Figure 8. SAS downregulates IL-1β-induced IκBα phosphorylation in ARPE-19 cells. ARPE-19 cells were starved in serum-free medium overnight and then incubated for 1 h with 2.5 or 5 µg/ml of SAS before the addition of 20 ng/ml of IL-1β for 5 min. After 5 min, the cells were lysed as described in the Materials and methods section. Proteins were separated by SDS–PAGE and subjected to immunoblotting with antibodies to phospho-IκBα, with tubulin as a control. The data represent one of two independent experiments.