Expression data from Amacr knock-out mouse intestine
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE40124 | GEO | 2015/12/22
SECONDARY ACCESSION(S): PRJNA172866
REPOSITORIES: GEO
Similar Datasets
Project description:Bile acids play multiple roles in vertebrate metabolism by facilitating lipid absorption in the intestine and acting as a signaling molecule in lipid and carbohydrate metabolism. Bile acids are also the main route to excrete excess cholesterol out of the body. Alpha-methyl-Coa racemase (Amacr) is one of the enzymes needed to produce bile acids from cholesterol. The mouse model lacking Amacr can produce only minor (less than 10%) amounts of bile acids, but still they are symptomless in normal laboratory conditions.
2015-12-22 | GSE40085 | GEO
Project description:Bile acids play multiple roles in vertebrate metabolism by facilitating lipid absorption in the intestine and acting as a signaling molecule in lipid and carbohydrate metabolism. Bile acids are also the main route to excrete excess cholesterol out of the body. Alpha-methyl-Coa racemase (Amacr) is one of the enzymes needed to produce bile acids from cholesterol. The mouse model lacking Amacr can produce only minor (less than 10%) amounts of bile acids, but still they are symptomless in normal laboratory conditions. Bile acid synthesis occurs in liver. In this experiment, liver samples from Amacr-/- and wild-type mice were collected and their gene expression levels were compared. 4 biological replicates per genotype.
2015-12-22 | E-GEOD-40085 | biostudies-arrayexpress
Project description:Bile acids play multiple roles in vertebrate metabolism by facilitating lipid absorption in the intestine and acting as a signaling molecule in lipid and carbohydrate metabolism. Bile acids are also the main route to excrete excess cholesterol out of the body. Alpha-methyl-Coa racemase (Amacr) is one of the enzymes needed to produce bile acids from cholesterol. The mouse model lacking Amacr can produce only minor (less than 10%) amounts of bile acids, but still they are symptomless in normal laboratory conditions. Cholesterol absorption occurs in the jejunum part of the intestine. In this experiment, the intestines from Amacr-/- and wild-type mice were divided into four equal segments and the endothelial layer was collected by scraping. The RNA from these samples was isolated and the gene expression levels in each segment were compared. 3 biological replicates per genotype/segment combination.
2015-12-22 | E-GEOD-40124 | biostudies-arrayexpress
Project description:Background: Genetic elimination of c-Met signaling in the liver has been shown to impact many cellular pathways involved in repair, regeneration, lipid homeostasis and redox balance. In this study, we analyzed a nutritional model of hepatic steatosis in Met fl/fl ; Alb-Cre +/- (MetKO) mice in a 129SV/C57BL/6 background fed a high cholesterol diet for 30 days. Methods: Liver injury was determined by histopathology and plasma enzymes, transcriptomic changes were examined using gene expression microarrays, and evaluation of key molecules involved in liver damage and lipid homestasis were evaluated by Western blot analysis. Results: We observed that in comparison with wild type mice subjected to the same diet, MetKO mice developed a strong liver lipid deposition, inflammatory infiltration and increment in total bile acids synthesis and liver damage markers. Global transcriptomic changes analysis confirmed the steatosis and cholestasis induced by the high cholesterol diet. In addition, we found affected pathways related to amino acids, glutathione and lipid metabolism, oxidative stress and mitochondria dysfunction. Oxidative stress exacerbation was corroborated by lipid and protein oxidation in liver tissue. To address further, Western blot studies revealed downregulation on Erk, NF-kB and Nrf2 survival pathways and target genes (cyclin D1, SOD1, gamma-GCS), an increment in proapoptotic proteins (p53, caspase 3) and changes in nuclear receptors such as RAR and RXR, which were increased, and CAR, FXR and PPAR alfa, which were decreased, in the MetKO diet. These results are in agreement with the steatosis and cholestasis phenotype. Conclusion: Our data provide evidence of c-Met signaling involvement in lipid metabolism, and bile acids synthesis and excretion. Disruption of these pathways leads to liver dysfunction, improper metabolism and hepatocellular damage. Global transcriptome changes between WT mice vs. c-Met KO mice fed a 2% cholesterol and 0.5% sodium cholate diet (high cholesterol) or a Chow regular diet (Chow) as control. Mice were fed a high cholesterol or chow regular diet for 30 days. Liver tissue was obtained, and RNA was extracted and subjected to Illumina microarray analysis.
