Figure 7
Selective unresponsiveness to the inhibition of p38 activation by cAMP resulted from impaired induction of DLC. A, L929 cells were treated with forskolin (10 μM) for various times as indicated. The expression of c-FLIPL, MKP-1, DLC and actin was analyzed by immunoblotting. B, L929 cells were transfected with a mammalian expression vector encoding Xpress-DLC or the empty vector (2 μg each well) with a transfection marker GFP (0.5 μg each well). After 24 h, the cells were pretreated with or without forskolin (10 μM, 30 min) and then stimulated with 10 ng/ml TNF-α for 24 h or left untreated. Cell death was measured by PI staining. The percentages of cell death in GFP+ cells are shown in the right panel as mean ± SD; n = 3. Left panel is representative of three independent experiments.