Glucagon contributes to liver zonation in mice [Gcg infusion]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE110673 | GEO | 2018/03/01
REPOSITORIES: GEO
Similar Datasets
Project description:Liver zonation characterizes the separation of metabolic pathways along the lobules and is required for optimal function. Wnt/beta-catenin signaling controls metabolic zonation by activating genes in the perivenous hepatocytes, while suppressing genes in the periportal counterparts. We now demonstrate that glucagon opposes the actions of Wnt/beta-catenin signaling on gene expression and metabolic zonation pattern. The effects were more pronounced in the periportal hepatocytes where 28% of all genes were activated by glucagon and inhibited by Wnt/beta-catenin. The glucagon and Wnt/beta-catenin receptors and their signaling pathways are uniformly distributed in periportal and perivenous hepatocytes and the expression is not regulated by the opposing signal. Collectively, our results show that glucagon controls gene expression and metabolic zonation in the liver through a counter play with the Wnt/beta-catenin signaling pathway.
2018-03-01 | GSE110672 | GEO
Project description:Hepatocellular carcinomas (HCCs) exhibit a diversity of molecular phenotypes, raising major challenges in clinical management. HCCs detected by surveillance programs at an early stage are candidates for potentially curative therapies (local ablation, resection, or transplantation). In the long term, transplantation provides the lowest recurrence rates. Treatment allocation is based on tumor number, size, vascular invasion, performance status, functional liver reserve, and the prediction of early (<2 years) recurrence, which reflects the intrinsic aggressiveness of the tumor. Well-differentiated, potentially low-aggressiveness tumors form the heterogeneous molecular class of nonproliferative HCCs, characterized by an approximate 50% beta-catenin mutation rate. To define the clinical, pathological, and molecular features and the outcome of nonproliferative HCCs, we constructed a 1,133-HCC transcriptomic metadata set and validated findings in a publically available 210-HCC RNA sequencing set. We show that nonproliferative HCCs preserve the zonation program that distributes metabolic functions along the portocentral axis in normal liver. More precisely, we identified two well-differentiated, nonproliferation subclasses, namely periportal-type (wild-type beta-catenin) and perivenous-type (mutant beta-catenin), which expressed negatively correlated gene networks. The new periportal-type subclass represented 29% of all HCCs; expressed a hepatocyte nuclear factor 4A-driven gene network, which was down-regulated in mouse hepatocyte nuclear factor 4A knockout mice; were early-stage tumors by Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program, and tumor-node-metastasis staging systems; had no macrovascular invasion; and showed the lowest metastasis-specific gene expression levels and TP53 mutation rates. Also, we identified an eight-gene periportal-type HCC signature, which was independently associated with the highest 2-year recurrence-free survival by multivariate analyses in two independent cohorts of 247 and 210 patients. CONCLUSION: Well-differentiated HCCs display mutually exclusive periportal or perivenous zonation programs. Among all HCCs, periportal-type tumors have the lowest intrinsic potential for early recurrence after curative resection. (Hepatology 2017;66:1502-1518).
2023-07-25 | GSE237977 | GEO
Project description:Hepatocytes perform different metabolic functions depending on their proximity to the portal triad (periportal) or central vein (perivenous) in the liver lobule. To improve our understanding of the spatial and functional heterogeneity of hepatocytes, we used single cell RNA sequencing (scRNA-seq) and a novel bioinformatics method, Wave-Crest, to reorder hepatocytes along the periportal to perivenous axis. After isolating hepatocytes from an 8-week old male C57BL/6 mouse, performing scRNA-seq, and reordering the cells along the periportal to perivenous axis, Wave-Crest allowed us to identify novel genes differentially expressed along the axis. Using immunocytochemistry, we verified that select novel genes were expressed in the spatial pattern predicted by Wave-Crest. Hence, our study demonstrates a new approach for recovering spatial information from scRNA-seq data.
2018-07-17 | GSE116140 | GEO
Project description:The metabolic functions of the liver are organized spatially in a phenomenon known as zonation. This spatial organization of metabolic functions is linked to the differential exposure of central and portal hepatocytes to either systemic circulation or nutrient-rich blood afferent from the gastrointestinal tract, respectively. The mechanistic target of rapamycin complex 1 (mTORC1) is the central hub of a critical signaling pathway that links cellular metabolism to fluctuations in the levels of nutrients and insulin. To understand how these two signaling cues are integrated in the liver, we have generated mice with constitutive nutrient and insulin signaling to mTORC1 in hepatocytes (RragaGTP/fl; Tsc1fl/fl; Albumin-CreTg mice). Simultaneous activation of nutrient and hormone signaling to mTORC1 results in impaired establishment of the metabolic zonal identity of hepatocytes, a maturation process that takes place within the first weeks after birth. Mechanistically, a decrease in levels of the morphogenic pathway Wnt/β-catenin in hepatocytes and reduced expression of the Wnt2 ligand by liver endothelial cells after birth underlie this impaired wave of hepatocyte maturation. Lack of postnatal establishment of metabolic zonation of the liver is recapitulated in a model of constant supply of nutrients by total parenteral nutrition to neonatal pigs. Collectively, our work shows the critical role of hepatocyte sensing of fluctuations in nutrients and hormones after birth for triggering the latent metabolic zonation program.
