Gene expression profiles in Ba/F3 cells expressing ETV6-PDGFRB, FIP1L1-PDGFRA or a control vector, treated or not with imatinib (Glivec)
The expression of the tumour suppressor HBP1 is down-regulated by growth factors via the PI3K/PKB/FOXO pathway.
Specimen part, Cell line, Treatment
View SamplesQuercetin has been shown to act as an anti-carcinogen in experimental colorectal cancer (CRC). The aim of the present study was to characterise transcriptome and proteome changes occurring in the distal colon mucosa of rats supplemented with 10 g quercetin/kg diet for 11 weeks. Transcriptome data analysed with Gene Set Enrichment Analysis showed that quercetin significantly downregulated the potentially oncogenic mitogen-activated protein kinase (Mapk) pathway. In addition, quercetin enhanced expression of tumor suppressor genes, including Pten, Tp53 and Msh2, and of cell cycle inhibitors, including Mutyh. Furthermore, dietary quercetin enhanced genes involved in phase I and II metabolism, including Fmo5, Ephx1, Ephx2 and Gpx2. Quercetin increased PPAR target genes, and concomitantly enhanced expression genes in volved in of mitochondrial fatty acid degradation. Proteomics performed in the same samples revealed 33 affected proteins, of which 4 glycolysis enzymes and 3 heatshock proteins were decreased. A proteome-transcriptome comparison showed a low correlation, but both pointed out towards altered energy metabolism.
Transcriptome and proteome profiling of colon mucosa from quercetin fed F344 rats point to tumor preventive mechanisms, increased mitochondrial fatty acid degradation and decreased glycolysis.
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View SamplesThe homeostasis of circulating B cell subsets in the peripheral blood of healthy adults is well regulated, but in disease it can be severely disturbed. Thus, a subgroup of patients with common variable immunodeficiency (CVID) presents with an extraordinary expansion of an unusual B cell population characterized by the low expression of CD21. Since these circulating atypical B cells in the blood of CVID patients could not be assigned to any certain B cell differentiation stage in the periphery, they were designated as CD21low B cells. Although, CD21low B cells are polyclonal and unmutated IgM+IgD+ B cells like naive B cells in the peripheral blood, they reveal several distinct phenotypic and functional features.
Circulating CD21low B cells in common variable immunodeficiency resemble tissue homing, innate-like B cells.
Specimen part, Disease
View SamplesHuman dendritic cells were exposed to LPS, in the absence and presence of adenosine receptor 3 inhibitor Overall design: 4 donors, 4 experimental conditions. VUF concentration used was 5 µM, LPS was 500 ng/ml. Exposure times were 6 hours
TLR-Induced IL-12 and CCL2 Production by Myeloid Cells Is Dependent on Adenosine A<sub>3</sub> Receptor-Mediated Signaling.
Specimen part, Subject
View SamplesDrosophila neuroblasts have emerged as a model for stem cell biology that is ideal for genetic analysis but is limited by the lack of cell-type specific gene expression data. Here, we describe a methodology to isolate large numbers of pure neuroblasts and differentiating neurons that retain both cell cycle and lineage characteristics. We determine transcriptional profiles by mRNA sequencing and identify 28 predicted neuroblast specific transcription factors, which can be arranged in a network containing hubs for Notch signaling, growth control and chromatin regulation. Overexpression and RNAi for these factors identify Klumpfuss as a regulator of self-renewal. We show that loss of Klu function causes premature differentiation while overexpression results in the formation of transplantable brain tumors. Our data represent a valuable resource for Drosophila developmental neurobiology and we describes methodology that can be applied to other invertebrate stem cell lineages as well. Overall design: comparison of transcriptomes of Drosophila melanogaster larval neuroblasts and their differentiated daughter cells (neurons)
FACS purification and transcriptome analysis of drosophila neural stem cells reveals a role for Klumpfuss in self-renewal.
Specimen part, Subject
View SamplesAngiopoietin-like protein 4 (ANGPTL4, also referred to as Fiaf) has been proposed as circulating mediator between the gut microbiota and fat storage in adipose tissue. Very little is known about mechanisms of regulation of ANGPTL4 in the colon. Here we show that transcription and subsequent secretion of ANGPTL4 in human T84 and HT-29 colonocytes is highly induced by physiological concentrations of products of bacterial fermentation, the short chain fatty acids (SCFA). Induction of ANGPTL4 by SCFA cannot be mimicked by the histone deacetylase inhibitor Trichostatin A. SCFA induce ANGPTL4 by activating the nuclear receptor PPAR, as shown by use of PPAR antagonist, PPAR knock-down, and transactivation assay, which shows activation of PPAR but not PPAR and PPAR. At concentrations required for PPAR activation and ANGPTL4 induction in colonocytes, SCFA do not stimulate PPAR in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPAR modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modelling. Consistent with the notion that fermentation leads to PPAR activation in vivo, feeding mice a diet rich in inulin was associated with induction of PPAR target genes and pathways in the colon, as shown by microarray and subsequent gene set enrichment analysis. It can be concluded that 1) SCFA potently stimulate ANGPTL4 synthesis in human colonocytes; 2) SCFA transactivate and bind to PPAR by serving as selective PPAR modulators. Our data point to activation of PPAR as a novel mechanism of gene regulation by SCFA in the colon.
Short-chain fatty acids stimulate angiopoietin-like 4 synthesis in human colon adenocarcinoma cells by activating peroxisome proliferator-activated receptor γ.
