Figure 1.

Effect of IL-1β on expression of IRAK pathway and IL-1β–mediated PI 3-kinase activation through IRAK. (A) When cells reached approximately 70% confluence, they were starved of serum for 24 hours. The serum-starved cells were treated with IL-1β (5 ng/mL) for 10 minutes and then maintained in DMEM for the designated time. At the end of treatment, cells were lysed with radio immunoprecipitation assay (RIPA) buffer and the cell debris was eliminated by centrifugation. After centrifugation, the supernatant was immunoblotted with the respective antibody. The serum-starved cells were pretreated with LY294002 (B) or IRAK inhibitor (C) for 2 hours and then treated with IL-1β for 10 minutes. The IL-1β–treated cells were maintained in DMEM for the designated time. At the end of treatment, cells were lysed and then immunoblot analysis was carried out with the respective antibody. Total Akt and β-actin were used to control protein concentration on immunoblot analysis. The results represent data obtained in three independent experiments. D-0, DMEM without serum.