Project description:Bile acids are not only physiological detergents facilitating nutrient absorption, but also signaling molecules regulating metabolic homeostasis. We reported recently that transgenic expression of CYP7A1 in mice stimulated bile acid synthesis and prevented Western diet-induced obesity, insulin resistance and hepatic steatosis. The aim of this experiment is to determine the impact of induction of hepatic bile acid synthesis on liver metabolism by determining hepatic gene expression profile in CYP7A1 transgenic mice. CYP7A1 transgenic mice and wild type control mice were fed either standard chow diet or high fat high cholesterol Western diet for 4 month. Hepatic gene expressions were measured by microarray analysis. Our results indicate that hepatic bile acid synthesis is closely linked to cholesterogenesis and lipogenesis, and maintaining bile acid homeostasis is improtant in hepatic metabolic homeostasis. Male aged matched (~ 12-14 weeks) CYP7A1 transgenic mice and their wild type control littermates were fed a standard chow diet or a high fat (42%) high cholesterol (0.2%) diet (Harlan Teklad #88137) for 4 month Four groups (4 mice/group) are included in the experiments: Group 1: WT _ Chow Group 2: CYP7A1-tg + chow Group 3: WT + Western diet Group 4: CYP7A1-tg _ Western diet Total liver mRNA was isolated with a RNeasy kit (Qiagen) and used for microarray analysis.
Project description:Bile acids are not only physiological detergents facilitating nutrient absorption, but also signaling molecules regulating metabolic homeostasis. We reported recently that transgenic expression of CYP7A1 in mice stimulated bile acid synthesis and prevented Western diet-induced obesity, insulin resistance and hepatic steatosis. The aim of this experiment is to determine the impact of induction of hepatic bile acid synthesis on liver metabolism by determining hepatic gene expression profile in CYP7A1 transgenic mice. CYP7A1 transgenic mice and wild type control mice were fed either standard chow diet or high fat high cholesterol Western diet for 4 month. Hepatic gene expressions were measured by microarray analysis. Our results indicate that hepatic bile acid synthesis is closely linked to cholesterogenesis and lipogenesis, and maintaining bile acid homeostasis is improtant in hepatic metabolic homeostasis.
Project description:Inactivating mutations in the copper transporter Atp7b result in Wilson’s disease. The Atp7b-/- mouse develops hallmarks of Wilson’s disease. The activity of several nuclear receptors is decreased in Atp7b-/- mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b-/- mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 weeks on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by LC-MS and correlated with transcriptomic data. Atp7b-/- mice fed a chow diet had lower fat mass and were more glucose tolerant than wild type (WT) littermate controls although body weights did not differ between genotypes. On Western diet, Atp7b-/- mice exhibited reduced adiposity and hepatic steatosis compared with WT controls. Atp7b-/- mice fed either diet were more insulin sensitive than WT controls; however, fasted Atp7b-/- mice exhibited hypoglycemia after administration of insulin, due to an impaired glucose counter-regulatory response, as evidenced by reduced hepatic glucose production. Coupling gene expression with metabolomic analyses, we observed striking changes in hepatic metabolic profiles in Atp7b-/- mice. In addition, the active phosphorylated form of AMP kinase was significantly increased in Atp7b-/- mice relative with WT controls. Alterations in hepatic metabolic profiles and nuclear receptor signaling were associated with improved glucose tolerance and insulin sensitivity, as well as impaired fasting glucose production in Atp7b-/- mice.
Project description:SHP (small heterodimer partner; NR0B2) belongs to the nuclear hormone receptor superfamily, which regulates numerous developmental and metabolic cellular functions. To study physiological function of SHP, we generated congenic SHP-/- mice on C57Bl/6 background. When the congenic SHP-/- mice were challenged with a western diet (harlan, TD.88137) for 22 weeks, they were resistant to diet induced obesity and hepatic steatosis compared to WT controls. However, their hepatic insulin sensitivity was compromised when assessed with phospho-Akt levels after insulin injection. Therefore, we investigated hepatic gene expression using illumina beadchip array to explore mechanisms underneath the unique liver physiology in SHP-/- mice. Livers were collected from C57Bl/6 wild type and C57Bl/6 SHP-/- mice fed chow or western diet. The 1 microgram of total RNA obtained from individual mouse (n=4 per group) and subjected to illumina beadchip gene expression profiling.
