Epithelial cell-derived prostaglandin D inhibits chronic allergic lung inflammation in mice.

The precise role of prostaglandin D (PGD) in allergic lung inflammation remains controversial. Here, we aimed to clarify the role of PGD in chronic allergic lung inflammation using hematopoietic PGD synthase (H-PGDS)-deficient mice. Repeated intranasal administration of ovalbumin (OVA) resulted in eosinophilic infiltration and mucin production in the lungs of wild type (WT) mice, leading to respiratory dysfunction. H-PGDS deficiency exacerbated these effects, which were accompanied by increased mRNA expression of TNF-α and eosinophil chemoattractants. The bronchial epithelium expressed both H-PGDS and TNF-α in the inflamed WT lung, and H-PGDS deficiency increased TNF-α expression further. In cultured bronchial tissue of WT mice, treatment with LPS elevated mRNA expression of TNF-α and eosinophil chemoattractants. H-PGDS deficiency promoted the expression of these factors, which was inhibited by treatment with PGD receptor, D prostanoid (DP) receptor agonist, or PGD metabolite 15-deoxy-Δ-PGJ (15d-PGJ). Treatment with TNF-α receptor antibody inhibited eosinophil chemoattractant expression. , administration of DP agonist or 15d-PGJ inhibited OVA-induced allergic lung inflammation. Bronchial epithelial cell-derived PGD attenuated lung eosinophilic infiltration with chronic allergic inflammation; these phenomena are at least partly attributed to the inhibition of TNF-α production DP activation or 15-deoxy-Δ-PGJ signaling.-Maehara, T., Nakamura, T., Maeda, S., Aritake, K., Nakamura, M., Murata, T. Epithelial cell-derived prostaglandin D inhibits chronic allergic lung inflammation in mice.