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

Commercially available calf serum did not supply the cultured murine fibroblast cell line L929 with amounts of selenium and alpha-tocopherol sufficient to protect against peroxide damage. Supplementation of the culture medium with 30 microM alpha-tocopherol or 50 nM sodium selenite led to a substantial increase of cellular alpha-tocopherol concentrations from 18 +/- 3.0 to 3179 +/- 93.0 pmol/10(6) cells or cellular selenium concentrations from 0.17 +/- 0.02 to 1.75 +/- 0.16 ng/10(6) cells, respectively. L929 fibroblasts grown in selenite-containing medium also had markedly raised activities of both cytosolic glutathione peroxidase (from 11 +/- 0.9 to 67.2 +/- 4.2 mU/10(7) cells) and phospholipid hydroperoxide glutathione peroxidase (from 0.2 to 9.5 +/- 0.9 mU/10(7)cells). Supplementation with alpha-tocopherol inhibited single-strand breaks induced by low concentrations of H2O2 only, whereas an adequate selenium supply almost completely inhibited single-strand breaks induced by up to 30 microM H2O2 and also significantly reduced H2O2-induced cell death. An inadequate selenium supply and corresponding increase of GPx activity upon selenite supplementation was also observed with other cell lines, for instance, D10N, ECV-304, HepG2, and THP-1. Our data strengthen the relevance of standardized and adequate supplementation of tissue culture media with antioxidants to improve viability and genetic stability of cultured cells in general and in particular, if they are oxidatively challenged.
 ...
PMID:Conventional cell culture media do not adequately supply cells with antioxidants and thus facilitate peroxide-induced genotoxicity. 885 40

Four different cell lines (Hep G2, THP-1, EL 4 6.1, and ECV 304) were grown in a selenium-deficient standard medium (5% fetal calf serum in RPMI 1640 resulting in 5.5 nM selenium of unknown bioavailability) and supplemented with increasing concentration of selenium in the form of sodium selenite, selenomethionine and serum-bound selenium. The activities of two types of glutathione peroxidases (cGPx and PHGPx) were measured to estimate the availability of selenium for selenoprotein synthesis. Only sodium selenite between 1 and 100 nM was found to consistently induce GPx activity in all cell lines, whereas selenomethionine in equal concentrations was practically ineffective. Only THP-1 cells were able to utilize selenium from serum as efficiently as sodium selenite. PHGPx activity similarly responded to selenium supplementation, but was not increased in EL 4 6.1 cells. Our data demonstrate that conventional tissue culture media require selenium supplementation to guarantee adequate selenoprotein biosynthesis in cultured cells. The chemical nature of the selenium compound used for such supplement is as critical for in vitro cultivated cells as for dietary intake.
 ...
PMID:Utilization of selenium from different chemical entities for selenoprotein biosynthesis by mammalian cell lines. 892 68

Routine determinations of glutathione peroxidases (GPx) still suffer from poor standardization and usually from lack of specification. The different types of glutathione peroxidases present in cellular homogenates may be differentially estimated by their distinct substrate specificities. Complex lipid hydroperoxides required for this approach, however, are not generally available nor easily standardized due to their molecular heterogeneity and tendency to form micelles. We therefore developed a simple procedure for the differential estimation of the major cellular types of GPx, the cytosolic GPx (cGPx) and the phospholipid hydroperoxide glutathione peroxidase (PHGPx) taking advantage of the peculiar susceptibility of PHGPx to deoxycholate. It proved to reliably determine the activities of both purified cGPx and PHGPx, in mixtures thereof, and in homogenates of tissue samples (e.g., testes), and some (e.g. ECV 304) but not all (e.g. THP-1) cultured cell lines. The method allows the differential estimation of cGPx and PHGPx, if the samples do not contain further types of GPx.
 ...
PMID:Attempt to differentiate between individual glutathione peroxidases in biological samples. 955 40