Gene expression of hepatocyt-specific knockout of Pten and of Pten and Tgfbr2 in mice
Epithelial Transforming Growth Factor-β Signaling Does Not Contribute to Liver Fibrosis but Protects Mice From Cholangiocarcinoma.
Sex, Specimen part
View SamplesIn comparing gene expression of normal and CML CD34+ quiescent (G0) and proliferating (G1/S/G2/M) cells, 292 genes were down-regulated and 192 genes were up-regulated in the CML G0 cells. The differentially expressed genes were grouped according to their reported functions and correlations were sought with biological differences previously observed between the same groups. The most apparent correlations include: i) Normal and CML G0 cells are more primitive than G1/S/G2/M cells; ii) CML G0 cells are in a more advanced stage of development and more poised to begin proliferating than normal G0 cells; iii) When CML G0 cells are stimulated to proliferate, they undergo further differentiation and maturation more rapidly than normal G0 cells, but both granulopoiesis and erythropoiesis are less efficient than normal; iv) Whereas normal G0 cells form only granulocyte/monocyte (GM) colonies when stimulated by cytokines, CML G0 cells consistently form a combination of GM and erythroid clusters and colonies; and v) Prominin-1 (CD133) is the gene most down-regulated in CML G0 cells and its down-regulation appears to be associated with the spontaneous formation of erythroid colonies by CML progenitors without EPO. The gene most over-expressed in CML G0 cells is LepR, but its role in contributing to the myeloid expansion and other abnormalities is unknown. It was hoped that LepR might serve as a therapeutic target, but leptin had no stimulatory or inhibitory effect on either normal or CML G0 cells, our attempts to make a specific LepR antibody were unsuccessful, and no other potentially targetable over-expressed surface antigens were identified.
Gene Expression Differences between Enriched Normal and Chronic Myelogenous Leukemia Quiescent Stem/Progenitor Cells and Correlations with Biological Abnormalities.
Specimen part, Disease, Disease stage
View SamplesWe analysed the effect of depriving the human cell of the catalytic activity of the nuclear 5' to 3' exoribonuclease XRN2. Catalytic amino acids in this protein had been defined previously, so it was possible to design a mutated catalytically inactive form of the protein (XRN2D233A-D235A) (PMID: 19194460). We created 293 Flp-In T-REx stable cell lines that induciby silence endogenous XRN2, and concomitantly express wild-type or inactive XRN2 in fusion with EGFP at the C-terminus. Thus, complementation of silencing of endogenous XRN2 with the expression of mutant version of the protein allows to directly link potential phenotypes with the lack of XRN2 enzymatic activity. To this end we isolated total RNA from tetracycline-treated cells, depleted it from rRNA and conducted strand-specific deep sequencing. Overall design: 6 samples were analysed. 3 replicates of control cells (endogenous copy of XRN2 gene is silenced and catalytically active exogenous XRN2-EGFP is expressed) and 3 replicates of cells deprived of XRN2 ribonucleolytic activity (endogenous copy of XRN2 gene is silenced and catalytically inactive exogenous XRN2(D233AD235A)-EGFP is expressed)
Versatile approach for functional analysis of human proteins and efficient stable cell line generation using FLP-mediated recombination system.
Specimen part, Subject
View SamplesAlcoholic hepatitis (AH) is the most severe form of alcoholic liver disease and occurs in patients with excessive alcohol intake It is characterized by marked hepatocellular damage, steatosis and pericellular fibrosis. Patients with severe AH have a poor short-term prognosis. Unfortunately, current therapies (i.e. corticosteroids and pentoxyphylline) are not effective in many patients and novel targeted therapies are urgently needed. The development of such therapies is hampered by a poor knowledge of the underlying molecular mechanisms. Based on studies from animal models, TNF alfa was proposed to play a pivotal role in the mechanisms of AH. Consequently, drugs interfering TNF alfa were tested in these patients. The results were disappointing due to an increased incidence of severe infections. Unluckily, there are not experimental models that mimic the main findings of AH in humans. To overcome this limitation, translational studies with human samples are required. We previously analyzed samples from patients with biopsy-proven AH. In these previous studies, we identified CXC chemokines as a potential therapeutic target for these patients. We expanded these previous observations by performing a high-throughout transcriptome analysis.
Transcriptome analysis identifies TNF superfamily receptors as potential therapeutic targets in alcoholic hepatitis.
No sample metadata fields
View SamplesUnveiling the regulatory pathways maintaining hepatic stellate cells (HSC) in a quiescent (q) phenotype is essential to develop new therapeutic strategies to treat fibrogenic diseases. To uncover the miRNA-mRNAs regulatory interactions in qHSCs, HSCs were FACS-sorted from healthy livers and activated HSCs were generated in vitro. MiRNA Taqman array analysis showed HSCs expressed a low number of miRNA, from which 46 were down-regulated and 212 up-regulated upon activation. Computational integration of miRNA and gene expression profiles revealed that 66% of qHSCs miRNAs correlated with more than 6 altered targeted mRNAs (17,2810,7 targets/miRNA), whereas aHSC-associated miRNAs had an average of 1,49 targeted genes. Interestingly, interaction networks generated by miRNA-targeted genes in qHSCs were associated with key HSCs activation processes. Next, selected miRNAs were validated in healthy and cirrhotic human livers and miR-192 was chosen for functional analysis. Down-regulation of miR-192 in HSC was found to be an early event during fibrosis progression in mouse models of liver injury. Moreover, mimic assays for miR-192 in HSCs revealed its role in HSC activation, proliferation and migration. Together, these results uncover the importance of miRNAs in the maintenance of qHSC phenotype and form the basis for understanding the regulatory networks in HSCs.
