Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UNIPROT:P04040 (Catalase)
3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enhanced production of superoxide anion (O2-) is considered to play a pivotal role in the pathogenesis of CNS neurons. Here, we report that O2- generated by xanthine (XA) + xanthine oxidase (XO) triggered cell death associated with nuclear condensation and DNA fragmentation in cerebellar granule neuron. XA + XO induced significant increases in amounts of intracellular reactive oxygen species (ROS) before initiating loss of cell viability, as determined by measurement of 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate, di(acetoxymethyl ester) (C-DCDHF-DA) for O2- and other ROS and hydroethidine (HEt) specifically for O2- by using fluorescence microscopy and flow cytometry. Catalase, but not superoxide dismutase (SOD), significantly protected granule neurons from the XA + XO-induced cell death. Catalase effectively reduced C-DCDHF-DA but not HEt fluorescence, whereas SOD reduced HEt but not C-DCDHF-DA fluorescence, indicating that HEt and C-DCDHF-DA fluorescence correlated with O2- and hydrogen peroxide, respectively. The NMDA antagonist MK-801 prevented the death. XA + XO induced an increase in L-glutamate release from cerebellar granule neurons. These results indicate that elevation of O2- induces cell death associated with increasing ROS production in cerebellar granule neurons and that XA + XO enhanced release of L-glutamate.
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PMID:Production of reactive oxygen species and release of L-glutamate during superoxide anion-induced cell death of cerebellar granule neurons. 942 77

Phenotypic and phylogenetic studies were performed with two strains (OCh 239T and OCh 210T, T = type strain) of aerobic bacteriochlorophyll-containing bacteria isolated from the charophytes and the epiphytes on the stromatolites, respectively, of a saline lake located on the west coast of Australia. Both strains were chemoheterotrophic, Gram-negative and motile rods with subpolar flagella. Catalase and oxidase were produced. ONPG reaction was positive. Cells utilized D-glucose, acetate, butyrate, citrate, DL-lactate, DL-malate, pyruvate, succinate, L-aspartate and L-glutamate. Acids were produced from D-fructose and D-glucose. Bacteriochlorophyll a was synthesized under aerobic conditions. Strain OCh 239T had nitrate reductase and phosphatase. Acids were produced from L-arabinose, D-galactose, lactose, maltose, D-ribose and sucrose. The strain could grow in 0-20.0% (w/v) NaCl. Strain OCh 210T had urease. Hydrolysis of gelatin was positive. Acids were produced from D-xylose. The strain could grow in 0.5-20.0% (w/v) NaCl. The results of 16S rRNA sequence comparisons revealed that strains OCh 239T and OCh 210T formed a new cluster within the alpha-3 group of the alpha subclass of the class Proteobacteria. The similarity value of the 16S rRNA sequences between strains OCh 239T and OCh 210T was 95.8%. Therefore, it was concluded that these two strains should be placed in a new genus, Roseivivax gen. nov., as the new species Roseivivax halodurans sp. nov. and Roseivivax halotolerans sp. nov. The type species of the genus is Roseivivax halodurans. The type strains of Roseivivax halodurans and Roseivivax halotolerans are OCh 239T (= JCM 10272T) and OCh 210T (= JCM 10271T), respectively.
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PMID:Roseivivax halodurans gen. nov., sp. nov. and Roseivivax halotolerans sp. nov., aerobic bacteriochlorophyll-containing bacteria isolated from a saline lake. 1031 85

beta-Amyloid (betaA) is cytotoxic to neurons in culture by increasing hydrogen peroxide and altering calcium homeostasis. We have evaluated betaA-induced cytotoxicity, peroxide generation and glutamate (Glu) uptake in cultured astrocytes. Twenty-four hours after a single addition of either betaA25-35 or betaA1-40there was a concentration-dependent decrease in viability. Catalase or vitamin E showed no protective effect against betaA25-35 Dithiothreitol (DTT), N-acetylcysteine (NAC) and cyclosporine A significantly prevented the toxic effects of both betaA25-35 and peroxide, while inhibition of peroxide detoxifying enzymes enhanced toxicity. Exposure to betaA25-35 or betaA1-40 increased peroxides at 2 h and 24 h, which was prevented by DTT and NAC, but not vitamin E. betaA25-35 inhibited Glu uptake in astrocytes and neurons in culture. Following exposure of neurons to betaA for 24 h there was decreased uptake and increased Glu levels in the culture medium, that resulted in gradual excitotoxicity.
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PMID:beta-Amyloid-induced cytotoxicity, peroxide generation and blockade of glutamate uptake in cultured astrocytes. 1138 55

