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: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:Edothelial cells were FACS sorted as CD31+CD45- population from PYMT-BO1 transplant tumor bearing WT and Cdh-cre Myct1 fl/fl mice on Day 14 post tumor transplantation