Dual Specificity Phosphatase 1 Regulates Human Inducible Nitric
Oxide Synthase Expression by p38 MAP Kinase
The effect of p38 MAPK inhibitor BIRB 796 on mouse iNOS protein expression and NO production in response to LPS in J774 cells. J774 cells were preincubated with increasing concentrations of BIRB 796 for 30 min and stimulated with LPS (10 ng/mL) for 24 h. iNOS protein expression was detected with Western blot. Chemiluminescent signal was quantified, and iNOS expression was normalized to lamin. The gels are representatives of six separate experiments with similar results. Results are expressed as a percentage of LPS, mean ± S.E.M., . NO production was measured as nitrite accumulated in the culture medium by Griess reaction, and the results are expressed as mean ± S.E.M., . One-way ANOVA with Dunnett’s posttest was performed, and statistical significance is indicated with compared to LPS-treated cells.