Unveiling 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 SamplesHepatic stellate cells (HSC) are the main stromal cell component of the liver. In healthy liver, quiescent HSC participate in the homeostasis of extracellular matrix (ECM) and store vitamin A. Liver injury causes HSC activation, where they participate in the wound-healing response, by producing ECM components as well as cytokines involved in liver regeneration and inflammation. Moreover, HSC are the main cell type responsible for fibrosis progression. The lack of homogeneous cultures and renewable sources of human HSC has limited the studies of the role of HSC in liver injury, repair anf fibrosis. Here we report a procedure to direct the differentiation of human pluripotent stem cells (PSC) to HSC. The HSClike population (iPS-HSC) was enriched in PDGFR positive cells that expressed key HSC markers. Whole genome transcriptomic analysis revealed that iPS-HSC displayed features intermediate to quiescent and activated HSC. Functional analysis demonstrated that iPS-HSC accumulated retinyl esters into lipid droplets and responded to injury mediators. Moreover, when cultured with HepaRG hepatocytes as aggregates, iPS-HSC support long-term hepatocyte metabolic function and respond to hepatocyte toxicity by activating and promoting organoid fibrogenesis.
Generation of Hepatic Stellate Cells from Human Pluripotent Stem Cells Enables In Vitro Modeling of Liver Fibrosis.
Specimen part
View SamplesObjective: Alcoholic hepatitis (AH) is characterized by the expansion of ductular reaction (DR) cells and expression of liver progenitor cell (LPC) markers. The aim of this study was to identify the gene expression profile and associated genes of DR cells and to evaluate its weight in alcoholic disease progression. Design: KRT7+, KRT7- and total liver fractions were laser microdissected from liver biopsies (n=6) of patients with AH and whole transcriptome was sequenced. Gene signature was assessed in transcriptomic data from 41 patients with alcoholic liver disease. Pro-inflammatory profile was evaluated in tissue and serum samples and in human LPC organoids. Results: Transcriptome analysis of KRT7+ DR cells uncovered intrinsic gene pathways of DR and allowed identifying genes associated with DR expressed in AH. In addition, DR gene signature and associated genes correlated with disease progression and poor outcome in AH patients. Importantly, DR presented a pro-inflammatory profile with expression of CXC and CCL chemokines and was associated with infiltrating neutrophils. Moreover, LPC markers correlated with liver expression and circulating levels of inflammatory mediators. In vitro, human LPC organoids mimicked ductular reaction gene expression profile and produced chemokines. Moreover, LPC promoted neutrophil migration and enhanced their inflammatory profile. Conclusions: Here we report for the first time the gene expression signature of DR in AH and its association with disease progression. Functional and experimental analysis demonstrates that DR cells have a pro-inflammatory profile, and suggest their involvement in neutrophil recruitment and liver inflammatory response.
Ductular Reaction Cells Display an Inflammatory Profile and Recruit Neutrophils in Alcoholic Hepatitis.
Sex, Age, Specimen part, Disease, Disease stage, Cell line, Treatment, Race
View SamplesObjective: Alcoholic hepatitis (AH) is characterized by the expansion of ductular reaction (DR) cells and expression of liver progenitor cell (LPC) markers. The aim of this study was to identify the gene expression profile and associated genes of DR cells and to evaluate its weight in alcoholic disease progression. Design: KRT7+, KRT7- and total liver fractions were laser microdissected from liver biopsies (n=6) of patients with AH and whole transcriptome was sequenced. Gene signature was assessed in transcriptomic data from 41 patients with alcoholic liver disease. Pro-inflammatory profile was evaluated in tissue and serum samples and in human LPC organoids. Results: Transcriptome analysis of KRT7+ DR cells uncovered intrinsic gene pathways of DR and allowed identifying genes associated with DR expressed in AH. In addition, DR gene signature and associated genes correlated with disease progression and poor outcome in AH patients. Importantly, DR presented a pro-inflammatory profile with expression of CXC and CCL chemokines and was associated with infiltrating neutrophils. Moreover, LPC markers correlated with liver expression and circulating levels of inflammatory mediators. In vitro, human LPC organoids mimicked ductular reaction gene expression profile and produced chemokines. Moreover, LPC promoted neutrophil migration and enhanced their inflammatory profile. Conclusions: Here we report for the first time the gene expression signature of DR in AH and its association with disease progression. Functional and experimental analysis demonstrates that DR cells have a pro-inflammatory profile, and suggest their involvement in neutrophil recruitment and liver inflammatory response.
