Project description:High sugar consumption, as well as high-fat diet, is a known cause of obesity and metabolic syndrome. However, the synergistic effect of high-sugar and high-fat consumption rarely has been evaluated, especially in terms of transcriptional regulation. Therefore, we focused on the effect of high sugar consumption on hepatic transcriptional networks in normal and high fat-fed mice. C57BL/6J mice were divided into four groups and were provided either 23%(w/v) sugar solution or plain water with either high-fat or normal-fat diet for 10 weeks. As a result, high sugar consumption significantly altered lipid metabolism-related genes in normal fat-fed mice; however, in high fat-fed mice, high sugar consumption altered inflammation-responsive genes rather than lipid metabolism. After all, these modulations eventually increased lipid accumulation in the liver and caused systemic metabolic disturbances. These observations for the first time suggested that high sugar consumption along with high-fat diet could lead to the development of severe metabolic syndrome via altering hepatic transcriptional networks.
Project description:Ramulus Mori (Sangzhi) alkaloids (SZ-A) improves lipid metabolism and adipose tissue inflammation in HFD-induced obese mice.This study compares transcriptome profiling (RNA-seq) in the epididymal adipose tissue of normal chow, high-fat diet (HFD) control and SZ-A-treated HFD mice to verify the regulatory mechanisms of SZ-A. These results demonstrated that SZ-A regulates lipid metabolism and inflammation.
Project description:Abnormalities in hepatic lipid metabolism are believed to play a critical role in the etiology of nonalcoholic steatohepatitis (NASH). Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol, which is the penultimate step in one pathway for triacylglycerol (TAG) synthesis. Hepatic expression of Mogat1, which encodes an MGAT enzyme, is increased in the livers of mice with hepatic steatosis and knocking down Mogat1 improves insulin sensitivity, but whether increased MGAT activity plays a role in the etiology of NASH is unclear. To examine the effects of knocking down Mogat1 in the liver on the development of NASH, C57BL/6 mice were placed on a diet containing high levels of trans fatty acids, fructose, and cholesterol (HTF-C diet) or a low fat control diet for 4 weeks. Mice were then injected with antisense oligonucleotides (ASO) to knockdown Mogat1 or a scrambled ASO control for 12 weeks while remaining on diet. HTF-C diet caused glucose intolerance, hepatic steatosis, and induced hepatic gene expression markers of inflammation, macrophage infiltration, and stellate cell activation. Mogat1 ASO treatment, which suppressed Mogat1 expression in liver, attenuated weight gain, improved glucose tolerance, and decreased hepatic TAG content compared to control ASO-treated mice on HTF-C chow. However, Mogat1 ASO treatment did not reduce hepatic DAG, cholesterol, or free fatty acid content, improve histologic measures of liver injury, or reduce expression of markers of stellate cell activation, liver inflammation, and injury. In conclusion, inhibition of hepatic Mogat1 in HTF-C diet-fed mice improves glucose tolerance and hepatic TAG accumulation without attenuating liver inflammation and injury. Total RNA obtained from liver of 4 control vs. 4 Mogat1 ASO treated higf-fat diet (HFD) fed mice.
Project description:Dietary proteins have profound effects on lipid metabolism but the mechanism remains to be elucidated. In the present study, we examined the temporal impact of dietary proteins in isoenergetic high fat diets on lipid metabolism of C57BL/6J mice. Mice were first fed a low protein (P) to carbohydrate (C) ratio high-fat diet (L-P/C-HF) for 10 weeks and then a half of mice were changed to a high protein to carbohydrate ratio high-fat diet (H-P/C-HF) for additional 4 weeks whereas the remaining mice continued eating the L-P/C-HF diet.
