Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04179 (MnSOD)
 2,777 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are numerous studies describing the neuroprotective effects of Ginkgo biloba extract EGb 761 on patients with disturbances of vigilance, memory and cognitive functions associated with aging and senility. Describing the pattern of gene expression in EGb 761-treated human hNT neurons may elucidate the molecular pathways leading to the neuroprotection. We used cDNA macroarrays including genes implicated in the antioxidant and stress responses to define the transcriptional effects of EGb 761 (250 microg/ml, 24 hr) on human hNT neurons. Seven genes were identified whose expression was strongly modified by the EGb 761 treatment. Three groups are distinguished: genes encoding transcription factors (increase of NF-kappaB p65 subunit and zinc finger protein 91 mRNAs, and decrease of c-myc transcripts), genes involved in antioxidant defenses (increase of the CuZn SOD mRNAs, and decrease of glutathione reductase and glutathione S-transferase pi mRNAs) and genes involved in stress responses (up-regulation of HSP70 transcripts). Consistent with the modulation of mRNAs by EGb 761, the enzymatic activities of glutathione reductase and glutathione S-transferase were decreased. Surprisingly, CuZn SOD activity was decreased despite increased abundance of the mRNAs; furthermore MnSOD activity was unmodified, and thus the effect of EGb 761 was specific to CuZn SOD. These results support the idea that modulation of target genes and transcription factors may be involved in the neuroprotective action of EGb 761.
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PMID:The Ginkgo biloba extract EGb 761 increases viability of hnt human neurons in culture and affectsthe expression of genes implicated in the stress response. 1239 74

HeLa cell line stably transfected with the tat gene from human immunodeficiency virus type 1 has a decreased antioxidant potential. In this work, we used this model to investigate the effect of a high glucose level (20 mM) on the glucose induced cytotoxicity and on the antioxidant system. In comparison to cell culture under control medium, HeLa-wild cell cultured under 20 mM glucose did not exhibit necrosis or apoptosis, contrary to HeLa-tat cell presenting a significant increase in necrotic or apoptotic state. Moreover after 48 h culture under high glucose level the HeLa-tat proliferation rate was not higher than the one of HeLa-wild cells. In HeLa-wild cell high glucose level resulted in an induction of glutathione reductase activity in opposition to HeLa-tat cells where no change was observed. High glucose level resulted in 20% increase in GSSG/GSH ratio in HeLa-wild cells and 38% increase in HeLa-tat cells. Moreover, high glucose level resulted in a dramatic cytosolic thiol decrease and an important lipid peroxidation in HeLa-tat cells. No significant change of these two parameters was observed in HeLa-wild cells. In both cell lines, high glucose resulted in an increase of total SOD activity, as a consequence of the increase in Cu,Zn-SOD activity. High glucose did not result in an increase of Mn-SOD activity in both cell lines. As a consequence of tat tranfection Mn-SOD activity was 50% lower in HeLa-tat cells in comparison to HeLa-wild cells. This work emphasizes the importance of the antioxidant system in the glucose induced cytotoxicity.
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PMID:Characterization of free radical defense system in high glucose cultured HeLa-tat cells: consequences for glucose-induced cytotoxicity. 1244 27

Gene expression of three antioxidant enzymes, Mn superoxide dismutase (MnSOD), Cu,Zn superoxide dismutase (Cu,ZnSOD), and glutathione reductase (GR) was investigated in stationary phase Saccharomyces cerevisiae during menadione-induced oxidative stress. Both GR and Cu,ZnSOD mRNA steady state levels increased, reaching a plateau at about 90 min exposure to menadione. GR mRNA induction was higher than that of Cu,ZnSOD (about 14-fold and 9-fold after 90 min, respectively). A different pattern of response was obtained for MnSOD mRNA, with a peak at about 15 min (about 8-fold higher) followed by a decrease to a plateau approximately 4-fold higher than the control value. However, these increased mRNA levels did not result in increased protein levels and activities of these enzymes. Furthermore, exposure to menadione decreased MnSOD activity to half its value, indicating that the enzyme is partially inactivated due to oxidative damage. Cu,ZnSOD protein levels were increased 2-fold, but MnSOD protein levels were unchanged after exposure to menadione in the presence of the proteolysis inhibitor phenylmethylsulfonyl fluoride. These results indicate that the rates of Cu,ZnSOD synthesis and proteolysis are increased, while the rates of MnSOD synthesis and proteolysis are unchanged by exposure to menadione. Also, the translational efficiency for both enzymes is probably decreased, since increases in protein levels when proteolysis is inhibited do not reflect the increases in mRNA levels. Our results indicate that oxidative stress modifies MnSOD, Cu,ZnSOD, and GR gene expression in a complex way, not only at the transcription level but also at the post-transcriptional, translational, and post-translational levels.
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PMID:Regulation of antioxidant enzymes gene expression in the yeast Saccharomyces cerevisiae during stationary phase. 1254 54

