Peroxisome proliferator-activated receptors (PPARs) are members of the
nuclear hormone receptor superfamily of
ligand-activated
transcription factors that are related to
retinoid,
steroid, and
thyroid hormone receptors. The
PPAR-gamma receptor subtype seems to play a pivotal role in the regulation of cellular proliferation and
inflammation. Recent evidence also suggests that the
cyclopentenone prostaglandin (PG) 15-deoxyDelta(12,14)-PGJ(2) (15d-PGJ(2)), which is a metabolite of
prostaglandin D(2), functions as an endogenous
ligand for
PPAR-gamma. We postulated that 15d-PGJ(2) would attenuate
inflammation. In the present study, we have investigated the effects of 15d-PGJ(2) of acute and chronic
inflammation (
carrageenan-induced
pleurisy and
collagen-induced arthritis, respectively) in animal models. We report for the first time, to our knowledge, that 15d-PGJ(2) (given
at 10, 30, or 100 microg/kg i.p. in the
pleurisy model or at 30 microg/kg i.p every 48 h in the
arthritis model) exerts potent anti-inflammatory effects (e.g., inhibition of pleural exudate formation, mononuclear cell infiltration, delayed development of clinical indicators, and histological injury) in vivo. Furthermore, 15d-PGJ(2) reduced the increase in the staining (immunohistochemistry) for
nitrotyrosine and
poly (ADP-ribose) polymerase and the expression of
inducible nitric-oxide synthase and
cyclooxygenase-2 in the lungs of
carrageenan-treated mice and in the joints from
collagen-treated mice. Thus, 15d-PGJ(2) reduces the development of acute and chronic
inflammation. Therefore, the
cyclopentenone prostaglandin 15d-PGJ(2) may be useful in the
therapy of acute and chronic
inflammation.