Purpose: We purified whole brain microglia of MFP2 knockout mice and control mice utilizing percoll gradient and FACS sorting, followed by microarray analysis to define the molecular changes in MFP2 knockout mice at the endstage of the disease. We compared the microglia transcriptome of Mfp2-/- microglia to that of SOD1-G93A microglia isolated from spinal cord to define the microglia signature associated with a non-neurodegenerative environment. Results and conclusions: Mfp2-/- microglia acquire an activation state characterized by activation of mammalian target of rapamycin (mTOR). In addition, activated microglia display reduced expression of genes that are normally highly expressed by surveillant microglia in steady-state conditions. The immunological profile of is heterogeneous and encompasses upregulation of both pro- and anti-inflammatory genes. In contrast to the neurodegeneration-specific microglia profile in SOD1-G93A mice, Mfp2-/- microglia do not induce genes associated with phagocytosis, lysosomal activation and neurotoxicity.
Identification of a chronic non-neurodegenerative microglia activation state in a mouse model of peroxisomal β-oxidation deficiency.
Sex, Age, Specimen part
View SamplesIn an attempt to elucidate the molecular mechanisms underlying the multiple roles of L1 in endothelium, we checked whether manipulating its expression affected the transcriptome of lECs. To this purpose, we compared the gene expression profiles of L1-overexpressing and control lECs by Affymetrix, which revealed a remarkable effect of L1 overexpression on lECs transcriptome.
Endothelial deficiency of L1 reduces tumor angiogenesis and promotes vessel normalization.
Specimen part
View SamplesExpression of a constitutively active Notch-1 intracellular domain (NICD) in MCF-10A cells was found to induce two distinct types of 3D structures: large, hyperproliferative structures and small, growth-arrested structures with reduced cell-to-matrix adhesion. These heterogeneous phenotypes reflect differences in Notch pathway activation levels. High Notch activity caused loss of cell adhesion and inhibition of proliferation, whereas low Notch activity maintained matrix adhesion and provoked a strong hyperproliferative response. In order to gain insight into the dosage-dependent transcriptional events triggered by Notch1 activation, gene expression profiles induced 48 hours after infection of MCF-10A cells with retroviral vectors expressing full-length Notch-1, L1601P+P, or NICD were compared. Full-length Notch-1 induced the weakest effect, L1601P+P induced an intermediate effect and NICD induced the strongest effect. Results provide insight into the dichotomous activites of Notch during development and tumorigenesis.
Dose-dependent induction of distinct phenotypic responses to Notch pathway activation in mammary epithelial cells.
Cell line
View SamplesHistidine-rich glycoprotein (HRG) is a 75 kDa heparin-binding plasma protein which has been implicated in regulation of tumor angiogenesis and growth. To exert some of its biological functions, HRG acts on macrophages.This study was performed to assess changes in gene expression in peritoneal macrophages treated with HRG using oligonucleotide microarrays
Genetic deficiency in plasma protein HRG enhances tumor growth and metastasis by exacerbating immune escape and vessel abnormalization.
Specimen part, Disease, Treatment, Time
View SamplesThe aim of this study is to profile gene expression dynamics during the in vitro differentiation of embryonic stem cells into ventral motor neurons. Expression levels were profiled using Affymetrix microarrays at six timepoints during in vitro differentiation: ES cells (Day 0), embryoid bodies (Day 2), retinoid induction of neurogenesis (Day 2 +8hours of exposure to retinoic acid), neural precursors (Day 3), progenitor motor neurons (Day 4), postmitotic motor neurons (Day 7).
Ligand-dependent dynamics of retinoic acid receptor binding during early neurogenesis.
Cell line
View SamplesIn this experiment, we sought to analyze how the transcriptome of WT, ?5|6, and ?5|6:7|9 cells vary during differentiation of ESCs into cervical motor neurons Overall design: 3 lines (WT, ?5|6, ?5|6:7|9)
CTCF establishes discrete functional chromatin domains at the Hox clusters during differentiation.
