Fig 2: Beige adipocytes rapidly lose their thermogenic characteristics after the withdrawal of external cues along with decreased expression of Ppara(A) Schematic illustration of experiments. Induced beige adipocytes were treated with rosiglitazone (1 µM) in vitro and ß3 agonist (1 mg kg-1) in vivo. After the introduction of beige adipocytes, the global RNA levels in beige adipocytes and inguinal beige fats between the induced models and withdrawn models (n = 3) were compared by RNA-sequencing.(B) Heatmap of representative thermogenic genes downregulated by the withdrawal of external stimuli. The log2-fold changes are shown in color scale. Pathway enrichment analysis of downregulated genes using Metascape.(C) Venn diagram of downregulated thermogenic genes.(D) Relative mRNA levels of Ppara and thermogenic genes during beige adipocyte differentiation by treatment with rosiglitazone (1 µM) in vitro (n = 4; mean ± SEM).(E) Relative mRNA levels of human PPARA in perirenal fat samples of human patients with pheochromocytoma or non-functional adrenal tumors (mean ± SEM; n = 7 independent samples for non-functional adrenal tumors and n = 11 independent samples for pheochromocytoma).(F) Correlation of the thermogenic related genes and PPARA expression in perirenal fat samples with pheochromocytoma.

Fig 3: The in vivorelevance of the CtBP2/PPARα interaction.A, the expression levels of PPARα target genes in liver-specific CtBP2 KO mice (LCKO) (n = 8 and n = 5 for flox and LCKO, respectively). Liver samples were collected after 5 to 6 h of food withdrawal. B and C, liver homogenates from high fat diet-induced obese mice (DIO, B), and genetically obese mice (ob/ob, C) were subjected to co-immunoprecipitation to analyze the endogenous CtBP2/PPARα complex. The densitometric quantification is shown to the right of each blot. D and E, recruitment of CtBP2 and PPARα to Cpt1 and Ppara gene promoters analyzed by ChIP. Chromatin was obtained from liver tissues of DIO (D) and ob/ob mice (E) along with their lean controls. Data are expressed as the mean ± SEM. ∗, ∗∗, and ∗∗∗ denotes p < 0.05, p < 0.01, and p < 0.001 evaluated by unpaired two-tailed Student’s t test. ChIP, chromatin immunoprecipitation; CPT, carnitine palmitoyltransferase; CtBP, C-terminal binding protein; PPARα, peroxisome proliferator-activated receptor alpha.