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PROVIDER: PRJNA1189879 | ENA |
REPOSITORIES: ENA
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Project description:Background. Abcb4 (-/-) mice secrete phosphatidylcholine-deficient bile and develop sclerosing cholangitis (SC). The cholangitis involves differential hepatic transcription of genes whose products govern inflammation, activation of hepatic stellate cells and fibrosis. This study was undertaken to test the hypothesis that several genes involved in regulation of tissue inflammation and fibrosis display transcription rates that reflect SC disease activity. Methods. Abcb4 (-/-) mice fed cholic acid (CA) display high SC activity and ursodeoxycholic acid (UDCA) fed mice display low SC activity. Differential hepatic transcription of genes was accordingly measured in abcb4 (-/-) mice maintained on CA- and UDCA-supplemented diets using cDNA microarrays. Abcb4 (+/+) mice served as controls. The differential transcription of selected genes was verified by real time polymerase chain reaction. Liver tissue pathology was quantified by histopathology scoring and immunohistochemistry to visualize bile duct cells and activated hepatic stellate cells. Results. Differential transcription of Ccl2, Ccl20, Cxcl10, Nfκb1, Nfκb2, Tgfβ1, Tgfβ2, Sparc, Ctgf, Lgals3, Elf3, Spp1, Pdgfa, Pdgfrb, Col1a1, Col1a2 and Col4a1 genes paralleled the differing SC activities of cholic acid- and UDCA-fed abcb4 (-/-) mice. Histopathology scores and immunohistochemistry showed greatly enhanced activation of hepatic stellate cells during high SC activity due to CA feeding. Conclusion. Differential transcription of several genes relating to tissue inflammation and hepatic stellate cell activation parallels SC activity in abcb4 (-/-) mice. Data on their differential transcription may be used to gauge SC disease activity.
2008-08-20 | GSE11507 | GEO
Project description:Chronic inflammation is a common underlying condition associated with tumor development, accounting for approximately 20% of human cancers. This association is especially apparent in Hepatocellular carcinoma (HCC), which often develops on the background of chronic hepatitis and hepatic fibrosis, slowly unfolding on a background of chronic inflammation. HCC is one of the most common tumors worldwide, exhibiting a very poor prognosis and high mortality rate with limited available therapeutic tools. The etiology of liver cancer is well known, however there is still a lack of precise knowledge about pathogenesis of HCC. IL-6 have been shown to be of importance for liver protection and prevention of liver injury in animal models of acute sclerosing cholangitis and correlate with increased HCC in human patients. Using a murine model of chronic cholangitis based on the ablation of the Mdr2 gene, this study has examined the role of IL-6 signaling in chronic hepatitis and in the subsequent development of liver cancer. The main observations of this study are that IL-6 signaling in male Mdr2-KO mice protects from the development of liver injury and fibrosis, but simultaneously promotes tumor initiation. Thus, IL-6 deficiency in male Mdr2-KO mice dissociates the tight correlation between liver fibrosis and the development of inflammation-associated HCC. To reveal the affected molecular pathways that lead to increased cholestasis and bile acid–induced liver injury, but reduced tumorigenesis in the male IL-6 deficient Mdr2-KO/IL6-KO mice, we performed gene array analysis and identified distinct classes of differentially-expressed genes in these mice. We performed genome-scale gene expression profiling by Affymetrix analysis on tumor-free livers samples from Mdr2-KO, Mdr2-KO/IL6-KO, and wild type C57BL/6 mice at the age of 14 months.
2015-05-01 | E-GEOD-37468 | 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: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
Project description:Chronic inflammation is a common underlying condition associated with tumor development, accounting for approximately 20% of human cancers. This association is especially apparent in Hepatocellular carcinoma (HCC), which often develops on the background of chronic hepatitis and hepatic fibrosis, slowly unfolding on a background of chronic inflammation. HCC is one of the most common tumors worldwide, exhibiting a very poor prognosis and high mortality rate with limited available therapeutic tools. The etiology of liver cancer is well known, however there is still a lack of precise knowledge about pathogenesis of HCC. IL-6 have been shown to be of importance for liver protection and prevention of liver injury in animal models of acute sclerosing cholangitis and correlate with increased HCC in human patients. Using a murine model of chronic cholangitis based on the ablation of the Mdr2 gene, this study has examined the role of IL-6 signaling in chronic hepatitis and in the subsequent development of liver cancer. The main observations of this study are that IL-6 signaling in female Mdr2-KO mice protects from the development of liver injury and fibrosis, but simultaneously reduced tumor initiation. To reveal the affected molecular pathways that lead to increased cholestasis and bile acid ?induced liver injury, and increased tumorigenesis in the female IL-6 deficient Mdr2-KO/IL6-KO mice, we performed gene array analysis and identified distinct classes of differentially-expressed genes in these mice. We performed genome-scale gene expression profiling by Affymetrix analysis on tumor-free livers samples from Mdr2-KO, Mdr2-KO/IL6-KO, and wild type C57BL/6 mice at the age of 14 months.
