Mutual Antagonistic Relationship Between Prostaglandin E2 and Interferon-(gamma): Implications for Rheumatoid Arthritis

ABSTRACT: PGE2 is a major mediator of inflammation and is present at high concentrations in the synovial fluid of rheumatoid arthritis (RA) patients. PGE2, acting through the EP4 receptor, has both pro- and anti-inflammatory roles in vivo. To shed light on this dual role of PGE2, we investigated its effects in whole blood and in primary human fibroblast-like synoviocytes. Gene expression analysis in human leukocytes, confirmed at the protein level, revealed an EP4-dependent inhibition of the expression of genes involved in the IFN-gamma activation pathway, including IFN-gamma itself. This effect of the PGE2/EP4 axis on IFN-gamma is a reciprocal phenomenon since IFN-gamma blocks PGE2 release and blocks EP receptor expression. The mutually antagonistic relationship between IFN-gamma and PGE2 extends to downstream cytokine- and chemokine-release; PGE2 counters the effects of IFN-gamma, on the release of IP-10, IL-8, TNFalpha and IL-1beta. To gain further insight into IFN-gamma-mediated cellular events in rheumatoid arthritis, we assessed the effects of IFN-gamma on gene expression in fibroblast-like synoviocytes. We observed an IFN-gamma-dependent up-regulation of macrophage-attracting chemokines, and down-regulation of metalloprotease expression. These results suggest the existence of a mutually antagonistic relationship between PGE2 and IFN-gamma which may represent a fundamental mechanism of immune control in diseases such as RA.

ORGANISM(S): Homo sapiens

PROVIDER: GSE11575 | GEO | 2008/05/29

SECONDARY ACCESSION(S): PRJNA106201

REPOSITORIES: GEO