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GSE79495
Mus musculus
15 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
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.
Publication Title
High Levels of Canonical Wnt Signaling Lead to Loss of Stemness and Increased Differentiation in Hematopoietic Stem Cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 49 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
REACH, the EU regulation on chemicals and their safe use, stipulates that about 30,000 chemical substances are to be assessed on their possible risks. Toxicological evaluation of these compounds will at least partly be based on animal testing. Especially reproductive toxicity is one of the most complicated, time-consuming and expensive in vivo endpoints. Introducing microarray-based endpoints can potentially refine in vivo toxicity testing. If compounds from a distinct chemical class induce reproducible gene-expression responses with a recognizable overlap, these gene-expression signatures may indicate intrinsic features of certain compounds, including toxicity. In the present study, we investigated this theory for the reproductive toxicity of phthalates.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Age, Specimen part, Compound
View Samples- Homo sapiens
- 28 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Subjects with incidental Lewy body disease (iLBD) may represent the premotor stage of Parkinsons disease (PD). To identify molecular mechanisms underlying neuronal dysfunction and alpha--synuclein pathology in the premotor phase of PD, we investigated the transcriptome of post-mortem substantia nigra (SN) of iLBD, PD donors and age-matched controls with Braak alpha--synuclein stage ranging from 0-6. In Braak alpha--synuclein stages 1 and 2, we observed deregulation of pathways linked to axonal degeneration, unfolded protein response (UPR), immune response and endocytosis, including axonal guidance signaling, protein kinase A signaling, mTOR signaling, EIF2 signaling and clathrin-mediated endocytosis. In Braak stages 3 and 4, we observed a deregulation in pathways involved in protein translation and cell survival, including mTOR and EIF2 signaling. In Braak stages 5 and 6, we observed deregulation of pathways such as dopaminergic signaling, axonal guidance signaling and thrombin signaling. Throughout the progression of PD pathology, we observed a deregulation of mTOR, EIF2 and regulation of eIF4 and p70S6K signaling in the SN. This implicates that molecular mechanisms related to UPR, axonal dysfunction, endocytosis and immune response are an early event in PD pathology, and may hold the key to altering the disease progression in PD.
Publication Title
Evidence for Immune Response, Axonal Dysfunction and Reduced Endocytosis in the Substantia Nigra in Early Stage Parkinson's Disease.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Pseudomonas aeruginosa
- 8 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Cell-surface signaling is a sophisticated regulatory mechanism used by gram-negative bacteria to sense signals from outside the cell and transmit them into the cytoplasm. This regulatory system consists of an outer membrane-localized TonB-dependent receptor (TonB-dependent transducer), a cytoplasmic membrane-localized anti-sigma factor and an extracytoplasmic function (ECF) sigma factor. By microarray analysis we have identified the regulons of four novel P. aeruginosa signaling systems. For that, the ECF sigmas PA0149, PA2050, PA2093 and PA4896 have been overexpressed in P. aeruginosa and their target gene candidates have been identified using DNA microarray.
Publication Title
No associated publication
Sample Metadata Fields
No sample metadata fields
View Samples- Pseudomonas aeruginosa
- 4 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Next to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS senses signals from outside the cell and transmits them into the cytoplasm. It consists of a TonB-dependent outer membrane receptor, a cytoplasmic membrane-localized sigma factor regulator (or anti-sigma factor), and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa ECF sigma factors are involved in the regulation of iron uptake, we have identified a novel ECF sigma factor (PA0675) involved in the regulation of virulence. By microarray analysis of cells overexpressing PA0675 from the pMUM3 plasmid we have identified the genes regulated by this sigma factor.
