Fig. 7.

Regulation of glucokinase expression by IR amount. a Levels of GCK mRNA were measured by RT-PCR in control and BACE1^−/− primary hepatocytes. Native HEK 293 cells (b) or HEK 293 cells overexpressing BACE1 (c) were transfected with empty vector (EV) or with IR coding vector together with human GCK promoter-driven Firefly luciferase and SV40-driven Renilla luciferase coding vectors where indicated, serum-deprived cells were treated with the BACE1 inhibitor (C3; 20 μM) and then stimulated with insulin (2 nM, 7 h). Firefly and Renilla luciferase were measured in cell lysates, and GCK promoter activity was calculated as the ratio of Firefly/Renilla luciferase and expressed as fold over the situation without IR overexpression nor insulin stimulation. Data are means ± s.d. Statistical analyses were made using unpaired t-test (a) or ANOVA, followed by Bonferonni’s test (b, c). *p < 0.05; **p < 0.01