2015-05-01 | E-GEOD-37559 | biostudies-arrayexpress
Project description:Background and aims: Signal transducer and activator of transcription 3 (Stat3) is the main mediator of interleukin-6 type cytokine signaling required for hepatocyte proliferation and hepatoprotection but its role in sclerosing cholangitis and other cholestatic liver diseases remains unresolved. Methods: We investigated the role of Stat3 in inflammation-induced cholestatic liver injury and used mice lacking the multidrug resistance gene 2 (mdr2-/-) as a model for SC. Results: We demonstrate that conditional inactivation of stat3 in hepatocytes and cholangiocytes (stat3 delta hc) of mdr2-/- mice strongly aggravated bile acid-induced liver injury and fibrosis. A similar phenotype was observed in mdr2-/- mice lacking IL-6 production. Biochemical and molecular characterization suggested that Stat3 exerts hepatoprotective functions in both, hepatocytes and cholangiocytes. Loss of Stat3 in cholangiocytes led to increased expression of TNFα which might reduce the barrier function of bile ducts. Loss of Stat3 in hepatocytes led to upregulation of bile acid biosynthesis genes and downregulation of hepatoprotective epidermal growth factor receptor and insulin-like growth factor 1 signaling pathways. Consistently, stat3deltahc mice were more sensitive to cholic acid-induced liver damage than control mice. Conclusions: Our data suggest that Stat3 prevents cholestasis and liver damage in sclerosing cholangitis via regulation of pivotal functions in hepatocytes and cholangiocytes. Affymetrix microarray analyses was performed to identify metabolic and molecular pathways in stat3Dhc mdr2-/- mice that lead to cholestasis and bile acid-induced liver injury. To avoid false positive results that are due to differential cellular composition, we defined the onset of fibrosis and expression of fibrogenic factors in stat3Dhc mdr2-/- mice.
2010-10-20 | E-GEOD-18759 | biostudies-arrayexpress
Project description:We found out that bile acid pathways were deeply altered in cachectic mice bearing ectopic tumor, leading to an increase in portal and liver conjugated bile acid levels. Counteracting this increased level in conjugated bile acids using cholestyramine, a bile acid sequestrant, reduced hepatic inflammation in cachectic mice with no impact on steatosis and minor effects on thermogenesis. Hepatic whole transcriptome analysis identified 16 pathways altered in cachectic mice which were counteracted by cholestyramine, pointing out the large contribution of bile acids to hepatic disturbances occurring in cancer cachexia.
2021-02-24 | GSE154219 | GEO
Project description:Autoimmune Hepatitis (AIH) and Primary Biliary Cholangitis (PBC) are autoimmune diseases that target the liver in which the immune system produces an inappropriate response to self-antigens resulting in inflammation, damage, and dysfunction of hepatic tissues. Despite progress in the understanding of the etiopathogenesis and in the diagnostic and therapeutic approach of these diseases, critical issues remain concerning the early diagnosis of affected individuals. The present study aims to detect and characterize by a gel-based bottom-up proteomic approach the acid-insoluble fraction of salivary proteome from patients affected by AIH and PBC with respect to healthy controls (HCs). The study was performed on the salivary acid-insoluble proteins after in-gel digestion starting from: i) the entire SDS-PAGE lane; ii) a portion of the SDS-PAGE at lowest molecular weight (MW </= 25 kDa).
2023-10-24 | PXD039847 | Pride
Project description:Primary sclerosing cholangitis (PSC) is characterized by chronic inflammation and progressive fibrosis of the biliary tree. The bile acid receptor TGR5 is found on biliary epithelial cells (BECs), where it promotes secretion, proliferation and tight junction integrity. Thus, we speculated that changes in TGR5 expression in BECs may contribute to PSC pathogenesis.
2021-03-12 | GSE168758 | GEO