The effects of glucocorticoid hormone on the expression of c‐jun

Abstract

The effects of glucocorticoid hormone on the expression of c‐jun in the fibroblasts were studied. The expression of c‐jun was repressed by dexamethasone in the NIH3T3 cells, but not in the transformed BI04‐1 or EJ‐Ras cells. The repression was not relieved by the addition of cycloheximide.

Oral steroids enhance epithelial repair in nasal polyposis via upregulation of the AP-1 gene network

“…Our results are in disagreement with a previous report in which raised c-Fos protein levels were detected in NP tissue and steroid treatment decreased the c-Fos protein level but did not affect the c-Fos mRNA level in NP tissues 18. Induction of AP-1 in response to GC treatment is highly complex and may be cell type-specific 19 20. c-Fos protein was expressed in endothelial cells, lymphocytes, granulocytes and monocytes.…”

The delayed induction of c-jun in apoptotic human leukemic lymphoblasts is primarily transcriptional

“…The regulation can be purely transcriptional, post-transcriptional, or both [26][27][28][29][30]. Glucocorticoid induces c-jun expression in some cells, but suppresses it in others [25,[31][32][33]. In both AtT-20 pituitary tumor cells and U-937 monocytic leukemia cells, Dex represses the transcription of c-jun [25,34].…”

Effects of dexamethasone on cytokine and phorbol ester stimulated c-Fos and c-Jun DNA binding and gene expression in human lung

“…Suppression of c-fos and c-jun expression is due to a rapid breakdown of mRNAs, both of which are known to contain adenine-uracil (AU)-rich regions in their 3' untranslated regions, and are thus susceptible to rapid ribonuclease (RNase) action. Glucocorticoids have been shown to affect mRNA degradation by binding to 3' regions of mRNAs without having a direct effect on transcription [23], and may alter c-jun and c-fos mRNA levels by directly binding to the 3' tail of their respective mRNAs. Alternatively, c-fos and c-jun transcription may be affected by glucocorticoid receptor binding to AP-1.…”

“…This difference in results may be resolved by expanding the time course to beyond 3 h and by increasing the number of time-points between 0 and 1 h, although other studies suggest that GR effects on c-jun expression are highly variable, depending on the cell types used [6,23]. It is also possible that GR controls the expression of a c-fos regulatory protein or its phosphorylation, thereby affecting c-fos transcription of mRNA half-life.…”