Fig. 1.

ChREBP is a repressor of Pdx-1 gene expression in MIN6 cells. (A,B) MIN6 cells were cultured for 48 h in the presence of scrambled or ChREBP siRNA (A), or in the presence of null or SREBP-DN adenoviruses (B), then overnight in 3 mM glucose and finally for 6 h in 3 or 30 mM glucose prior to cell lysis, total RNA extraction and real-time quantitative RT-PCR (see Section 2). (C,D) Pdx-1 promoter activity was monitored via nuclear and cytoplasmic microinjection of Pdx-1 promoter–reporter system and anti-ChREBP (C) or anti-SREBP (D) antibodies (1 mg ml⁻¹), or control IgG as indicated, before culture at the indicated glucose concentrations for 6 h and luciferase imaging as described in Section 2. (E,F) Pdx-1 promoter activity was monitored as above but after co-microinjection of pChREBP (E) or SREBP-CA (F) plasmids. Data are the means ± SEM of three separate experiments.