Canonical Wnt signalling regulates the self-renewal of most if not all stem cell systems. In the blood system, the role of Wnt signalling has been subject of much debate, with positive and negative roles of Wnt signalling proposed for hematopoietic stem cells (HSC). As we have shown previously, this controversy can be largely explained by the effects of different dosages of Wnt signalling. What remained unclear however, was why high Wnt signals would lead to loss of reconstituting capacity. To better understand this phenomenon, we have taken advantage of a series of hypomorphic mutant Apc alleles resulting in a broad range of Wnt dosages in HSCs, purified those HSCs and performed whole genome gene expression analyses. Gene expression profiling and functional studies show that HSCs with APC mutations lead to high Wnt levels , enhanced differentiation and diminished proliferation, but have no effect on apoptosis, collectively leading to loss of stemness. Thus, we provide mechanistic insight into the role of APC mutations and Wnt signalling in HSC biology. As Wnt signals are explored in various in vivo and ex vivo expansion protocols for HSCs, our findings also have clinical ramifications.
High Levels of Canonical Wnt Signaling Lead to Loss of Stemness and Increased Differentiation in Hematopoietic Stem Cells.
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View SamplesThe supraoptic nucleus (SON) of the hypothalamus is an important integrative brain structure that co-ordinates responses to perturbations in water balance and regulates maternal physiology through the release of the neuropeptide hormones vasopressin and oxytocin into the circulation. Both dehydration and lactation evoke a dramatic morphological remodelling of the SON, a process known as function-related plasticity. We hypothesise that some of the changes seen in SON remodelling are mediated by differential gene expression, and have thus used microarrays to document global changes in transcript abundance that accompany chronic dehydration in female rats, and in lactation. In situ hydridisation analysis has confirmed the differential expression of 3 of these genes, namely Tumour necrosis factor induced protein 6, Gonadotrophin inducible transcription factor 1 and Ornithine decarboxylase antizyme inhibitor 1. Comparison of differential gene expression patterns in male and female rats subjected to dehydration and in lactating rats has enabled the identification of common elements that are significantly enriched in gene classes with particular functions. Two of these are related to the requirement for increased protein synthesis and hormone delivery in the physiologically stimulated SON (translation initiation factor activity and endoplasmic reticulum-Golgi intermediate compartment respectively), whilst others are consistent with concept of SON morphological plasticity (collagen fibril organisation, extracellular matrix organization and biogenesis, extracellular structure organization and biogenesis and homophilic cell adhesion). We suggest that the genes co-ordinately regulated in the SON as a consequence of dehydration and lactation form a network that mediates the plastic processes operational in the physiologically activated SON.
Transcriptomic analysis of the osmotic and reproductive remodeling of the female rat supraoptic nucleus.
Sex, Specimen part, Treatment
View SamplesInterferon (IFN) is a unique type I IFN that is not induced by pattern-recognition response elements. IFN is constitutively expressed in mucosal tissues including the female genital mucosa. We show here that IFN induces an antiviral state in human macrophages that blocks HIV-1 replication.
IFN-<b>ε</b> protects primary macrophages against HIV infection.
Specimen part, Treatment, Time
View SamplesA previously predictive CEBPA double mutant (CEBPAdm) signature was hampered by the recently reported CEBPA silenced AML cases that carry a similar gene expression profile (GEP). Two independent AML cohorts were used to train and evaluate the predictive value of the CEBPAdm signature in terms of sensitivity and specificity. A predictive signature was created, containing 25-probe sets by using a logistic regression model with Lasso regularization, which selects discriminative probe sets between the classes, CEBPAdm and all other AML cases, CEBPA wild type (CEBPAwt) and CEBPA single mutant (CEBPAsm). Subsequently, a classifier was trained on the entire HOVON-SAKK cohort based on a two-class approach; CEBPAdm versus all other cases (CEBPAwt and CEBPAsm). This trained classifier subsequently classified 16 candidate CEBPAdm cases in the AMLSG-cohort out of 154 AML cases. This approach showed perfect sensitivity and specificity (both 100%). In addition, we have performed a classification between CEBPAdm ,CEBPAsm, and CEBPAwt to infer if we were able to accurately classify CEBPAsm cases. We observed that all CEBPAsm cases were classified as CEBPAwt, thus CEBPAsm cases do not have a consistent gene expression pattern and are different from the CEBPAdm group.
Prognostic impact, concurrent genetic mutations, and gene expression features of AML with CEBPA mutations in a cohort of 1182 cytogenetically normal AML patients: further evidence for CEBPA double mutant AML as a distinctive disease entity.
No sample metadata fields
View SamplesGene Expression Profiling of a Mouse Xenograft Model of Triple-Negative Breast Cancer Brain Metastases With and Without Vorinostat Treatment.
Vorinostat inhibits brain metastatic colonization in a model of triple-negative breast cancer and induces DNA double-strand breaks.
Treatment
View SamplesCalcific aortic valve disease is the most common form of valvular heart disease in the Western World. Milder degrees of aortic valve calcification is called aortic sclerosis and severe calcification with impaired leaflet motion is called aortic stenosis.
MicroRNA-125b and chemokine CCL4 expression are associated with calcific aortic valve disease.
Specimen part, Disease, Disease stage
View SamplesDifferentially expressed genes along the paraxial mesoderm of 12 somite stage zebrafish embryos are identified
Spatiotemporal compartmentalization of key physiological processes during muscle precursor differentiation.
Specimen part
View SamplesWe previously isolated a subclone, MIN6 clone 4, from the parental MIN6 cells, that shows well-regulated insulin secretion in response to glucose, glybenclamide, and KCl, even after prolonged culture. To investigate the molecular mechanisms responsible for preserving GSIS in this subclone, we compared four groups of MIN6 cells: Pr-LP (parental MIN6, low passage number), Pr-HP (parental MIN6, high passage number), C4-LP (MIN6 clone 4, low passage number), and C4-HP (MIN6 clone 4, high passage number). Based on their capacity for GSIS, we designated the Pr-LP, C4-LP, and C4-HP cells as responder cells. In a DNA microarray analysis, we identified a group of genes with high expression in responder cells (responder genes), but extremely low expression in the Pr-HP cells.
Microarray analysis of novel candidate genes responsible for glucose-stimulated insulin secretion in mouse pancreatic β cell line MIN6.
Cell line
View SamplesAssessment of mRNA expression levels in fat biopsies from subcutaneous adipose tissue from unrelated individuals.
Galanin preproprotein is associated with elevated plasma triglycerides.
No sample metadata fields
View SamplesThe Drosophila midgut is an ideal model system to study molecular mechanisms that interfere with the intestinal stem cells’ (ISCs) ability to function in tissue homeostasis. Due to the lack of a combination of molecular markers suitable to isolate ISCs from aged intestines, it has been a major challenge to study endogenous molecular changes of ISCs during aging. Our FACS-based approach using the esg-GAL4, UAS-GFP fly line allowed the isolation of a cell population enriched for ISCs from young and old midguts by their small size, little granularity and low GFP intensity. The isolated ISCs were subsequently used for RNA sequencing to identify endogenous changes in the transcriptome of young versus old ISCs. Overall design: Cell populations enriched for ISCs isolated from young (6-8 days old) and old (59-65 days old) midguts were sorted. Cells from three different batches of young and old midguts were subjected to Next Generation Sequencing using Illumina Genome Analyzer IIx.
Nipped-A regulates intestinal stem cell proliferation in <i>Drosophila</i>.
Age, Specimen part, Subject
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