The stable Cr(VI)-tolerant chr1-66T mutant of Schizosaccharomyces pombe, which carries one simple gene mutation responsible for Cr(VI) tolerance, accumulated and reduced the chromate anion (CrO(4)(2-)) significantly more slowly than did its parental strain 6chr(+). The mutant chr1-66T proved to be sensitive to oxidative stressors such as H(2)O(2), menadione, tert-butyl hydroperoxide and Cd(2+). Both the Cr(VI) tolerance and the oxidative stress sensitivity were attributed to a decreased specific glutathione reductase activity. These effects were also enhanced with a decrease in the specific mitochondrial Mn-SOD activity.
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PMID:Chromate tolerance caused by reduced hydroxyl radical production and decreased glutathione reductase activity in Schizosaccharomyces pombe. 1274 51

The heavy metal cadmium is very toxic to biological systems. Although its effect on the growth of microorganisms and plants has been investigated, the response of antioxidant enzymes of Aspergillus nidulans to cadmium is not well documented. We have studied the effect of cadmium (supplied as CdCl(2)) on catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR). 0.005 mM CdCl(2) had a very slight stimulatory effect on the growth rate of A. nidulans, but at concentrations above 0.025 mM, growth was totally inhibited. The accumulation of Cd within the mycelium was directly correlated with the increase in the concentration of CdC(2) used in the treatments. Although a cadmium-stimulated increase in SOD activity was observed, there was no change in the relative proportions of the individual Mn-SOD isoenzymes. Higher concentrations of CdCl(2) induced a small increase in total CAT activity, but there was a major increase in one isoenzymic form, that could be separated by gel electrophoresis. GR activity increased significantly following treatment with the highest concentration (0.05 mM) of CdCl(2). The increases in SOD, CAT, and GR activities suggest that CdCl(2) induces the formation of reactive oxygen species inside the mycelia of A. nidulans.
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PMID:Growth inhibition of the filamentous fungus Aspergillus nidulans by cadmium: an antioxidant enzyme approach. 1283 9

The pine vole, Microtus pinetorum, was evaluated as a laboratory animal model for infection with Rickettsia rickettsii. Voles demonstrated signs of acute disease, and 45% of infected animals died following intraperitoneal infection with 3 x 10(6) plaque forming units of R. rickettsii. Spleen, liver, kidney, lung, brain, testes and blood were analyzed for rickettsial burden by a quantitative PCR assay. The distribution of rickettsiae in tissues during the course of infection was determined by immunohistochemical staining and pathological changes in tissues were correlated with the clinical severity of infection. Quantitative RT-PCR assays were designed to measure the mRNA levels of the antioxidant enzyme genes for catalase, glutathione peroxidase, glutathione reductase, heme oxygenase, Cu-Zn superoxide dismutase (SOD) and Mn-SOD, and 2 housekeeping genes, actin and glyceraldehyde phosphate dehydrogenase. Tissues from acutely ill animals on days 2 to 6 of infection, convalescent animals, and uninfected control animals were studied. The number of transcripts of each enzyme gene was determined and compared to the degree of rickettsial infection present. These studies demonstrate that the pine vole is a valuable experimental model for studying infection with R. rickettsii. Our results provide the first experimental evidence that R. rickettsii causes alteration(s) of the anti-oxidant system in vivo.
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PMID:Rickettsia rickettsii infection in the pine vole, Microtus pinetorum: kinetics of infection and quantitation of antioxidant enzyme gene expression by RT-PCR. 1286 Jun 75

Fresh peppers (Capsicum annuum L., variety California) in their green and red ripe stages were stored at 20 degrees C for 7 and 19 days to determine the effects of storage on whole fruit antioxidant capacity (TAA) and ascorbate (ASC) content, as well as on some antioxidant enzyme activities, such as catalase (CAT), superoxide dismutase (SOD), and those of the ASC-glutathione cycle. At least one Mn-SOD, two Fe-SODs, and three CuZn-SODs were detected in the fruit extract after native polyacrylamide gel electrophoresis. All of the SOD isozymes and glutathione reductase had higher activity levels in the red control fruits than in the green fruits, whereas the activities of monodehydroascorbate and dehydroascorbate reductase were higher in green fruits. Ascorbate peroxidase (APX) was found to be similar in both fruits. SODs, CAT, and APX seem to be involved in pepper fruit ripening and senescence during storage at 20 degrees C, perhaps influencing the active oxygen species levels in the fruit. TAA, as well as the ASC content, was higher in red peppers than in green, and storage increased the ASC in both green and red fruits.
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PMID:Antioxidant systems and their relationship with the response of pepper fruits to storage at 20 degrees C. 1451 58

