Exposure to high levels of arsenic in drinking water is associated with several types of cancers including lung, bladder and skin, as well as vascular disease and diabetes. Drinking water standards are based primarily on epidemiology and extrapolation from higher dose experiments, rather than measurements of phenotypic changes associated with chronic exposure to levels of arsenic similar to the current standard of 10ppb, and little is known about the difference between arsenic in food as opposed to arsenic in water. Measurement of phenotypic changes at low doses may be confounded by the effect of laboratory diet, in part because of trace amounts of arsenic in standard laboratory chows, but also because of broad metabolic changes in response to the chow itself. Finally, this series contrasts 8hr, 1mg/kg injected arsenic with the various chronic exposures, and also contrasts the acute effects of arsenic, dexamethasone or their combination. Male C57BL/6 mice were fed on two commercially available laboratory diets (LRD-5001 and AIN-76A) were chronically exposed, through drinking water or food, to environmentally relevant concentrations of sodium arsenite, or acutely exposed to dexamethasone.
Laboratory diet profoundly alters gene expression and confounds genomic analysis in mouse liver and lung.
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View SamplesExposure to high levels of arsenic in drinking water is associated with several types of cancers including lung, bladder and skin, as well as vascular disease and diabetes. Drinking water standards are based primarily on epidemiology and extrapolation from higher dose experiments, rather than measurements of phenotypic changes associated with chronic exposure to levels of arsenic similar to the current standard of 10ppb, and little is known about the difference between arsenic in food as opposed to arsenic in water. Measurement of phenotypic changes at low doses may be confounded by the effect of laboratory diet, in part because of trace amounts of arsenic in standard laboratory chows, but also because of broad metabolic changes in response to the chow itself. Finally, this series contrasts 8hr, 1mg/kg injected arsenic with the various chronic exposures, and also contrasts the acute effects of arsenic, dexamethasone or their combination. Male C57BL/6 mice were fed on two commercially available laboratory diets (LRD-5001 and AIN-76A) were chronically exposed, through drinking water or food, to environmentally relevant concentrations of sodium arsenite, or acutely exposed to dexamethasone.
Chronic exposure to arsenic in the drinking water alters the expression of immune response genes in mouse lung.
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View SamplesEpithelial organs including the lung are known to possess regenerative abilities through activation of endogenous stem cell populations but the molecular pathways regulating stem cell expansion and regeneration are not well understood. Here we show that Gata6 regulates the temporal appearance and number of bronchioalveolar stem cells (BASCs) in the lung leading to the precocious appearance of BASCs and concurrent loss in epithelial differentiation in Gata6 null lung epithelium. This expansion of BASCs is the result of a dramatic increase in canonical Wnt signaling in lung epithelium upon loss of Gata6. Expression of the non-canonical Wnt receptor Fzd2 is down-regulated in Gata6 mutants and increased Fzd2 or decreased -catenin expression rescues, in part, the lung epithelial defects in Gata6 mutants. During lung epithelial regeneration, we show that canonical Wnt signaling is activated in the niche containing BASCs and forced activation of Wnt signaling leads to a dramatic increase in BASC numbers. Moreover, Gata6 is required for proper lung epithelial regeneration and postnatal loss of Gata6 leads to increased BASC expansion and decreased differentiation. Together, these data demonstrate that Gata6 regulated Wnt signaling controls the balance between stem/progenitor expansion and epithelial differentiation required for both lung development and regeneration.
A Gata6-Wnt pathway required for epithelial stem cell development and airway regeneration.
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View SamplesInteraction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them.
Spatial mapping of thymic stromal microenvironments reveals unique features influencing T lymphoid differentiation.
Specimen part
View SamplesAs4.1 cells are a renin-expressing cell line commonly used to study the molecular regulation of the mouse renin gene. In the present study, the global gene expression profile was assessed in these cells under control conditions (VEHICLE) and after treatment with interleukin (IL) or hydrogen peroxide (HP), both of which negatively regulate mouse renin gene expression.
Regulation of renin gene expression by oxidative stress.
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View Samplesexpression analysis from a genetically engineered mouse model of osteosarcoma
Conditional mouse osteosarcoma, dependent on p53 loss and potentiated by loss of Rb, mimics the human disease.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
The role of hypoxia in 2-butoxyethanol-induced hemangiosarcoma.
Specimen part, Treatment, Time
View SamplesMice were treated with either 100mg/kg baclofen or 0.5% methylcellulose alone by oral gavage for 1 or 5 days.
The role of hypoxia in 2-butoxyethanol-induced hemangiosarcoma.
Specimen part, Treatment, Time
View SamplesMice were dosed with 2-BE (900mg/kg) or vehicle by oral gavage and sacrificied either after 4 hours of a single dose or after 7 days of daily dosing.
The role of hypoxia in 2-butoxyethanol-induced hemangiosarcoma.
Specimen part, Treatment, Time
View Samples