2012-07-10 | E-GEOD-30651 | biostudies-arrayexpress
Project description:The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, stresses, and hormones. To identify the metabolic role of Mig-6 in the liver, we conditionally ablated Mig-6 in the liver using the Albumin-Cre mouse model (Albcre/+Mig-6f/f; Mig-6d/d). Mig-6d/d mice exhibit hepatomegaly and fatty liver. Serum levels of total, LDL, and HDL cholesterol and hepatic lipid were significantly increased in the Mig-6d/d mice. The daily excretion of fecal bile acids was significantly decreased in the Mig-6d/d mice. DNA microarray analysis of mRNA isolated from the livers of these mice showed alterations in genes that regulate lipid metabolism, bile acid, and cholesterol synthesis, while the expression of genes that regulate biliary excretion of bile acid and triglyceride synthesis showed no difference in the Mig-6d/d mice compared to Mig-6f/f controls. These results indicate that Mig-6 plays an important role in cholesterol homeostasis and bile acid synthesis. Mice with liver specific conditional ablation of Mig-6 develop hepatomegaly and increased intrahepatic lipid and provide a novel model system to investigate the genetic and molecular events involved in the regulation of cholesterol homeostasis and bile acid synthesis. Defining the molecular mechanisms by which Mig-6 regulates cholesterol homeostasis will provide new insights into the development of more effective ways for the treatment and prevention of cardiovascular disease. Eight week old Mig-6f/f vs Mig-6d/d male mice after undergoing a 24 hour fast
2011-08-30 | E-GEOD-31752 | biostudies-arrayexpress
Project description:Obesity-induced insulin resistance of the liver is characterised by increased gluconeogenesis, which contributes to elevated blood glucose levels in individuals with type 2 diabetes. Research into how fatty acids induce insulin resistance has commonly focused on the induction of insulin resistance. We hypothesise that by shifting focus to the reversal of an insulin resistant phenotype, novel insights can be made into the mechanisms by which insulin resistance can be overcome. Using global gene and lipid expression profiling, we aimed to identify biological pathways altered in parallel with restoration of palmitate-induced deregulation of glucose production using metformin and sodium salicylate. FAO hepatoma cells were treated with palmitate (0.075mM, 48h) with or without metformin (0.25mM) and sodium salicylate (2mM) in the final 24h of palmitate treatment, and effects on glucose production were determined. Microarray followed by gene set enrichment analysis was performed to investigate pathway regulation. A lipidomic analysis (HPLC-MS/MS) and measurement of secreted bile acids and cholesterol were performed. Reversal of palmitate-induced impairment of glucose production by metformin and sodium salicylate was characterised by down-regulated expression of metabolic pathways regulating acetyl-CoA to cholesterol and bile acid biosynthesis. Total levels of intracellular and secreted cholesterol and bile acids were not different between impaired and restored glucose production. Total intracellular levels of diacylgycerol, triacylglycerol and cholesterol esters increased with palmitate (impaired glucose production), however, these were not further altered with metformin and sodium salicylate (restored glucose production). Six individual lipid species containing 18:0 and 18:1 side-chains were reduced by metformin and sodium salicylate. Widespread lipid metabolism changes induced by the reversal of palmitate-induced deregulation of glucose production with metformin and sodium salicylate were identified. While cholesterol and bile acid levels remained unchanged, the flux through these pathways may in part explain these findings. The identification of lipid species containing 18:0 and 18:1 side chains being regulated alongside changes to glucose production may indicate potential mediators of glucose production and insulin resistance. Three-condition experiment, Vehicle, Palmitate (PA) and Palmitate (PA) + Metformin (Met) + Sodium Sailcylate (NaS) with biological replicates: 8 Vehicle, 20 PA and 20 PA+Met+NaS , independently grown and harvested. One replicate per array.
