FIGURE 2. Endogenous IL-6 mRNA is stabilized by p38α signaling.
A, p38α+/+ MEFs were seeded into 60-mm plates. After 24 h of IL-1 β (1 ng/ml) stimulation with or without SB203580 (5 μM), actinomycin D (10 μg/ml) was added, and total RNA was harvested at indicated time points. Reverse transcription-PCR for IL-6 and GAPDH were performed as described under “Experimental Procedures.” B, graphical depiction of IL-6 mRNA decay from panel A normalized to GAPDH. C, p38α+/+ and p38α−/− MEF cells were stimulated by IL-1 β (1 ng/ml) for 24 h. Actinomycin D (10 μg/ml) was added, and the mRNA level of IL-6 was measured by quantitative real-time PCR. Data represent the average of three independent experiments.