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GSE106073
Homo sapiens
12 Downloadable Samples
Illumina HumanHT-12 V4.0 expression beadchip
Description
Converting epithelial into mesenchymal cells through epithelial-mesenchymal transition (EMT) requires massive changes in gene expression. How this is brought about is currently not clear. Here we examined the impact of the EMT master regulator SNAIL1 on the FOXA family of transcription factors which are distinguished by their particular competence to induce chromatin reorganization for the activation of transcriptional enhancer elements. We show that the expression of SNAIL1 and FOXA genes is anti-correlated in transcriptomes of colorectal tumors and cell lines. In two cellular EMT models, ectopically expressed Snail1 downregulates FOXA factors and directly represses FOXA1. To elucidate how FOXA factors contribute to the control of epithelial gene expression, we determined by ChIP-seq data analysis FOXA chromosomal distribution in relation to chromatin structural features characterizing distinct states of transcriptional activity. This revealed a preferential localization of FOXA1 and FOXA2 to transcriptional enhancers at signature genes that distinguish epithelial from mesenchymal colon tumors. To validate the significance of this association, we investigated the impact of FOXA factors on structure and function of transcriptional enhancers at the epithelial genes CDH1, CDX2 and EPHB3. Expression of dominant negative FOXA2 led to chromatin condensation at these enhancer elements. Site- directed mutagenesis of FOXA binding sites in reporter gene constructs and by genome- editing in situ impaired enhancer activity and completely abolished the active chromatin state of the EPHB3 enhancer. Conversely, expression of FOXA factors in cells with inactive CDX2 and EPHB3 enhancers led to chromatin opening and de novo deposition of the H3K4me1 and H3K27ac marks. These findings establish the pioneer function of FOXA factors at enhancer regions of epithelial genes and demonstrate their essential role in maintaining enhancer structure and function. Thus, by repressing FOXA family members, Snail1 targets transcription factors at strategically important positions in gene-regulatory hierarchies which may facilitate transcriptional reprogramming during EMT.
Publication Title
SNAIL1-mediated downregulation of FOXA proteins facilitates the inactivation of transcriptional enhancer elements at key epithelial genes in colorectal cancer cells.
Sample Metadata Fields
Cell line, Treatment
View Samples- Mus musculus
- 27 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Acetaminophen (APAP), a widely used analgesic and antipyretic that is considered to be relatively safe at recommended doses, is the leading cause of drug-induced liver failure in the United States. 3-Hydroxyacetanilide (AMAP), a regioisomer of acetaminophen is useful as a comparative tool for studying APAP-induced toxicity since it is non-toxic relative to APAP. TGF-alpha transgenic mouse hepatocytes were treated with both isomers to investigate mitogen-activated protein kinase cascades in order to differentiate their toxicological outcomes. Mitogen-activated protein kinase (MAPK) cascade expression and activation were measured using microarray and Bioplex technologies, respectively. APAP treatment led to c-Jun N-terminal kinase (JNK) activation, whereas AMAP treatment led to the activation of extracellular-signal-regulated protein kinase (ERK). The microarray data suggested APAP treatment may upregulate gene expression at multiple levels of the JNK cascade including a JNK-related scaffold protein. Expression data was related to phosphoprotein levels using the Bioplex system. APAP treatment led to a significant activation of JNK compared to its regioisomer. In contrast, microarray analysis of AMAP showed a slight upregulation of ERK gene activity. Furthermore, Bioplex data showed AMAP treatment led to significant ERK phosphorylation compared to APAP. Cell viability assays confirmed that APAP-induced activation of JNK was related to higher rates of cell death, whereas activation of ERK by AMAP may be cytoprotective.
Publication Title
Differential regulation of mitogen-activated protein kinase pathways by acetaminophen and its nonhepatotoxic regioisomer 3'-hydroxyacetanilide in TAMH cells.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Critically ill preterm infants experience multiple stressors while hospitalized. Morphine is commonly prescribed to ameliorate their pain and stress. We hypothesized that neonatal stress will have a dose-dependent effect on hippocampal gene expression, and these effects will be altered by morphine treatment. Male C57BL/6 mice were exposed to 5 treatment conditions between postnatal day 5 and 9: 1) Control, 2) mild stress + saline, 3) mild stress + morphine, 4) severe stress + saline and 5) severe stress + morphine. Hippocampal RNA was extracted and analyzed using Affymetrix Mouse Gene 1.0 ST Arrays. Single gene analysis and gene set analysis were used to compare groups with validation by qPCR. Stress resulted in enrichment of genes sets related to fear response, oxygen carrying capacity and NMDA receptor synthesis. Morphine downregulated gene sets related to immune function. Stress plus morphine resulted in enrichment of mitochondrial electron transport gene sets, and down-regulation of gene sets related to brain development and growth. We conclude that neonatal stress alone influences hippocampal gene expression, morphine alters a subset of stress-related changes in gene expression and influences other gene sets. Stress plus morphine show interaction effects not present with either stimulus alone. These changes may alter neurodevelopment.
Publication Title
Effects of neonatal stress and morphine on murine hippocampal gene expression.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Comparison of rosette leaves of two different RAP2.2 overexpressing lines with wild type leaves. The AP2/EREBP transcription factor RAP2.2 was shown to bind to a cis-acting motif within the phytoene synthase promoter from Arabidopsis. To investigate effects of increased RAP2.2 levels, two RAP2.2 overexpressing Arabidopsis thaliana (ecotype Wassilewskija) lines were generated: one line, nosr2, carried the nos promoter and showed a two-fold increase in RAP2.2 transcript level, the second line, cmr-5, carried four copies of the CaMV-35S enhancer and showed a 12-fold increase. However, neither weak nor strong increase in RAP2.2 transcript amounts had any effect on RAP2.2 protein levels as shown by Western blot analysis. The strong robustness of RAP2.2 protein levels towards transcriptional changes can be explained by specific protein degradation which includes SINAT2, an E3 ubiquitin ligase which was isolated using a two-hybrid approach. Accordingly, global gene expression analysis using both RAP2.2 overexpressing lines showed only minor transcriptional changes which are probably due to minor growth variation than to mechanisms involved in the down-regulation of RAP2.2 protein amounts.
