In this study we investigated the effect of normal chow (0 % cholesterol) or a semisynthetic diet (high sugar, 0.02 % cholesterol) fed to mice lacking either Mc4r, Ldlr or both and wildtype animals (total of 4 genotypes) by generating an expression profile of their livers after 6 months by RNA sequencing. Overall design: We investigated mice lacking either Mc4r, Ldlr or both and wildtype animals fed with normal chow or a semisynthetic diet with 10 replicates for each of the 8 resulting groups (4 genotypes * 2 diets).
Severe Atherosclerosis and Hypercholesterolemia in Mice Lacking Both the Melanocortin Type 4 Receptor and Low Density Lipoprotein Receptor.
Age, Specimen part, Cell line, Subject
View SamplesIn vitro differentiation of embryonic stem cells (ESC) provides models that reproduce in vivo development and cells for therapy. Whether the epigenetic signatures that are crucial for brain development and function and that are sensitive to in vitro culture are similar between native brain tissues and their artificial counterpart generated from ESC is largely unknown. Here, using RNA-seq we have compared the parental origin-dependent expression of imprinted genes (IGs), a model of epigenetic regulation, in cerebral cortex generated either in vivo, or from ESCs using in vitro corticogenesis, a model that reproduces the landmarks of in vivo corticogenesis. For a majority of IGs, the expressed parental alleles were the same for in vivo and in vitro cortex. In most cases, this choice was already set in ESCs and faithfully maintained during the 3 weeks of in vitro corticogenesis. Confirming these findings, methylation, which selects the parental allele to be transcribed, was also largely equivalent between the 2 types of cortex and ESCs. Our results thus indicate that the allele specific expression of imprinted transcripts, a model of epigenetic regulation resulting from a differential methylation of parental genomes, is mostly mimicked in cortical cells derived from ESC. Overall design: We have crossed two strains of mice (B6 and JF1) that display more than 12 million of SNPs (Takada et al., Genome Res. 2013 Aug;23(8):1329-38. doi: 10.1101/gr.156497.113). We have then analyzed allele specific expression transcriptome-wide using RNA-seq on hybrid F1 cortex generated either in vivo or in vitro from ESCs. In addition, we have used 2 different developmental stages of in vivo cortex (E13.5, P0) and three stages in vitro (undiffererentiated ESC, and differentiated into cortex for 12 and 21 days) to measure the dynamics of parental expression. Please note that [1] the same raw data files were used to generate the ''*allele-specific_sense_read_bases_by_gene_withoutContamination.txt'' processed data files. [2] The samples associated with each file are indicated in the file column header (as their GSM accession numbers). [3] The readme.txt file contains the data processing steps, file description.
In Vitro Corticogenesis from Embryonic Stem Cells Recapitulates the In Vivo Epigenetic Control of Imprinted Gene Expression.
No sample metadata fields
View SamplesNitric oxide and NO-derived species (RNS) are defense molecules with broad antimicrobial activity. Micro-organisms have developed strategies to sense RNS and counteract their damaging effects. We used Saccharomyces cerevisiae, harbouring a deletion of YHB1 that encodes the main NO scavenger enzyme, to study consequences of RNS exposure on whole genome transcriptional response. The expression of >700 genes was altered on RNS treatment. No major role for ROS-scavenging enzymes was found, and the respiratory chain, the main site of ROS production, had only minor involvement in the RNS-induced stress. The changes were generally transient and also found after treatment with the respiratory inhibitor myxothiazol. 117 genes however showed a persistent response which was not observed after myxothiazol treatment. Of these, genes of the glutathione and DNA repair systems, iron homeostasis and transport were found up-regulated. Severe repression of genes of respiratory chain enzymes was observed. Many of these genes are known to be regulated by the transcription factor Hap1p suggesting that RNS might interfere with Hap1p activity. We showed also that Msn2/4p and Yap1p, key regulators of the response to, respectively, general stress and oxidative stress, played a role in mediating the RNS-induced response.
Transcriptional response to nitrosative stress in Saccharomyces cerevisiae.
Compound, Time
View SamplesThe mitochondrial respiratory chain is composed of lipoprotein complexes imbedded in the inner mitochondrial membrane. This chain of enzymes transfers electrons from NADH and FADH2, provided from divers metabolic pathways, to oxygen. It couples the transfer of electrons to the translocation of protons across the membrane. Several clinical syndromes have been associated with respiratory dysfunction caused by mitochondrial or nuclear mutations. A number of mutations in the mitochondrial genes encoding for cytochrome b (CYTB) and cytochrome oxidase (COX 1, 2 and 3) have been linked with diseases. We are using yeast mutants to characterize the deleterious effect of mutations reported in patients on the assembly and catalytic properties of the affected enzymes, and to study the impact of mutations in nuclear genes, such as OXA1, encoding for factors required for the assembly of the respiratory complexes. In this work, we monitored the effects of the mutations causing respiratory defect on the whole genome expression. We compared the change in gene expression in rho0 cells (with a complete deletion of the mitochondrial genome, and by consequence without respiratory chain), in cells with either a single defective enzyme or several, and in cells after prolonged treatment with the bc1 inhibitors myxothiazol or antimycin. The impact of the mutations on the respiratory function ranged from mild to severe. The expression of approx. 350 genes was changed in at least one mutant. Cluster analysis was performed using the Cluster program (Eisen, 1998, PNAS 95:14863). Four groups of genes were studied in more details: Group A, the most repressed genes; Group B, the most over-expressed genes; Group C, genes more repressed in rho0 and Doxa1 cells; and Group D, genes more over-expressed in Doxa1.
