Transrepression of NF-κB is not required for glucocorticoid-mediated protection of TNF-α-induced apoptosis on fibroblasts

The cellular resistance to tumor necrosis factor (TNF) of most cell types has been attributed to both a protective pathway induced by this cytokine and the preexistence of protective factors in the target cell. NF-κB has been postulated as one of the principal factors involved in antiapoptotic gene...

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Autores principales: Costas, M.A., Müller Igaz, L., Holsboer, F., Arzt, E.
Formato: Artículo publishedVersion
Lenguaje:Inglés
Publicado: 2000
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01674889_v1499_n1-2_p122_Costas
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Sumario:The cellular resistance to tumor necrosis factor (TNF) of most cell types has been attributed to both a protective pathway induced by this cytokine and the preexistence of protective factors in the target cell. NF-κB has been postulated as one of the principal factors involved in antiapoptotic gene expression control on TNF-resistant cells. We have previously shown that glucocorticoids protect the naturally TNF-sensitive L-929 cells from apoptosis. Here we analyze the role of NF-κB and glucocorticoids on TNF-induced apoptosis in L-929 cells. We found that inhibition of NF-κB enhanced the sensitivity to TNF-induced apoptosis. Glucocorticoids inhibited NF-κB transactivation via IκB induction. Moreover, glucocorticoids protected from TNF-induced apoptosis even when NF-κB activity was inhibited by stable or transient expression of the superrepressor IκB. These results demonstrate that although glucocorticoids inhibit NF-κB transactivation in these cells, this is not required for their protection from TNF-induced apoptosis. (C) 2000 Elsevier Science B.V.