2024-03-18 | PXD041439 | Pride
Project description:The mammalian liver is composed of repeating hexagonal units termed lobules. Spatially-resolved single-cell transcriptomics revealed that about half of hepatocyte genes are differentially expressed across the lobule. Technical limitations impede reconstructing similar global spatial maps of other hepatocyte features. Here, we used zonated surface markers to sort hepatocytes from defined lobule zones with high spatial resolution. We applied transcriptomics, miRNA array measurements and Mass spectrometry proteomics to reconstruct spatial atlases of multiple zonated hepatocyte features. We found that protein zonation largely overlapped mRNA zonation, with the periportal HNF4α as an exception. We identified zonation of miRNAs such as miR-122, and inverse zonation of miRNAs and their hepatocyte target genes, implying potential regulation through zonated mRNA degradation. These targets included the pericentral Wnt receptors Fzd7 and Fzd8 and the periportal Wnt inhibitors Tcf7l1 and Ctnnbip1. Our approach facilitates reconstructing spatial atlases of multiple cellular features in the liver and other structured tissues.
2019-07-26 | GSE134827 | GEO
Project description:Up to 41% of hepatocellular carcinomas (HCCs) result from activating mutations in the CTNNB1 gene encoding β-catenin. β-catenin has dual cellular functions as a component of the Wnt signaling pathway and adherens junctions. HCC-associated CTNNB1 mutations stabilize the β-catenin protein, leading to nuclear and/or cytoplasmic localization of β-catenin and downstream activation of Wnt target genes. In patient HCC samples, β-catenin nuclear and cytoplasmic localization are typically patchy, even among HCC with highly active CTNNB1 mutations. The functional and clinical relevance of this heterogeneity in β-catenin activation are not well understood. To define mechanisms of β-catenin-driven HCC initiation, we generated a Cre-lox system that enabled switching on activated β-catenin in 1) a small number of hepatocytes in early development; or 2) the majority of hepatocytes in later development or adulthood. We discovered that switching on activated β-catenin in a subset of larval hepatocytes was sufficient to drive HCC initiation. To determine the role of Wnt/β-catenin signaling heterogeneity later in hepatocarcinogenesis, we performed RNA-seq analysis of zebrafish β-catenin-driven HCC. Ingenuity Pathway Analysis of differentially expressed genes in the Cre-lox HCC model revealed that “Cancer” and “Liver Tumor” categories were significantly altered, indicating transcriptional similarities with human HCC and other vertebrate HCC models. At the single-cell level, 2.9% to 15.2% of hepatocytes from zebrafish β-catenin-driven HCC expressed two or more of the Wnt target genes axin2, mtor, glula, myca, and wif1, indicating focal activation of Wnt signaling in established tumors. Thus, heterogeneous β-catenin activation drives HCC initiation and persists throughout hepatocarcinogenesis.
2019-09-27 | GSE137787 | GEO
Project description:Up to 41% of hepatocellular carcinomas (HCCs) result from activating mutations in the CTNNB1 gene encoding β-catenin. β-catenin has dual cellular functions as a component of the Wnt signaling pathway and adherens junctions. HCC-associated CTNNB1 mutations stabilize the β-catenin protein, leading to nuclear and/or cytoplasmic localization of β-catenin and downstream activation of Wnt target genes. In patient HCC samples, β-catenin nuclear and cytoplasmic localization are typically patchy, even among HCC with highly active CTNNB1 mutations. The functional and clinical relevance of this heterogeneity in β-catenin activation are not well understood. To define mechanisms of β-catenin-driven HCC initiation, we generated a Cre-lox system that enabled switching on activated β-catenin in 1) a small number of hepatocytes in early development; or 2) the majority of hepatocytes in later development or adulthood. We discovered that switching on activated β-catenin in a subset of larval hepatocytes was sufficient to drive HCC initiation. To determine the role of Wnt/β-catenin signaling heterogeneity later in hepatocarcinogenesis, we performed RNA-seq analysis of zebrafish β-catenin-driven HCC. Ingenuity Pathway Analysis of differentially expressed genes in the Cre-lox HCC model revealed that “Cancer” and “Liver Tumor” categories were significantly altered, indicating transcriptional similarities with human HCC and other vertebrate HCC models. At the single-cell level, 2.9% to 15.2% of hepatocytes from zebrafish β-catenin-driven HCC expressed two or more of the Wnt target genes axin2, mtor, glula, myca, and wif1, indicating focal activation of Wnt signaling in established tumors. Thus, heterogeneous β-catenin activation drives HCC initiation and persists throughout hepatocarcinogenesis.