2013-11-08 | E-GEOD-52204 | biostudies-arrayexpress
Project description:Specific bile acids are potent signaling molecules that modulate metabolic pathways affecting lipid, glucose and bile acid homeostasis, and the microbiota. Bile acids are synthesized from cholesterol in the liver, and the key enzymes involved in bile acid synthesis (Cyp7a1, Cyp8b1) are regulated transcriptionally by the nuclear receptor FXR. We have identified an FXR-regulated pathway upstream of a transcriptional repressor that controls multiple bile acid metabolism genes. We identify MafG as an FXR target gene and show that hepatic MAFG overexpression represses genes of the bile acid synthetic pathway and modifies the biliary bile acid composition. In contrast, loss-of-function studies using MafG(+/-) mice causes de-repression of the same genes with concordant changes in biliary bile acid levels. Finally, we identify functional MafG response elements in bile acid metabolism genes using ChIP-seq analysis. Our studies identify a molecular mechanism for the complex feedback regulation of bile acid synthesis controlled by FXR.
2016-02-04 | GSE77529 | GEO
Project description:Specific bile acids are potent signaling molecules that modulate metabolic pathways affecting lipid, glucose and bile acid homeostasis, and the microbiota. Bile acids are synthesized from cholesterol in the liver, and the key enzymes involved in bile acid synthesis (Cyp7a1, Cyp8b1) are regulated transcriptionally by the nuclear receptor FXR. We have identified an FXR-regulated pathway upstream of a transcriptional repressor that controls multiple bile acid metabolism genes. We identify MafG as an FXR target gene and show that hepatic MAFG overexpression represses genes of the bile acid synthetic pathway and modifies the biliary bile acid composition. In contrast, loss-of-function studies using MafG(+/-) mice causes de-repression of the same genes with concordant changes in biliary bile acid levels. Finally, we identify functional MafG response elements in bile acid metabolism genes using ChIP-seq analysis. Our studies identify a molecular mechanism for the complex feedback regulation of bile acid synthesis controlled by FXR
2016-02-04 | GSE77507 | GEO
Project description:The study evaluated effects of dietary cholesterol (CH), taurocholate (TC), choline (CN) and taurine (TA) in Atlantic salmon fed a plant based diet for 77 days. The additives did not affect growth or organ weights of Atlantic salmon, but promoted induction of cholesterol and plant sterol efflux in the intestine, whereas sterol uptake was suppressed. Microarray analyses in the liver indicated decreased cholesterol biosynthesis and enhanced conversion to bile acids. The marked effect of cholesterol on bile acid synthesis suggests that dietary cholesterol can be used to stimulate bile acid synthesis in fish. The study clearly demonstrated how Atlantic salmon adjusted metabolic functions in response to the dietary load of cholesterol, and has expanded our understanding of sterol metabolism and turnover that adds to the knowledge of these processes in fish. Feed supplementation with choline improved lipid absorption and suppressed abnormal accumulation of fat in the gut.
2013-10-31 | GSE51887 | GEO
Project description:Deoxycholic acid (DCA) is a secondary bile acid produced by a small number of commensal species of bacteria present in the mammalian gut. Elevated DCA concentration correlates with disease states including colon cancer and cholesterol gallstones, but the associated mechanisms are not fully understood. Both primary and secondary bile acids are also capable of affecting gene expression through nuclear receptors such as FXR. To better understand the impact of a commensal-derived secondary bile acid on host metabolism we fed DCA to germ-free (GF) mice, which normally lack DCA, and compared the hepatic transcriptomes of bile acid fed GF mice to GF mice receiving a control diet, as well as to those of conventionally housed control animals. Interestingly, the feeding of DCA to GF mice, but not the feeding of cholic acid (CA) from which DCA is derived, results in an up-regulation of genes of cholesterol biosynthetic pathways. GF mice normally have elevated hepatic cholesterol compared to conventionally housed mice. Despite increase in the expression of cholesterol biosynthetic genes, the DCA fed GF mice showed a markedly decreased level of hepatic cholesterol equivalent to the hepatic cholesterol concentration of conventionally colonized animals. Total cholesterol in the serum was unaffected by DCA, but there was a decrease in the HDL lipoprotein fraction as well as an increase in the non-HDL lipoprotein fraction of the serum cholesterol. DCA, but not CA, is sufficient to modulate host lipoprotein metabolism. Taken together, these results suggests that a minor component of the gut microbiome has a significant impact on cholesterol homeostasis through secondary metabolism of bile acids and suggests a possible therapeutic intervention route through the microbial metabolic pathways. two mouse strains, three diets, one time point
2015-01-08 | E-GEOD-34730 | biostudies-arrayexpress