De accumulation (C), membrane translocation of PKCe (D), and impairment of
De accumulation (C), membrane translocation of PKCe (D), and impairment of insulin-stimulated Akt2 (E) and FoxO1 (F) phosphorylation following lipid gavage with lard. n = 50 per group. P 0.05. Con, gavaged manage.TLR-4 eficient mice when fed a saturated fat diet (Fig. 3D). Consistent using the accumulation of DAGs, there was a 30 improve in activation and membrane translocation of PKCe (Fig. 3E). To assess the impact of saturated fat feeding on insulin sensitivity in TLR-4 eficient mice, we performed i.p. glucose tolerance tests (IPGTTs). The mice fed saturated fat were clearly glucose intolerant and insulin resistant, as reflected by larger plasma glucose concentrations at all time K-Ras Formulation points (Fig. 3F) and larger plasma insulin concentrations in the fasted state and at 90 min (Fig. S5).TLR-4 Deficient Mice Develop Hepatic Insulin Resistance When Fed a Diet regime Rich in Saturated Fat. To additional investigate the impact ofsaturated fat feeding on insulin sensitivity inside the setting of TLR-4 deficiency, we performed hyperinsulinemic-euglycemic clamp experiments comparing TLR-4 eficient 10ScNJ mice fed either regular chow or saturated fat for ten d and compared them with age- and weight-matched WT mice (10ScSnJ). To account for the documented alterations in appetite that accompany TLR-4 deficiency, we matched the weight gain in TLR-4 eficient and control mice fed saturated fat over their respective chow groups (saturated fat-fed TLR-4 eficient mice gained 1.9 g 0.5 and control gained 1.five g 0.6, a lot more than their respective chow groups). Despite the fact that plasma glucose levels had been not different12782 | pnas.orgcgidoi10.1073pnas.through the clamp (Fig. 4A), the glucose infusion rates needed to sustain euglycemia had been 40 reduced in both TLR-4 eficient and control mice when fed saturated fat compared with chow (Fig. 4B) reasserting that they had been certainly insulin-resistant. Whole-body glucose turnover (Fig. 4C) was decreased by 2030 in both TLR-4 eficient and manage mice when fed saturated fat. Basal hepatic glucose CCR2 manufacturer production was not unique; having said that (Fig. 4D), each the high fat fed TLR-4 eficient and control mice manifested pronounced hepatic insulin resistance (Fig. 4 D and E). Even though mice fed a chow diet plan displayed effective suppression of glucose production during the hyperinsulinemic-euglycemic clamp (77.8 six.5 for control and 77.1 5.6 for TLR-4 deficient, respectively), this suppression was reduced in mice fed the saturated fat diet (to 32.five 10.7 for handle and 46.four 6.5 for TLR-4 deficient, respectively) (Fig. 4E). Discussion The certain lipid species and molecular mechanisms by which hepatic steatosis outcomes in hepatic insulin resistance has been a hotly debated topic. We discovered that overfeeding of each saturatedand unsaturated fat-rich diets activates a DAG-PKCe mechanism resulting in inhibition of insulin-stimulated, IRS-2 ssociated PI3kinase activity and an impairment of downstream insulin signalingGalbo et al.Fig. 3. TLR-4 eficient mice usually are not protected from saturated fat-induced hepatic steatosis and hepatic insulin resistance. Saturated fat-feeding of TLR-4deficient mice resulted in hepatic steatosis and an increase in hepatic triglycerides (A), cytosolic- (B), and membrane DAGs (C) as well as ceramides (D). Fatty liver improvement was linked with membrane translocation of PKCe (E) and insulin resistance as assessed by IPGTT (F). n = 70 per group. P 0.05.as previously described (4, 21). Current research have proposed that particularly s.