Project description:Adipose tissue plays an important role in storing excess nutrients and preventing ectopic lipid accumulation in other organs. Obesity leads to excess lipid storage in adipocytes, resulting in the generation of stress signals and the derangement of metabolic functions. SIRT1 is an important regulatory sensor of nutrient availability in many metabolic tissues. Here we report that SIRT1 functions in adipose tissue to protect from the development of inflammation and obesity under normal feeding conditions, and the progression to metabolic dysfunction under dietary stress. Genetic ablation of SIRT1 from adipose tissue leads to gene expression changes that highly overlap with changes induced by high fat diet in wild type mice, suggesting that dietary stress signals inhibit the activity of SIRT1. Indeed, we show that high fat diet induces the cleavage of SIRT1 in adipose tissue by the inflammation-activated caspase-1, providing a link between dietary stress and predisposition to metabolic dysfunction. Four replicates from four different biological conditions: 1) SIRT1 wild-type fed low fat diet, 2) SIRT1 wild-type fed high fat diet, 3) SIRT1 knock-out fed low fat diet, 4) SIRT1 knock-out fed high fat diet
Project description:Xbp1 is an important regulator of unfolded protein response and lipid metabolism. Its dyregulation has been associcated in human NASH. Feeding a high fat diet with fructose/sucrose to mice causes progressive, fibrosing steatohepatitis. This study is to use RNA-Seq to identify differentially expressed genes in hepatic Xbp1 deficient mice livers fed with a high fat diet compared to controls. Hepatic Xbp1 deficient mice or flox controls were fed either regular chow or a high fat diet (n=4). Samples from each cohort were pooled into two replicates.
Project description:C57BL/6J (B6) and DBA/2J (D2) mice were fed a high-fat/high-cholesterol diet in order to investigate the responses to that diet over time and their underlying genetic factors. We observed distinctly diverse responses between B6 and D2 mice, including dynamic distribution of cholesterol in serum and bile, hepatic apoptosis and dynamic formation of gallstones and atherosclerosis. Hepatic microarray analysis revealed distinctly different gene expression patterns in functional pathway groups including lipid metabolism, oxidative stress, immune/inflammation response and apoptosis, which might account for the different responses.This might provide us not only new insights into gallstones formation and atherosclerosis, but also opportunities to identify candidate genes for high-fat/high-cholesterol related diseases. C57BL/6J (B6) and DBA/2J (D2) mice were fed a high-fat/high-cholesterol diet in 0,1,4 12,21 weeks,respectively. Liver tissues of mice from each time-point were removed for RNA extraction. Equal amounts of RNA samples from five mice of each strain at each time-point were pooled and then used to generate biotinylated cRNA targets for Affymetrix GeneChip Mouse Genome 430 2.0 Array.
Project description:We identified differentially expressed genes in epididymal white adipose tissue of high fat diet(HFD)-fed mice compared to low fat diet-fed mice using microarray analysis. Microarray analysis revealed that genes related to lipolysis, fatty acid metabolism, mitochondrial energy transduction, oxidation-reduction, insulin sensitivity, and skeletal system development were downregulated in HFD-fed mice, and genes associated with extracellular matrix (ECM) components, ECM remodeling, and inflammation were upregulated. The top 10 up- or downregulated genes include Acsm3, mt-Nd6, Fam13a, Cyp2e1, Rgs1, and Gpnmb, whose roles in obesity-associated adipose tissue deterioration are poorly understood. Total RNA of epididymal white adipose tissue was obtained from low fat diet (10 kcal% fat)- and high fat diet(45 kcal% fat)-fed mice and mRNA expression was measured using microarray analysis.
Project description:Analysis of effect of luteolin on lipid metabolism at gene expression level. The hypothesis tested in the present study was that luteolin treatment with obesogenic diet suppressed the hepatic lipogenesis pathways. Conversely, in adipose tissue, luteolin stimulated the lipogenesis pathway and it also simultaneously increased the expression of genes controlling lipolysis and TCA cycle. Results provide important information about the effect on diet-induced obesity and its metabolic complications. Total RNA of liver and adipose tissues was obtained from normal diet, high-fat diet and luteolin added high-fat diet-fed mice and mRNA expression-associated with lipid metabolism was measured.