Publication Title
Transcription factor RAP2.2 and its interacting partner SINAT2: stable elements in the carotenogenesis of Arabidopsis leaves.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Aim of the study was to characterize the transcriptional response of human primary renal proximal tubule epithelial cells (RPTEC) to low oxygen stress.
Publication Title
The histone demethylases JMJD1A and JMJD2B are transcriptional targets of hypoxia-inducible factor HIF.
Sample Metadata Fields
Sex, Age, Specimen part, Disease, Disease stage
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U95 Version 2 Array (hgu95av2)
Description
mRNA expression levels in synovial fibroblasts in 6 rheumatoid arthritis patients versus 6 osteoarthritis patients.
Publication Title
Constitutive upregulation of the transforming growth factor-beta pathway in rheumatoid arthritis synovial fibroblasts.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 248 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Craniosynostosis is a disease defined by premature fusion of one or more cranial sutures. The mechanistic pathology of isolated single-suture craniosynostosis is complex and while a number of genetic biomarkers and environmental predispositions have been identified, in many cases the causes remain controversial and inconclusive at best. After controlling for variables contributing to potential bias, FGF7, SFRP4, and VCAM1 emerged as potential genetic biomarkers for single-suture craniosynostosis due to their significantly large changes in gene expression compared to the control population. Furthermore, pathway analysis implicated focal adhesion and extracellular matrix (ECM)-receptor interaction as differentially regulated gene networks when comparing all cases of single-suture synostosis and controls. Lastly, overall gene expression was found to be highly conserved between coronal and metopic cases, as evidenced by the fact that WNT2 and IGFBP2 were the only differentially regulated genes identified in a direct comparison. These results not only confirm the roles of previously reported craniosynostosis-related targets but also introduce novel genetic biomarkers and pathways that may play critical roles in its pathogenesis.
Publication Title
Differential expression of extracellular matrix-mediated pathways in single-suture craniosynostosis.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 55 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Chlorpyrifos (CPF) is an organophosphorus (OP) insecticide that is still widely used despite statutory restrictions on home use. CPF is converted to chlorpyrifos oxon (CPO) by oxidative desulfuration in liver. Paraoxonase (PON1) polymorphisms affects the catalytic efficiency of the hydrolysis of OPs, including CPO. We used both wt (PON1+/+) and PON1 knockout (PON1-/-) mice and PON1-/- mice carrying transgenes encoding the human alloforms tgHuPON1Q192 and tgHuPON1R192 to gain insight into the mechanisms of neurotoxicity of CPO throughout postnatal development, and to ascertain the importance of the PON1Q192R polymorphism for protecting against developmental toxicity of CPO. Whole-genome microarrays were used to measure gene expression changes associated with chronic CPO exposure of developing (PND 4-21) PON1-/-, tgHuPON1Q192R transgenic and PON1+/+ mice.
Publication Title
Repeated developmental exposure of mice to chlorpyrifos oxon is associated with paraoxonase 1 (PON1)-modulated effects on cerebellar gene expression.
Sample Metadata Fields
Specimen part
View Samples- Danio rerio
- 30 Downloadable Samples
- Affymetrix Zebrafish Genome Array (zebrafish)
Description
Chemical exposures in fish have been linked to loss of olfaction leading to an inability to detect predators and prey and decreased survival. However, the mechanisms underlying olfactory neurotoxicity are not well characterized, especially in environmental exposures which involve chemical mixtures. We used zebrafish to characterize olfactory transcriptional responses by two model olfactory inhibitors, the pesticide chlorpyrifos (CPF) and mixtures of CPF with the neurotoxic metal copper (Cu).
Publication Title
Transcriptional biomarkers and mechanisms of copper-induced olfactory injury in zebrafish.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
We have previously found that overexpression of CHF1/Hey2 in the myocardium prevents the development of phenylephrine-induced hypertrophy. To determine the role of CHF1/Hey2 in pressure overload hypertrophy, we performed ascending aortic banding on wild type and transgenic mice overexpressing CHF1/Hey2 in the myocardium. We found that both wild type and transgenic mice developed increased ventricular weight to body weight ratios one week after aortic banding. Wild type mice also developed decreased fractional shortening after one week when compared to preoperative echocardiograms and sham operated controls. Transgenic mice, in comparison, demonstrated preserved fractional shortening. Histological examination of explanted heart tissue demonstrated extensive fibrosis in wild type hearts, but minimal fibrosis in transgenic hearts. TUNEL staining demonstrated increased apoptosis in the wild type hearts but not in the transgenic hearts. Exposure of cultured neonatal myocytes from wild type and transgenic animals to hydrogen peroxide, a potent inducer of apoptosis, demonstrated increased apoptosis in the wild type cells. Gene Set Analysis of microarray data from wild type and transgenic hearts one week after banding revealed suppression and activation of multiple pathways involving apoptosis, cell signaling and biosynthesis. These findings demonstrate that CHF1/Hey2 promotes physiological over pathological hypertrophy in pressure overload through suppression of apoptosis and global regulation of multiple transcriptional pathways.
Publication Title
CHF1/Hey2 promotes physiological hypertrophy in response to pressure overload through selective repression and activation of specific transcriptional pathways.
Sample Metadata Fields
No sample metadata fields
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