We have shown that the ameliorative effect of stannous chloride (SnCl2) pretreatment on potassium dichromate (K2Cr2O7)-induced renal damage 24 h after K2Cr2O7 injection was associated with the induction of heme oxygenase-1 (HO-1). In this work we evaluated: (a) if the protective effect of SnCl2 (given 12 h before K2Cr2O7) is associated with changes in the renal activity of HO-1, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT) 24 and 48 h after K2Cr2O7 injection, and (b) if HO-1 induction is indispensable before K2Cr2O7 injection. It was found that the protective effect of SnCl2 on renal function was observed both at 24 and 48 h reaching its maximum at 24 h when HO-1 expression was higher. Cu,Zn-SOD, Mn-SOD, and GR activities remained unchanged whereas GPx and CAT activities decreased at 48 h in K2Cr2O7-treated rats. The activity of Cu,Zn-SOD, Mn-SOD, GPx, CAT, and GR was unchanged in the SnCl2-treated rats. To fulfill the objective (b) groups of rats treated with K2Cr2O7 and SnCl2 (given at the same time or 12 h after K2Cr2O7) were studied 24 h after K2Cr2O7-injection. The simultaneous injections of SnCl2 and K2Cr2O7 had no protective effect whereas the injection of SnCl2 12 h after K2Cr2O7 exacerbated renal damage. 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.
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PMID:Protective effect of SnCl2 on K2Cr2O7-induced nephrotoxicity in rats: the indispensability of HO-1 preinduction and lack of association with some antioxidant enzymes. 1451 51

In Candida albicans, trehalose plays an essential role as a protector of cell integrity against oxidative challenge. A double homozygous mutant, tps1/tps1, deficient in trehalose synthesis, displayed severe cell mortality when exposed to high H(2)O(2) concentrations, compared with its congenic parental (CAI-4) strain (Alvarez-Peral et al., 2002). We have examined the putative role of a set of well-known antioxidant enzymes as components of the defence mechanism against oxidative challenges. When exposed to mild non-lethal oxidative treatment (0.5 mM H(2)O(2)), a significant induction of catalase, glutathione reductase (GR), and Cu,Zn-superoxide dismutase (SOD) was recorded in tps1/tps1 exponential cultures. However, in CAI-4 cells, subjected to the same conditions, there was only a clear activation of catalase, Mn-SOD and Cu,Zn-SOD activities. The degree of activation was always much more pronounced in the trehalose-deficient mutant than in its wild-type counterpart, except for Mn-SOD activity. After exposure to severe oxidative stress (50 mM H(2)O(2)) only GR and catalase activities increased in tps1/tps1 cultures, whereas in CAI-4 cells GR but not catalase was induced. In both cell strains, 50 mM H(2)O(2) caused inhibition of the Mn- and Cu,Zn-SOD isozymes, this inhibition being more pronounced in tps1/tps1 cells. C. albicans is able to acquire adaptive oxidative tolerance by pretreatment with a low non-stressing concentration of H(2)O(2) before exposure to a drastic oxidative challenge. When these antioxidant activities were measured during the adaptive response, a greater degree of enzymatic antioxidant induction was consistently observed in the tps1/tps1 mutant with respect to the CAI-4 strain. Together with a higher intrinsic sensitivity of tps1/tps1 cells, we suggest that this unexpected increase might be explained in terms of a compensatory mechanism to overcome the lack of endogenous trehalose upon drastic oxidative exposure, although this induction was not sufficient to improve the percentage of cell viability.
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PMID:Role of antioxidant enzymatic defences against oxidative stress H(2)O(2) and the acquisition of oxidative tolerance in Candida albicans. 1458

Pepper is a vegetable of importance in human nutrition. Currently, one of the most interesting properties of natural products is their antioxidant content. In this work, the purification and characterisation of peroxisomes from fruits of a higher plant was carried out, and their antioxidative enzymatic and non-enzymatic content was investigated. Green and red pepper fruits (Capsicum annuum L., type Lamuyo) were used in this study. The analysis by electron microscopy showed that peroxisomes from both types of fruits contained crystalline cores which varied in shape and size, and the presence of chloroplasts and chromoplasts in green and red pepper fruits, respectively, was confirmed. Peroxisomes were purified by differential and sucrose density-gradient centrifugations. In the peroxisomal fractions, the activity of the photorespiration, beta-oxidation and glyoxylate cycle enzymes, and the ROS-related enzymes catalase, superoxide dismutase, xanthine oxidase, glutathione reductase and NADP(+)-dehydrogenases, was determined. Most enzymes studied had higher specific activity and protein content in green than in red fruits. By native PAGE and western blot analysis, the localisation of a Mn-SOD in fruit peroxisomes was demonstrated. The ascorbate and glutathione levels were also determined in crude extracts and in peroxisomes purified from both green and red peppers. The total ascorbate content (200-220 mg per 100 g FW) was similar in crude extracts from the two types of fruits, but higher in peroxisomes from red peppers. The glutathione concentration was 2-fold greater in green pepper crude extracts than in red fruits, whereas peroxisomes from both tissues showed similar values. The presence in pepper peroxisomes of different antioxidative enzymes and their corresponding metabolites implies that these organelles might be an important pool of antioxidants in fruit cells, where these enzymes could also act as modulators of signal molecules (O2*-, H202) during fruit maturation.
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PMID:Peroxisomes from pepper fruits (Capsicum annuum L.): purification, characterisation and antioxidant activity. 1471 45


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