Inhibition by glucocorticoids of tumor necrosis factor-mediated cytotoxicity. Evidence against lipocortin involvement |
| |
Authors: | R Beyaert P Suffys F Van Roy W Fiers |
| |
Institution: | Laboratory of Molecular Biology, State University of Gent, Belgium. |
| |
Abstract: | The role of the phospholipase inhibitor proteins, lipocortin-I and -II, in tumor necrosis factor (TNF)-mediated cytotoxicity against L929 fibrosarcoma cells was investigated. We previously reported that TNF-mediated cytotoxicity was inhibited by dexamethasone (DEX), suggesting an involvement of lipocortins. Now we show that, despite inhibition by DEX of TNF-induced arachidonic acid release, DEX has no effect on the synthesis of these lipocortins. Moreover, TNF itself has no effect on the synthesis and phosphorylation of lipocortin-I and -II. Also there was no difference in expression levels of lipocortin-I and -II between TNF-sensitive and -resistant cells. These data strongly suggest that the protective effect of DEX and other glucocorticoids is not mediated by lipocortins. |
| |
Keywords: | |
|
|