Project description:We investigated the plasma and liver proteome changes in liver fibrosis in mice induced by hepatocyte-specific knockout of nicotinamide phosphoribosyltransferase (Nampt) upon a low-methionine, choline-free 60% high-fat (MCD) diet at multiple time points. We also investigated whether supplementation with nicotinamide riboside could alleviate liver injury and how the liver proteome changes upon NR supplementation.
Project description:Metabolic dysregulation is an important feature of malignant tumors. Serine synthesis pathway (SSP) reshapes tumor cells to enhance their growth and survival capabilities, especially under serine starvation. However, whether and how SSP is involved in the progression of liver cancer has not been clearly stated. We applied a combination of quantitative proteomics and transcriptomics and discovered the increased expression of PHGDH and PSAT1 in mice liver cancer induced by SB. PHGDH is the first rating-limited enzyme of SSP and the conditional knockout of PHGDH in liver impaired the advanced liver cancer formation. However, the specific inhibition of enzymatic activity of PHGDH in liver has no obvious suppressive effect on advanced liver cancer. Further, we explored a non-metabolic function of PHGDH, which used its ACT domain to bind and regulate cMyc transcriptional activity, then selectively activated genes expression of Lcn2, Got1, Fabp5 and Psat1, indicating PHGDH drives/links multiple metabolic pathways and augmented its function through its non-metabolic role. In addition, the mutant p53 would release the suppression of PHGDH in mice liver cancer model and clinical liver cancer samples. Hence, the mutant p53/PHGDH/cMyc axis could be a potential target to cure advanced liver cancer.
Project description:Liver firbrosis model of hepatocyte-specific FOXA2 knockout mice. Adeno-associated virus AAV8-TBG-Control or AAV8-TBG-Cre was injected via the tail vein of FOXA2flox/flox (FOXA2f/f) mice 2 weeks prior to CCl4 administration. Hepatic fibrosis was induced by injection of CCl4 twice per week for 4 weeks.
Project description:PHGDH was knocked out in human glioblastoma (GBM)-associated endothelial cells (ECs) using CRISPR-Cas9/gRNA. RNA was isolated and analyzed by RNAseq. The effects of PHGDH knockout on gene expression were determined.
Project description:D-3-Phosphoglycerate dehydrogenase (Phgdh; EC 1.1.1.95) is a necessary enzyme for de novo L-serine biosynthesis via the phosphorylated pathway. We demonstrated previously that Phgdh is expressed exclusively by neuroepithelium and radial glia in developing mouse brain and later mainly by astrocytes. Mutations in the human PHGDH gene cause serine deficiency disorders (SDD) associated with severe neurological symptoms such as congenital microcephaly, psychomotor retardation, and intractable seizures. We recently demonstrated that genetically engineered mice, in which the gene for Phgdh has been disrupted, have significantly decreased levels of serine and glycine, and exhibit malformation of brain such as microcephaly. The Phgdh null (KO) embryos exhibit lethal phenotype after gestational day 14, indicating that the phosphorylated pathway is essential for embryogenesis, especially for brain development. It is worth noting that the Phgdh knockout (KO) embryos primarily displayed microcephaly, which is the most conspicuous phenotype of patients with SDD. Thus, Phgdh KO mice are a useful animal model for studying the effect of diminished L-serine levels on development of the central nervous system and other organs. To better understand the mechanism underlying the molecular pathogenesis of SDD, we sought to examine whether gene expression is altered in the Phgdh KO mouse model. We identify genes that have altered expression in the head of the Phgdh KO embryos using the GeneChip array. Some of the genes identified by this method belong in functional categories that are relevant to the biochemical and morphological aberrations of the Phgdh deletion. Experiment Overall Design: Total RNA samples were prepared from head tissues from 2 embryos of Phgdh knockout and littermate wild-type controls. Experiment Overall Design: RNA of 4 biological replicates was hybridized to Affymetrix Mouse Genome 430 2.0 arrays. Five microgram total RNA was labelled according to the ENZO-protocol, fragmented and hybridized according to Affymetrix's protocols.
Project description:The analysis examined the effects of a global ERK1 and/or tamoxifen-inducible, hepatocyte-specific ERK2 knockout on the liver transcriptome. Transcriptomes from the livers with a ERK1/2 double knockout were compared to the livers of mice with an ERK1 or ERK2 knockout.
Project description:Krüppel-like factor 6 (KLF6) is a transcription factor and tumor suppressor. Loss or reduction of KLF6 is linked with progression of experimental and human hepatocellular carcinoma. Despite its important contributions to liver homeostasis and growth, there are no data characterizing the involvement of KLF6 to hepatic regeneration. Microarray data from wildtype and DeltaKlf6 mice were used to identify regulating mechanisms and potential mediators within liver regeneration Wildtype and hepatocyte specific Klf6 knockout mice (DeltaKlf6) were employed for 70% partial liver resection/hepatectomy (PHx) in order to analyse liver regeneration. Twelve hours after partial hepatectomy animals were scrificed and remnant liver tissue was used for further experiemnts. For the overall study we used 6 animals per group, and included RNA from liver tissue of 3 wildtype and 3 DeltaKlf6 animals for the microarray analysis. Wildtype animals were used as controls.
Project description:Death receptor-mediated hepatocyte apoptosis is implicated in a wide range of liver diseases including viral hepatitis, alcoholic hepatitis, ischemia/reperfusion injury, fulminant hepatic failure, cholestatic liver injury and cancer. Deletion of NF-ĸB essential modulator in hepatocytes (NemoΔhepa) causes the spontaneous development of hepatocellular carcinoma preceded by steatohepatitis in mice and thus serves as an excellent model for the progression from chronic hepatitis to liver cancer. In the present study we aimed to dissect the death-receptor mediated pathways that contribute to liver injury in NemoΔhepa mice. Therefore, we generated NemoΔhepa/TRAIL-/- and NemoΔhepa/TNFR1-/- animals and analyzed the progression of liver injury. NemoΔhepa/TRAIL-/- displayed a similar phenotype to NemoΔhepa mice characteristic of high apoptosis, infiltration of immune cells, hepatocyte proliferation and steatohepatitis. These pathophysiological features were significantly ameliorated in NemoΔhepa/TNFR1-/- livers. Hepatocyte apoptosis was increased in NemoΔhepa and NemoΔhepa/TRAIL-/- mice while NemoΔhepa/TNFR1-/- animals showed reduced cell death concomitant with a strong reduction in pJNK levels. Cell cycle parameters were significantly less activated in NemoΔhepa/TNFR1-/- livers. Additionally, markers of liver fibrosis and indicators of tumour progression were significantly decreased in these animals. The present data demonstrate that the death receptor TNFR1 but not TRAIL is important in determining progression of liver injury in hepatocyte-specific Nemo knockout mice. Expression profiling of livers from wild type, NEMO, NEMO-TRIAL, and NEMO-TNFR null mice