Figure 6. Restoration of DNL and TAG synthesis prevents lipotoxicity-induced liver damage.
(A) RT-qPCR analysis of liver gene expression from Control (HDAC3f/f/SCAPf/f injected with AAV8:GFP + AAV8:Null), DLKO (HDAC3f/f/SCAPf/f injected with AAV8:Cre + AAV8:Null) and DLKO+nSREBP1c (HDAC3f/f/SCAPf/f injected with AAV8:Cre + AAV8:HA-nSREBP1c) mice sacrificed 10 days post AAV8 injection. n = 5 mice per group.
(B) Hepatic TAG measurements in mice described in (A).
(C) H&E staining of representative livers from Control, DLKO, and DLKO+nSREBP1c mice from (A). Green arrowhead points to a density of immune cell infiltrates that are lacking in Control and DLKO+nSREBP1c livers. Scale bar, 100 μm.
(D) RT-qPCR analysis of liver antioxidant and inflammatory gene expression from the mice described in (A).
(E) Kaplan-Meier survival curve of DLKO and DLKO+nSREBP1c mice. n = 4 mice per group.
(F) Hepatic DNL rate in vivo measured by tracing hepatic 2H-palmitate synthesis from deuterated water during a 6-hour interval. n = 4 mice per group.
(G and H) Hepatic levels of acylcarnitines (G) and other lipids (H) as measured by liquid chromatography mass spectrometry. Average ion counts of each metabolite across all conditions are shown in (G). Biological replicates are depicted in each row and each column represents a specific lipid metabolite in (H). The heat map highlights relative changes for each lipid metabolite with respect to its average ion counts in all three conditions. FFA, free fatty acids. MAG, monoacylglycerols. DAG, diacylglycerol. TAG, triacylglycerol. n = 4 to 5 mice per group. These mice were sacrificed 12 days after AAV8 injections. Ion counts and lipid identifications are available in Table S4.
(I) Summary of lipid metabolism in HDAC3 LKO, SCAP LKO, and DLKO livers.
All error bars, s.e.m. Significance was determined by one-way ANOVA followed by Holm-Sidak correction (A,B) or Tukey’s correction (B,F) (*P < 0.05 for comparison between control and experimental mice). (G and H) Significance of lipidomics data was determined by one-way ANOVA followed by FDR correction (*P < 0.05). See also Figure S6.