This 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 SamplesA robust system using disease relevant cells to systematically evaluate the role in diabetes for loci identified through genome wide association studies (GWAS) is urgently needed. Toward this goal, we created isogenic mutant human embryonic stem cell (hESC) lines in GWAS-identified candidate diabetes genes including CDKAL1, KCNQ1 and KCNJ11, and used directed differentiation to evaluate the function of derivative human beta-like cells. The mutations did not affect the generation of insulin+ cells, but impaired insulin secretion both in vitro and in vivo, coinciding with defective glucose homeostasis. CDKAL1-/- insulin+ cells also displayed hypersensitivity to lipotoxicity. A high-content chemical screen identified a candidate drug that rescued CDKAL1-/--specific defects by inhibiting the AP1 (FOS/JUN) pathway. These studies establish a platform using isogenic hESCs to evaluate the function of GWAS-identified loci, and identify a drug candidate that rescues gene-specific defects, paving the way to precision therapy of metabolic diseases.A robust system using disease relevant cells to systematically evaluate the role in diabetes for loci identified through genome wide association studies (GWAS) is urgently needed. Toward this goal, we created isogenic mutant human embryonic stem cell (hESC) lines in GWAS-identified candidate diabetes genes including CDKAL1, KCNQ1 and KCNJ11, and used directed differentiation to evaluate the function of derivative human beta-like cells. The mutations did not affect the generation of insulin+ cells, but impaired insulin secretion both in vitro and in vivo, coinciding with defective glucose homeostasis. CDKAL1-/- insulin+ cells also displayed hypersensitivity to lipotoxicity. A high-content chemical screen identified a candidate drug that rescued CDKAL1-/--specific defects by inhibiting the AP1 (FOS/JUN) pathway. These studies establish a platform using isogenic hESCs to evaluate the function of GWAS-identified loci, and identify a drug candidate that rescues gene-specific defects, paving the way to precision therapy of metabolic diseases. Overall design: RNA-seq was used to compare the gene expression in wildtype and CDKAL1-/- hESC derived insulin-GFP+ cells. In addiiton, RNA-seq was used to compare the gene expression in CDKAL1-/- hESC derived insulin-GFP+ cells cultured in control or high palmitate condition to examine the upregulation of ER stress pathway.
An Isogenic Human ESC Platform for Functional Evaluation of Genome-wide-Association-Study-Identified Diabetes Genes and Drug Discovery.
No sample metadata fields
View SamplesDevelopment and function of tissues and organs are powered by the activity of mitochondria. In humans, inherited genetic mutations that lead to progressive mitochondrial pathology often manifest during infancy and can lead to death, reflecting the indispensable nature of mitochondrial function and biogenesis. Here, we describe a zebrafish mutant for the gene mia40a, the life-essential homologue of the evolutionarily conserved Mia40 oxidoreductase which drives the biogenesis of cysteine-rich mitochondrial proteins. We report that mia40a mutant animals undergo progressive cellular respiration defects and develop enlarged mitochondria in skeletal muscles before their ultimate at the larval stage. We generated a rich transcriptomic and proteomic resource that allowed us to identify abnormalities in the development of endodermal organs, in particular the liver and pancreas. We identify the acinar cells of the exocrine pancreas to be severely affected by mutations in the MIA pathway. Our data contribute to a better understanding of the molecular, cellular and organismal effects of mitochondrial deficiency, important for the accurate diagnosis and future treatment strategies of these diseases. Overall design: Embryos obtained from an in-cross of heterozygous mia40awaw1/+ siblings were genotyped at 3 dpf. Pools of five mia40+/+ or mia40waw1/waw1 larvae, derived from the same clutch, were collected at indicated time-points for RNA extraction and transcriptomic profiling. Larvae used in 8 dpf experiments were subjected to external feeding from 5dpf before being collected for the analysis at 8dpf.
Loss of the Mia40a oxidoreductase leads to hepato-pancreatic insufficiency in zebrafish.
Specimen part, Subject
View SamplesmiRNA regulate gene expression at the post-transcriptionnal level. To gain further insight into this process, we analysed by Affymetrix microarray, the transcriptome of Dicer WT or Dicer deleted mouse CD4 T cells.
microRNA-mediated regulation of mTOR complex components facilitates discrimination between activation and anergy in CD4 T cells.
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 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 SamplesThis work is part of an existing collaboration between the two laboratories, funded by the EU (EU-RTN-INTEGA). Both parties will share the cost of this microarray experiment. Background: We have demonstrated that ethylene-insensitive mutants and wild type(col-0) Arabidopsis plants treated with an ethylene perception inhibitor have increased levels of expression of genes, such as GASA1 and g-TIP, that are thought to be regulated by GA (Vriezen et al, unpublished results). However, this observation was based on an RNA gel blot analysis and therefore limited to few genes. Aim: To investigate whether plants with decreased ethylene perception are generally hypersensitive to GA or whether this effect is restricted to specific genes. We plan to undertake a complete transcriptome analysis of GA-treated wild type andetr1-1 plants. The aim is to identify genes that are induced directly as a result of the GA treatment, and we will therefore focus on the time window 0-3h. Tissues to be sampled: Plants will be grown in vitroon MS/2 containing 1% sucrose, pH 5.7, at 22 C,70% RH, under white light (54 PAR) and a photoperiod of 16h light/8h dark. Plants will be treated at 14 days and harvested entirely, i.e. roots and shoots are extracted together. Experimental set-up: Col-0 and the ethylene-insensitive mutant etr1-1 will be sprayed with 50 microM GA4 in water. GA4 is the major bio-active GA in Arabidopsis. Samples will be taken after 0, 30 min, 1h, and 3h. In order to correct for touch-induced genes a control, which is sprayed with water only and harvested at 1h, will be included for both genotypes. The total number of chips to be hybridized is 10. The time course with 4 data points is preferred to a single time point with 3 repeats, because it will allow us to follow the induction kinetics and identify early response genes. For each timepoint, RNA will be extracted from at least 40 individuals.
Reciprocal influence of ethylene and gibberellins on response-gene expression in Arabidopsis thaliana.
Specimen part
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