The p38 MAPK pathway is involved in the TGIF1-dependent radiation and TNF-α-induced proinflammatory state in HUVECs.
A, HUVECs were transfected with pCMV-myc TGIF1 or siRNA TGIF1 or siRNAp38α for 24 h and irradiated at 10 Gy or treated with 0.1 ng/ml TNF-α. mRNA IL-8 levels were determined by real-time PCR. *, p < 0.05 versus control cells; #, p < 0.05 versus TNF-α-treated cells. B, HUVECs were transfected for 24 h with control or with pCMV-myc-TGIF1 vector and treated or not with the p38α/β inhibitor SB206580 (10 μm). IL-6 and IL-8 protein secretion was determined in supernatant 8 h after irradiation. Results are ± S.E. (error bars) of three independent experiments done in triplicate. *, p < 0.05 versus control cells; #, p < 0.05 versus irradiated cells transfected with TGIF1 vector.