Project description:Apolipoprotein E-knock out (apoE-KO) mouse is known as a model animal for atherosclerosis accompanied by spontaneous hypercholesterolemia. When apoE-KO mice were fed a chow supplemented with 1.25% cholesterol (high-Chol diet), cholesterol and bile acids were highly increased in the liver within a week. However, the amount of triacylglycerol (TG) in very low-density lipoprotein (VLDL), but not in the liver, was reduced by 78%. The epididymal adipose tissue was almost diminished in the long term. Cholesterol metabolism is tightly regulated by both cholesterol and its metabolites in the mammalian liver, but the regulatory mechanism of TG synthesis remains to be elucidated. To evaluate the impact of high-Chol diet for 1 week on gene expression in the liver of apoE-KO mice, DNA microarray analysis was performed with comparison to apoE-KO mice fed a normal chow. We found that mRNA expression related to lipid metabolism was suppressed by the high-Chol diet in the liver of apoE-KO mice, which includes beta-oxidation and glycerol-3-phosphate (G3P) pathway for TG synthesis. In particular, the mRNA and protein expression of lipin-1 and lipin-2 was markedly decreased. PGC-1?, which up-regulates the transcription of lipin-1, was also suppressed. Lipin is reported to function as a coactivator of PGC-1? and is an inducible amplifier of PPAR?, indicating that the suppression of genes involved in beta-oxidation could be induced by suppression of the lipins. These data using apoE-KO mice indicate that cholesterol and its metabolites are involved in regulating TG metabolism through a suppression of lipin-1 and lipin-2 in the liver. This research provides evidence for the mechanism of lipin expression in the liver. Apo E-KO mice at 10 weeks of age were fed normal chow (control) or high-Chol diet containing 1.25% cholesterol for 1 week. Three independent experiments were performed at each diet.
Project description:Apolipoprotein E-knock out (apoE-KO) mouse is known as a model animal for atherosclerosis accompanied by spontaneous hypercholesterolemia. When apoE-KO mice were fed a chow supplemented with 1.25% cholesterol (high-Chol diet), cholesterol and bile acids were highly increased in the liver within a week. However, the amount of triacylglycerol (TG) in very low-density lipoprotein (VLDL), but not in the liver, was reduced by 78%. The epididymal adipose tissue was almost diminished in the long term. Cholesterol metabolism is tightly regulated by both cholesterol and its metabolites in the mammalian liver, but the regulatory mechanism of TG synthesis remains to be elucidated. To evaluate the impact of high-Chol diet for 1 week on gene expression in the liver of apoE-KO mice, DNA microarray analysis was performed with comparison to apoE-KO mice fed a normal chow. We found that mRNA expression related to lipid metabolism was suppressed by the high-Chol diet in the liver of apoE-KO mice, which includes beta-oxidation and glycerol-3-phosphate (G3P) pathway for TG synthesis. In particular, the mRNA and protein expression of lipin-1 and lipin-2 was markedly decreased. PGC-1α, which up-regulates the transcription of lipin-1, was also suppressed. Lipin is reported to function as a coactivator of PGC-1α and is an inducible amplifier of PPARα, indicating that the suppression of genes involved in beta-oxidation could be induced by suppression of the lipins. These data using apoE-KO mice indicate that cholesterol and its metabolites are involved in regulating TG metabolism through a suppression of lipin-1 and lipin-2 in the liver. This research provides evidence for the mechanism of lipin expression in the liver.
Project description:Cholangiocyte organoids provide a powerful tool for characterizing bile duct epithelium and expanding cholangiocytes for tissue engineering purposes. However, this involves invasively obtained tissue-biopsies via surgery which is not preferential and limits the patient-specific capacities of these cultures. To overcome this, organoid culture were initiated from minimal invasive bile-samples obtained during routine clinical procedures. Characterization revealed that these bile-cholangiocyte organoids originate from the extrahepatic bile duct and are capable to repopulate human extrahepatic bile duct scaffolds. With this, bile duct tissue engineering as well as personalized disease modelling is in sight.
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA in shock experiments as well as during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection.
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection
Project description:ApoE-KO mice were treated with silicon monoxide for 16 weeks. Protein abundance changes in relation to untreated control were measured in liver samples fractionated to cytosol and mitochondria by SWATH-MS.