Figure 3.

Serum increases GR transrepression of IL6 through AP1 elements. HeLa cells were transiently transfected with TAT3-Luc (A) or pHH-Luc (B), together with Renilla-Luc and GR. 24 h later, cells were transferred to culture in either 10 or 50% serum then treated with Dex for 16 h before luciferase assay. HeLa cells were cultured in either 10 or 50% serum overnight, and then treated with either 100 nM Dex (C) or 100 μM ZnSO₄ (D) for 4 h before RNA purification and MT1X transcript measured by qRT-PCR (normalised to GAPDH). Cells were cultured in 10 or 50% serum overnight then treated with 5 ng/ml TNF for 1 h and Dex for a further 4 h. RNA was extracted and IL6 transcript measured by qRT-PCR (normalised to GAPDH) (E). HeLa cells were transiently transfected with WT or AP1 deletant IL6-Luc plasmids then cultured in 10 or 50% serum. Cells were treated with 100 nM PMA and 100 nM Dex for 16 h and then lysed for luciferase assay (F). Graphs show mean±s.e.m. Experiments were carried out in triplicate and repeated three times. *P<0.05, **P<0.01, and ***P<0.001. NS, not significant.