Ductular Reaction Cells Display an Inflammatory Profile and Recruit Neutrophils in Alcoholic Hepatitis.
Specimen part
View SamplesQuiescent and dividing hemopoietic stem cells (HSC) display marked differences in their ability to move between the peripheral circulation and the bone marrow. Specifically, long-term engraftment potential predominantly resides in the quiescent HSC subfraction, and G-CSF mobilization results in the preferential accumulation of quiescent HSC in the periphery. In contrast, stem cells from chronic myeloid leukemia (CML) patients display a constitutive presence in the circulation. To understand the molecular basis for this, we have used microarray technology to analyze the transcriptional differences between dividing and quiescent, normal, and CML-derived CD34+ cells.
Transcriptional analysis of quiescent and proliferating CD34+ human hemopoietic cells from normal and chronic myeloid leukemia sources.
Specimen part, Disease, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNAs of the miR-290-295 Family Maintain Bivalency in Mouse Embryonic Stem Cells.
Specimen part
View SamplesThe protein Dicer is required for microRNA (miRNA) biogenesis. Dicer-deficient cells therefore lack almost all mature, functional miRNAs. We investigated the role of miRNAs in regulation of gene expression in mouse
MicroRNAs of the miR-290-295 Family Maintain Bivalency in Mouse Embryonic Stem Cells.
Specimen part
View SamplesWe describe a critical role for Cdk6 in JAK2V617F+ MPN evolution. The absence of Cdk6 ameliorates clinical symptoms and prolongs survival of JAK2V617F fl/+ vav-Cre mice. The Cdk6 protein interferes with three hallmarks of disease: besides regulating malignant stem cell quiescence, it promotes NFkB signaling and contributes to cytokine production while inhibiting apoptosis. The treatment with palbociclib did not mirror these effects, showing that the functions of Cdk6 in MPN pathogenesis are largely kinase-independent. Overall design: LSK-sorted (FACS) bone marrow cells from 8-week-old VavCre;Jak2+/+; Cdk6+/+, VavCre;Jak2V617F; Cdk6+/+, VavCre;Jak2V617F; Cdk6-/-, VavCre; Jak2+/+; Cdk6-/- mice, and the same cell type from palbociclib-treated (38mg/kg, 3x in one week) VavCre;Jak2V617F; Cdk6+/+ mice, n=3 for all genotypes
CDK6 coordinates <i>JAK2</i> <sup><i>V617F</i></sup> mutant MPN via NF-κB and apoptotic networks.
Specimen part, Treatment, Subject
View SamplesMicroarray studies revealed that as a first hit, SV40 T/t-antigen causes deregulation of 462 genes in mammary gland cells (ME-cells) of WAP-SVT/t transgenic animals. The majority of deregulated genes are cell-proliferation specific and Rb-E2F dependent, causing ME-cell proliferation and gland hyperplasia but not breast cancer formation. In the breast tumor cells, a further 207 genes are differentially expressed, most of them belonging to the cell communication category. In tissue culture, breast tumor cells frequently switch off WAP-SVT/t transgene expression and regain the morphology and growth characteristics of normal-ME-cells, although the tumor-revertant cells are aneuploid and only 114 genes regain the expression level of normal-ME-cells. The profile of retransformants shows that only 38 deregulated genes appear to be tumor-relevant and that none of them is considered to be a typical breast cancer gene.
Gene expression profiling: cell cycle deregulation and aneuploidy do not cause breast cancer formation in WAP-SVT/t transgenic animals.
No sample metadata fields
View SamplesAlternative promoters (APs) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic impact of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes, and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, while in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor (ER) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ER coregulators. Finally, genes with differentially regulated promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show in particular that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation, and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in estrogen-regulated genes, demonstrates the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome, as well as their physiopathologic significance in breast cancer.
Estrogen regulation and physiopathologic significance of alternative promoters in breast cancer.
Disease, Disease stage, Cell line, Time
View Samples