MEK inhibitor P98059 blocks phosphorylation of ERK1/2 and also restores susceptibility of GC-treated monocytes to STS-induced apoptosis, whereas PKC inhibitor GF 109203X has no effect. Monocytes were preincubated in the presence of 10μM PD98059 (A) or 10μM GF 109203X (B) or left untreated for 30 minutes before stimulation with 100nM DEX (GC) or medium as a control (Co). Subsequently, cells were challenged to apoptosis induced by STS (■) or left untreated (□). After 6 hours, proportion of apoptotic cells was assessed by annexin V staining. Plots show the mean ± SEM of 4 independent experiments. After 16 hours of culture, cells were lysed, and immunoblotting was performed using antiphosphorylated and total ERK1/2 antibodies. The figure shows immunoblots from 1 representative experiment of 4.