Figure 4
Inhibition of known TGF-β non-canonical signalling pathways does not prevent the impairment of GRE activity. BEAS-2B cells transiently transfected with GRE-SEAP reporter construct were pre-incubated for 30 min with inhibitors (1 μM SB431542: TGF-β type 1 activin receptor-like kinase (ALK) receptors, 10 μM LY294002: non-selective PI3-kinase inhibitor, 1 μM U0126: MEK1/2 inhibitor, 1 μM SB202190: p38MAPK inhibitor, 10 μM 5Z-7-oxozeaenol: TAK1 inhibitor, 1 μM SP600125: JNK inhibitor, 10 μM IKK2 inhibitor VIII: selective IKK2 inhibitor, 10 μM TDZD-8: selective GSK-3 inhibitor) prior to the addition of 40pM TGF-β for 24 h and stimulation with 30nM dexamethasone for a further 24 h. Supernatants were then collected for determination of SEAP level and results were then expressed as a percentage of the level induced in response to 30nM dexamethasone. Data are presented as mean and SEM for n = 3-4 independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 significantly different from control expression.