Project description:The aim of this study was to assess whether chronic treatment with RPV can modulate the progression of chronic liver disease, especially of non-alcoholic fatty liver disease (NAFLD), through a nutritional model in wild-type mice Mice were daily treated with RPV (p.o.) and fed with normal or high fat diet during 3 months to induce fatty liver disease
Project description:To test whether NDGA attenuate dyslipidemia and hepatic steatosis by enhancing fatty acid oxidation through activation of PPAR-α. Using wild type (WT, C57BL/6) fed with chow diet as control, WT mice were either fed with high-fat diet or high-fat diet with NDGA (2.5g/kg food); ob/ob mice were fed with either chow or chow with NDGA (2.5 g/kg food), and maintained on the respective diets for 16 weeks. The expression of lipid metabolism related genes in the liver of these mice were analyzed using Phalanx GPL6845 platform (Mouse OneArray V1). Together with other biochemical/physiological data, our results suggest that the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation and energy utilization via the activation of PPAR- α receptor activity.
Project description:Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit a marked difference in their susceptibility to atherosclerosis and the arterial wall has proven to be a source of the difference in atherosclerosis susceptibility. Genome-wide gene expression analysis was conducted in aortic walls of the two strains. Total RNA was extracted from aortas of 6-week-old female B6 and C3H apoE-deficient (apoE-/-) mice fed a chow or Western diet. 1514 genes in chow fed mice and 590 genes in Western fed mice were found to be differentially expressed between the two strains. RNA was extracted from aorta using a Trizol protocol. Total RNA was pooled in an equal amount from 4 mice for each group. Standard Affymetrix procedures were performed using 8ug of total RNA. Microarrays were used to detect gene expression in aortic walls of two apoE-deficient mouse strains when fed a chow or western diet. Experiment Overall Design: 4 groups of mice were studied: C57BL/6 apoE-/- mice on chow diet (03-62_BC), C57BL/6 apoE-/- mice on Western diet (03-62_BW), C3H/HeJ apoE-/- mice on chow diet (03-62_CC), and C3H/HeJ apoE-/- mice on Western diet (03-62_CW). Mice were weaned at 3 weeks of age onto a chow diet. At 4 weeks of age, mice were switched onto a western diet or continued the chow diet for 2 additional weeks.
Project description:Hepatic stellate cells are involved in the development of hepatic fibrosis. We here perform transcriptional profiling of hepatic stellate cells (HSCs) isolated from Western diet/high fructose-fed C57BL6/J mice, carbon tretrachloride (CCl4)-treated C57BL6/J mice, and of murine HSCs differentiated in vitro. Specifically, gene expression profiles are obtained from hepatic stellate cells isolated from C57BL6 mice fed a Western Diet supplemented with high fructose for 12, 16 or 24 weeks or normal chow. From hepatic stellate cells isolated from C57BL6 mice treated CCl4 for 1, 4 or 8 weeks or treated with vehicle. From hepatic stellate cells isolated from healthy C57BL6 mice and seeded on normal plastic cell culture dishes for 1, 4, 8, or 12 days. And from hepatic stellate cells isolated from healthy C57BL6 mice and seeded on normal plastic cell culture dishes for 6 days in the presence of 10uM U0126 or DMSO.
Project description:This study sought to interrogate the effects of lipids and lipid metabolites on the hepatic proteome. Protein expression in high-fat diet (HFD) mouse livers vs. livers of normal chow fed (NC) mice were investigated using multiplexed quantitative LC-MS/MS (TMT labeling). This experiment contains additional replicates for normal chow and mice on high-fat diet for 16 weeks.