Publication Title
A Novel extracytoplasmic function (ECF) sigma factor regulates virulence in Pseudomonas aeruginosa.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 76 Downloadable Samples
- Affymetrix HT HG-U133+ PM Array Plate (hthgu133pluspm)
Description
Background
Publication Title
Loss of photoreceptorness and gain of genomic alterations in retinoblastoma reveal tumor progression.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 19 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
In high income countries 90% of the patients achieve complete remission after induction chemotherapy. However, 30-40% of these patients suffer from relapse. These patients face a dismal prognosis, as the majority (>60%) of relapsed patients die within 5 years. As a result, outcome for pediatric acute myeloid leukemia (AML) patients remains poor and has stabilized over the past 15 years. To prevent or better treat relapse of AML is the best option to improve outcome. Despite patient specific differences, most patients do respond to initial therapy. This suggests that at relapse, mechanisms are active that cause the altered response to chemotherapy. Detailed understanding of mechanisms that cause relapse remain largely elusive. To gain insight in the molecular pathways that characterize relapsed AML, we performed genome wide gene expression profiling on paired initial diagnosis and relapsed AML samples of 23 pediatric AML patients. We used pathway analysis to find which molecular pathways are involved in altered gene expression between diagnosis and relapse samples of individual AML patients.
Publication Title
Gene expression profiles associated with pediatric relapsed AML.
Sample Metadata Fields
Disease
View Samples- Sus scrofa
- 16 Downloadable Samples
- Affymetrix Porcine Genome Array (porcine)
Description
The molecular mechanism underlying cardiac remodeling following myocardial infarction have been incompletely understood. Until now, most studies have been performed in rodents. We studied cardiac remodeling in the physiologically more relevant animal model, the swine.
Publication Title
Left ventricular remodeling in swine after myocardial infarction: a transcriptional genomics approach.
Sample Metadata Fields
Sex
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix HT HG-U133+ PM Array Plate (hthgu133pluspm)
Description
In order to identify the gene targets of frequently altered chromosomal regions in retinoblastoma, a meta-analysis of genome-wide copy number alterations studies on primary retinoblastoma tissue and retinoblastoma cell lines was performed. Published studies were complemented by copy number and gene expression analysis on primary and cell line samples of retinoblastoma. This dataset includes the gene expression data of the retinoblastoma cell lines
Publication Title
A Meta-Analysis of Retinoblastoma Copy Numbers Refines the List of Possible Driver Genes Involved in Tumor Progression.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 8 Downloadable Samples
- VUmc/Illumina Sentrix MouseRef8 v1.1
Description
Diabetes mellitus [DM], with its burden of premature morbidity and mortality, represents one of the major threats to human health in the 21st century (Zimmet 2001). Accelerated atherosclerosis affecting arteries that supply the heart, brain and lower extremities is responsible for an increased risk of acute ischemic events. DM is also associated with microvascular disease, which is a leading cause of blindness, renal failure and debilitating neuropathies. Endothelial dysfunction, increased vascular permeability and microvascular cell loss by apoptosis are all hallmarks of diabetic microangiopathy. Diabetic patients not only incur cardiovascular complications more frequently, but also experience worse outcomes due to attenuation of vascular repair mechanisms. This impairment includes quantitative and qualitative abnormalities of bone marrow [BM]-derived progenitor cells (Emanueli 2002&2004; Loomans 2004; Krankel 2005; Fadini 2006). The mechanisms underlying BM dysfunction remain however enigmatic, especially when considering the privileged location that protects stem cells [SC] and progenitor cells [PC] of the marrow from external insults (Kopp 2008 and Kiel 2008). BM endothelial cells [EC] are instead an obvious target of DM, because they are directly exposed to blood glucose and incapable to regulate glucose influx. Strangely enough, little is known about the impact of diabetes on BM microvasculature. We hypothesize that damage induced by DM might start at the microvascular level, in a similar fashion to microangiopathy, which occurs in kidney, retina, heart and brain. We also propose that enduring microvascular cell loss might result in marrow hypo-perfusion and destabilization of SC homeostasis.
Publication Title
No associated publication
Sample Metadata Fields
No sample metadata fields
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