15-deoxy-Δ^12,14-prostaglandin J₂ inhibits the IL-1β-induced expression of granulocyte-macrophage colony-stimulating factor in BEAS-2B bronchial epithelial cells

15-Deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is an agonist for peroxisome proliferator-activated receptor-γ (PPAR-γ), which plays an important role in various biological processes including inflammatory responses. We have addressed the effect of 15d-PGJ₂ on the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in a cell line derived from human bronchial epithelial cells (BEAS-2B). Besides being a hematopoietic growth factor, GM-CSF activates mature leukocytes and is involved in regulation of inflammatory responses. Cultures of BEAS-2B were stimulated with interleukin-1β (IL-1β), and the expressions of GM-CSF mRNA and protein were analyzed by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. IL-1β stimulated the expression of GM-CSF in BEAS-2B cells in concentration- and time-dependent manners. When the cells were pretreated with 15d-PGJ₂ for 1 hour, the IL-1β-induced GM-CSF expression was inhibited in a concentration-dependent manner (2-50 μM). Ciglitazone, another agonist of PPAR-γ, did not affect the IL-1β-induced GM-CSF expression in BEAS-2B cells. A PPAR-γ antagonist, bisphenol A diglycide ether (BADGE), did not reverse the inhibitory effects of 15d-PGJ₂ on GM-CSF expression. 15d-PGJ₂ regulates GM-CSF expression in the bronchial epithelium, which may be mediated through a mechanism unrelated to PPAR-γ.