Project description:Suppressor of cytokine signaling 3 (SOCS3) down-regulates several signaling pathways in multiple cell types, and previous data suggest that SOCS3 may shut off cytokine activation at the early stages of liver regeneration. We developed hepatocyte-specific Socs3 knockout (Socs3 h-KO) mice to directly study the role of SOCS3 during liver regeneration after 2/3 partial hepatectomy (PH). Socs3 h-KO mice demonstrate marked enhancement of DNA replication and liver weight restoration after 2/3 PH in comparison with littermate controls. Without SOCS3, signal transducer and activator of transcription 3 (STAT3) phosphorylation is prolonged, and activation of the mitogenic kinases extracellular signal-regulated kinase 1/2 (ERK1/2) is enhanced after PH. In vitro, we show that SOCS3 deficiency enhances hepatocyte proliferation in association with enhanced STAT3 and ERK activation after epidermal growth factor (EGF) or interleukin 6 (IL-6) stimulation. Microarray analyses show that SOCS3 modulates a distinct set of genes after PH, which fall into diverse physiologic categories. Using a model of chemical-induced carcinogenesis, we found that Socs3 h-KO mice develop hepatocellular carcinoma (HCC) at an accelerated rate. By acting on cytokines and multiple proliferative pathways, SOCS3 modulates both physiologic and neoplastic proliferative processes in the liver, and may act as a tumor suppressor. Experiment Overall Design: Hepatocyte-specific excision of the Socs3 gene was achieved by breeding Socs3 fl/fl mice with mice expressing the Cre recombinase transgene under control of the albumin promoter (Alb-Cre+), yielding Socs3 h-KO mice. Socs3 fl/fl, Alb-Cre- littermates were used as controls for all experiments, and are henceforth referred to as littermates. All mice (C57BL/6) were free of Helicobacter species, housed in a specific pathogen free facility with 12-h light/dark cycles with free access to standard food and water. 2/3 PH and sham operations were performed as previously described (15, 50) (n=3-6 mice per genotype per time point). Liver remnants were weighed after removal of necrotic stumps and sutures, and compared to post-operative body weight. For HCC experiments, a single i.p. injection of DEN (5mg/kg, Sigma) was performed 12-14 d after birth. For short time points, a single injection of DEN (100mg/kg) (31) was given to 4 wk old mice. At indicated time points, mice were sacrificed by CO2 inhalation. All animal studies were carried out under approved IACUC protocols at the University of Washington.
Project description:The etiology of non-alcoholic steatohepatitis (NASH) has been complicated. An increasing body of literature has indicated that hepatic oxidative stress exerts a causal role in driving NASH. Nevertheless, how the anti-oxidant defense system guards against oxidative stress and NASH remains unclear. In this study, we sought to investigate how the peroxidase peroxiredoxin 1 protects against NASH. To this end, we fed WT and hepatic PRDX1 knockout (Alb-Cre;Prdx1fl/fl) a methionine and choline deficient diet (MCD) for 5 weeks and collected liver samples for RNA sequencing analysis. As revealed by gene-set enrichment analysis (GSEA) and KEGG pathway enrichment analysis, there was an enrichment of genes involved in JAK-STAT signaling. Further, we observed that the expression of many genes involved in JAK-STAT signaling such as Pdgfb and Pdgfra was significantly increased in Alb-Cre;Prdx1fl/fl mice. Collectively, these results suggest that increased JAK-STAT signaling accounts for the deteriorated NASH phenotypes in Alb-Cre;Prdx1fl/fl mice.
Project description:The floxed insulin receptor was specifically targetted for deletion in the mammary gland using a mouse strain bearing Cre recombinase under the BLG promoter. Data analysis: Genespring was used for data analysis All entities (28853) were filtered on variance between samples, eliminating from further analysis of genes whose coefficient of variation was greater than 50%. The remaining 2239 genes were filtered on expression levels between 20 and 20,000 intensity units An unpaired T-test was used to find genes that differed significantly (P<0.05) between experimentals and controls The remaining 2014 genes were filtered for a 1.1 absolute fold change between experimentals and controls. Of the remaining expression of 890 genes was down in the Cre+ mice and expression was up for 457 genes in the Cre+ mice. Mouse strains containing a floxed insulin receptor (IRfl/fl) were crossed with a mouse expressing Cre recombinase from a BLG promoter RNA was applied to Affymetrix MoGene_1_0-st-v1 chips Three replicates from each strain were used for analysis.
Project description:We wished to investigate the role of E-cadherin loss in our mouse parietal cell/pre-parietal cell E-cadherin knock-out, p53 knock-out, oncogenic Kras induced model of gastric cancer. As such, we isolated RNA from stomach tissue from our E-cadherin knock-out model (Atp4b-Cre;Cdh1(fl/fl);Kras(LSL-G12D/+);Trp53(fl/fl);Rosa26(LSL-YFP/LSL-YFP)) and our E-cadherin heterozygous model (Atp4b-Cre;Cdh1(fl/+);Kras(LSL-G12D/+);Trp53(fl/fl);Rosa26(LSL-YFP/LSL-YFP)). We then performed a microarray on this stomach tissue from four independent mice of each genotype. Differentially expressed genes were identified and gene set overlap analysis was used to identify pathways enriched in one model over the other.
Project description:The total abundance of phosphatidylcholine (PC) is known to influence lipoprotein production. However, the role of specific phospholipid species in lipid transport has been difficult to assess due to an inability to selectively manipulate membrane composition in vivo. Here we show that the LXR-regulated phospholipid remodeling enzyme lysophosphatidylcholine acyltransferase 3 (Lpcat3) is a critical determinant of membrane phospholipid composition and lipoprotein production. Mice lacking Lpcat3 in the liver show defects in lipoprotein production. The objective of generating this dataset was to analyze the effects of Lpcat3 loss of function on baseline gene expression in mouse liver. This dataset compares gene expression in Lpcat3fl/fl and Lpcat3fl/fl Albumin-Cre liver samples from 12-week old male mice that were subjected to 6 hr fasting. Each sample contains tissues from 5 mice.
Project description:To identify the intracellular targets of endothelial cell-specific ANGPTL2 that control HSC stemness, HSCs from Angptl2fl/fl or Cdh5-Cre;Angptl2fl/fl were sorted, followed by the extraction of total RNA and subjected to the RNA-sequencing.
