Escherichia coli exhibits diauxic growth in sugar mixtures due to CRP-mediated catabolite repression and inducer exclusion related to phosphotransferase system enzyme activity. Replacement of the native crp gene with a catabolite repression mutant (referred to as crp*) alleviates diauxic effects in E. coli and enables co-utilization of glucose and other sugars. While previous studies have examined the effects of expressing CRP* mutants on the expression of specific catabolic genes, little is known about the global transcriptional effects of CRP* expression.
Transcriptional effects of CRP* expression in Escherichia coli.
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View SamplesFOXE3 is a lens specific transcription factor that has been associated with anterior segment ocular dysgenesis. To determine the transcriptional target(s) of FOXE3 that are indispensable for the anterior segment development, we examined the transcriptome and the proteome of cells expressing truncated FOXE3 responsible for Peters anomaly identified through linkage-coupled next-generation whole exome sequencing. We found that DNAJB1, an autophagy-associated protein, was the only candidate exhibiting differential expression in both screens. We confirmed the candidacy of DNAJB1 through chromatin immunoprecipitation and luciferase assays while knockdown of DNAJB1 in human lens epithelial cells resulted in mitotic arrest. Subsequently, we targeted dnajb1a in zebrafish through injection of a splice-blocking morpholino. The dnajb1a morphants exhibited underdeveloped cataractous lenses with persistent apoptotic nuclei. In conclusion, we have identified DNAJB1 as a transcriptional target of FOXE3 in a novel pathway that is crucial for development of the anterior segment of the eye. Overall design: Human Embryonic Kidney (HEK293FT) cells were transfected with the expression vector (pT-RexTM-DEST30) harboring either the wild type or the mutant (C240*) FOXE3 ORF (open reading frame). The experimental design included a total of eight biological replicates of cells expressing the wild type and eight replicates of mutant FOXE3 along with eight non-transfected controls. Cells were harvested 24-hour post-transfection and subjected to total RNA isolation for the preparation of whole transcriptome next-generation sequencing libraries. Initially, we examined the quality of transcriptome libraries on a MiSeq genome analyzer. Subsequent to confirmation of the quality, all libraries were paired-end sequenced (2 x 100 bp) using Illumina TruSeq Cluster V3 flow cell at a concentration of 13.0 pM in two separate lanes (12 bar-coded mRNA pooled libraries in each lane) on a HiSeq 2000 genome analyzer.
FOXE3 contributes to Peters anomaly through transcriptional regulation of an autophagy-associated protein termed DNAJB1.
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View SamplesAstrocytes were purified from postnatal day 2 mouse cortices by immunopanning with HepaCAM. Inhibitors and DMSO were added on in-vitro day 2. HBEGF was depleted on the cell prep day and till in-vitro day 7. In-vitro day 2, 7 and 14 samples were collected on designed timepointed. Overall design: Three EGFR inhibitor samples and three relative DMSO control samples, three P53 inhibitor samples and three relative DMSO control samples, two HBEGF samples and two HBEGF withdrawal samples, three samples for each in-vitro day 2, 7 and 14.
Astrocyte-to-astrocyte contact and a positive feedback loop of growth factor signaling regulate astrocyte maturation.
Specimen part, Cell line, Subject
View SamplesTo better understand the mechanistic basis of aging and its relationship with retinal degeneration, we examined gene expression changes in aging rod photoreceptors. Rod photoreceptor cell death is a feature of normal retinal aging and is accelerated in many retinal degenerative diseases, including AMD, the leading cause of untreatable adult blindness in the United States and other western countries. To our knowledge, the examination of age-related gene expression changes in a specific neuronal cell-type is novel, and it has allowed us to identify significant age-related changes with better resolution than is possible with whole retina samples. We used flow cytometry and a transgenic mouse with GFP-tagged rod photoreceptors to purify this specific cell population, and gene expression changes were evaluated at three time points using microarrays and quantitative RT-PCR. Our results suggest that aging is progressive, beginning even in young adult mice. Although rod photoreceptors are highly specialized neurons, our analyses revealed changes in consensus pathways of aging, including oxidative phosphorylation and stress responses affecting transcription and inflammation. In addition, we identified stress response processes that may be especially relevant for the aging retina and retinal diseases, such as angiogenesis and nuclear receptor signaling pathways that affect retinoid and lipid metabolism.
Distinct signature of altered homeostasis in aging rod photoreceptors: implications for retinal diseases.
Age, Specimen part
View SamplesThe study aims to define gene expression changes associated with mithramycin treatment of Ewing Sarcoma cell lines.
Identification of an inhibitor of the EWS-FLI1 oncogenic transcription factor by high-throughput screening.
Cell line, Treatment
View SamplesThis dataset contains Affymetrix Mouse Genome 430 2.0 Array data obtained from K7M2 cells over-expressing ezrinT567A and the wild-type
Dysregulation of ezrin phosphorylation prevents metastasis and alters cellular metabolism in osteosarcoma.
