Figure 4.

(a) Effect of PPARγ agonist 15d-PGJ₂ on iNOS mRNA expression in J774 macrophages. Cells were incubated with LPS (10 ng ml⁻¹) and 15d-PGJ₂ (10 μM). Total RNA was extracted at the indicated time points and iNOS mRNA was measured by real-time PCR. The results were normalized against GAPDH mRNA. Levels of iNOS mRNA are expressed relative to that induced by LPS at 6 h (set to 100%). Results are expressed as mean±s.e.m. (n=3). ^**P<0.01 as compared to cells treated with LPS alone. (b) Effect of PPARγ agonist 15d-PGJ₂ on iNOS protein expression in J774 macrophages. Cells were stimulated by LPS (10 ng ml⁻¹) and treated with increasing concentrations of 15d-PGJ₂. After 24 h incubations, proteins were extracted and iNOS protein was measured by western blot. Protein levels are expressed relative to that in LPS-treated cells (set to 100%). Actin was used as a loading control. Results are expressed as mean±s.e.m. (n=3). ^*P<0.05 and ^**P<0.01 as compared to cells treated with LPS alone. (c) Effect of PPARγ agonist 15d-PGJ₂ on NO production in J774 macrophages. Cells were stimulated by LPS (10 ng ml⁻¹) and treated with increasing concentrations of 15d-PGJ₂. After 24 h incubation, nitrite accumulated into the culture medium was measured by Griess reaction as a marker of NO production. Results are expressed as mean±s.e.m. (n=6). ^**P<0.01 as compared to cells treated with LPS alone.