15-deoxy-delta(12-14)-prostaglandin-j2 and Respiratory-Distress-Syndrome

Acute lung injury (ALI) is a disease process that is characterized by diffuse inflammation in the lung parenchyma. Recent studies demonstrated that cyclooxygenase-2 (COX-2) induced at the late phase of inflammation aids in the resolution of inflammation by generating 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2). Transcription factor Nrf2 is activated by electrophiles and exerts antiinflammatory effects by inducing the gene expression of antioxidant and detoxification enzymes.. Because 15d-PGJ2 is an endogenous electrophile, we hypothesized that it protects against ALI by activating Nrf2.. To test this hypothesis, we generated a reversible ALI model by intratracheal injection of carrageenin, an inducer of acute inflammation, whose stimulation has been known to induce COX-2.. We found that ALI induced by carrageenin was markedly exacerbated in Nrf2-knockout mice, compared with wild-type mice. Analysis of bronchoalveolar lavage fluids also revealed that the magnitude and the duration of acute inflammation, indicated by albumin concentration and the number of neutrophils, were significantly enhanced in Nrf2-knockout mice. Treatment of wild-type mice with NS-398, a selective COX-2 inhibitor, significantly exacerbated ALI to the level of Nrf2-knockout mice. In the lungs of NS-398-treated wild-type mice, both the accumulation of 15d-PGJ2 and the induction of Nrf2 target antioxidant genes were significantly attenuated. Exogenous administration of 15d-PGJ2 reversed the exacerbating effects of NS-398 with the induction of antioxidant genes.. These results demonstrated in vivo that 15d-PGJ2 plays a protective role against ALI by exploiting the Nrf2-mediated transcriptional pathway.

Topics: Animals; Carrageenan; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; DNA-Binding Proteins; Macrophages; Mice; Mice, Inbred BALB C; NF-E2-Related Factor 2; Nitrobenzenes; Pneumonia; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Respiratory Distress Syndrome; Sulfonamides; Trans-Activators

15-Deoxy-delta(12,14)-prostaglandin J(2) (15d-prostaglandin J(2)) has received attention for its anti-inflammatory properties. The present study investigated the efficacy of 15d-prostaglandin J(2) on acute lung injury induced by lipopolysaccharide in mice. ICR mice were administered with 15d-prostaglandin J(2) (10 microg/kg, 100 microg/kg, or 1 mg/kg) before intratracheal challenge with lipopolysaccharide (125 microg/kg). Treatment with 15d-prostaglandin J(2) did not ameliorate rather enhanced at a dose of 1 mg/kg the neutrophilic lung inflammation and pulmonary edema by lipopolysaccharide. The enhancement was concomitant with the increased lung expression of interleukin-1 beta, macrophage inflammatory protein-1 alpha, and macrophage chemoattractant protein-1. 15d-prostaglandin J(2) increased the nuclear protein expression of peroxisome proliferator-activated receptor (PPAR)-gamma and inhibited the nuclear localization of nuclear factor-kappa B related to lipopolysaccharide. 15d-prostaglandin J(2) increased the phosphorylation of c-Jun in the presence or absence of lipopolysaccharide. Our data suggest that 15d-prostaglandin J(2) may not be useful but potentially harmful for the therapeutic option of acute lung injury.

Topics: Animals; Drug Synergism; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; Prostaglandin D2; Respiratory Distress Syndrome