Hematopoietic stem cells (HSCs), which reside in bone marrow niches, are exposed to low levels of oxygen and follow an oxygen gradient throughout their differentiation. Hypoxia-inducible factors (HIFs) are the main factors regulating the cell response to oxygen variation. Recent studies using conditional knockout mouse models have unveiled a major role of HIF-1a in the maintenance of murine HSCs, however the role of HIF-2a is still unclear. Here, we show that knockdown of HIF-2a and to a much lower extent, HIF-1a impedes the long-term repopulating ability of human CD34+ umbilical cord blood derived cells. The defects observed in hematopoietic stem and progenitor cell (HSPC) function after HIF-2a knockdown was due to an increase in the production of reactive oxygen species (ROS), which increases the endoplasmic reticulum (ER) stress in HSPCs and triggers apoptosis by the activation of the unfolded-protein-response (UPR) pathway. Importantly, HIF-2a deregulation also resulted in a significant decrease of engraftment of human acute myeloid leukemia (AML) cells. Overall, our data demonstrates a key role of HIF-2a in the maintenance of human HSPCs and in the survival of primary AML cells.
HIF-2α protects human hematopoietic stem/progenitors and acute myeloid leukemic cells from apoptosis induced by endoplasmic reticulum stress.
Specimen part
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Long-term exposure of MCF-12A normal human breast epithelial cells to ethanol induces epithelial mesenchymal transition and oncogenic features.
Specimen part, Cell line
View SamplesAlcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohol's oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. Here, we use the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0-2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4 wk incubation, cells were also tested for anchorage independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immuno-cytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype and mRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage independence in normal breast epithelial cells.
Long-term exposure of MCF-12A normal human breast epithelial cells to ethanol induces epithelial mesenchymal transition and oncogenic features.
Specimen part, Cell line
View SamplesAlcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohol's oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. Here, we use the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0-2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4 wk incubation, cells were also tested for anchorage independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immuno-cytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype and mRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage independence in normal breast epithelial cells.
Long-term exposure of MCF-12A normal human breast epithelial cells to ethanol induces epithelial mesenchymal transition and oncogenic features.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Long-term exposure of MCF-7 breast cancer cells to ethanol stimulates oncogenic features.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
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View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 Neural Precursor cells
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
No sample metadata fields
View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 undifferentiated hES cells
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
No sample metadata fields
View SamplesAnalysis of genes that were differentially expressed in mutant VUB03_DM1 as compared to controls VUB01 and SA01 Mesodermal Precursors Cells.
Mutant human embryonic stem cells reveal neurite and synapse formation defects in type 1 myotonic dystrophy.
No sample metadata fields
View SamplesHigh environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28C) or thermoneutral conditions (15C) with pair-feeding for four days. After synchronization growth of dominant follicles was monitored by ultrasonogrphy, and 21 hrs after an induced pre-ovulatory LH surge antral steroid hormones and granulosa cell-specific gene expression profiles were determined. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system.
Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles.
Specimen part
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