Multiple defects in the respiratory chain lead to the repression of genes encoding components of the respiratory chain and TCA cycle enzymes.
Compound
View SamplesEpigenetic code modifications by histone deacetylase inhibitors (HDACi) have recently been proposed as potential new therapies for hematological malignancies. Chronic Lymphocytic Leukemia (CLL) remains incurable despite the introduction of new treatments. CLL cells are characterized by an apoptosis defect rather than excessive proliferation, but proliferation centers have been found in organs such as bone marrow and lymph nodes.
Antileukemic activity of valproic acid in chronic lymphocytic leukemia B cells defined by microarray analysis.
Sex, Age
View SamplesIt is now well established that bone marrow (BM) constitutes a microenvironment required for differentiation. Bone marrow mesenchymal stromal cells (BM-MSCs) strongly support MM cell growth, by producing a high level of Interleukin-6 (IL-6), a major MM cell growth factor. BM-MSCs also support osteoclastogenesis and angiogenesis. Previous studies have suggested that the direct (VLA-4, VCAM-1, CD44, VLA-5, LFA-1, syndecan-1,) and indirect interactions (soluble factors) between MM plasma cells and BM-MSCs result in constitutive abnormalities in BM-MSCs. In particular, MM BM-MSCs express less CD106 and fibronectin and more DKK1, IL-1 and TNF- as compared with normal BM-MSCs. In order to gain a global view of the differences between BM-MSCs from MM patients and healthy donors, we used gene expression profiling to identify genes associated to the transformation of MM BM-MSCs.
Evidences of early senescence in multiple myeloma bone marrow mesenchymal stromal cells.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThe goal of this study was to identify genes which are differentiatlly expresesd upon induced inactivation of Rfx6 in beta cell in adult mice Overall design: Rfx6fl/fl; Ins1-CreERT2 (mut) and Rfx6fl/fl (ctrl) 8 weeks old mice were injected subcutaneously with tamoxifen daily during 3 days. Pancreatic islets were isolated 5 days after the first injection and RNA purified.
Rfx6 maintains the functional identity of adult pancreatic β cells.
No sample metadata fields
View SamplesIslets are known to respond to changes in ambient glucose. To quantify the transcriptome-wide changes in ambient glucose, we compared transcriptome of islets exposed to low and high glucose. Overall design: Isolated islets from wild type male mice. Islets from adult males were pooled, cultured overnight in RPMI containing 11 mM glucose. The next day, all islets were starved in RPMI containing 2.8 mM glucose for 2 hours before stimulation with 2.8 mM glucose or 16.8 mM glucose for 12 hours. Islets were lysed in Trizol for RNA isolation and library construction.
The transcriptional landscape of mouse beta cells compared to human beta cells reveals notable species differences in long non-coding RNA and protein-coding gene expression.
No sample metadata fields
View SamplesThe loss of E-cadherin causes dysfunction of the cell-cell junction machinery, which is an initial step in epithelial-to-mesenchymal transition (EMT), facilitating cancer cell invasion and the formation of metastases. A set of transcriptional repressors of E-cadherin (CDH1) gene expression, including Snail1, Snail2 and Zeb2 mediate E-cadherin down-regulation in breast cancer. However, the molecular mechanisms underlying the control of E-cadherin expression in breast cancer progression remain largely unknown. Here, by using global gene expression approaches, we uncover a novel function for Cdc42 GTPase-activating protein (CdGAP) in the regulation of expression of genes involved in EMT. We found that CdGAP used its proline-rich domain to form a functional complex with Zeb2 to mediate the repression of E-cadherin expression in ErbB2-transformed breast cancer cells. Conversely, knockdown of CdGAP expression led to a decrease of the transcriptional repressors Snail1 and Zeb2, and this correlated with an increase in E-cadherin levels, restoration of cell-cell junctions, and epithelial-like morphological changes. In vivo, loss of CdGAP in ErbB2-transformed breast cancer cells impaired tumor growth and suppressed metastasis to lungs. Finally, CdGAP was highly expressed in basal-type breast cancer cells, and its strong expression correlated with poor prognosis in breast cancer patients. Together, these data support a previously unknown nuclear function for CdGAP where it cooperates in a GAP-independent manner with transcriptional repressors to function as a critical modulator of breast cancer through repression of E-cadherin transcription. Targeting Zeb2-CdGAP interactions may represent novel therapeutic opportunities for breast cancer treatment. Overall design: Total RNA profiles of ErbB2-expressing control mammary tumor explants cells (shCON) and CdGAP-depleted cells (shCdGAP) were generated by deep sequencing, in triplicate, using Illumina HiSEq2000.
The Cdc42/Rac1 regulator CdGAP is a novel E-cadherin transcriptional co-repressor with Zeb2 in breast cancer.
Specimen part, Subject
View SamplesComparison of Chronic Lymphocytic Leukemia patients expressing high or low levels of ZAP70 mRNA: prognostic factors and interaction with the microenvironment.
Gene expression profiling reveals differences in microenvironment interaction between patients with chronic lymphocytic leukemia expressing high versus low ZAP70 mRNA.
Sex, Age
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