UCP2 KO mice exhibit ameliorated obesity and inflammation induced by high-fat diet feeding

Fig. 1. UCP2 KO mice were protected from high fat diet (HFD)-induced obesity. (A) 6-week-old C57BL6 mice were fed an HFD for 16 weeks, adipocytes and SVF from eWAT were isolated, and Ucp2 mRNA expression was analyzed (n = 5 for NCD and n = 11 for HFD). 3T3L1 cells were differentiated and the mRNA expression levels of the (B) differentiation marker Pparγ and (C) Ucp2 were detected. (D) Photographs of WT and KO mice after 2 weeks of NCD and HFD. (E) Body weight graph of 6-18-week-old mice in each group. (F) Graph of body weight gain throughout the experiment. (G) Body composition data. (H) Photographs of WAT of HFD-induced WT and KO mice. (I) WAT weight graph. (J) H&E staining of epididymal adipose tissue. (K) Adipocyte sizes were quantified. Data are presented as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.

Fig. 2. An epidydimal adipose tissue macrophage is reduced in HFD treated KO mice. (A) F4/80 IHC staining of crown-like structure (CLS) formation in eWAT. (B) Number of CLSs was analyzed. (C) Relative mRNA expression of pro-inflammatory markers (M1 polarization). (D) Relative mRNA expression of anti-inflammatory markers (M2 polarization). (E) CCl2 mRNA expression. (F) Relative mRNA expression of apoptosis markers. Data are presented as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.

Fig. 3. No difference was observed in CL 316,243-induced β3 adrenergic stimulation between the two genotypes. (A) Schematic diagram of CL injection experiment. (B) Body weight gain graph, (C) fat composition, (D) lean composition. (E) WAT weight differences normalized by total body weight, and (F) absolute fat weight differences of Saline injected WT, Saline injected KO, CL injected WT, and CL injected KO mice. (G) Relative mRNA expression of browning markers and (H) UCP1 protein expression in iWAT was normalized to the levels of α-actin. (I) H&E staining of eWAT, iWAT, and BAT. Data are presented as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.

Fig. 4. Cold-induced browning capacity was comparable between WT and KO mice. (A) Schematic diagram of cold-induced browning. (B) Body weight gain graph. Body composition of (C) fat, (D) lean, (E) weights of WAT normalized by body weight and (F) actual weights are listed. (G) Relative mRNA expression of browning markers was analyzed in iWAT. (H) UCP1 protein expression in iWAT was normalized to the levels of α-actin. (I) H&E staining of eWAT, iWAT, and BAT. Data are presented as the mean ± SEM.