Active Oxygen Generation by the Reaction of Selenite with Reduced Glutathione in Vitro

Seko, Yoshiyuki; Saito, Yoshihiro; Kitahara, Jun; Imura, Nobumasa

doi:10.1007/978-3-642-74421-1_14

Cited by 117 publications

(94 citation statements)

References 11 publications

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“…Whereas MSeA reacts with GSH to deliver CH 3 SeH directly to cells (22), selenite undergoes thioldependent reduction via reduced GSH to H 2 Se, which is then methylated to produce CH 3 SeH (20,21). H 2 Se can also be incorporated into selenoproteins as selenocysteine or react with molecular oxygen to generate superoxide radicals (20,23,24). Our goal was to characterize the effects of selenite on AR signaling in prostate cancer cells and to determine whether selenite and MSeA shared similar molecular mechanisms of action.…”

Section: Discussionmentioning

confidence: 99%

“…Glutathione (GSH) is the main intracellular thiolbased antioxidant and high doses of selenite not only consume total GSH but also generate superoxide radicals (20,23,24). Alterations in the intracellular redox state can affect the activity of redox-sensitive proteins via the oxidation of critical cysteine residues, which may in turn have downstream effects on signal transduction and gene transcription.…”

Section: Introductionmentioning

confidence: 99%

“…Studies using animal carcinogenesis models have implicated the monomethyl selenium metabolite, methylselenol (CH 3 SeH), as an active anticancer selenium metabolite (22). The further oxidative metabolism of H 2 Se can also produce superoxide anions and induce oxidative stress (20,23,24).…”

Section: Introductionmentioning

confidence: 99%

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Inhibition of androgen receptor signaling by selenite and methylseleninic acid in prostate cancer cells: two distinct mechanisms of action

Husbeck

Bhattacharyya

Feldman

et al. 2006

Molecular Cancer Therapeutics

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The development of prostate cancer and its progression to a hormone-refractory state is highly dependent on androgen receptor (AR) expression. Recent studies have shown that the selenium-based compound methylseleninic acid (MSeA) can disrupt AR signaling in prostate cancer cells. We have found that selenite can inhibit AR expression and activity in LAPC-4 and LNCaP prostate cancer cells as well but through a different mechanism. On entering the cell, selenite consumes reduced glutathione (GSH) and generates superoxide radicals. Pretreatment with N-acetylcysteine, a GSH precursor, blocked the down-regulation of AR mRNA and protein expression by selenite and restored AR ligand binding and prostatespecific antigen expression to control levels. MSeA reacts with reduced GSH within the cell; however, Nacetylcysteine did not effect MSeA-induced downregulation of AR and prostate-specific antigen. The superoxide dismutase mimetic MnTMPyP was also found to prevent the decrease in AR expression caused by selenite but not by MSeA. A Sp1-binding site in the AR promoter is a key regulatory component for its expression. Selenite decreased Sp1 expression and activity, whereas MSeA did not. The inhibition of Sp1 by selenite was reversed in the presence of N-acetylcysteine. In conclusion, we have found that selenite and MSeA disrupt AR signaling by distinct mechanisms. The inhibition of AR expression and activity by selenite occurs via a redox mechanism involving GSH, superoxide, and Sp1.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Inhibition of androgen receptor signaling by selenite and methylseleninic acid in prostate cancer cells: two distinct mechanisms of action

Husbeck

Bhattacharyya

Feldman

et al. 2006

Molecular Cancer Therapeutics

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“…Molecular oxygen and trace metals are important reagents in the spontaneous generation of cysteine sulfenic acid, which can serve as a means of regulating protein activity by helping to absorb oxidative insults [44]. However, inorganic forms of selenium can react with tissue thiols to create selenotrisulfides which are prone to reaction with other thiols, generating free radicals by redox catalysis [45] and accelerating oxidation. Longer storage generally led to a decrease in muscle proteins sulfhydryl group content [46].…”

