Susceptibility of Glutathione Peroxidase and Glutathione Reductase to Oxidative Damage and the Protective Effect of Spin Trapping Agents

Tabatabaie, Tahereh; Floyd, Ronald A.

doi:10.1006/abbi.1994.1418

Cited by 165 publications

(74 citation statements)

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“…with the previous reports (1)(2)(3)(4)(5). The underlying reasons of reduced lens GPx, GR and GST activities in advanced disease are highly complex, as can be the result of downregulated or insufficiently expressed genes (14), as well as oxidative modifications of enzymatic molecules, potentiated by extensive loss of the cellular GSH pool (25,26). As shown in our study, the concentration of lenticular GSH was independently associated with cataract maturity [OR 17.93 (CI 4.04-79.63); p=0.0001], thereby confirming its pi votal antioxidant role in this organ, as emphasized by others (3).…”

Section: Discussionsupporting

confidence: 57%

The Impact of Senile Cataract Maturity on Blood Oxidative Stress Markers and Glutathione-Dependent Antioxidants: Relations with Lens Variables

Mirić¹,

Kisic²,

Zoric³

et al. 2012

Journal of Medical Biochemistry

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The Impact of Senile Cataract Maturity on Blood Oxidative Stress Markers and Glutathione-Dependent Antioxidants: Relations with Lens VariablesOxidative stress is implicated in senile cataract (SC) genesis, although the impact of SC maturity on blood oxidative stress markers is unclear. Total hydroperoxides, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) were measured in the blood and lens samples of patients having either immature (n=31) or mature SC (n=50), and in 22 blood samples from noncataract controls. Compared to controls, SC patients had higher plasma MDA and serum GST, and decreased plasma GR and GSH levels. Plasma GPx as well as hydroperoxides differed from control values only in patients with mature SC. The multivariate logistic regression analysis showed that the fall of plasma GR activity (OR 5.14; CI 1.82-14.51;p=0.0020), as well as serum GST activity (OR 3.84; CI 1.36-10.83;p=0.0108) were independently associated with the maturity of SC. Lens hydroperoxides, MDA and GST, showed no correlation with correspondent blood values, in contrast to GPx (r=0.715; p<0.001) and GR (r=0.703; p<0.001). This study showed that the severity of SC is associated with increased systemic oxidative stress, which could be due to the fall of GSH-dependent antioxidant enzymes activities.

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Section: Discussionsupporting

confidence: 57%

The Impact of Senile Cataract Maturity on Blood Oxidative Stress Markers and Glutathione-Dependent Antioxidants: Relations with Lens Variables

Mirić¹,

Kisic²,

Zoric³

et al. 2012

Journal of Medical Biochemistry

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“…Indeed, it has been reported that CAT and GPXs can be inactivated by oxidative attack. 55,56 In this report, using LECs derived from mice with targeted inactivation of PRDX6, we show that PRDX6-deficient LECs display phenotypic changes, spontaneous apoptosis, and enhanced expression of a-SM actin (a bio-marker for cataractogenesis). These changes of Prdx6 À/À LECs are indistinguishable from those of TGFb-induced changes in LECs.…”

Section: Discussionmentioning

confidence: 79%

Impaired homeostasis and phenotypic abnormalities in Prdx6−/−mice lens epithelial cells by reactive oxygen species: increased expression and activation of TGFβ

et al. 2005

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PRDX6, a member of the peroxiredoxins (PRDXs) family, is a key player in the removal of reactive oxygen species (ROS). Using targeted inactivation of the Prdx6 gene, we present evidence that the corresponding protein offsets the deleterious effects of ROS on lens epithelial cells (LECs) and regulates gene expression by limiting its levels. PRDX6-depleted LECs displayed phenotypic alterations and elevated a-smooth muscle actin and big-h3 expression (markers for cataractogenesis), indistinguishable from transforming growth factor b (TGFb)-induced changes. Biochemical assays disclosed enhanced levels of ROS, as well as high expression and activation of TGFb1 in Prdx6 À/À LECs. A CAT assay revealed transcriptional repression of lens epithelium-derived growth factor (LEDGF), HSP27, and aB-crystallin promoter activities in these cells. A gel mobility shift assay demonstrated the attenuation of LEDGF binding to heat shock or stress response elements present in these genes. A supply of PRDX6 toPrdx6 À/À LECs reversed these changes. Based on the above data, we propose a rheostat role for PRDX6 in regulating gene expression by controlling the ROS level to maintain cellular homeostasis.

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“…The oxidative processes result in the loss of key antioxidant enzymes (Kono and Fridovich, 1982;Tabatabaie and Floyd, 1994), which may exacerbate oxidative stress-mediated cytotoxicity. However, it is also possible that prokaryotes and eukaryotes compensate for the inactivation of antioxidant enzymes by the enhanced expression of SOD, catalase, and other antioxidant enzymes.…”

Section: Discussionmentioning

confidence: 99%

“…The two strains were expected to exhibit differences in regard to sensitivity to the toxic effects of singlet oxygen. To determine if such differences do indeed exist between the two types of cells, we examined growth kinetics, viability, modulation of activities of major antioxidant enzymes, and oxidative damage to protein upon exposure to methylene blue and visible light (MB/light), which generates singlet oxygen (Tabatabaie and Floyd, 1994). The data suggest that the oxyR regulon plays an important protective role in singlet oxygen-mediated cellular damage, presumably through the protection of antioxidant enzymes.…”

Section: Introductionmentioning

confidence: 99%

Control of Singlet Oxygen-induced Oxidative Damage in Escherichia coli

Kim¹,

Kim²,

Park³

2002

BMB Reports

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Singlet oxygen ( 1 O 2 ) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. The oxyR gene product regulates the expression of the enzymes and proteins that are needed for cellular protection against oxidative stress. In this study, the role of oxyR in cellular defense against a singlet oxygen was investigated using Escherichia coli oxyR mutant strains. Upon exposure to methylene blue and visible light, which generates singlet oxygen, the oxyR overexpression mutant was much more resistant to singlet oxygen-mediated cellular damage when compared to the oxyR deletion mutant in regard to growth kinetics, viability and protein oxidation. Induction and inactivation of major antioxidant enzymes, such as superoxide dismutase and catalase, were observed after their exposure to a singlet oxygen generating system in both oxyR strains. However, the oxyR overexpression mutant maintained significantly higher activities of antioxidant enzymes than did the oxyR deletion mutant. These results suggest that the oxyR regulon plays an important protective role in singlet oxygen-mediated cellular damage, presumably through the protection of antioxidant enzymes.

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Susceptibility of Glutathione Peroxidase and Glutathione Reductase to Oxidative Damage and the Protective Effect of Spin Trapping Agents

Cited by 165 publications

References 0 publications

The Impact of Senile Cataract Maturity on Blood Oxidative Stress Markers and Glutathione-Dependent Antioxidants: Relations with Lens Variables

The Impact of Senile Cataract Maturity on Blood Oxidative Stress Markers and Glutathione-Dependent Antioxidants: Relations with Lens Variables

Impaired homeostasis and phenotypic abnormalities in Prdx6−/−mice lens epithelial cells by reactive oxygen species: increased expression and activation of TGFβ

Control of Singlet Oxygen-induced Oxidative Damage in Escherichia coli

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