Integrative miRNA and Gene Expression Profiling Analysis of Human Quiescent Hepatic Stellate Cells.
Specimen part
View SamplesWe previously showed that severe liver diseases are characterized by expansion of liver progenitor cells (LPC), which correlates with disease severity. However, the origin and role of LPC in liver physiology and in the hepatic response to injury remains a contentious topic. We have now used genetic lineage tracing of Hnf1-expressing biliary duct cells to assess their contribution to LPC expansion and hepatocyte generation during normal liver homeostasis, and following different types of liver injury. We found that ductular reaction cells in human cirrhotic livers express HNF1. However, HNF1 expression was not present in newly generated EpCAM-positive hepatocytes. Using a tamoxifen-inducible Hnf1CreER/R26RYFP/LacZ mouse, we show that there is no contribution of the biliary epithelium to hepatocyte turnover during liver homeostasis in healthy mice. Moreover, after loss of liver mass, Hnf1+ LPC did not contribute to hepatocyte regeneration. We also assessed the contribution of Hnf1+ cells following acute and repeated liver injury. All animal models showed expansion of LPC, as assessed by immunostaining and gene expression profile of sorted YFP-positive cells. A contribution of Hnf1+ LPC to hepatocyte generation was not detected in animal models of liver injury with preserved hepatocyte regenerative potential such as acute acetaminophen, carbon tetrachloride injury, or chronic diethoxycarbonyl-1,4-dihydro-collidin (DDC)-diet. However, in mice fed with choline-deficient ethionine-supplemented (CDE)-diet, which causes profound hepatocyte damage and arrest, a small number of hepatocytes were derived from Hnf1+ cells. Conclusion: Hnf1+ cells do not participate in hepatocyte turnover in the healthy liver or during liver regeneration after partial hepatectomy. After liver injury, LPC arise from the biliary duct epithelium, which gives rise to a limited number of hepatocytes only when hepatocyte regeneration is compromised.
The biliary epithelium gives rise to liver progenitor cells.
No sample metadata fields
View SamplesGonadal sex determining (GSD) genes that initiate fetal ovarian and testicular development and differentiation are expressed in the cells of the urogenital ridge that differentiate as somatic support cells (SSCs), i.e., granulosa cells of the ovary and Sertoli cells of the testis. To identify potential new mammalian GSD genes, we analyzed the gene expression differences between XX and XY SSCs cells isolated from the gonads of embryonic day (E) 13 mouse fetuses carrying an EGFP reporter transgene expressed specifically in SSCs. In addition, genome wide expression differences between XX and XY E13 whole gonads were examined. Newly identified differentially expressed transcripts are potential GSD genes involved in unexplained human sex reversal cases.
Transcriptional profile of mouse pre-granulosa and Sertoli cells isolated from early-differentiated fetal gonads.
No sample metadata fields
View SamplesLuteinising hormone (LH) is a key regulator of male fertility through its effects on testosterone secretion by Leydig cells. Mice in which the LH receptor is knocked out (LuRKO) show reduced testicular size, reduced testosterone, elevated serum LH, and a spermatogenic arrest that can be rescued by administration of testosterone. This study examines the onset of spermatogenic arrest in LuRKO males using transcriptional profiling of developing mutant and control testes. We also examine the initial stages of testosterone rescue of the phenotype, in order to identify key upstream regulators of testosterone-dependent spermatogenesis.
Transcriptional profiling of luteinizing hormone receptor-deficient mice before and after testosterone treatment provides insight into the hormonal control of postnatal testicular development and Leydig cell differentiation.
Specimen part
View SamplesThere is massive destruction of transcripts during maturation of mouse oocytes. The objective of this project was to identify and characterize the transcripts that are degraded versus those that are stable during the transcriptionally silent germinal vesicle (GV)-stage to metaphase II (MII)-stage transition using the microarray approach. A system for oocyte transcript amplification using both internal and 3-poly(A) priming was utilized to minimize the impact of complex variations in transcript polyadenylation prevalent during this transition. Transcripts were identified and quantified using Affymetrix Mouse Genome 430 v2.0 GeneChip. The significantly changed and stable transcripts were analyzed using Ingenuity Pathways Analysis and GenMAPP/MAPPFinder to characterize the biological themes underlying global changes in oocyte transcripts during maturation. It was concluded that the destruction of transcripts during the GV to MII transition is a selective rather than promiscuous process in mouse oocytes. In general, transcripts involved in processes that are associated with meiotic arrest at the GV-stage and the progression of oocyte maturation, such as oxidative phosphorylation, energy production, and protein synthesis and metabolism, were dramatically degraded. In contrast, transcripts encoding participants in signaling pathways essential for maintaining the unique characteristics of the MII-arrested oocyte, such as those involved in protein kinase pathways, were the most prominent among those stables.
Selective degradation of transcripts during meiotic maturation of mouse oocytes.
No sample metadata fields
View SamplesGobal expression analysis in four somatic tissues (brain, liver, kidney and muscle) of adult 40,XX and 39,XO mice with the aim of identifying which genes are expressed from both X chromosomes as well as those genes deregulated in X chromosome monosomy.
Transcriptional changes in response to X chromosome dosage in the mouse: implications for X inactivation and the molecular basis of Turner Syndrome.
Sex, Age, Specimen part
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