Diabetic embryopathy can affect any developing organ system, although cardiovascular malformations, neural tube defects and caudal dysgenesis syndrome are the most prominent congenital malformations. We hypothesize that the metabolic imbalance occurring in diabetic pregnancy de-regulates tissue specific gene expression programs in the developing embryo. In order to identify genes whose expression is affected by maternal diabetes, we analyzed gene expression profiles of diabetes-exposed mouse embryos by using Affymetrix microarrays. We identified 129 genes with altered expression levels; 21 genes had increased and 108 genes had decreased expression levels in diabetes-exposed embryos relative to controls. A substantial fraction of these genes (35) are essential for normal embryonic development as shown by functional studies in mouse models. The largest fraction of diabetes-affected genes was in transcription factor and DNA-binding/chromatin remodeling functional categories (19%), which directly affect transcription. These findings suggest that transcriptional regulation in the developing embryos is perturbed by maternal diabetes and that transcriptional regulation plays a major role in the responses of embryos to intrauterine exposure to diabetic conditions. Interestingly, we found the expression of hypoxia-inducible factor 1 (Hif1) deregulated in the embryos exposed to the conditions of maternal diabetes. Since hypoxic stress is associated with the complications of diabetic pregnancy, we performed a post-hoc analysis of our microarray data with a specific focus on known HIF1 target genes. Of 39 genes detected in our microarrays, the expression changes of 22 genes (20 were increased and two genes were decreased in diabetes-exposed embryos) were statistically significant. These results indicate that HIF1-regulated pathways are affected in diabetes-exposed embryos. These results strongly suggest that de-regulation of hypoxia/HIF1 activated pathways could be the one of the key molecular events associated with the exposure to the teratogenic intrauterine environment of a diabetic mother.
Maternal diabetes alters transcriptional programs in the developing embryo.
Specimen part
View SamplesExposure to maternal diabetes during pregnancy alters transcriptional profiles in the developing embryo. The enrichment, within the set of de-regulated genes, of those encoding transcriptional regulatory molecules provides support for the hypothesis that maternal diabetes affects specific developmental programs.
Maternal diabetes alters transcriptional programs in the developing embryo.
Specimen part, Disease, Disease stage
View SamplesAIMS/HYPOTHESIS: Pregnancies complicated by diabetes have a higher risk of adverse outcomes for mothers and children, including predisposition to disease later in life, such as metabolic syndrome and hypertension. We hypothesized that adverse outcomes from diabetic pregnancies may be linked to compromised placental function. Our goal in this study was to identify cellular and molecular abnormalities in diabetic placenta.
Altered gene expression and spongiotrophoblast differentiation in placenta from a mouse model of diabetes in pregnancy.
Sex, Specimen part
View SamplesTumor hypoxia levels range from mild to severe and have different biological and therapeutical consequences, but are not easily assessable in patients. We present a method based on diagnostic dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) that visualizes a continuous range of hypoxia levels in tumors of cervical cancer patients. Hypoxia images were generated using an established approach based on pixel-wise combination of the DCE-MRI parameters e and Ktrans, reflecting oxygen consumption and supply, respectively. An algorithm to retrieve hypoxia levels from the images was developed and validated in 28 xenograft tumors, by comparing the MRI-defined levels with hypoxia levels derived from pimonidazole stained histological sections. We further established an indicator of hypoxia levels in patient tumors based on expression of nine hypoxia responsive genes. A strong correlation was found between these indicator values and the MRI-defined hypoxia levels in 63 patients. Chemoradiotherapy outcome of 74 patients was most strongly predicted by moderate hypoxia levels, whereas more severe or milder levels were less predictive. By combining gene expression profiles and MRI-defined hypoxia levels in cancer hallmark analysis, we identified a distribution of levels associated with each hallmark; oxidative phosphorylation and G2/M checkpoint were associated with moderate hypoxia, and epithelial-to-mesenchymal transition and inflammatory responses with significantly more severe levels. At the mildest levels, interferon response hallmarks, together with stabilization of HIF1A protein by immunohistochemistry, appearred significant. Thus, our method visualizes the distribution of hypoxia levels within patient tumors and has potential to distinguish levels of different prognostic and biological significance.
MRI Distinguishes Tumor Hypoxia Levels of Different Prognostic and Biological Significance in Cervical Cancer.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells.
Specimen part, Subject
View SamplesMolecular mechanisms underlying terminal differentiation of B-cells into plasma cells are major determinants of adaptive immunity but remain only partially understood. Here, we present the transcriptional and epigenomic landscapes of cell subsets arising from activation of human naive B-cells and differentiation into plasmablasts. Cell proliferation of activated B cells was linked to a slight decrease in DNA methylation levels but followed by a committal step in which an S-phase-synchronized differentiation switch was associated with an extensive DNA demethylation and local acquisition of 5-hydroxymethylcytosine at enhancers and genes related to plasma cell identity.
