamin E (400 mg/kg/day), and gentamicin plus vitamins C and E together for 10 days, and from animals treated with physiological saline solution alone during this period. We found no significant differences between control and gentamicin groups with respect to XO and Cu,Zn-SOD activities. However, the activities of
Mn-SOD
, GSH-Px, and CAT were found to be significantly depressed in the gentamicin-treated group relative to controls. In the gentamicin plus vitamin C group, the renal tissue
Mn-SOD
activity was found to be higher as compared with control and gentamicin groups. In this group, XO, GSH-Px and CAT activities were also higher than in the gentamicin-treated group, but no statistically significant differences existed between the values of this group and controls. Similar results were also observed in the gentamicin plus vitamin E group for
Mn-SOD
, GSH-Px, CAT, and XO. In this group, the Cu,Zn-SOD activity was found to be decreased as compared with control and gentamicin groups. In the gentamicin plus vitamins C and E group, the Cu,Zn-SOD activity was found to be decreased, the XO activity to be unchanged, and
Mn-SOD
, GSH-Px, and CAT activities to be increased as compared with the gentamicin and control groups. The results suggest that the enzymatic antioxidant defense system was significantly disturbed because of the suppressed activities of
Mn-SOD
, GSH-Px, and CAT in the kidney tissues from animals treated with gentamicin. However, vitamins C and E given concurrently with gentamicin completely abrogated this enzymatic suppression.
...
PMID:Reduced enzymatic antioxidant defense mechanism in kidney tissues from gentamicin-treated guinea pigs: effects of vitamins E and C. 868 38
The alterations of superoxide dismutase iso-enzyme (Cu,Zn-SOD and
Mn-SOD
) activities, contents, and mRNA expressions with aging were studied in rat soleus muscle (SO) and extensor digitorum longus muscle (EDL). The activity and content of Cu,Zn-SOD in both muscles were significantly higher in old rats (24 months old) than in young rats (4 months old), whereas those of
Mn-SOD
showed no difference between young and old rats. After normalization to citrate synthase (CS) activity, however
Mn-SOD
/CS ratio in SO also showed the age-related increase. Moreover, the activities of other major antioxidant enzymes, glutathione peroxidase (GPX) and
catalase
(
CAT
), indicated age-related increases only in SO. As for the expressions of mRNAs for SOD iso-enzymes, that of Cu,Zn-SOD in either muscle showed no significant change with aging, unlike its activity and content, although that of
Mn-SOD
was decreased with aging only in EDL. Thus, aging appeared to raise the level of antioxidant enzyme system in rat skeletal muscle. However, the resistance of Cu,Zn-SOD and
Mn-SOD
to oxidative stress accompanied by aging was different, the former being obviously greater than the latter. Such changes also differed in muscle fiber type suggesting that fast-twitch fibers are more susceptible to age-related oxidative stress than slow-twitch fibers.
...
PMID:Alterations of superoxide dismutase iso-enzyme activity, content, and mRNA expression with aging in rat skeletal muscle. 871 78
Antioxidant enzyme activities in fibroblasts and erythrocytes prepared from normal and psoriatic patients were measured and compared. The most significant differences were noted in superoxide dismutase (SOD) activities. A dramatic (5.2-fold) increase in
Mn-SOD
activity along with a lesser (1.8-fold) increase in CuZn-SOD activity was observed in fibroblasts from lesional and nonlesional psoriatic skin. The increase of
Mn-SOD
activity was correlated with an increase of both protein and mRNA. A slight (1.2-fold) increase in CuZn-SOD activity was also found in psoriatic as compared to normal red blood cells, while
Mn-SOD
activity was not present in these cells. In contrast, both glutathione peroxidase and
catalase
activities were only slightly (1.3-fold) increased in psoriatic fibroblasts, with no appreciable change noted in psoriatic erythrocytes. Likewise, glutathione levels were observed to be similar in normal and psoriatic cells. The increases in SOD activities did not appear to correlate with the severity of the disease as expressed by the Psoriatic Area Severity Index score or with plasma inflammatory markers. These results demonstrate that antioxidant enzyme activities, particularly
Mn-SOD
in fibroblasts and CuZn-SOD in erythrocytes, are significantly elevated in cells from psoriatic patients.
...
