Cyclopentenone prostaglandins suppress activation of microglia: down-regulation of inducible nitric-oxide synthase by 15-deoxy-Delta12,14-prostaglandin J2.

:Mechanisms leading to down-regulation of activated microglia and astrocytes are poorly understood, in spite of the potentially detrimental role of activated glia in neurodegeneration. Prostaglandins, produced both by neurons and glia, may serve as mediators of glial and neuronal functions. We examined the influence of cyclopentenone prostaglandins and their precursors on activated glia. As models of glial activation, production of inducible nitric-oxide synthase (iNOS) was studied in lipopolysaccharide-stimulated rat microglia, a murine microglial cell line BV-2, and IL-1beta-stimulated rat astrocytes. Cyclopentenone prostaglandins were potent inhibitors of iNOS induction and were more effective than their precursors, prostaglandins E2 and D2. 15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) was the most potent prostaglandin among those tested. In activated microglia, 15d-PGJ2 suppressed iNOS promoter activity, iNOS mRNA, and protein levels. The action of 15d-PGJ2 does not appear to involve its nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) because troglitazone, a specific ligand of PPARgamma, was unable to inhibit iNOS induction, and neither troglitazone nor 15d-PGJ2 could stimulate the activity of a PPAR-dependent promoter in the absence of cotransfected PPARgamma. 15d-PGJ2 did not block nuclear translocation or DNA-binding activity of the transcription factor NFkappaB, but it did inhibit the activity of an NFkappaB reporter construct, suggesting that the mechanism of suppression of microglial iNOS by 15d-PGJ2 may involve interference with NFkappaB transcriptional activity in the nucleus. Thus, our data suggest the existence of a novel pathway mediated by cyclopentenone prostaglandins, which may represent part of a feedback mechanism leading to the cessation of inflammatory glial responses in the brain.

Petrova TV ，Akama KT ，Van Eldik LJ 《PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA》

The 15-deoxy-delta12,14-prostaglandin J2 inhibits the inflammatory response in primary rat astrocytes via down-regulating multiple steps in phosphatidylinositol 3-kinase-Akt-NF-kappaB-p300 pathway independent of peroxisome proliferator-activated receptor

Giri S ，Rattan R ，Singh AK ，Singh I ... -  《JOURNAL OF IMMUNOLOGY》

Role of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and its natural ligand 15-deoxy-Delta12, 14-prostaglandin J2 in the regulation of microglial functions.

Bernardo A ，Levi G ，Minghetti L 《EUROPEAN JOURNAL OF NEUROSCIENCE》

Anti-inflammatory actions of 15-deoxy-delta 12,14-prostaglandin J2 and troglitazone: evidence for heat shock-dependent and -independent inhibition of cytokine-induced inducible nitric oxide synthase expression.

Maggi LB Jr ，Sadeghi H ，Weigand C ，Scarim AL ，Heitmeier MR ，Corbett JA ... -  《DIABETES》

Contrasting effects of peroxisome-proliferator-activated receptor (PPAR)gamma agonists on membrane-associated prostaglandin E2 synthase-1 in IL-1beta-stimulated rat chondrocytes: evidence for PPARgamma-independent inhibition by 15-deoxy-Delta12,14prostagl

Bianchi A ，Moulin D ，Sebillaud S ，Koufany M ，Galteau MM ，Netter P ，Terlain B ，Jouzeau JY ... -  《-》