Figure 2.

Nuclear factor kappa B (NF-κB) activity plays a critical role in regulating the promoter activity of connective tissue growth factor (CTGF) gene in activated hepatic stellate cell (HSC) in vitro. Passaged HSCs were co-transfected with the ctgf promoter luciferase reporter plasmid pCTGF-Luc plus a cDNA expression plasmid. A total of 3.5 μg (a) or 4.5 μg (b) of plasmid DNA per well was used for co-transfection of HSC in six-well culture plates. It included 2 μg of pCTGF-Luc, 0.5 μg of pSV-β-gal and 1.0 μg (a) or 2 μg (b) of the cDNA expression plasmid at indicated doses plus the empty vector pcDNA. The latter was used to ensure an equal amount of total DNA in transfection assays. After recovery, cells were treated with or without curcumin for 24 h. Luciferase assays were performed. Luciferase activities were expressed as relative units after β-galactosidase normalization (means±s.d.; n⩾6). (a) Luciferase assays of cells co-transfected with pCMV-IKK-2 S177E/S181E (a-IKK2), encoding constitutively active form of IKK2, or with pCMV-IKK-2-WT (IKK2-WT), expressing wild-type IKK2. ^*P<0.05 versus cells transfected with no pa-IKK2 or pIKK2-WT, but treated with curcumin (the second column on the left). (b) Luciferase assays of cells co-transfected with pCMV-IκBα-M, encoding dominant-negative form of IκBα (dn-IκBα) or with pCMV-IκBα-WT encoding wild-type IκBα (IκBα-WT). ^*P<0.05 versus cells transfected with no dn-IκBα-M or IκBα-WT (the first column on the left).