Ion in Mice Fed Saturated Fat, but Has No Direct Effects
Ion in Mice Fed Saturated Fat, but Has No Direct Effects on Hepatic Insulin Signaling. To examine the postulated direct roleled to a doubling of liver triglycerides (Fig. 2C) and cytosolic BChE Compound diacylglycerols (Fig. S4B). Following the gavage, we observed a three- to sixfold improve in membrane translocation of PKCe (Fig. 2D) also as a 355 and 60 reduction in insulinstimulated phosphorylation of Akt2 (Fig. 2E) and FoxO1 (Fig. 2F), respectively. These findings as a result indicate that the TLR-4 MyD88 pathway will not be directly Aurora A web eliciting the inhibitory effects of saturated fat on insulin signaling.TLR-4-Deficient Mice Aren’t Protected from Development of Fatty Liver, Ceramide and DAG Accumulation, PKCe Activation, and Hepatic Insulin Resistance When Fed a Eating plan Wealthy in Saturated Fat. To expandof TLR-4 receptor signaling specific to saturated fat-induced hepatic insulin resistance, we treated mice with antisense oligonucleotides (ASOs) targeting either TLR-4, its adaptor protein MyD88 or perhaps a control and fed them a diet wealthy in saturated fat for ten d. Though fat-fed mice treated with a handle ASO created fatty liver (Fig. 2A), knockdown of either TLR-4 or MyD88 prevented hepatic steatosis from occurring (Fig. 2A). To improved understand this phenotype, we performed metabolic cage research on these mice. We identified that despite the fact that knockdown of TLR-4 or MyD88 did not influence power expenditure (Fig. S3A) or the respiratory exchange ratio (Fig. S3B), it drastically lowered the caloric intake of mice fed a high-fat eating plan (Fig. 2B) and was associated with enhanced plasma levels in the anorexic cytokine TNF- (Fig. S3C). To circumvent the effects of TLR-4 or MyD88 on appetite and examine the direct effects on insulin-stimulated Akt2 phosphorylation and activity, we decided to expose chow-fed mice to lipid gavage with saturated fat-rich lard. Just after 6 h, the lard gavage resulted in a threefold increase in plasma triglycerides in all mice, compared with ungavaged handle mice (Fig. S4A). Lipid gavageGalbo et al.on the results we had obtained by way of our TLR-4MyD88-ASO studies, we decided to examine if 10ScNJ mice carrying a spontaneous deletion within the TLR-4 gene were immune to saturated fat-induced insulin resistance. Because the TLR-4 pathway had apparent effects on appetite and also other groups had reported that 10ScNJ mice had been less inclined to develop obesity (20), we decided to supplement the strong saturated fat diet with liquid heavy cream within the drink. Heavy cream derives 95 of its total calories from fat, of which 65 are from saturated fat. Just after 15 d, the saturated fat-fed mice had a substantially larger weight acquire than the chow-fed mice (2.7 g 0.2 vs.1.three g 0.2) and an increased physique fat mass (4.1 g 0.three vs. 1.six g 0.three). Saturated fatfed mice created hepatic steatosis with a rise of two- to threefold in liver triglycerides (Fig. 3A), threefold in cytosolic DAGs (Fig. 3B), and 30 in membrane DAGs (Fig. 3C). Interestingly, we observed a 20 rise in hepatic ceramides in thePNAS | July 30, 2013 | vol. 110 | no. 31 |Medical SCIENCESFig. two. TLR-4MyD88 knockdown in mice reduces caloric intake, but doesn’t straight guard mice from saturated fat-induced defects in hepatic insulin signaling. Mice treated with ASOs against either TLR-4 or MyD88 have been protected against hepatic triglyceride deposition (A) when fed a diet program wealthy in saturated fat because of a decreased caloric intake (B). Nonetheless, TLR-4MyD88 knockdown didn’t defend mice from hepatic triglyceri.