Figure 2.

TNFα increases PML protein accumulation in a p38 kinase-dependent manner. (a) The effects of MAPK inhibitors on TNFα-mediated PML protein accumulation. HUVECs were pretreated with kinase inhibitors SP600125 (JNK) (10 μM), SB202195 (p38) (10 μM) or U0126 (ERKs) (10 μM) before 16 h of TNFα (20 ng/ml) treatment. Cells were harvested and whole-cell lysates prepared for western blotting with the indicated antibodies. The relative ratio of PML to β-actin is shown in the bottom. (b) Inhibition of p38 kinase activity by SB202190. HUVECs were treated with DMSO or SB202190 (10 μM) before TNFα treatment and harvested at indicated times for western blotting with the indicated antibodies. α-Tubulin was included as a loading control. (c) The effect of p38 knockdown on TNFα-mediated PML protein accumulation. HUVECs were transiently transfected with a control or two independent p38 siRNAs, treated with or without TNFα, harvested and western blotted with the indicated antibodies