title: Involvement of the Retinoid X Receptor Ligand in the Anti-Inflammatory Effect Induced by Peroxisome Proliferator-Activated Receptor γ Agonist In Vivo.
abstract: Peroxisome proliferator-activated receptor γ (PPARγ) forms a heterodimeric DNA-binding complex with retinoid X receptors (RXRs). It has been reported that the effect of the PPAR agonist is reduced in hepatocyte RXR-deficient mice. Therefore, it is suggested that the endogenous RXR ligand is involved in the PPARγ agonist-induced anti-inflammatory effect. However, the participation of the RXR ligand in the PPARγ-induced anti-inflammatory effect is unknown. Here, we investigated the influence of RXR antagonist on the anti-inflammatory effect of PPARγ agonist pioglitazone in carrageenan test. In addition, we also examined the influence of PPAR antagonist on the anti-inflammatory effect induced by RXR agonist NEt-3IP. The RXR antagonist suppressed the antiedema effect of PPARγ agonist. In addition, the anti-inflammatory effect of RXR agonist was suppressed by PPARγ antagonist. PPARγ agonist-induced anti-inflammatory effects were reversed by the RXR antagonist. Thus, we showed that the endogenous RXR ligand might contribute to the PPARγ agonist-induced anti-inflammatory effect.
authors.affiliation: Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530, Japan.
authors.forename: Atsuki
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kakuta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyachi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sugimoto