2019-09-27 | GSE137784 | GEO
Project description:Biliary epithelial cells (BECs) form bile ducts in the liver, and are facultative liver stem cells that establish a ductular reaction (DR) to support liver regeneration following injury. Liver damage induces periportal LGR5+ putative liver stem cells which can form BEC-like organoids, suggesting RSPO-LGR4/5-mediated WNT/β-catenin activity is important for a DR. We addressed the roles for this and other signaling pathways in a DR by performing a focused CRISPR-based loss-of-function screen in BEC-like organoids, followed by in vivo validation and single-cell RNA sequencing. We found BECs lack and do not require LGR4/5-mediated WNT/β-Catenin signaling during DR, while YAP and mTORC1 signaling are required for this process. Upregulation of LGR5/AXIN2 is required in hepatocytes to enable their regenerative capacity in response to injury. Together, these data highlight heterogeneity within the BEC pool and delineate signaling pathways involved.
2018-08-27 | GSE111269 | GEO
Project description:The structural-functional organization of ammonia and glutamine metabolism in the liver acinus involves highly specialized hepatocyte subpopulations such as glutamine producing perivenous scavenger cells. However, it is still unclear whether this cell population is homogeneous and involves further subpopulations. This was investigated in the present study by proteome profiling of periportal glutamine synthetase-negative hepatocytes and perivenous glutamine synthetase (GS) expressing scavenger cells isolated from mouse and rat liver. Apart from established markers of GS+ hepatocytes such as glutamate transporter 1 (GLT1), ornithine aminotransferase (OAT) or ammonium transporter Rh type B (RHBG), we identified novel scavenger cell-specific proteins such as the basal transcription factor 3 (BTF3) and the heat-shock protein 25 (HSP25). Interestingly, BTF3 and HSP25 were heterogeneously distributed among GS+ hepatocytes as shown by immunofluorescence analyses in mouse, rat and human liver slices. Feeding experiments showed that RHBG but not GS protein levels were increased in the liver of mice fed with a high protein diet compared to standard chow. While the spatial distribution of GS and carbamoylphosphate synthetase-1 (CPS1) was not affected, periportal areas constituted by GLS2 positive hepatocytes were enlarged or reduced in response to high or low protein diet, respectively. The data suggest that the population of perivenous GS+ scavenger cells is heterogeneous and not uniform as previously suggested which may reflect a functional heterogeneity, possibly relevant for liver regeneration.
2021-08-05 | PXD023561 | Pride
Project description:β-catenin signaling can be both a physiological and an oncogenic pathway in the liver. It controls compartmentalized gene expression, allowing the liver to ensure its essential metabolic function. It is activated by mutations in 20 to 40% of hepatocellular carcinomas with specific metabolic features. We decipher the molecular determinants of β-catenin-dependent zonal transcription using mice with β-catenin-activated or -inactivated hepatocytes, characterizing in vivo their chromatin occupancy by Tcf4 and β-catenin, their transcriptome and their metabolome. We find that Tcf4 DNA-bindings depend on β-catenin. Tcf4/β-catenin binds Wnt-responsive elements preferentially around β-catenin-induced genes. In contrast, genes repressed by β-catenin bind Tcf4 on Hnf4-responsive elements. β-catenin, Tcf4 and Hnf4α interact, dictating β-catenin transcription which is antagonistic to that elicited by Hnf4α. Finally, we find the drug/bile metabolism pathway to be the one most heavily targeted by β-catenin, partly through xenobiotic nuclear receptors. We conclude that β-catenin patterns the zonal liver together with Tcf4, Hnf4α and xenobiotic nuclear receptors. This network represses lipid metabolism, and exacerbates glutamine, drug and bile metabolism, mirroring hepatocellular carcinomas with β-catenin mutational activation. In vivo liver samples in 4 conditions: Betacat activated (WCE, Tcf4 chipseq, Betacat chipseq, mRNAseq with 2 replicates), Betacat null (WCE, Tcf4 chipseq, mRNAseq with 2 replicates), Betacat control (mRNAseq with 2 replicates), Wild type (mRNAseq with 2 replicates)
2014-01-18 | E-GEOD-35213 | biostudies-arrayexpress