Project description:Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease, is characterized by hepatic steatosis and hepatocellular injury and progresss cirrhosis and hepatocellular carcinoma. Sterol regulatory elment-binding proteins (SREBPs) are master regulators of lipogenesis. Liver-specific PTEN knockout (KO) mice show constitutive upregulation of SREBP through PI3K-Akt pathway activation, leading to spontaneous fatty liver and subsequent HCC development. SREBP cleavage-activating protein (SCAP) plays a critical role in SREBP activation. We sought to determine the impact of SREBP inhibition on NASH and HCC development. To this end, we additionaly inhibited SREBP pathway in liver-specific PTEN mice by ablating SCAP and generated liver-specific PTEN/SCAP double KO (DKO) mice. However unexpectedly, inhibition of SCAP/SREBP pathway markedly exacerbated liver injury (5weeks), fibrosis (5months), and carcinogenesis (7 months) in PTEN KO mice. To elucidate the mechanisms of liver tumorigenesis in liver-specific PTEN/SCAP DKO mice, we conducted transcriptome analyses of the livers.
Project description:Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease, is characterized by hepatic steatosis and hepatocellular injury and progresses to cirrhosis and hepatocellular carcinoma. Sterol regulatory element-binding proteins (SREBPs) are master regulators of lipogenesis. Liver-specific PTEN knockout (KO) mice show constitutive upregulation of SREBP through PI3K-Akt pathway activation, leading to spontaneous fatty liver and subsequent HCC development. SREBP cleavage-activating protein (SCAP) plays a critical role in SREBP activation. We sought to determine the impact of SREBP inhibition on NASH and HCC development. To this end, we additionally inhibited SREBP pathway in liver-specific PTEN mice by ablating SCAP and generated liver-specific PTEN/SCAP double KO (DKO) mice. However unexpectedly, inhibition of SCAP/SREBP pathway markedly exacerbated liver injury (5weeks), fibrosis (5months), and carcinogenesis (7 months) in PTEN KO mice. To elucidate the mechanisms of liver injury in liver-specific PTEN/SCAP DKO mice, we conducted transcriptome analyses of the livers.
Project description:To know the crosstalk between Hippo and AKT pathways in the liver metabolism, we generated liver-specific Pten (AKT signaling), Sav1 (Hippo signaling) and double-knockout mice and analysed the liver mRNA expression globally from 4groups (WT, Pten KO, Sav1 KO and Pten;Sav1 dKO).
Project description:Differential gene expression of mouse cytokines and chemokines in Rag1 knockout (Rag1-/- or Rag1-KO) and Rag1-/- Tbx21-/- double knockout (Rag1-Tbet-DKO) was tested in fatty liver ischemic-reperfusion injury (IRI). C57BL/6 mice harboring Rag1-/- or Rag1-/- Tbx21-/- deletions were fed with a normal chow diet (ND, 4.09 kcal/gram,13.4% kJ/fat) or a high-fat diet (HFD, 5.10 kcal/gram, 60% kJ/fat). To induce liver ischemic-reperfusion injury in mice, an atraumatic micro clip was placed across the hepatic hilus, which interrupted the blood supply to the left and median lobes of the liver for 45-minutes of partial warm ischemia time. After 24 hours of liver IRI, the affected left lobe of the liver was harvested and stored in Allprotect Tissue Reagent (Qiagen). We used Qiagen RT² Profiler™ PCR Array for mouse cytokines & chemokines to distinguish immunologically related and diet-specific gene signatures specific to liver IRI in Rag1-KO and Rag1-Tbet-DKO mice.
