Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P36969 (phospholipid hydroperoxide glutathione peroxidase)
 344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Irradiation of Ehrlich ascites tumor cells with ultraviolet light or exposure to the Fenton reaction results in lesions in the mitochondrial energy-coupling system. Formation of the membrane potential and its utilization for ATP synthesis are more affected than the respiratory chain. Preincubation of the cells with pantothenic acid or its derivatives which can serve as precursors of CoA largely protects against the damage of mitochondrial energetics by oxygen reactive species formed by UV light or the Fenton reaction. Incubation of Ehrlich ascites tumor cells with pantothenic acid increases their content of glutathione (most of which is present in the reduced form) by 40%. It is concluded that the protective effect of precursors of CoA against lesions of the mitochondrial energy-coupling system by oxygen reactive species is mainly due to removal of free radicals and peroxides by glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase.
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PMID:Noxious effects of oxygen reactive species on energy-coupling processes in Ehrlich ascites tumor mitochondria and the protection by pantothenic acid. 872 26

Selenoprotein biosynthesis may not only be affected by the availability of selenium and the transcription rate of pertinent genes but also by the activity of components of the selenocysteine incorporation complex, SelA, B, C, or D. Incorporation of selenocysteine into selenoproteins requires a complex co-translational mechanism guaranteeing the correct recoding of the termination codon TGA as selenocysteine codon. A particular tRNA(Ser)(Sec) is enzymatically transformed by selenophosphate into tRNA(Sec) which recognizes the UGA codon by means of a specific elongation factor (SelB) and a peculiar mRNA secondary structure. Selenophosphate is formed from selenide and ATP by the SelD gene product, selenophosphate synthase (SelD). To further elucidate the biological role of phospholipid hydroperoxide GPx (PHG-Px), we transformed cells with a heterologous (pig) PHGPx gene and/or an additional (human) SelD gene and studied the behaviour of these cells under selenium depletion and repletion. Transfection of the endothelial cell line ECV 304 with either PHGPx cDNA or SelD cDNA did not result in a substantial increase of PHGPx activities, independent of selenium supply. However, cells co-transfected with both, PHGPx and SelD cDNA, expressed significantly higher PHGPx activity. This effect was much more pronounced under selenium limiting conditions. The enhanced PHGPx activity correlated with two functional parameters, increased capability to reduce hydroperoxides and less sensitivity against H2O2-induced cytotoxicity. Thus, the ECV cells, stably transfected with PHGPx and SelD cDNA, provide a model to specifically investigate the role of PHGPx in endothelial cell function.
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PMID:Determinants of PHGPx expression in a cultured endothelial cell line. 931 7

Vascular invasion of calcified cartilage, during endochondral ossification, is initiated and sustained by invasive cells (endothelial cells and macrophages) which degrade the tissue by releasing lytic enzymes. Concurrently, reactive oxygen species (ROS) are also released by these cells and we hypothesize that ROS also contribute to the degradation of the tissue. As a preliminary approach to this problem, the antioxidant activities and the effect of ROS on hypertrophic cartilage and chondrocytes (HCs) were investigated. Compared to resting or articular chondrocytes, HCs exhibited higher catalase but lower SOD specific activities and lower PHGPx concentration, thus revealing a defence activity specific against H2O2. Moreover, dose-dependent depletion of ATP occurred after few minutes of exposure to ROS, and a long-term treatment (16 h incubation with ROS) promoted the release of LDH activity and a significant variation of the poly- to mono-unsaturated fatty acid ratio. Finally, the incubation of HCs with low ROS doses induced the release of sedimentable alkaline phosphatase activity (matrix vesicles). How the obtained results fit the in vivo occurring events is discussed.
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PMID:Sensitivity of chondrocytes of growing cartilage to reactive oxygen species. 981 64

This study evaluated the effects of dietary organic selenium (Se) on viability of chilled boar semen. Twelve boars were divided into three groups: control (CON), 0.3 mg kg(-1) sodium selenite; inorganic (INO), 0.5 mg kg(-1) sodium selenite and organic (ORG), 0.5 mg kg(-1) Se yeast. The experiment was conducted within 10 weeks, and analysis was performed fortnightly, in storage semen by 72 h. No effect was observed on motility; however, straightness and linearity percentages were higher (P < 0.05) in the animals receiving CON diet compared with INO group. Percentages of cells with both plasma and acrosomal intact membranes, lipidic membrane peroxidation and mitochondrial membrane potential were similar on all treatments. Animals receiving CON diet presented higher (P < 0.05) values of ATP when compared with INO group. The PHGPx was higher (P < 0.05) in animals that received ORG in comparison with INO group. In conclusion, organic selenium supplementation increases PHGPx but does not improve chilled semen viability in 72 h.
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PMID:Organic selenium supplementation increases PHGPx but does not improve viability in chilled boar semen. 2442 35