Hydrogen Peroxide Induces Up-Regulation of Fas in Human Endothelial Cells

• Published in: The Journal of immunology (1950) 1998-04, Vol.160 (8), p.4042-4047
• Main Authors: Suhara, Toshimitsu, Fukuo, Keisuke, Sugimoto, Tomosada, Morimoto, Shigeto, Nakahashi, Takeshi, Hata, Shigeki, Shimizu, Masumi, Ogihara, Toshio
• Format: Article
• Language: English
• Subjects: Apoptosis - drug effects; Apoptosis - immunology; Cells, Cultured; DNA - metabolism; Endothelium, Vascular - cytology; Endothelium, Vascular - drug effects; Endothelium, Vascular - immunology; Enzyme Inhibitors - pharmacology; fas Receptor - genetics; fas Receptor - metabolism; Genistein - pharmacology; Humans; Microscopy, Electron; Phosphoprotein Phosphatases - antagonists & inhibitors; Protein-Tyrosine Kinases - antagonists & inhibitors; RNA, Messenger - genetics; RNA, Messenger - metabolism; Up-Regulation - drug effects; Vanadates - pharmacology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.160.8.4042

Hydrogen peroxide (H2O2), an oxidant generated by inflammatory cells, is an important mediator of injury of endothelial cells (ECs). Here we show that H2O2 induces up-regulation of the expression of Fas, a death signal, in human ECs in culture. Flow cytometric analysis with a mAb against human Fas showed that incubation for 24 h with H2O2 induced a dose-dependent increase in the level of Fas in ECs. Coincubation with catalase, which rapidly degrades H2O2, inhibited H2O2-induced up-regulation of Fas. H2O2 also induced a dose-dependent increase in Fas mRNA level. A significant increase in Fas mRNA levels was observed from 6 h after stimulation with H2O2. Vanadate, a protein phosphatase inhibitor, significantly enhanced Fas mRNA and protein levels in H2O2-treated ECs. On the other hand, genistein, a tyrosine kinase inhibitor, inhibited H2O2-induced Fas mRNA expression. Furthermore, a flow cytometric method with propidium iodide staining and electron microscopic analysis showed that incubation with an agonistic Ab against Fas (anti-Fas IgM) induced apoptosis in H2O2-treated cells. These findings suggest that H2O2 induces up-regulation of Fas in ECs and that activation of protein tyrosine kinase may be involved in the mechanism of H2O2-induced Fas expression. Therefore, Fas-mediated apoptosis may have a pathologic role in H2O2-induced EC injury and thereby provide a new therapeutic target.