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 eating plan (Fig. 3D). Consistent together with the accumulation of DAGs, there was a 30 increase in activation and membrane translocation of PKCe (Fig. 3E). To assess the effect 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 have been clearly glucose intolerant and insulin resistant, as reflected by greater plasma glucose concentrations at all time points (Fig. 3F) and larger plasma insulin concentrations inside the fasted state and at 90 min (Fig. S5).TLR-4 Deficient Mice Develop Hepatic Insulin Resistance When Fed a Diet Rich in Saturated Fat. To further investigate the impact ofsaturated fat feeding on insulin sensitivity within the setting of TLR-4 deficiency, we performed hyperinsulinemic-euglycemic clamp experiments comparing TLR-4 eficient 10ScNJ mice fed either common 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 acquire 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.five and manage gained 1.5 g 0.6, more than their respective chow groups). Although plasma glucose levels had been not different12782 | pnas.orgcgidoi10.1073pnas.through the clamp (Fig. 4A), the glucose infusion rates required to maintain euglycemia were 40 decrease in both TLR-4 eficient and handle 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 handle mice when fed saturated fat. Basal hepatic glucose production was not diverse; having said that (Fig. 4D), each the high fat fed TLR-4 eficient and handle mice manifested pronounced hepatic insulin resistance (Fig. 4 D and E). While mice fed a chow diet program displayed efficient suppression of glucose production during the hyperinsulinemic-euglycemic clamp (77.eight 6.5 for handle and 77.1 5.6 for TLR-4 deficient, respectively), this suppression was reduced in mice fed the saturated fat diet (to 32.five ten.7 for control and 46.four six.5 for TLR-4 deficient, respectively) (Fig. 4E). Discussion The distinct lipid species and molecular mechanisms by which hepatic steatosis results in hepatic insulin resistance has been a hotly debated subject. We located that IL-6 supplier overfeeding of both 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 are not protected from saturated CLK site fat-induced hepatic steatosis and hepatic insulin resistance. Saturated fat-feeding of TLR-4deficient mice resulted in hepatic steatosis and a rise in hepatic triglycerides (A), cytosolic- (B), and membrane DAGs (C) also as ceramides (D). Fatty liver development was connected 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.