Section: Changes In Meat Protein Sulfhydryls After Modulation With Sementioning

confidence: 99%

Carbonyl and sulfhydryl groups of chicken meat proteins after dietary modulation with selenium

2015

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Abstract:The objective of the study was to investigate the effects of selenium modulation on the alteration of carbonyl and sulfhydryl groups in proteins in chicken breast and leg meat. Selenium, in the form of sodium selenite and selenized yeast, was applied to broiler chicken at 0.26, 0.38 and 0.50 mg Se kg -1 . The alteration of protein carbonyl and sulfhydryl groups, as well as total antioxidative potential of breast and leg meat were analyzed in fresh, chilled and frozen material. Protein reactive groups were effectively protected against oxidatively induced changes (carbonyl groups formation) by dietary selenium supplementation, during frozen storage of both types of chicken muscles, either with white fibre domination (breast) or with red fibre domination (leg). The inorganic form of selenium was effective in decreasing the loss of protein sulfhydryl groups in muscles with red fibre domination during frozen storage. In conclusion, selenium compounds can be used in broiler nutrition as a protein antioxidizing agent, especially in perspective of the long storage of meat under freezing conditions.

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“…Production of superoxide anion by the reaction of selenite with sulfhydryl compounds such as reduced glutathione (GSH) has been reported. [11][12][13][14] Seko and Imura 15) revealed that selenomethionine may cause oxidative damage derived from the generation of AOS when it is metabolized to selenopersulfide (GSSeH) or selenide (Se 2-). Hasegawa et al 16) reported that the chemical form of metabolite in small intestine or liver of mice treated with selenocystine is selenocysteine-glutathione selenenyl sulfide (CySeSG).…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Hydroxyl Radical Formation from Superoxide Anion Radical in the Presence of Organic Selenium Compounds.

Okuno

Kawai

Hasegawa³

et al. 2001

JOURNAL OF HEALTH SCIENCE

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The generation of superoxide anion or hydroxyl radical derived from the organic selenium compounds selenomethionine, selenoethionine, selenocystine, selenocystamine and selenocysteine-glutathione selenenyl sulfide (CySeSG) was investigated by the electron spin resonance (ESR) technique with 5,5-dimethyl-1-pyrroline Noxide (DMPO) as a spin trapping agent. The intensity of ESR signals of DMPO-OOH adduct formed by the reaction of the hypoxanthine/xanthine oxidase reaction system with DMPO decreased in the presence of selenomethionine or selenoethionine. However, the decrease of this ESR signal intensity was not due to superoxide anion-scavenging ability of these selenium compounds. When selenomethionine or selenoethionine existed in the superoxide anion generating system at a higher concentration, a new ESR signal was recognized. This signal disappeared with the addition of a hydroxyl radical-scavenging reagent and was similar to the signal of DMPO-OH adduct. The lack of structural change in selenomethionine or selenoethionine following reaction with components of the superoxide anion generating system suggested that these selenium compounds act as a catalyst. Such a phenomenon was not observed in the superoxide anion generating system in the presence of selenocystine, selenocystamine or CySeSG. These findings suggested that coexistence of selenomethionine or selenoethionine under mammalian physiological conditions generating superoxide anion may possibly form a hydroxyl radical.

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Active Oxygen Generation by the Reaction of Selenite with Reduced Glutathione in Vitro

Cited by 117 publications

References 11 publications

Inhibition of androgen receptor signaling by selenite and methylseleninic acid in prostate cancer cells: two distinct mechanisms of action

Inhibition of androgen receptor signaling by selenite and methylseleninic acid in prostate cancer cells: two distinct mechanisms of action

Carbonyl and sulfhydryl groups of chicken meat proteins after dietary modulation with selenium

Enhancement of Hydroxyl Radical Formation from Superoxide Anion Radical in the Presence of Organic Selenium Compounds.

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