Figure 4.

TNF-α/IFN-γ-induced CTSS expression was mediated by STAT1, NF-κB, and p38 MAPK. Cells were treated as in Figure 3. (a) The expression of CTSS mRNA was measured by quantitative real-time PCR. (b) Protein levels of CTSS in cell lysates or conditioned media were measured by western blotting. Band intensity was analyzed using ImageJ software and the combined sum of pro and active CTSS band intensities was normalized to that of β-actin. The mRNA and protein levels, relative to those in the TNF-α/IFN-γ-stimulated DMSO control samples, are presented as mean fold-changes ± SEM of independent experiments (N = 3 or 4). Statistical comparisons were performed using a one-way ANOVA followed by Bonferroni’s post-hoc test (** p < 0.01, *** p < 0.001).