title: IL-1β stimulates IL-8 production, including prostaglandin E2 receptor EP4-triggered pathways, in synoviocyte MH7A cells.
abstract: Prostaglandin E2 (PGE2) is an important modulator of cytokine-driven inflammation. Using GeneChip analysis, we found that interleukin (IL)-1β induces the gene expression of PTGER4, which encodes the PGE2 receptor subtype EP4 (PGE2EP4). This subtype is one of four PGE2 receptors occurring in synoviocyte MH7A cells. Immunofluorescence microscopy revealed a corresponding upregulation in the production of PGE2EP4 protein in IL-1β-pretreated MH7A cells. PGE2 alone has no effect on IL-8 production, but in cells pretreated with IL-1β it markedly enhances IL-8 production. Moreover, a stimulatory effect of PGE2 on IL-8 production in the synoviocyte MH7A cells was observed. These results indicate that, in the synovial tissues of patients with rheumatoid arthritis, PGE2 stimulates the release of IL-8 from the fibroblastic cells classified as present, thereby exacerbating inflammation.
authors.affiliation: Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Shibata
authors.forename: Hideo
authors.initials: H
authors.lastname: Kasai
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shimada
authors.forename: Tohru
authors.initials: T
authors.lastname: Koitabashi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Arai
authors.forename: Rika
authors.initials: R
authors.lastname: Sai
authors.forename: Hiroko
authors.initials: H
authors.lastname: Terao
authors.forename: Masafumi
authors.initials: M
authors.lastname: Horikiri
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Negishi
authors.forename: Keiji
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Abiko