The mitochondrial respiratory chain is a major source of reactive oxygen species (ROS) under pathological conditions including myocardial ischemia and reperfusion. Limitation of electron transport by the inhibitor rotenone immediately before ischemia decreases the production of ROS in cardiac myocytes and reduces damage to mitochondria. We asked if ROS generation by intact mitochondria during the oxidation of complex I substrates (glutamate, pyruvate/malate) occurred from complex I or III. ROS production by mitochondria of Sprague-Dawley rat hearts and corresponding submitochondrial particles was studied. ROS were measured as H2O2 using the amplex red assay. In mitochondria oxidizing complex I substrates, rotenone inhibition did not increase H2O2. Oxidation of complex I or II substrates in the presence of antimycin A markedly increased H2O2. Rotenone prevented antimycin A-induced H2O2 production in mitochondria with complex I substrates but not with complex II substrates. Catalase scavenged H2O2. In contrast to intact mitochondria, blockade of complex I with rotenone markedly increased H2O2 production from submitochondrial particles oxidizing the complex I substrate NADH. ROS are produced from complex I by the NADH dehydrogenase located in the matrix side of the inner membrane and are dissipated in mitochondria by matrix antioxidant defense. However, in submitochondrial particles devoid of antioxidant defense ROS from complex I are available for detection. In mitochondria, complex III is the principal site for ROS generation during the oxidation of complex I substrates, and rotenone protects by limiting electron flow into complex III.
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PMID:Production of reactive oxygen species by mitochondria: central role of complex III. 1284 17

Aging alters cellular responses to both heat and oxidative stress. Thiol-mediated metabolism of reactive oxygen species (ROS) is believed to be important in aging. To begin to determine the role of thiols in aging and heat stress, we depleted liver glutathione (GSH) by administering l-buthionine sulfoximine (BSO) in young (6 mo) and old (24 mo) Fisher 344 rats before heat stress. Animals were given BSO (4 mmol/kg ip) or saline (1 ml ip) 2 h before heat stress and subsequently heated to a core temperature of 41 degrees C over a 90-min period. Liver tissue was collected before and 0, 30, and 60 min after heat stress. BSO inhibited glutamate cysteine ligase (GCL, the rate-limiting enzyme in GSH synthesis) catalytic activity and resulted in a decline in liver GSH and GSSG that was more pronounced in young compared with old animals. Catalase activity did not change between groups until 60 min after heat stress in young BSO-treated rats. Young animals experienced a substantial and persistent reduction in Cu,Zn-SOD activity with BSO treatment. Mn-SOD activity increased with BSO but declined after heat stress. The differences in thiol depletion observed between young and old animals with BSO treatment may be indicative of age-related differences in GSH compartmentalization that could have an impact on maintenance of redox homeostasis and antioxidant balance immediately after a physiologically relevant stress. The significant changes in antioxidant enzyme activity after GSH depletion suggest that thiol status can influence the regulation of other antioxidant enzymes.
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PMID:Aging reduces responsiveness to BSO- and heat stress-induced perturbations of glutathione and antioxidant enzymes. 1594 71