PMID:Antioxidant enzymes in psoriatic fibroblasts and erythrocytes. 875 78
Maternal diabetes during pregnancy is associated with an increased rate of congenital malformations in the offspring. The exact molecular etiology of the disturbed embryogenesis is unknown, but an involvement of radical oxygen species in the teratological process has been suggested. Oxidative damage presupposes an imbalance between the activity of the free oxygen radicals and the antioxidant defence mechanisms on the cellular level. The aim of the present study was to investigate if maternal diabetes in vivo, or high glucose in vitro alters the expression of the free oxygen radical scavenging enzymes superoxide dismutase (CuZnSOD and
MnSOD
),
catalase
and glutathione peroxidase in rat embryos during late organogenesis. We studied offspring of normal and diabetic rats on gestational days 11 and 12, and also evaluated day-11 embryos after a 48 hour culture period in 10 mM or 50 mM glucose concentration. Both maternal diabetes and high glucose culture caused growth retardation and increased rate of congenital malformations in the embryos. The CuZnSOD and
MnSOD
enzymes were expressed on gestational day 11 and both CuZnSOD,
MnSOD
and
catalase
were expressed on day 12 with increased concentrations of
MnSOD
transcripts when challenged by a diabetic milieu. There was a good correlation between mRNA, protein, and activity levels, suggesting that the regulation of these enzymes occurs primarily at the pretranslational level. Maternal diabetes in vivo and high glucose concentration in vitro induced increased
MnSOD
expression, concomitant with increased total SOD activity, and a tentative decrease in
catalase
expression and activity in the embryos. These findings support the notion of enhanced oxidative stress in the embryo as an etiologic agent in diabetic teratogenesis.
...
PMID:Altered levels of scavenging enzymes in embryos subjected to a diabetic environment. 880 88
Subversion of mitochondrial electron transport to the production of O2.- has been proposed as a mechanism of tumor necrosis factor (TNF)-mediated cell killing and to a lesser extent interleukin-1 (IL-1) and lipopolysaccharide (LPS) cytotoxicity. We utilized the O2.- -sensitive aconitases to measure changes in steady-state 02.- levels in the mitochondrial matrix and cytoplasm of cultured mammalian cells in response to these inflammatory mediators. TNF alpha did not measurably affect aconitase activity, and thus mitochondrial 02.- production, in either cultured human A549 cells or murine L929 cells while TNF alpha clearly caused cytotoxicity as revealed by impaired mitochondrial respiration. IL-1 alpha and Escherichia coli LPS also failed to affect the aconitase activity in A549 cells. Neither the O2.- scavenger Mn(III) TMPyP nor the H2O2 scavenger
catalase
protected L929 cells against the cytotoxicity of TNF alpha. In conclusion, TNF, IL-1, and LPS do not appear to exert cytotoxicity, or
MnSOD
gene induction effects, by eliciting mitochondrial O2.- production.
...
PMID:Failure of tumor necrosis factor and interleukin-1 to elicit superoxide production in the mitochondrial matrices of mammalian cells. 883 51
The pathogenesis of influenza virus infections of the lungs is in part mediated by oxidative stress. Such infections might therefore be expected to induce expression of stress-response genes and genes encoding antioxidant enzymes and to activate transcriptional regulatory proteins. Mice (C57B1/6 and C3H/HeJ) were infected intranasally with influenza virus A/PR/8/34 (H1N1). Expression of the genes encoding the antioxidant enzymes manganese superoxide dismutase (Mn- SOD), indoleamine-2, 3-dioxygenase (IDO), heme oxygenase-1, and glutathione peroxidase were increased in the lungs of virus-infected animals. Cu/ZnSOD and
catalase
mRNA were not induced by viral infection. Activation of the transcriptional regulatory proteins AP-1, C/EBP, and NF-kappa B (which are known to be affected by oxidant stress) was demonstrated by electrophoretic mobility shift assay after viral infection. In the case of
MnSOD
, despite increased gene expression enzyme activity was not increased. In contrast, for heme oxygenase-1 both mRNA and activity were increased. C3H/ HeJ and C57B1/6 mice, which are known to have different responses to other types of oxidant stress, also differed in their responses to viral infection. Induction of heme oxygenase-1 expression was greater in C57B1/6 mice than in C3H/ HeJ mice, although inhibiting this enzyme did not alter virus-induced mortality. In contrast, IDO was more strongly induced in C3H/HeJ mice. Activation of NF-kappa B was much more marked in C57B1/6 mice than in C3H/HeJ mice. Although virus replication and inflammatory responses were equivalent in the two strains, lung injury (as measured by wet-to-dry wt ratios) and mortality were greater in C3H/HeJ mice than in C57B1/6 mice, a difference that may be related to differing oxidant stress responses. Thus influenza pneumonia causes an oxidant stress response in the lungs, the nature of which is determined in part by the genetic background of the host.
