Fig. 9. A57, a novel inhibitor targets CREB/CRTC2 interaction.

a Structure of APC (left), the reserved α,β-unsaturated ketone group (middle), and compound A57 (right). b IC₅₀ of A57 and APC determined using a CREB/CRTC2 two-hybrid reporter system. One of three independent experiments presented here. Data are represented as mean ± SEM (n = 3 per treatment). IC₅₀ determined by nonlinear regression curve fit in Graphpad 8.0. c IC₅₀ of compound A57, A58 (top) and racemic A1011 determined by CREB/CRTC2 two-hybrid system (bottom). The compounds A57, A58 and A1011 were incubated with cells for 12-h. One of three independent experiments presented here. Data are represented as mean ± SEM (n = 3 per treatment). IC₅₀ determined by nonlinear regression curve fit in Graphpad 8.0. d mRNA level of gluconeogenesis marker, Pck1 and G6pc in primary hepatocytes incubated with APC or A57 (10 mM) 1-h prior to glucagon (100 nM) stimulation for 4-h (n = 6 per treatment). One of three independent experiments presented here. Data are represented as mean ± SEM. *P < 0.05; **P < 0.01; P values were determined by two-way ANOVA followed Bonferroni’s multiple comparisons test. e Measure of 16-h fasting blood glucose in Crtc2KO mice and wild-type littermates induced by high-fat diet (DIO) for 8 weeks and oral APC, A57 (20 mg/kg) or vehicle (VEH) daily for 3 days (n = 6 per group). One of three independent experiments presented here. Data are represented as mean ± SEM. *P < 0.05; **P < 0.01; P values were determined by two-way ANOVA followed Bonferroni’s multiple comparisons test. The db/db mice were orally treated with A57 (5 mg/kg), APC (5 mg/kg), or vehicle (VEH), one dose per day for 3 weeks. f Measure of 16-h fasting blood glucose levels in these db/db mice after one oral administration of compounds (n = 5 per group). One of three independent experiments presented here. Data are represented as mean ± SEM. ns, P > 0.05; *P < 0.05; **P < 0.01; P values were determined by one-way ANOVA followed Turkey’s multiple comparisons test. g Oral glucose-tolerance test (OGTT) in these db/db mice administrated oral drugs for 3 weeks (left) (n = 5 per group). Area under curve (AUC) analysis is shown as a bar graph (right). One of three independent experiments presented here. Data are represented as mean ± SEM. *P < 0.05; **P < 0.01; P values were determined by two-way ANOVA followed Bonferroni’s multiple comparisons test. h The molecular mechanism of how these small molecules, APC and A57, improve metabolic syndrome by disrupting the interaction between CREB and CRTC2. Source data for this figure are provided as a Source data file.