Search results for "GLUTATHIONE"
showing 10 items of 743 documents
Down-regulation of Glutathione and Bcl-2 Synthesis in Mouse B16 Melanoma Cells Avoids Their Survival during Interaction with the Vascular Endothelium
2003
B16 melanoma (B16M) cells with high GSH content show high metastatic activity. However, the molecular mechanisms linking GSH to metastatic cell survival are unclear. The possible relationship between GSH and the ability of Bcl-2 to prevent cell death was studied in B16M cells with high (F10) and low (F1) metastatic potential. Analysis of a Bcl-2 family of genes revealed that B16M-F10 cells, as compared with B16M-F1 cells, overexpressed preferentially Bcl-2 (approximately 5.7-fold). Hepatic sinusoidal endothelium-induced B16M-F10 cytotoxicity in vitro increased from approximately 19% (controls) to approximately 97% in GSH-depleted B16M-F10 cells treated with an antisense Bcl-2 oligodeoxynucl…
Molecular mechanisms of Id2 down-regulation in rat liver after acetaminophen overdose. Protection by N-acetyl-L-cysteine.
2010
Id2 is a pleiotropic protein whose function depends on its expression levels. Id2-deficient cells show increased cell death. This study explored the molecular mechanisms for the modulation of Id2 expression elicited by GSH and oxidative stress in the liver of acetaminophen (APAP)-intoxicated rats. APAP-overdose induced GSH depletion, Id2 promoter hypoacetylation, RNApol-II released and, therefore, Id2 down-regulation. Id2 expression depends on c-Myc binding to its promoter. APAP-overdose decreased c-Myc content and binding to Id2 promoter. Reduction of c-Myc was not accompanied by decreased c-myc mRNA, suggesting a mechanism dependent on protein stability. Administration of N-acetyl-cystein…
Bcl-2 and Mn-SOD antisense oligodeoxynucleotides and a glutamine-enriched diet facilitate elimination of highly resistant B16 melanoma cells by tumor…
2005
Mitochondrial glutathione (mtGSH) depletion increases sensitivity of Bcl-2-overexpressing B16 melanoma (B16M)-F10 cells (high metastatic potential) to tumor necrosis factor-alpha (TNF-alpha)-induced oxidative stress and death in vitro. In vivo, mtGSH depletion in B16M-F10 cells was achieved by feeding mice (where the B16M-F10 grew as a solid tumor in the footpad) with an L-glutamine (L-Gln)-enriched diet, which promoted in the tumor cells an increase in glutaminase activity, accumulation of cytosolic L-glutamate, and competitive inhibition of GSH transport into mitochondria. L-Gln-adapted B16M-F10 cells, isolated using anti-Met-72 monoclonal antibodies and flow cytometry-coupled cell sortin…
Characterization of rat glutathione transferases in olfactory epithelium and mucus
2019
International audience; The olfactory epithelium is continuously exposed to exogenous chemicals, including odorants. During the past decade, the enzymes surrounding the olfactory receptors have been shown to make an important contribution to the process of olfaction. Mammalian xenobiotic metabolizing enzymes, such as cytochrome P450, esterases and glutathione transferases (GSTs), have been shown to participate in odorant clearance from the olfactory receptor environment, consequently contributing to the maintenance of sensitivity toward odorants. GSTs have previously been shown to be involved in numerous physiological processes, including detoxification, steroid hormone biosynthesis, and am…
Attenuation by oralN-acetylcysteine of bleomycin-induced lung injury in rats
2001
Antioxidant therapy may be useful in diseases with impaired oxidant-antioxidant balance such as pulmonary fibrosis. This study examines the effect ofN-acetylcysteine (NAC) on bleomycin-induced lung fibrosis in rats.NAC (3 mmol·kg−1; oral) was given daily from 1 week prior to a single intratracheal instillation of bleomycin (2.5 U·kg−1) or saline, until 14 days postinstillation.NAC partially decreased the augmented collagen deposition in bleomycin-exposed rats (hydroxyproline content was 4,354±386 and 3,416±326 µg·lung−1in vehicle-treated and NAC-treated rats, respectively; p<0.05). The histological assessment using a semiquantitative score showed less collagen deposition and inflammatory…
The major isozyme of rat cardiac glutathione transferases. Its correspondence to hepatic transferase X.
