r-project. org) was employed to perform quantile normalization of probe intensity data, and to identify significantly differentially expressed genes. Data are presented as mean ± standard error of the mean (SEM). Data were analyzed using a two-way analysis Raf inhibitor of variance with a Bonferroni post hoc test (GraphPad PRISM, version 4.0). P < 0.05 was considered as significant. We validated

that deletion of the SOCS3 gene was limited to the liver in mice acutely injected with interleukin-6 (Fig. 1A and Supporting Information Fig. 1). As expected, the HFD increased liver SOCS3 expression in littermate control floxed WT mice but not in SOCS3 LKO mice (Fig. 1A). SOCS1 and SOCS3 are highly homologous, but we found no difference in HFD induction of SOCS1 between genotypes (data not shown). On a control chow diet, SOCS3 LKO mice weighed the same as WT littermates. However, when fed an HFD (from 6 weeks of age onward), they gained more weight (Fig. 1B). Epididymal fat pad weights were significantly larger in absolute terms (Fig. 1C) and as percentage of total body mass (data not shown) in SOCS3 LKO mice fed an HFD indicating that the increased weight gain in SOCS3 LKO mice was due to increased adiposity. To assess the mechanisms contributing to increased weight gain in SOCS3 LKO mice we measured food intake and energy expenditure. On an HFD, www.selleckchem.com/products/azd-1208.html SOCS3 LKO mice consumed significantly

more food per day (Fig. 1D), even when corrected for body mass (data not shown), and expended less energy (Fig. 1E). Glucose oxidation rate was reduced in chow-fed and tended to

be reduced in HFD-fed SOCS3 LKO mice (data not shown). There was no difference in the rates of fat oxidation over a 24-hour light/dark cycle on either diet (data not shown). Taken together, these data suggest that increased adiposity in SOCS3 LKO mice on an HFD was due to reduced daily energy expenditure 上海皓元医药股份有限公司 and increased caloric intake. We measured serum glucose and insulin concentrations as well as glucose tolerance and found that on a chow diet SOCS3 LKO mice were comparable to WT littermates (Fig. 2A-C). In contrast, HFD-fed SOCS3 LKO mice developed hyperglycemia (Fig. 2A) and a greater degree of hyperinsulinemia (Fig. 2B) and glucose intolerance (Fig. 2D) than WT littermates. These data suggest that deletion of liver SOCS3 accelerates the onset of HFD-induced insulin resistance. To assess the specific contribution of hepatic versus peripheral insulin resistance to glucose homeostasis in SOCS3 LKO mice we conducted euglycemic-hyperinsulinemic clamps. Basal glucose turnover was similar between the two groups of mice on both diets (Supporting Table 1). In chow fed mice the glucose infusion rate (GIR), and the glucose disposal rate (GDR) were not different between groups (Fig. 3A,B). As anticipated, the HFD significantly reduced both GIR and GDR relative to chow fed mice, but this reduction was significantly greater in SOCS3 LKO mice (Fig.