Sex, Age, Specimen part
View SamplesAngiopoietin-like protein 4 (ANGPTL4, also referred to as Fiaf) has been proposed as a circulating mediator between the gut microbiota and fat storage in adipose tissue. Very little is known about the mechanisms of regulation of ANGPTL4 in the colon. Here we show that transcription and subsequent secretion of ANGPTL4 in human T84 and HT-29 colonocytes is highly induced by physiological concentrations of products of bacterial fermentation, the short-chain fatty acids. Short-chain fatty acids induce ANGPTL4 by activating the nuclear receptor PPAR, as shown by microarray, transactivation assays, coactivator peptide recruitment assay, and use of PPAR antagonist. At concentrations required for PPAR activation and ANGPTL4 induction in colonocytes, SCFA do not stimulate PPAR in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPAR modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modelling. It can be concluded that 1) SCFA potently stimulate ANGPTL4 synthesis in human colonocytes, and 2) SCFA transactivate and bind to PPAR by serving as selective PPAR modulators. Our data point to activation of PPAR as a novel mechanism of gene regulation by SCFA in the colon.
Short-chain fatty acids stimulate angiopoietin-like 4 synthesis in human colon adenocarcinoma cells by activating peroxisome proliferator-activated receptor γ.
Specimen part, Cell line, Treatment
View SamplesAlmost a quarter of pediatric patients with Acute Lymphoblastic Leukemia (ALL) suffer from relapses. The biological mechanisms underlying therapy response and development of relapses have remained unclear. In an attempt to better understand this phenomenon, we have analyzed 41 matched diagnosis relapse pairs of ALL patients using genomewide expression arrays (82 arrays) on purified leukemic cells. In roughly half of the patients very few differences between diagnosis and relapse samples were found (stable group), suggesting that mostly extra-leukemic factors (e.g., drug distribution, drug metabolism, compliance) contributed to the relapse. Therefore, we focused our further analysis on 20 samples with clear differences in gene expression (skewed group), reasoning that these would allow us to better study the biological mechanisms underlying relapsed ALL. After finding the differences between diagnosis and relapse pairs in this group, we identified four major gene clusters corresponding to several pathways associated with changes in cell cycle, DNA replication, recombination and repair, as well as B cell developmental genes. We also identified cancer genes commonly associated with colon carcinomas and ubiquitination to be upregulated in relapsed ALL. Thus, about half of relapses are due to selection or emergence of a clone with deregulated expression of a genes involved in pathways that regulate B cell signaling, development, cell cycle, cellular division and replication.
Genome-wide expression analysis of paired diagnosis-relapse samples in ALL indicates involvement of pathways related to DNA replication, cell cycle and DNA repair, independent of immune phenotype.
Sex, Specimen part, Disease
View SamplesBackground and Purpose—Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. Methods—We determined expression levels with RNA sequencing. Applying a multivariate negative binomial model, we identified genes that were differentially expressed between 44 aneurysms and 16 control arteries, and between 22 ruptured and 21 unruptured aneurysms. The differential expression of 8 relevant and highly significant genes was validated using digital polymerase chain reaction. Pathway analysis was used to identify enriched pathways. We also analyzed genes with an extreme pattern of differential expression: only expressed in 1 condition without any expression in the other. Results—We found 229 differentially expressed genes in aneurysms versus controls and 1489 in ruptured versus unruptured aneurysms. The differential expression of all 8 genes selected for digital polymerase chain reaction validation was confirmed. Extracellular matrix pathways were enriched in aneurysms versus controls, whereas pathways involved in immune response and the lysosome pathway were enriched in ruptured versus unruptured aneurysms. Immunoglobulin genes were expressed in aneurysms, but showed no expression in controls. Conclusions—For rupture of intracranial aneurysms, we identified the lysosome pathway as a new pathway and found further evidence for the role of the immune response. Our results also point toward a role for immunoglobulins in the pathogenesis of aneurysms. Immune-modifying drugs are, therefore, interesting candidate treatment strategies in the prevention of aneurysm development and rupture. Overall design: RNA sequencing of 44 intracranial aneurysm samples (including 21 unruptured, 22 ruptured and 1 undetermined) and 16 control samples of the intracranial cortical artery
RNA Sequencing Analysis of Intracranial Aneurysm Walls Reveals Involvement of Lysosomes and Immunoglobulins in Rupture.
Sex, Age, Subject
View SamplesColon cancer is a major cause of cancer deaths in Western countries and is associated with diets high in red meat. Heme, the iron-porphyrin pigment of red meat, induces cytotoxicity of gut contents which injures surface cells leading to compensatory hyperproliferation of crypt cells. This hyperproliferation results in epithelial hyperplasia which increases the risk of colon cancer. In humans, a high red-meat diet increases Bacteroides spp in feces. Therefore, we simultaneously investigated the effects of dietary heme on colonic microbiota and on the host mucosa of mice. Whole genome microarrays showed that heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. Using 16S rRNA phylogenetic microarrays, we investigated whether bacteria play a role in this changed signaling. Heme increased Bacteroidetes and decreased Firmicutes in colonic contents. This shift was most likely caused by a selective susceptibility of Gram-positive bacteria to heme cytotoxic fecal water, which is not observed for Gram-negative bacteria, allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria most probably increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There was no functional change in the sensing of the bacteria by the mucosa, as changes in inflammation pathways and Toll- like receptor signaling were not detected. This unaltered host-microbe cross-talk indicates that the changes in microbiota did not play a causal role in the observed hyperproliferation and hyperplasia.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part
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