Effect of 15-deoxy-Δ12,14-prostaglandin J2 on IL-1β-induced expression of epithelial neutrophil-activating protein-78 in human endothelial cells

Epithelial neutrophil-activating peptide-78 (ENA-78) is a member of CXC chemokines. It is produced by endothelial cells stimulated with interleukin-1 (IL-1), along with other CXC chemokines such as IL-8 and growth-related oncogene protein-α (GRO-α). IL-1-induced ENA-78 production by endothelial cells may be important for the regulation of neutrophil activation. 15-Deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is a natural ligand for peroxisome proliferator-activated receptor-γ (PPAR-γ) and affects the expression of various genes. We examined the effect of 15d-PGJ₂ on the expression of ENA-78 in cultured endothelial cells stimulated with IL-1β. 15d-PGJ₂ inhibited the IL-1β-induced expression of ENA-78, but not the expression of IL-8 or GRO-α in response to IL-1. Ciglitazone, another agonist for PPAR-γ, had no effect on the expression of ENA-78, suggesting that 15d-PGJ₂ may inhibit the expression of ENA-78 in a PPAR-γ-independent manner. 15d-PGJ₂ may modulate inflammatory reactions by regulating the balance of CXC chemokines in endothelial cells.