Fig. 4. Loss of FLCN in the liver suppresses de novo lipogenesis.

(A) Heatmap of normalized expression values of de novo lipogenesis genes from RNA-seq described in Fig. 3. (B and C) mRNA expression of de novo lipogenesis genes in livers of control, LiFKO, Tfe3 KO, and DKO mice fed (B) an AMLN diet (n = 3 to 9) for 17 to 18.5 weeks or (C) an FPC diet regimen (TD160785 with sugar water; n = 5 to 11) for 16 weeks. (D) Protein expression of SREBP1, ACLY, ACSS2, and FASN in livers from control, LiFKO, and DKO mice fed an FPC diet regimen (TD160785 with sugar water) for 16 weeks. HSP90 from Fig. 3D was used as loading control. Mice were euthanized after a 4- to 6-hour fast, and thus only the precursor form of SREBP1 was detected. (E) Control, LiFKO, and DKO mice (n = 6 or 7) were fed an AMLN diet for 7 to 11 days, fasted from 9 a.m. to 7 p.m., refed for 2 hours, and force-fed a bolus of ¹³C-fructose and ¹²C-glucose. The mice were fed overnight and killed the next morning. LC-MS was performed to examine the amount of ¹³C label incorporation into hepatic fatty acids. (F) Control, LiFKO, and DKO mice (n = 9 to 11) were fed an FPC diet regimen (TD190142 with sugar water) for 9 days and then injected intraperitoneally (i.p.) with deuterium oxide (²H₂O) at ~7 p.m. Five hours later, the mice were killed, and their livers harvested. LC-MS was performed to examine the amount of deuterium label incorporation into hepatic fatty acids. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; one-way ANOVA with Tukey’s multiple comparisons test. Data are depicted as mean ± SEM.