1986
1. A major isozyme of rat heart glutathione transferase was purified to homogeneity by Sephadex G-200 gel filtration, ammonium sulfate precipitation, CM-cellulose chromatography and affinity chromatography on S-hexylglutathione-linked Sepharose 6B. 2. The purified isozyme was a dimer with an apparent relative molecular mass of 50000 composed of two Yb-size subunits (Mr= 26 500). The isozyme is immunologically related to rat liver glutathione transferase X and 3–3, especially closely to transferase X, and no immunological cross-reactivity with subunits 1 and 2 of hepatic glutathione transferases was observed. The isoelectric point (pI = 6.9) of the isozyme was identical with and the substrat…
Elimination of Ehrlich tumours by ATP-induced growth inhibition, glutathione depletion and X-rays
1995
ATP-induced tumour growth inhibition is accompanied by a selective decrease in the content of the tripeptide glutathione (GSH) within the cancer cells in vivo. Depletion of cellular GSH sensitizes tumours to chemotherapy and radiation, but the usefulness of this depletion depends on whether the levels of GSH can be reduced in the tumour relative to normal tissues. We report here that administration of ATP in combination with diethylmaleate and X-rays leads to complete regression of 95% of Ehrlich ascites tumours in mice. This shows that an aggressive tumour can be eliminated by using a therapy based on modulation of GSH levels in cancer cells.
Tissue oxygenation in brain, muscle and fat in a rat model of sleep apnea: differential effect of obstructive apneas and intermittent hypoxia.
2011
Study Objectives: To test the hypotheses that the dynamic changes in brain oxygen partial pressure (PtO 2) in response to obstructive apneas or to intermittent hypoxia differ from those in other organs and that the changes in brain PtO 2 in response to obstructive apneas is a source of oxidative stress. Design: Prospective controlled animal study. Setting: University laboratory. Participants: 98 Sprague-Dawley rats. Interventions: Cerebral cortex, skeletal muscle, or visceral fat tissues were exposed in anesthetized animals subjected to either obstructive apneas or intermittent hypoxia (apneic and hypoxic events of 15 s each and 60 events/h) for 1 h. Measurements and Results: Arterial oxyge…
Glutathione Peroxidase 1 Activity and Cardiovascular Events in Patients With Coronary Artery Disease
2003
Along with superoxide dismutase, glutathione peroxidase 1 is one of the cellular antioxidant enzymes that have a key role in controlling reactive oxygen species. It uses glutathione to reduce hydrogen peroxide to water and lipid peroxides to their respective alcohols. There are suggestions from in vitro and animal studies that these enzymes could protect against atherosclerosis. This prospective study examined the possibility that relatively high activity of antioxidant enzymes protects against cardiovascular events. The study population included 636 patients suspected of having coronary artery disease who were followed for a median period of 4.7 years. Stable angina was present in 510 pati…
In vivo GSH depletion induces c-myc expression by modulation of chromatin protein complexes.
2009
Abstract We hypothesize that glutathione (GSH) fluctuations could have a prominent role in the modulation of c-myc expression through a mechanism affecting chromatin remodeling complexes. This could lead to an open chromatin structure accessible to transcription factors. We studied the in vivo effect of GSH depletion on these complexes bound to the c-myc promoter in the liver of l-buthionine-(S,R)-sulfoximine (BSO)-treated rats. Using chromatin immunoprecipitation we found that 3 h after BSO treatment the repressing complexes Id2 and Sin3A (part of a histone–deacetylase complex) were released from the c-myc promoter. STAT3 was phosphorylated and associated with its coactivator p300 with int…