Fig. 2: Fibroblast growth factor 18 is elevated in the livers of Cflar^LKO mice.

a, b Eight-week-old female Cflar^FF and Cflar^LKO mice were fed the CDE diet for 4 weeks, and gene expression in the whole liver was analyzed by RNA-seq. Gene Ontology (GO) enrichment analysis was performed using DAVID 6.8 (a). Statistical analysis was determined by one-sided Fisher’s exact test. Heatmap showing the Z score scaled expression levels of representative genes in the indicated categories (n = 3 mice) (b). c Kinetics of the expression of the indicated genes in the livers of 8-week-old female mice before (–) and after CDE diet feeding for 4 weeks. Results are means ± SE (n = 5 mice). Pooled results from four independent experiments are shown. d, e Expression of Fgf18 in the liver by HTVi results in the proliferation of hepatocytes. Eight-week-old female wild-type (WT) mice were injected with the indicated expression vectors by the HTVi method. Liver sections were stained with anti-CK19, anti-desmin, or anti-Ki67 antibodies (d) (n = 4 mice). Scale bar, 100 μm. The CK19⁺, desmin⁺, or Ki67⁺ areas were calculated and are expressed as positive areas per FOV (e). Results are means ± SE (n = 4 mice) and represent two independent experiments. f, g Mice were treated as in (a), and the expression of Fgf18, Hnf4a, and Lrat was determined by RNAscope (n = 3 mice) (f). Red puncta indicate Hnf4a (upper panels) and Lrat (lower panels). White arrowheads indicate Fgf18 mRNA⁺ puncta (green). Nuclei were stained with DAPI (blue). White dotted lines outline the margins of hepatocytes. Scale bar, 100 μm. The total Fgf18 mRNA⁺ areas and numbers of Fgf18 mRNA⁺ puncta in Hnf4a⁺ hepatocytes and Lrat⁺ HSCs were calculated (g). Results are mean ± SE (n = 3 mice). Statistical significance was determined by the two-way ANOVA with Tukey’s multiple comparison test (c), one-way ANOVA with Dunnett’s multiple comparison test (e), or two-tailed unpaired Student’s t test (g). Source data are provided as a Source Data file.