Project description:Liver sinusoidal endothelial cells (LSEC) are unique endothelial cell typelining the sinusoids of the liver and we have shown that these cells respond in a unique matter when exposed to saturated and unsaturated free fatty acids (FFA) and bile acids. We used microarray to analyze the transcriptional differences between the LSEC exposed to free fatty acids and bile acid receptor agonists to further shed light on their role in non-alcoholic fatty liver disease. The Murine Liver Sinusoidal Endothelial Cell Line (TSEC) was treated with palmitic and oleic acid or the bile acid receptor agonist INT-767 for 8 hours. Total RNA was then harvested to determine transcriptional differences.
Project description:Liver sinusoidal endothelial cells (LSEC) are unique endothelial cell typelining the sinusoids of the liver and we have shown that these cells respond in a unique matter when exposed to saturated and unsaturated free fatty acids (FFA) and bile acids. We used microarray to analyze the transcriptional differences between the LSEC exposed to free fatty acids and bile acid receptor agonists to further shed light on their role in non-alcoholic fatty liver disease.
Project description:The farnesoid X receptor (FXR) is a nuclear receptor activated by bile acids and regulates bile acid metabolism, glucose and cholesterol homeostasis. From mouse studies we know that the novel FXR agonist obeticholic acid (OCA) regulates expression of many genes in the liver, but there is currently no data on the effects of OCA on human liver gene expression. This is especially relevant since the novel FXR agonist OCA is currently tested in clinical trials for the treatment of several diseases, such as nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD) and Type 2 Diabetes. In this study we investigate the effect of OCA treatment on gene expression profiles and localization of FXR to the genome in relevant liver samples. ChIP-Seq for FXR in Liver tissue from 2 male mice treated with OCA/INT-747 (10mg/kg/day) and 2 male mice treated with vehicle (1% methyl cellulose).
Project description:The farnesoid X receptor (FXR) is a nuclear receptor activated by bile acids and regulates bile acid metabolism, glucose and cholesterol homeostasis. From mouse studies we know that the novel FXR agonist obeticholic acid (OCA) regulates expression of many genes in the liver, but there is currently no data on the effects of OCA on human liver gene expression. This is especially relevant since the novel FXR agonist OCA is currently tested in clinical trials for the treatment of several diseases, such as nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD) and Type 2 Diabetes. In this study we investigate the effect of OCA treatment on gene expression profiles and localization of FXR to the genome in relevant liver samples.
Project description:Two of the most highly abundant transcripts in liver sinusoidal endothelial cells are Stab1 and Stab2, we investigated downstream effects on liver sinusoidal endothelial cells by disrupting their expression. We used microarrays to detail the global programme of gene expression in liver sinusoidal endothelial cells deficient for Scavenger-Receptor type H compared to Wildtype.
Project description:Farnesoid X receptor (FXR) agonism is emerging as an important potential therapeutic mechanism of action for multiple chronic liver diseases. The bile acid–derived FXR agonist obeticholic acid (OCA; 6-ethyl chenodeoxycholic acid) has shown promise in a phase 2 study in patients with nonalcoholic steatohepatitis (NASH). Here, we report efficacy of a novel, non–bile acid FXR agonist tropifexor (LJN452) in two distinct preclinical models of NASH. The efficacy of tropifexor at <1 mg/kg doses was superior to that of OCA at 25 mg/kg in the liver in both NASH models. In a chemical and dietary model of NASH (STAM model), tropifexor reversed established fibrosis and reduced nonalcoholic fatty liver disease activity score and hepatic triglycerides. In an insulin-resistant, obese NASH model (AMLN), tropifexor markedly reduced steatohepatitis, fibrosis, and profibrogenic gene expression. Transcriptome analysis of livers from AMLN mice revealed 461 differentially expressed genes following tropifexor treatment, which included a combination of signatures associated with reduction of oxidative stress, fibrogenesis, and inflammation. Conclusion: Based on the preclinical validation in animal models, tropifexor is a promising investigational therapy that is currently under phase 2 development for NASH.
