MD-2 expression is not regulated by dexamethasone in HepG2 cells. (A) Effect of IL-6 and dexamethasone on the expression of a luciferase reporter gene driven by the MD-2 promoter transfected in HepG2 cells. HepG2 cells transfected with an MD-2 promoter driving the firefly luciferase reporter gene were stimulated for 6 hours with IL-6 (10 ng/mL) and dexamethasone (dex, 10 μM). Firefly luciferase activity was normalized with renilla luciferase activity. Mean values plus or minus SD are shown. This experiment was performed in triplicates and is representative of 3 different experiments. (B) Effect of IL-6 and dexamethasone on the expression of MD-2 mRNA in HepG2 cells. MD-2 mRNA expression (normalized with GAPDH mRNA) was measured by quantitative RT-PCR in HepG2 cells stimulated for 6 hours with IL-6 (10 ng/mL) and dexamethasone (dex, 10 μM). Mean values plus or minus SD are shown. This experiment was performed in triplicates and is representative of 3 different experiments. (C) Effect of IL-6 and dexamethasone on the secretion of sMD-2 protein by HepG2 cells. Western blot of sMD-2 (23 kDa) in supernatant of HepG2 cells stimulated for 24 hours with IL-6 (10ng/mL) and dexamethasone (10μM). This experiment was performed in triplicates and is representative of 3 different experiments.