Effects of 15-deoxy-Delta12,14-prostaglandin J2 on the expression of Toll-like receptor 4 and 2 in the murine lung in the presence of lipopolysaccharide.

1. Previously, we have demonstrated that 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) enhances acute lung injury induced by lipopolysaccharide (LPS) in mice. The enhancement in acute lung injury by 15d-PGJ2 was concomitant with the enhanced expression of several pro-inflammatory cytokines in the lung. However, other underlying mechanisms of this enhancement remain to be elucidated. The present study investigated the effects of 15d-PGJ2 on the expression of Toll-like receptor (TLR) 4 and 2 in the lung in the absence or presence of LPS. 2. In the present study, ICR mice were divided into four experimental groups that received (intratracheally) vehicle, LPS (125 microg/kg), 15d-PGJ2 (1 mg/kg) or 15d-PGJ2 + LPS. The mRNA expression of both TLR4 and 2 in the lung was evaluated 4 h after intratracheal administration. 3. 15-Deoxy-Delta12,14-prostaglandin J2 enhanced the mRNA expression of both TLR4 and 2 in the presence of LPS. 4. These results suggest that the enhancing effects of 15d-PGJ2 on LPS-induced acute lung injury may be explained, at least in part, by its effect on the lung expression of TLR4 and 2.