Variable glutathione levels and expression of antioxidant enzymes in human endothelial cells.
We have investigated the relationship between intracellular glutathione levels and the inducibility of the mRNAs encoding the major antioxidant enzymes Cu,Zn superoxide dismutase (Cu,Zn SOD), catalase (CAT), glutathione peroxidase (GP), and the stress protein heme oxygenase (HO) following exposure of human umbilical vein endothelial cells (HUVEC) to either hypoxanthine-xanthine oxidase or 95% O2. Treatment of HUVEC with 2 and 200 microM buthionine sulfoximine (BSO) for 16 h reduced total glutathione (GSH) levels by 51 and 95%, respectively, whereas treatment with 100 microM diethylmaleate (DEM) for 24 h increased the cellular GSH content by 58%. None of these treatments affected the responsiveness of HUVEC to a subsequent oxidant challenge, in terms of antioxidant enzymes activities and mRNA levels. On the contrary, HO mRNA was significantly induced by both BSO and DEM, as well as by hyperoxia, albeit to a different extent. We conclude that intracellular redox changes do not appear to regulate the expression of the mRNAs encoding Cu,Zn SOD, CAT, and GP. Furthermore, factors other than endogenous thiols may play a role in the control of HO mRNA expression.
Jornot
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Respiratory Division, University Hospital, Geneva, Switzerland.
Junod
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AF
D015152:Blotting, Northern; D019328:Buthionine Sulfoximine; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D019803:Glutathione Disulfide; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008298:Maleates / Q000494:pharmacology; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D014471:Umbilical Veins; D014969:Xanthine Oxidase / Q000494:pharmacology
D007042:Hypoxanthines; D008298:Maleates; D012333:RNA, Messenger; D008717:Methionine Sulfoximine; D019271:Hypoxanthine; D019328:Buthionine Sulfoximine; D007770:L-Lactate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; C014476:diethyl maleate; D005978:Glutathione; D010100:Oxygen; D019803:Glutathione Disulfide