Declines in oxidative and thermal stress tolerance are well documented in aging systems. It is thought that these alterations are due in part to reductions in antioxidant defenses. Although intracellular thiols are major redox buffers, their role in maintaining redox homeostasis is not completely understood, particularly during aging, where the reliance on antioxidant enzymes and proteins may be altered. To determine whether thiol supplementation improved the antioxidant enzyme profile of aged animals after heat stress, young and old Fischer 344 rats were treated with N-acetylcysteine (NAC; 4 mmol/kg ip) 2 h before heat stress. Liver tissue was collected before and 0, 30, and 60 min after heat stress. Aging was associated with a significant decline in tissue cysteine and glutathione (GSH) levels. There was also an age-related decrease in copper-zinc superoxide dismutase activity. Heat stress did not alter liver GSH, glutathione disulfide, or antioxidant enzyme activity. With NAC treatment, old animals took up more cysteine than young animals as reflected in an increase in liver GSH and a corresponding decrease in glutamate cysteine ligase activity. Catalase activity increased after NAC treatment in both age groups. Copper-zinc superoxide dismutase activity did not change with heat stress or drug treatment, whereas manganese superoxide dismutase activity was increased in old animals only. These data indicate that GSH synthesis is substrate limited in old animals. Furthermore, aged animals were characterized by large fluctuations in antioxidant enzyme balance after NAC treatment, suggesting a lack of fine control over these enzymes that may leave aged animals susceptible to subsequent stress.
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PMID:Thiol supplementation in aged animals alters antioxidant enzyme activity after heat stress. 1609 96

A novel thermophilic, alkali-tolerant, and CO-tolerant strain JW/WZ-YB58(T) was isolated from green mat samples obtained from the Zarvarzin II hot spring in the Uzon Caldera, Kamchatka (Far East Russia). Cells were Gram-type and Gram stain-positive, strictly aerobic, 0.7-0.8 mum in width and 5.5-12 mum in length and produced terminal spherical spores of 1.2-1.6 mum in diameter with the mother cell swelling around 2 mum in diameter (drumstick-type morphology). Cells grew optimally at pH(25 degrees C) 8.2-8.4 and temperature 50-52 degrees C and tolerated maximally 6% (w/v) NaCl. They were strict heterotrophs and could not use either CO or CO(2 )(both with or without H(2)) as sole carbon source, but tolerated up to 90% (v/v) CO in the headspace. The isolate grew on various complex substrates such as yeast extract, on carbohydrates, and organic acids, which included starch, D: -galactose, D: -mannose, glutamate, fumarate and acetate. Catalase reaction was negative. The membrane polar lipids were dominated by branched saturated fatty acids, which included iso-15:0 (24.5%), anteiso-15:0 (18.3%), iso-16:0 (9.9%), iso-17:0 (17.5%) and anteiso-17:0 (9.7%) as major constituents. The DNA G+C content of the strain is 45 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain JW/WZ-YB58(T) is distantly (<93% similarity) related to members of Bacillaceae. On the basis of 16S rRNA gene sequence, physiological and phenotypic characteristics, the isolate JW/WZ-YB58(T) (ATCC BAA-1258; DSM 17740) is proposed to be the type strain for the type species of the new taxa within the family Bacillaceae, Thermalkalibacillus uzoniensis gen. nov. sp. nov. The Genbank accession number for the 16S rRNA gene sequence is DQ221694.
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PMID:Thermalkalibacillus uzonensis gen. nov. sp. nov, a novel aerobic alkali-tolerant thermophilic bacterium isolated from a hot spring in Uzon Caldera, Kamchatka. 1656 84

