Adipocyte-specific ablation of FNIP1 promotes browning of WAT. (A) Schematic showing the generation of adipocyte-specific FNIP1 KO mice. (B) Representative Western blot analysis of FNIP1 protein expression in eWAT, iWAT, and BAT from indicated male mice. n = 8 mice per group. (C) H&E staining of iWAT, eWAT, and BAT of indicated male mice. Scale bar: 20 μm. n = 8 mice per group. (D) IHC staining with a UCP1-specific antibody in iWAT sections of indicated male mice. Scale bar: 50 μm (20×) or 20 μm (40×). n = 8 mice per group. (E) Left: Representative Western blot analysis of entire iWAT lysates for male mice of the indicated genotypes. Right: Quantification of the UCP1/tubulin signal ratios. n = 8 mice per group. (F) Volcano plot showing fold changes versus P values for analyzed RNA-seq data generated from the iWAT of 8-wk-old male FNIP1 AKO mice compared with littermate controls (WT). Significantly upregulated genes are represented by orange dots, whereas downregulated genes are represented by green dots. (G) GO enrichment analysis of gene transcripts upregulated in male FNIP1 AKO iWAT. (H) Expression of genes (qRT-PCR) involved in the thermogenic and mitochondrial oxidative program in iWAT from the indicated male mice. n = 4–6 mice per group. (I) Representative Western blot analysis of entire iWAT lysates for male mice of the indicated genotypes. n = 11–12 mice per group. Values represent mean ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001. P value was determined using two-tailed unpaired Student’s t-test. Data are representative of two (B, C, D, and H) or three independent experiments (E and I). Source data are available for this figure: SourceData F1.