Liver fibrosis is characterized by the excessive formation and accumulation of matrix proteins as a result of wound healing in the liver. A main event during fibrogenesis is the activation of the liver resident quiescent hepatic stellate cell (qHSC). Recent studies suggest that reversion of the activated HSC (aHSC) phenotype into a quiescent-like phenotype could be a major cellular mechanism underlying fibrosis regression in the liver, thereby offering new therapeutic perspectives for the treatment of liver fibrosis. The goal of the present study is to identify experimental conditions that can revert the activated status of human HSCs and to map the molecular events associated with this phenotype reversion by gene expression profiling
In vitro reversion of activated primary human hepatic stellate cells.
Sex, Age, Specimen part, Subject
View SamplesAdult-derived human liver stem/progenitor cells (ADHLSC) are obtained after primary culture of the liver parenchymal fraction. The cells are of fibroblastic morphology and exhibit a hepato-mesenchymal phenotype. Hepatic stellate cells (HSC) derived from the liver non-parenchymal fraction present a comparable morphology as ADHLSC. Because both ADHLSC and HSC are described as liver stem/progenitor cells, we strived to extensively compare both cell populations at different levels and to propose tools demonstrating their singularity.
Gene expression profiling and secretome analysis differentiate adult-derived human liver stem/progenitor cells and human hepatic stellate cells.
Specimen part
View SamplesThree master regulatory transcription factors Pdx1, MafA and Ngn3 have the ability to transdifferentiate pancreatic acinar cells to insulin-producing beta cells in mice. BRD7552 was identified as a small-molecule inducer that can upregulate the expression of Pdx1 in PANC-1 cells by high-throughput qPCR screening.
A small-molecule inducer of PDX1 expression identified by high-throughput screening.
Specimen part, Cell line, Treatment, Time
View SamplesMitochondrial biogenesis and metabolism recently emerged as critical modulators of stemness properties and differentiation programmes. The increase in mitochondrial biogenesis and metabolic shift toward increased oxidative phosphorylations (OXPHOS) appear as hallmarks of stem cell differentiation processes. While several mechanisms support the involvement of mitochondrial biogenesis and function in the regulation of stem cell differentiation, the mechanisms triggering mitochondrial biogenesis in the context of cell differentiation remain elusive. In this study, we performed transcriptomic and bioinformatic analyses in order to get deeper insights into the cross-regulation of mitochondrial biogenesis and hepatogenic differentiation of human bone marrow mesenchymal stem cells (BM-MSCs). We identified a transcriptional regulatory network involved in the co-regulation of stem cell differentiation and mitochondrial biogenesis. Overall design: Transcriptomics analyses performed at early time points of the hepatogenic differentiation of BM-MSC
MPV17 does not control cancer cell proliferation.
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View SamplesThe molecular determinants of a healthy human liver cell phenotype remain largely uncharacterized. In addition, the gene expression changes associated with activation of primary human hepatic stellate cells, a key event during fibrogenesis, remain poorly characterized. Here, we provide the transriptomic profile underpinning the healthy phenotype of human hepatocytes, liver sinusoidal endothelial cells (LSECs) and quiescent hepatic stellate cells (qHSCs) as well as activated HSCs (aHSCs)
Genome-wide analysis of DNA methylation and gene expression patterns in purified, uncultured human liver cells and activated hepatic stellate cells.
Sex, Age, Specimen part, Subject
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 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 SamplesWe identified a congenic mouse with an introgressed region from the A/J donor inbred strain on an inbred C57BL/6J background that showed a reduced locomotor stimulant response to methamphetamine. We conducted microarray analysis of the striatum from drug-naive female and male mice that were 6-9 weeks old. The congenic region is on chromosome 11 and spans approximately 84-96 Mb. There were two groups of mice used in the analysis: B6 control mice versus congenic mice. Congenic mice were collapsed across heterozygous and homozygous genotypes.
Congenic dissection of a major QTL for methamphetamine sensitivity implicates epistasis.
Sex
View SamplesMicrocephaly and medulloblastoma result from mutations that compromise genomic stability. We report that Atr, which is mutated in the microcephalic disorder Seckel syndrome, is required to maintain chromosomal integrity during postnatal cerebellar neurogenesis. Atr deletion in cerebellar granule neuron progenitors (CGNPs) induced proliferation-associated DNA damage, p53 activation, apoptosis, and cerebellar hypoplasia. Co-deletions of either Bax and Bak or p53 prevented apoptosis in Atr-deleted CGNPs, but failed to fully rescue cerebellar growth. Atr-deficient CGNPs showed impaired cell cycle checkpoint function and continued to proliferate, accumulating chromosomal abnormalities. RNA-Seq demonstrated that the transcriptional response to Atr-deficient proliferation was p53-driven. Acute Atr inhibition in vivo by nanoparticle-formulated VE-822 reproduced the disruptions seen with Atr deletion. Our data show that p53-driven apoptosis and senescence, and non-apoptotic cell death redundantly limit growth in Atr-deficient progenitors. These overlapping mechanisms that suppress growth in Atr-disrupted CGNPs may be exploited for treatment of CGNP-derived medulloblastoma using Atr inhibition. Overall design: RNA-Seq on total RNA from P3 mouse cerebella of Math1-Cre;Atr-loxP/loxP;Bax-loxP/loxP;Bak--/- (n=5), Math1-Cre;Bax-loxP/loxP;Bak--/- (n=4), Math1-Cre;Atr-loxP/loxP;p53-loxP/loxP (n=5), and Math1-Cre;p53-loxP/loxP (n=3), all run in 2 lanes
ATR maintains chromosomal integrity during postnatal cerebellar neurogenesis and is required for medulloblastoma formation.
Specimen part, Cell line, Subject
View SamplesThe combination of JQ1 and Vemurafenib acted synergistically in BRAF-mutant cell lines, resulting in marked apoptosis in vitro, with up-regulation of pro-apoptotic proteins. In vivo, combination treatment suppressed tumor growth and significantly improved survival compared to either drug alone. RNA sequencing of tumor tissues revealed almost four thousand genes that were uniquely modulated by the combination, with several anti-apoptotic genes significantly down-regulated. Overall design: 16 samples analyzed from 8 mice (each mouse was bearing two tumors, one on each flank) in 4 treatment groups (control, vemurafenib alone, JQ1 alone, JQ1+vemurafenib)
BET and BRAF inhibitors act synergistically against BRAF-mutant melanoma.
Cell line, Treatment, Subject
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