Peroxisome proliferator-activated receptor gamma ligands suppress the transcriptional activation of cyclooxygenase-2. Evidence for involvement of activator protein-1 and CREB-binding protein/p300.
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Subbaramaiah K, Lin DT, Hart JC, Dannenberg AJ
Peroxisome proliferator-activated receptor gamma ligands suppress the transcriptional activation of cyclooxygenase-2. Evidence for involvement of activator protein-1 and CREB-binding protein/p300.
J Biol Chem. 2001 Apr 13;276(15):12440-8. Epub 2001 Jan 23.
- PubMed ID
- 11278336 [ View in PubMed]
- Abstract
We investigated whether peroxisome proliferator-activated receptor gamma (PPARgamma) ligands (ciglitazone, troglitazone, and 15-deoxy-Delta(12,14) prostaglandin J(2)) inhibited cyclooxygenase-2 (COX-2) induction in human epithelial cells. Ligands of PPARgamma inhibited phorbol ester (phorbol 12-myristate 13-acetate, PMA)-mediated induction of COX-2 and prostaglandin E(2) synthesis. Nuclear run-offs revealed increased rates of COX-2 transcription after treatment with PMA, an effect that was inhibited by PPARgamma ligands. PMA-mediated induction of COX-2 promoter activity was inhibited by PPARgamma ligands; this suppressive effect was prevented by overexpressing a dominant negative form of PPARgamma or a PPAR response element decoy oligonucleotide. The stimulatory effects of PMA were mediated by a cyclic AMP response element in the COX-2 promoter. Treatment with PMA increased activator protein-1 (AP-1) activity and the binding of c-Jun, c-Fos, and ATF-2 to the cyclic AMP response element, effects that were blocked by PPARgamma ligands. These findings raised questions about the mechanism underlying the anti-AP-1 effect of PPARgamma ligands. The induction of c-Jun by PMA was blocked by PPARgamma ligands. Overexpression of either c-Jun or CREB-binding protein/p300 partially relieved the suppressive effect of PPARgamma ligands. When CREB-binding protein and c-Jun were overexpressed together, the ability of PPARgamma ligands to suppress PMA-mediated induction of COX-2 promoter activity was essentially abrogated. Bisphenol A diglycidyl ether, a compound that binds to PPARgamma but lacks the ability to activate transcription, also inhibited PMA-mediated induction of AP-1 activity and COX-2. Taken together, these findings are likely to be important for understanding the anti-inflammatory and anti-cancer properties of PPARgamma ligands.
DrugBank Data that Cites this Article
- Drug Targets
Drug Target Kind Organism Pharmacological Action Actions Troglitazone Peroxisome proliferator-activated receptor gamma Protein Humans YesAgonistRegulatorDetails - Pharmaco-transcriptomics
Drug Drug Groups Gene Gene ID Change Interaction Chromosome Ciglitazone Experimental PPARG 5468 upregulated ciglitazone results in increased expression of PPARG mRNA 3p25.2 Troglitazone Approved Investigational Withdrawn PPARG 5468 upregulated troglitazone results in increased expression of PPARG mRNA 3p25.2