...
PMID:Oxidant stress responses in influenza virus pneumonia: gene expression and transcription factor activation. 884 86
Seventy male factory workers were studied. The lead concentrations in their blood (Pb-B) were 16.55 +/- 11.53 micrograms/100 ml (range 1.5 to 50.2 micrograms/100 ml). The subjects were divided into three groups according to Pb-B (in microgram/100 ml): group A, Pb-B < or = 10 (n = 22); group B, 10 < Pb-B < or = 20 (n = 30); group C, Pb-B > 20 (n = 18). The mean +/- S.D. in each group was 5.57 +/- 2.53, 15.02 +/- 2.75, and 32.52 +/- 9.49 micrograms/100 ml, respectively. Pb in plasma was 0.011 +/- 0.010, 0.017 +/- 0.033, and 0.021 +/- 0.021 microgram/liter, and Pb in the RBC was 0.281 +/- 0.246, 0.701 +/- 0.325, and 1.626 +/- 0.861 micrograms/g Hb, respectively. In addition to Pb concentration, the concentrations of 34 elements in the plasma or in the RBC were determined. Se concentrations in RBC in each group were 0.618 +/- 0.139, 0.670 +/- 0.207, and 0.728 +/- 0.200 microgram/g Hb, and the mean values were significantly different between groups A and C (p < 0.05). For Se concentration in plasma, the mean +/- S.D. in each group was 0.132 +/- 0.035, 0.130 +/- 0.031, and 0.126 +/- 0.021 microgram/ml, respectively, and there was no significant difference between groups. On the other hand, when the activities of total SOD,
Mn-SOD
, Cu, Zn-SOD, and
catalase
in the plasma and the activities of GSH-Px both in the plasma and in the RBC were assayed, some differences were found. The activities in GSH-Px in RBC were 17.19 +/- 5.03, 17.59 +/- 3.95, and 15.25 +/- 3.18 mumol/g Hb/min, and those in plasma were 0.069 +/- 0.032, 0.081 +/- 0.023, and 0.080 +/- 0.028 mumol/ml/min. In group C, GSH-Px activity was lower in the RBC and higher in the plasma than those in group A, and it was observed that the Se concentration was higher in RBC, and that there was no remarkable change in the plasma. Catalase activity in group C was 3.58 +/- 0.81 mgH2O2/ml/30 min, which was significantly higher than that in group A (2.81 +/- 0.90 mgH2O2/ml/30 min). Further investigation is necessary in order to explain the above results. The regular indices used for evaluating lead exposure, showed significant correlations with Pb-B: r = -0.786 vs delta-Aminolevulinic acid (ALA) dehydratase activity in blood, r = 0.927 vs. inhibition rate, and r = 0.339 vs. ALA in urine.
...
PMID:Indices of lead-exposure in blood and urine of lead-exposed workers and concentrations of major and trace elements and activities of SOD, GSH-Px and catalase in their blood. 884 89
This study examined the effects of glycocorticoids, insulin, thyroxine, and epinephrine upon the activities of CuZn- and Mn-superoxide dismutases (SOD),
catalase
, and glutathione peroxidase (GPX) and upon hydrogen peroxide production in rat macrophages obtained from the intraperitoneal cavity. The experiments were performed in vivo under conditions causing hormonal dysfunctions: adrenal demedullation, dexamethasone treatment, thyroidectomy, administration of L-tri-iodothyronine (T3) and L-thyroxine (T4), and diabetes. Macrophages were also cultured for 24 hr in the presence of dexamethasone, thyroid hormones, and insulin as to evaluate possible interferences caused in vivo by changes in other hormones. The results indicated that these hormones do control the activities of the antioxidant enzymes and hydrogen peroxide production both in vivo and in vitro. Insulin increased the activities of CuZn-SOD,
catalase
, and GPX and reduced that of
Mn-SOD
. Thyroid hormones raised the activities of CuZn- and
Mn-SOD
and decreased that of GPX, whereas glucocorticoids reduced both
Mn-SOD
and GPX. The removal of the adrenal medulla caused a decrease of
Mn-SOD
and GPX activities in the macrophages. Hydrogen peroxide production was increased by insulin and reduced by thyroid hormones and glucocorticoids. The changes in antioxidant enzyme activities caused by these hormones in macrophages may indicate important mechanisms for the establishment of impaired immune function in endocrine pathologies.
...
PMID:Hormonal regulation of superoxide dismutase, catalase, and glutathione peroxidase activities in rat macrophages. 884 37
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