Fig. 4.

Overexpression of XBP1 stimulated promoter activity of the FAS promoter. A, Spliced (XBP1S) or unspliced (XBP1U) was introduced into hepa1c1c7 cells with Lipofectamine2000 for 72 h. Protein levels were determined by immunoblotting with specific antibodies noted. B, The FAS promoter was introduced into hepa1c1c7 cells with XBP1S and XBP1U proteins via transient transfection for 36 h. Promoter activity was measured by luciferase assays and normalized to protein levels. Results represent mean ± sem of three independent experiments, each in triplicate.