Cell-Cycle-Dependent Reconfiguration of the DNA Methylome during Terminal Differentiation of Human B Cells into Plasma Cells.
No sample metadata fields
View Samplesaffy_seed_kinetic_wheat - affy_seed_kinetic_wheat - Study gene expression during the grain developmental -The aim of the study is to identify the genes that are differentially expressed during the grain development in wheat.-Study gene expression during the grain developmental Sample at 100 degree days, year 2004 and 2006 Sample at 200 degree days, year 2004 and 2006 Sample at 250 degree days, year 2004 and 2006 Sample at 300 degree days, year 2004 and 2006 Sample at 400 degree days, year 2004 and 2006
RNA-seq in grain unveils fate of neo- and paleopolyploidization events in bread wheat (Triticum aestivum L.).
No sample metadata fields
View SamplesBackground: Information on the carcinogenic potential of chemicals is only availably for High Production Volume products. There is however, a pressing need for alternative methods allowing for the chronic toxicity of substances, including carcinogenicity, to be detected earlier and more reliably. Here we applied advanced genomics to a cellular transformation assay to identify gene signatures useful for the prediction of risk for carcinogenicity. Methods: Genome wide gene expression analysis and qRT-PCR were applied to untransformed and transformed Balb/c 3T3 cells that exposed to 2, 4-diaminotoluene (DAT), benzo(a)pyrene (BaP), 2-Acetylaminoflourene (AAF) and 3-methycholanthrene (MCA) for 24h and 120h, at different concentrations, respectively. Furthermore, various bioinformatics tools were used to identify gene signatures predicting for the carcinogenic risk. Results: Bioinformatics analysis revealed distinct datasets for the individual chemicals tested while the number of significantly regulated genes increased with ascending treatment concentration of the cell cultures. Filtering of the data revealed a common gene signature that comprised of 13 genes whose regulation in cancer tissue has already been established. Strikingly, this gene signature was already identified prior to cell transformation therefore confirming the predictive power of this gene signature in identifying carcinogenic risks of chemicals. Comparison of fold changes determined by microarray analysis and qRT-PCR were in good agreement. Conclusion: Our data describes selective and commonly regulated carcinogenic pathways observed in an easy to use in vitro carcinogenicity assay. Here we defined a set of genes which can serve as a simply assay to predict the risk for carcinogenicity by use of an alternative in vitro testing strategy.
Toxicogenomics applied to in vitro carcinogenicity testing with Balb/c 3T3 cells revealed a gene signature predictive of chemical carcinogens.
Cell line, Treatment, Time
View SamplesApproximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes.
Determination of molecular markers for BRCA1 and BRCA2 heterozygosity using gene expression profiling.
Specimen part
View SamplesIn zebrafish, parental exposure to ionizing radiation has been associated with effects in offspring, such as increased DNA damage and reactive oxygen species. Here, we assessed short (one month) and long term effects (one year) on gene expression in embryonic offspring (5.5 hours post fertilization) from zebrafish exposed during gametogenesis to gamma radiation (8.7 or 53 mGy/h for 27 days, total dose 5.2 or 31 Gy). One month after exposure, a global change in gene expression was observed in offspring from the 53 mGy/h group, followed by embryonic death at late gastrula, whereas offspring from the 8.7 mGy/h group was unaffected. One year after exposure, embryos from the 8.7 mGy/h group exhibited 2455(61.8% downregulated) differentially expressed genes. Overlaps in differentially expressed genes and enriched biological pathways were evident between the 53 mGy/h group one month and 8.7 mGy/h one year after exposure, which could be linked to effects in adults and offspring, such as DNA damage and lipid peroxidation. Interestingly, pathways between the two groups were oppositely regulated. Our results indicate latent effects following ionizing radiation exposure in parents that can be transmitted to offspring and warrants monitoring effects over subsequent generations. Overall design: One month after exposure, mRNA from F1 5.5 hpf embryos from parents exposed to 8.7 and 53 mGy/h gamma radiation during gametogenesis was sequenced on the Illumina 4000 platform with three replicas per treatment. One year after exposure, mRNA from F1 embryos from the same parents exposed to 8.7 mGy/h was sequenced with three biological replicates. In both cases, F1 embryos from non-exposed parents were used as control and mRNA sequenced in triplicates, taken at the same time points as the exposed samples.
Parental exposure to gamma radiation causes progressively altered transcriptomes linked to adverse effects in zebrafish offspring.
No sample metadata fields
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