A Quantification of PSP/reg gene expression following inhibition of HNF1A and HNF4A function in INS-1 cells. INS-1 cells were treated with 500 ng /ml doxycycline from 0 to 48 h to induce DN-HNF1A and DN-HNF4A respectively. mRNA expression of PSP/reg was examined using real-time qPCR relative to β-actin. Expression levels were normalized to control cells and data represent means ± SEM from n = 3 cultures.* p < 0.05 difference from non-induced controls. Experiments were repeated 3 times with similar results (A, B) Whole cell lysates were analysed by Western blotting on 15% SDS-PAGE. Membranes were probed with a polyclonal antibody recognizing PSP/reg. Tubulin served as a loading control. (C, D) Quantification of PSP/reg protein levels by densitometry in cells treated with doxycycline as indicated. Western blots were analysed as described in the Materials and methods section and normalised to control. Data shown represent mean ± SEM from three independent experiments. *indicates p < 0.05 compared with untreated controls (E, F).