Cell line
View SamplesEupolauridine and liriodenine are plant-derived aporphinoid alkaloids that exhibit potent inhibitory activity against the opportunistic fungal pathogens Candida albicans and Cryptococcus neoformans. However, the molecular mechanism of this antifungal activity is unknown. In this study, we show that eupolauridine 9591 (E9591), a synthetic analog of eupolauridine, and liriodenine methiodide (LMT), a methiodide salt of liriodenine, mediate their antifungal activities by disrupting mitochondrial iron-sulfur (Fe-S) cluster synthesis. Several lines of evidence supported this conclusion. First, both E9591 and LMT elicited a transcriptional response indicative of iron imbalance, causing the induction of genes that are required for iron uptake and for the maintenance of cellular iron homeostasis. Second, a genome-wide fitness profile analysis showed that yeast mutants with deletions in iron homeostasisrelated genes were hypersensitive to E9591 and LMT. Third, treatment of wild-type yeast cells with E9591 or LMT generated cellular defects that mimicked deficiencies in mitochondrial Fe-S cluster synthesis, including an increase in mitochondrial iron levels, a decrease in the activities of Fe-S cluster enzymes, a decrease in respiratory function, and an increase in oxidative stress. Collectively, our results demonstrate that E9591 and LMT perturb mitochondrial Fe-S cluster biosynthesis; thus, these two compounds target a cellular pathway that is distinct from the pathways commonly targeted by clinically used antifungal drugs. Therefore, the identification of this pathway as a target for antifungal compounds has potential applications in the development of new antifungal therapies.
Two plant-derived aporphinoid alkaloids exert their antifungal activity by disrupting mitochondrial iron-sulfur cluster biosynthesis.
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View SamplesSilencing of tumor suppressor genes plays a vital role in head and neck carcinogenesis. Aberrant hypermethylation in the promoter region of some known or putative tumor suppressor genes (TSGs) occurs frequently during the development of various cancers including head and neck squamous cell carcinoma (HNSCC). In this study we used an expanded mRNA expression profiling approach followed by microarray expression analysis to identify epigenetically inactivated genes in HNSCC. Two HNSCC cell lines were treated with 5-aza-2-deoxycytidine followed by microarray analysis to identify epigenetically silenced genes in HNSCC. 1960, 614, and 427 genes were upregulated in HNSCC cell lines JHU-012, JHU-011 and the combination of both cell lines, respectively. HNSCC tumor and normal mucosal samples were used for gene profiling by a 47K mRNA gene expression array and we found, 7140 genes were downregulated in HNSCC tumors compared to normal mucosa as determined by microarray analysis and were integrated with cell line data. Integrative analysis defined 126 candidate genes, of which only seven genes showed differentially methylation in tumors and no methylation in normal mucosa after bisulfite sequencing. After validation by QMSP, one gene, GNG7, was confirmed as being highly methylated in tumors and unmethylated in normal mucosal and salivary rinse samples demonstrating cancer-specific methylation in HNSCC tissues. TXNIP and TUSC2 were partially methylated in tumors and normal salivary rinses but unmethylated in normal mucosa. We concluded GNG7 as a highly specific promoter methylated gene associated with HNSCC. In addition, TXNIP and TUSC2 are also potential biomarkers for HNSCC.
Identification of guanine nucleotide-binding protein γ-7 as an epigenetically silenced gene in head and neck cancer by gene expression profiling.
Sex
View SamplesThis study provides a comprehensive evaluation of changes in gene expression during treatment with Genistein in vitro.
Dose- and Time-Dependent Transcriptional Response of Ishikawa Cells Exposed to Genistein.
Treatment
View SamplesWe have determined the gene expression profile induced by 17 alpha-ethynyl estradiol (EE) in Ishikawa cells, a human uterine-derived estrogen-sensitive cell line, at various doses (1 pM, 100 pM, 10 nM, and 1 microM) and time points (8, 24, and 48 h). The transcript profiles were compared between treatment groups and controls (vehicle-treated) using high-density oligonucleotide arrays to determine the expression level of approximately 38,500 human genes. By trend analysis, we determined that the expression of 2560 genes was modified by exposure to EE in a dose- and time-dependent manner (p </= 0.0001). The annotation available for the genes affected indicates that EE exposure results in changes in multiple molecular pathways affecting various biological processes, particularly associated with development, morphogenesis, organogenesis, cell proliferation, cell organization, and biogenesis. All of these processes are also affected by estrogen exposure in the uterus of the rat. Comparison of the response to EE in both the rat uterus and the Ishikawa cells showed that 71 genes are regulated in a similar manner in vivo as well as in vitro. Further, some of the genes that show a robust response to estrogen exposure in Ishikawa cells are well known to be estrogen responsive, in various in vivo studies, such as PGR, MMP7, IGFBP3, IGFBP5, SOX4, MYC, EGR1, FOS, CKB, and CCND2, among others. These results indicate that transcript profiling can serve as a viable tool to select reliable in vitro systems to evaluate potential estrogenic activities of target chemicals and to identify genes that are relevant for the estrogen response.
The genomic response of a human uterine endometrial adenocarcinoma cell line to 17alpha-ethynyl estradiol.
No sample metadata fields
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