Extended Data Fig. 8: Galactose triggers mTORC1 inhibition to promote Foxo1-induced IGFBP-1 expression in hepatocytes.
a,b, Representative immunoblot analysis of phosphorylated S6 (p-S6) and phosphorylated S6K1 (p-S6K1) in the liver tissue from tamoxifen-treated Rptor+/+Alb-CreER and Rptorfl/flAlb-CreER mice (a) and Pten+/+Alb-CreER, Ptenfl/flAlb-CreER mice (b) fed on a high-galactose (Gal) diet or normal (Ctrl) diet. c,d, Representative immunoblot analysis of phosphorylated Foxo1 (p-Foxo1) and total Foxo1 in liver tissue from tamoxifen-treated Rptor+/+Alb-CreER, Rptorfl/flAlb-CreER mice (c) and Pten+/+Alb-CreER, Ptenfl/flAlb-CreER mice (d) fed on a high-galactose (Gal) diet or normal control (Ctrl) diet. Liver samples in a–d were collected at day 14 after galactose treatment. e,f, Igfbp1 mRNA level (e, n = 3 biological replicates per group) and protein level in supernatant (f, n = 6 biological replicates per group) from primary hepatocytes treated with DMSO or 1 μM AS184256 for 24 h supplied with 10 mM galactose or not. g, Schematic diagram of the Igfbp1 promoter constructed using a luciferase reporter vector. “WT” and “Mut” represent the wild-type and mutant versions of the Foxo1-binding site, respectively. Luc denotes luciferase. h, Luciferase assay of HEK293T cells transfected with a Foxo1 overexpression plasmid and a luciferase reporter plasmid containing the IGFBP-1 promoter region (n = 4 biological replicates per group), as constructed in (g). “NC” refers to the negative control. The experiments were independently repeated two times. Data are presented as mean ± SEM (e,f,h). P values were calculated by one-way ANOVA with Tukey’s multiple comparisons (e,f) and two-tailed Student’s t-test (h). ns, not statistically significant.
