Cyclopentenone prostaglandins PGA2 and 15-deoxy-delta12,14 PGJ2 suppress activation of murine microglia and astrocytes: implications for multiple sclerosis.

The cyclopentenone prostaglandin (cPG) 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) has been identified as a potent antiinflammatory agent that is able to inhibit the activation of macrophages and microglia. Additionally, 15d-PGJ(2) is able to ameliorate the clinical manifestations of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Many biological effects of 15d-PGJ(2) have been attributed to the peroxisome proliferator activated receptor-gamma (PPAR-gamma). PGA(2), like 15d-PGJ(2), is a cPG. The aim of this study is to compare the relative effectiveness of these two cPGs in inhibiting the inflammatory response of mouse microglia and astrocytes, two cell types that upon activation may contribute to the pathology of EAE and MS. Purified primary mouse microglia and astrocytes were treated with either 15d-PGJ(2) or PGA(2) and then stimulated with either lipopolysaccharide (LPS) or a combination of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha. The results show that 15d-PGJ(2) and PGA(2) both potently inhibited the production of nitrite, as well as proinflammatory cytokines and chemokines, from microglia and astrocytes. Generally, regulation of NO production was more sensitive to 15d-PGJ(2), however, cytokine and chemokine production was more sensitive to PGA(2) treatment. These results demonstrate for the first time that PGA(2) is a potent antiinflammatory mediator.