Project description:Abstract: Interruption of bile acid recirculation through inhibition of the apical sodium-dependent bile acid transporter (ASBT) is a promising strategy to alleviate hepatic cholesterol accumulation in non-alcoholic steatohepatitis, and improve the metabolic aspects of the disease. Putative disease-attenuating effects of the ASBT inhibitor volixibat (5, 15, and 30 mg/kg) were investigated in high-fat diet (HFD)-fed Ldlr-/-.Leiden mice over 24 weeks. Plasma and fecal bile acid levels, plasma insulin, lipids, and liver enzymes were monitored. Final analyses included liver histology, intrahepatic lipids, mesenteric white adipose tissue mass, and liver gene profiling. Consistent with its mechanism of action, volixibat significantly increased total bile acid excretion. At the highest dose, volixibat significantly attenuated the HFD-induced increase in hepatocyte hypertrophy, hepatic triglyceride and cholesteryl ester levels, and mesenteric white adipose tissue deposition, while total plasma bile acid levels remained constant. Non-alcoholic fatty liver disease activity score was significantly lower in volixibat-treated mice than in the HFD controls. Gene profiling showed that volixibat reversed the inhibitory effect of the HFD on metabolic master regulators, including peroxisome proliferator-activated receptor-γ coactivator-1β, insulin receptor, and sterol regulatory element-binding transcription factor 2. Volixibat may have beneficial effects on physiological and metabolic aspects of non-alcoholic steatohepatitis pathophysiology.
Project description:To identify leukocyte adhesion receptors which differentially regulate recruitment in human liver sinusoidal endothelial cells compared to a protoptypic venular endothelium Gene expression was measured in four groups Group 1: cultured human liver sinusoidal endothelial cells (HSEC) Group 2: cultured human umbilical vein endothelial cells (HUVEC) Group3: Interferon gamma and tumour necrosisfactor alpha treated HSEC and Group 4: Interferon gamma and tumour necrosisfactor alpha treated HUVEC. Two replicates were used for each group.
Project description:TGR5 (Gpbar1) is a G protein-coupled receptor responsive to bile acids (BAs), which is expressed in different non-parenchymal cells of the liver, including biliary epithelial cells, liver-resident macrophages, sinusoidal endothelial cells (LSECs) and activated hepatic stellate cells (HSCs). Mice with targeted deletion of TGR5 are more susceptible towards cholestatic liver injury induced by cholic acid-feeding and bile duct ligation, resulting in a reduced proliferative response and increased liver injury. Conjugated lithocholic acid (LCA) represents the most potent TGR5 BA ligand and LCA-feeding has been used as a model to rapidly induce severe cholestatic liver injury in mice. Thus, TGR5 knockout (KO) mice and wildtype littermates were fed a diet supplemented with 1%LCA for 84 hours. Liver injury and gene expression changes induced by the LCA-diet revealed an enrichment of pathways associated with inflammation, proliferation and matrix remodelling. Knockout of TGR5 in mice caused upregulation of endothelin-1 (ET-1) expression in the livers. Analysis of TGR5-dependent ET-1 signalling in isolated LSECs and HSCs demonstrated that TGR5 activation reduces ET-1 expression and secretion from LSECs and triggers internalization of the ET-1 receptor in HSCs dampening ET-1 responsiveness. Thus, we identified two independent mechanisms by which TGR5 inhibits ET-1 signalling and modulates portal pressure.
Project description:Chronic jet lag induces spontaneous hepatocellular carcinoma (HCC) in wild-type mice following a pathophysiological pathway very similar to that observed in obese humans. This process initiates with non-alcoholic fatty liver disease (NAFLD), progresses to steatohepatitis and fibrosis before HCC detection, and is driven by persistent genome-wide gene deregulation that induces global liver metabolic dysfunction. Nuclear receptor-controlled cholesterol/bile acid and xenobiotic metabolism are found among top deregulated pathways. Ablation of the bile acid receptor FXR dramatically increases intrahepatic bile acid levels and jet-lag-induced HCC, while loss of CAR, a well-known liver tumor promoter, inhibits NAFLD-induced hepatocarcinogenesis. Circadian disruption activates CAR by promoting cholestasis, peripheral clock disruption, and sympathetic dysfunction. Thus, FXR and CAR are clock-controlled therapeutic targets for spontaneous HCC