These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Synthetic peroxisome proliferator-activated receptor gamma agonists rosiglitazone and troglitazone suppress transcription by promoter 3 of the human thromboxane A2 receptor gene in human erythroleukemia cells.
    Author: Coyle AT, Kinsella BT.
    Journal: Biochem Pharmacol; 2006 Apr 28; 71(9):1308-23. PubMed ID: 16499875.
    Abstract:
    The human thromboxane (TX)A2 receptor (TP) gene encodes two TP isoforms, TPalpha and TPbeta, that are regulated by distinct promoters designated promoter Prm1 and Prm3, respectively. Previous studies established that 15d-Delta12,14-prostaglandin J2 (15d-PGJ2) selectively inhibits Prm3 activity and TPbeta expression through a peroxisome proliferator-activated receptor (PPAR)gamma mechanism without affecting Prm1 activity or TPalpha expression in human megakaryocytic erythroleukemia (HEL) 92.1.7 cells. Herein, we investigated the effect of synthetic thiazolidinedione (TZD) PPARgamma ligands rosiglitazone and troglitazone on TP gene expression in HEL cells. Like 15d-PGJ2, both TZDs suppressed Prm3 activity, TPbeta mRNA expression and TP-mediated calcium mobilization without affecting Prm1 or TPalpha mRNA expression. However, unlike 15d-PGJ2, both TZDs mediated their PPARgamma-dependent effects through trans-repression of an activator protein-1 (AP-1) element, a site previously found to be critical for basal Prm3 activity. These data provide further evidence for the role of PPARgamma in regulating the human TP gene; they highlight further differences in TPalpha and TPbeta expression/regulation and point to essential differences between natural and synthetic PPARgamma agonists in mediating those effects.
    [Abstract] [Full Text] [Related] [New Search]