Project description:In order to facilitate inter-tissue communication and exchange of proteins, lipoproteins, and metabolites with the circulation, hepatocytes have an intricate and efficient intracellular trafficking system regulated by small Rab GTPases. Rab30, a putative Golgi-localized Rab GTPase, is induced in the mouse liver by fasting and its expression is further amplified in liver-specific carnitine palmitoyltransferase 2 knockout mice (Cpt2L-/-) that lack the ability to oxidize fatty acids in a Pparα-dependent manner. Live-cell super-resolution imaging and biochemical in vivo proximity labeling demonstrated that Rab30-marked vesicles are highly dynamic and interact with proteins throughout the secretory pathway. Rab30 whole-body, liver-specific, and Rab30;Cpt2 liver-specific double knockout (DKO) mice are viable and display intact Golgi ultrastructure. However, the loss of Rab30 in Rab30;Cpt2 DKO mice suppresses serum dyslipidemia observed in Cpt2L-/- single knockout mice. Corresponding with decreased serum triglyceride and cholesterol levels, Rab30;Cpt2 DKO mice exhibit decreased circulating but not hepatic ApoA4 protein, indicative of a trafficking defect. Together, these data suggest a role for Rab30 in the selective sorting of lipoproteins to influence hepatocyte and circulating triglyceride levels particularly during times of excessive lipid burden.
Project description:In order to facilitate inter-tissue communication and exchange of proteins, lipoproteins, and metabolites with the circulation, hepatocytes have an intricate and efficient intracellular trafficking system regulated by small Rab GTPases. Rab30, a putative Golgi-localized Rab GTPase, is induced in the mouse liver by fasting and its expression is further amplified in liver-specific carnitine palmitoyltransferase 2 knockout mice (Cpt2L-/-) that lack the ability to oxidize fatty acids in a Pparα-dependent manner. Live-cell super-resolution imaging and biochemical in vivo proximity labeling demonstrated that Rab30-marked vesicles are highly dynamic and interact with proteins throughout the secretory pathway. Rab30 whole-body, liver-specific, and Rab30;Cpt2 liver-specific double knockout (DKO) mice are viable and display intact Golgi ultrastructure. However, the loss of Rab30 in Rab30;Cpt2 DKO mice suppresses serum dyslipidemia observed in Cpt2L-/- single knockout mice. Corresponding with decreased serum triglyceride and cholesterol levels, Rab30;Cpt2 DKO mice exhibit decreased circulating but not hepatic ApoA4 protein, indicative of a trafficking defect. Together, these data suggest a role for Rab30 in the selective sorting of lipoproteins to influence hepatocyte and circulating triglyceride levels particularly during times of excessive lipid burden.
Project description:Mice developed ovarian tumors after Arid1a and Pten double knockout. Gene expression profiles of 5 such ovarian tumors were compared with those of 4 normal ovaries. The differentially expressed genes were then used to investigate the similarity between the mouse ovarian tumors and major subtypes of human ovarian cancers. Total RNA obtained from the mouse ovarian tumors developing after Arid1a and Pten knockout compared to normal mouse ovaries.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to reveal dynamics of liver tumourigenesis in different mouse model and identify some key regulators that control HCC initiation or progression. We also try to define a index based on transcriptome of samples to quantify tumor development stage. Methods: mRNA profiles of wild-type (WT), hepatocyte-specific shp2 deletion (Shp2−/−) mice (SKO), hepatocyte-specific pten deletion (Pten−/−) mice (PKO), and hepatocyte-specific shp2 and pten deletion mice (DKO) were generated by deep sequencing. The sequence reads that passed quality filters were mapped to Mouse genome using STAR, and mRNA profiles were obtained using cuffdiff. Results: quanlity control of mRNA profiles showed that the data captured key features of phenotypes. Significantly changed genes, pathways, biolgocial processes, ligand and receptor, epigenetic regulators et al of SKO, PKO, DKO mice at differnet age were obtaiend. Temporal gene expression patterns during liver tumorigenesis in SKO, PKO and DKO mice were obtained. Conclusions: Our study represents the first detailed analysis of temporal transcriptomes during liver tumourigenesis, with biologic replicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comprehensive investigations of expression profiles.