No sample metadata fields
View SamplesTranscriptional programming of cell identity promises to open up new frontiers in regenerative medicine by enabling the efficient production of clinically relevant cell types. We examine if such cellular programming is accomplished by transcription factors that each have an independent and additive effect on cellular identity, or if programming factors synergize to produce an effect that is not independently obtainable. The combinations of Ngn2-Isl1-Lhx3 and Ngn2-Isl1-Phox2a transcription factors program embryonic stem cells to express a spinal or cranial motor neuron identity respectively. The two alternate expression programs are determined by recruitment of Isl1/Lhx3 and Isl1/Phox2a pairs to distinct genomic locations characterized by two alternative dimeric homeobox motifs. These results suggest that the function of programming modules relies on synergistic interactions among transcription factors and thus cannot be extrapolated from the study of individual transcription factors in a different cellular context.
Synergistic binding of transcription factors to cell-specific enhancers programs motor neuron identity.
Cell line, Treatment
View SamplesUnderstanding the trancriptional role of FOXF1 in mesenchymal activation
Loss of FOXF1 expression promotes human lung-resident mesenchymal stromal cell migration via ATX/LPA/LPA1 signaling axis.
No sample metadata fields
View SamplesBasic helix-loop-helix (bHLH) proneural transcription factors (TFs) Ascl1 and Neurog2 are integral to the development of the nervous system. Here, we investigated the molecular mechanisms by which Ascl1 and Neurog2 control the acquisition of generic neuronal fate and impose neuronal subtype identity. Using direct neuronal programming of embryonic stem cells, we found that Ascl1 and Neurog2 regulate distinct targets by binding to largely different sets of sites. Their divergent binding pattern is not determined by the previous chromatin state but distinguished by specific E-box enrichments which reflect the DNA sequence preference of the bHLH domain. The divergent Ascl1 and Neurog2 binding patterns result in distinct chromatin accessibility and enhancer activity landscapes that shape the binding and activity of downstream TFs during neuronal specification. Our findings suggest that proneural factors contribute to neuronal diversity by differentially altering the chromatin landscapes that shape the binding of neuronally expressed TFs. Overall design: Single-cell RNA-seq was used to characterize gene expression in mixed populations of mES cells containing induced expression of either Ascl1 or Neurog2.
Proneural factors Ascl1 and Neurog2 contribute to neuronal subtype identities by establishing distinct chromatin landscapes.
Specimen part, Treatment, Subject
View SamplesHypermethylation of tumor suppressor gene (TSG) promoters confers growth advantages to cancer cells, but how these changes arise is poorly understood. Here, we report that tumor hypoxia reduces the activity of oxygen-dependent TET enzymes, which catalyze DNA de-methylation through 5-methylcytosine oxidation. This occurs independently of hypoxia-associated alterations in TET gene expression, basal metabolism, HIF activity or nuclear reactive oxygen species, but directly depends on oxygen shortage. Hypoxia-induced loss of TET activity increases hypermethylation at gene promoters in vitro, while also in patients, gene promoters are markedly more methylated in hypoxic than normoxic tumors. Affected genes are frequently involved in DNA repair, cell cycle regulation, angiogenesis and metastasis, indicating cellular selection of hypermethylation events. Overall, up to 50% of the tumor-associated hypermethylation is ascribable to hypoxia across various cancer types. Accordingly, spontaneous murine breast tumors become hypermethylated when rendered hypoxic through vessel pruning, whereas vessel normalisation rescues this effect. Tumor hypoxia thus acts as a novel regulator underlying DNA methylation. Overall design: RNAseq of MCF7 cells grown under hypoxic and normoxic conditions. Submission includes data on 5 independent RNAseq experiments, each containing biological replicates grown under hypoxic conditions (0.5% oxygen), and under normoxic conditions.
Tumour hypoxia causes DNA hypermethylation by reducing TET activity.
Subject
View Samples