Expression of iNOS protein in pAECs treated with LPS (10 μg/ml) for different time periods (7, 15, 24 h). A) LPS induced a significant increase of iNOS protein expression with respect to the control (CTR = mean ± SEM of all control time points). The data represent the mean ± SEM (n = 3) of relative protein content (AU = Arbitrary Units). The different letters above the bars indicate significant differences among the various time points (p < 0.05, ANOVA post hoc Tukey’s test, n = 3). B) Representative Western Blot of iNOS and relative housekeeping β-tubulin were reported.