Figure 10.

Forced expression of sterol regulatory element-binding protein-1 (SREBP-1) stimulated the pparγ promoter activity and increased the trans-activation activity of peroxisome proliferator-activated receptor-γ (PPARγ) in cultured hepatic stellate cells (HSCs). Semi-confluent HSC in 6-well plates were co-transfected with a luciferase reporter plasmid and the cDNA expression plasmid pSREBP-1, or pdn-SREBP-1, at indicated doses. pSREBP-1 contained a full fragment of wild-type pSREBP-1 cDNA, whereas pdn-SREBP-1 contained a full length of dominant negative pSREBP-1 cDNA. Cells were treated with or without curcumin at 20 µmol·L⁻¹ for 24 h. Luciferase activities were expressed as relative units after β-galactosidase normalization (means ± SD; n≥ 6). *P < 0.05 versus the control cells **P < 0.05 versus the cells treated with curcumin. (A). Luciferase assays of cells co-transfected with the pparγ promoter luciferase reporter plasmid pPPARγ-Luc plus pSREBP-1, or pdn-SREBP-1, at indicated doses; (B). Luciferase assays of cells co-transfected with the PPARγtrans-activity luciferase reporter plasmid pPPRE-Luc, containing three copies of the PPARγ response elements (PPRE), plus pSREBP-1, or pdn-SREBP-1, at indicated doses.