Isolated soybean leaf mesophyll cells decarboxylated exogenously added [1-(14)C]glycolate and [1-(14)C]glycine in the dark. The rate of CO(2) release from glycine was inhibited over 90% by isonicotinic acid hydrazide and about 80% by KCN, two inhibitors of the glycine to serine plus CO(2) reaction. The release of CO(2) from glycolate was inhibited by less than 50% under the same conditions. This indicates that about 50% of the CO(2) released from glycolate occurred at a site other than the glycine to serine reaction. The sensitivity of this alternative site of CO(2) release to an inhibitor of glycolate oxidase (methyl-2-hydroxy-3-butynoate) but not an inhibitor of the glutamate:glyoxylate aminotransferase (2,3-epoxypropionate) indicates that this alternative (isonicotinic acid hydrazide insensitive) site of CO(2) release involved glyoxylate. Catalase inhibited this CO(2) release. Under the conditions used it is suggested that about half of the CO(2) released from glycolate occurred at the conversion of glycine to serine plus CO(2) while the remaining half of the CO(2) loss resulted from the direct oxidation of glyoxylate by H(2)O(2).The rate of glycine decarboxylation by the glycine to serine reaction was apparently controlled by the amount of NAD in the mitochondria. Mitochondrial electron transport inhibitors, KCN and actinomycin A, inhibited glycine decarboxylation while an uncoupler, 2,4-dinitrophenol, stimulated the reaction. Competition within the mitochondria between the enzymes of dark respiration and glycine decarboxylation for limiting NAD may force substantial amounts of the glycolate formed to be decarboxylated by the direct oxidation of glyoxylate.
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PMID:Mechanism of decarboxylation of glycine and glycolate by isolated soybean cells. 1666 Oct 90

Some effects of cadmium exposure (100 microg/L for 4, 8, 12, and 24 h) on the estuarine polychaete Laeonereis acuta (Nereididae) were evaluated. This polychaete was able to accumulate cadmium in the body, with the metal stored mainly in the cytosolic fraction (>10 kDa). Activity of the antioxidant enzymes superoxide dismutase, glutathione S-transferase, and glutathione reductase (GR) as well as the total oxyradical scavenger capacity, the glutamate cysteine ligase catalytic subunit gene expression, and the metallothionein-like proteins content were not affected by cadmium at any exposure time tested. Catalase (CAT) activity, however, was significantly lower (p < 0.05) in worms treated with cadmium compared with that in controls after 8 h of exposure. At the same exposure time, lipid peroxide levels were increased (p < 0.05) in worms exposed to cadmium compared with those in control worms. Interestingly, CAT and GR activities decreased over time (p < 0.05) independent of cadmium treatment, which is a result that could be attributed to starvation. The effects caused by cadmium in the present study were observed only after 8 h of exposure, demonstrating that cadmium can generate oxidative stress.
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PMID:Short-term responses to cadmium exposure in the estuarine polychaete Laeonereis acuta (polychaeta, Nereididae): subcellular distribution and oxidative stress generation. 1670 67

Exercise provides cardioprotection against ischemia-reperfusion injury, a process involving mitochondrial reactive oxygen species (ROS) generation and calcium overload. This study tested the hypotheses that isolated mitochondria from hearts of endurance-trained rats have decreased ROS production and improved tolerance against Ca(2+)-induced dysfunction. Male Fischer 344 rats were either sedentary (Sed, n = 8) or endurance exercise trained (ET, n = 11) by running on a treadmill for 16 wk (5 days/wk, 60 min/day, 25 m/min, 6 degrees grade). Mitochondrial oxidative phosphorylation measures were determined with glutamate-malate or succinate as substrates, and H(2)O(2) production and permeability transition pore (PTP) opening were determined with succinate. All assays were carried out in the absence and presence of calcium. In response to 25 and 50 microM CaCl(2), Sed and ET displayed similar decreases in state 3 respiration, respiratory control ratio, and ADP:O ratio. Ca(2+)-induced PTP opening was also similar. However, H(2)O(2) production by ET was lower than Sed (P < 0.05) in the absence of calcium (323 +/- 12 vs. 362 +/- 11 pmol.min(-1).mg protein(-1)) and the presence of 50 microM CaCl(2) (154 +/- 3 vs. 197 +/- 7 pmol.min(-1).mg protein(-1)). Rotenone, which blocks electron flow from succinate to complex 1, reduced H(2)O(2) production and eliminated differences between ET and Sed. Mitochondrial superoxide dismutase and glutathione peroxidase were not affected by exercise. Catalase activity was extremely low but increased 49% in ET (P < 0.05). In conclusion, exercise reduces ROS production in myocardial mitochondria through adaptations specific to complex 1 but does not improve mitochondrial tolerance to calcium overload.
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PMID:Exercise training decreases rat heart mitochondria free radical generation but does not prevent Ca2+-induced dysfunction. 1730 8


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