We used microarrays to detail the global gene expression changes following RNAi knock-down of dTip60 in Drosophila SL2 cells
Widespread regulation of gene expression in the Drosophila genome by the histone acetyltransferase dTip60.
Cell line
View Samples1,2-unsaturated pyrrolizidine alkaloids (PA) are plant metabolites predominantly occurring in the plant families Asteraceae and Boraginaceae. Acute and chronic PA poisoning causes severe hepatotoxicity. So far, the molecular mechanisms of PA toxicity are not well understood. To analyze its mode of action, primary human hepatocytes were exposed to a non-cytotoxic dose of 100 M of four structurally different PA: echimidine, heliotrine, senecionine, senkirkine. Changes in mRNA expression were analyzed by a whole genome microarray. Employing cut-off values with a |fold change| of 2 and a q-value of 0.01, data analysis revealed numerous changes in gene expression. In total, 4556, 1806, 3406 and 8623 genes were regulated by echimidine, heliotrine, senecione and senkirkine, respectively. 1304 genes were identified as commonly regulated. PA affected pathways related to cell cycle regulation, cell death and cancer development. The transcription factors TP53, MYC, NFB and NUPR1 were predicted to be activated upon PA treatment. Furthermore, gene expression data showed a considerable interference with lipid metabolism and bile acid flow. The associated transcription factors FXR, LXR, SREBF1/2, and PPAR// were predicted to be inhibited. In conclusion, though structurally different, all four PA significantly regulated a great number of genes in common. This proposes similar molecular mechanisms, although the extent seems to differ between the analyzed PA as reflected by the potential hepatotoxicity and individual PA structure.
Disturbance of gene expression in primary human hepatocytes by hepatotoxic pyrrolizidine alkaloids: A whole genome transcriptome analysis.
No sample metadata fields
View SamplesThe meninges are generally considered relatively inert tissues that house the CSF and provide protection for the brain and spinal cord. However, our previous studies using Kit mutant (Kit W/Wv) mast cell-deficient mice demonstrated that mast cells residing in the dura mater and pia mater exacerbate the severity of experimental autoimmune encephalomyelitis (EAE), the rodent model of the CNS demyelinating disease, multiple sclerosis. These data suggest that the meninges are sites of active immune responses in disease. Gene expression profiles of meningeal tissue from wild type and mast cell deficient mice prior to and at day 6 post-EAE induction were found highly distinct. Increases in both mast cell- and neutrophil-associated transcripts were among the notable disease-related changes observed in wild type mice. Kinetic analyses show that meningeal mast cells are activated within 24 hours of disease induction to express multiple mediators including IL-1b and TNF as well as the neutrophil chemoattractant, CXCL2, an observation corresponding with an influx of neutrophils to the meninges. Neutrophil recruitment as well as the disease-related loss of BBB integrity is dependent on mast cell-derived TNF. These data provide unequivocal evidence that the meninges are sites of early inflammatory events in EAE. Mast cells residing within these tissues promote disease by orchestrating an early and efficient immune cell co-localization resulting in a robust local inflammatory response and a breach of the proximal BBB. We hypothesize that these events reflect an aberrant manifestation of the normal immune surveillance role of the meninges in infection settings.
Mast cell activation and neutrophil recruitment promotes early and robust inflammation in the meninges in EAE.
Specimen part, Disease
View SamplesMale and female CD-1 mice were administered dietary Phenobarbital for 2 or 7 days. In-life, enzyme activity, cell proliferation, genomic analysis, and Bench-mark dose modeling was carried out.
Dose-response modeling of early molecular and cellular key events in the CAR-mediated hepatocarcinogenesis pathway.
Specimen part
View SamplesDiesel exhaust (DE) has been shown to enhance allergic sensitization in animals following high dose instillation or chronic inhalation exposure scenarios. The purpose of this study was to determine if short term exposures to diluted DE enhance allergic immune responses to antigen, and identify possible mechanisms using microarray technology. BALB/c mice were exposed to filtered air or diluted DE to yield particle concentrations of 500 or 2000 g/m3 4 hr/day on days 0-4. Mice were sensitized intranasally with ovalbumin (OVA) antigen or saline on days 0-2, and 18 and all were challenged with OVA on day 28. Mice were necropsied either 4 hrs after the last DE exposure on day 4, or 18, 48, and 96 hrs after challenge. Immunological endpoints included OVA-specific serum IgE, biochemical and cellular profiles of bronchoalveolar lavage (BAL), and cytokine production in the BAL. OVA-sensitized mice exposed to both concentrations of DE had increased eosinophils, neutrophils, lymphocytes, and IL-6 post-challenge compared to OVA control, while DE/saline exposure yielded increases in neutrophils at the high dose only. Microarray analysis demonstrated distinct gene expression profiles for the high dose DE/OVA and DE/saline groups. DE/OVA induced pathways involved in oxidative stress and metabolism while DE in the absence of allergen sensitization modulated cell cycle control, growth and differentiation, G-proteins, and cell adhesion pathways. This study shows for the first time early changes in gene expression induced by the combination of diesel exhaust inhalation and antigen sensitization, which resulted in stronger development of an allergic asthma phenotype.
Increased transcription of immune and metabolic pathways in naive and allergic mice exposed to diesel exhaust.
No sample metadata fields
View SamplesThe forkhead O transcription factors (FOXO) integrate a range of extracellular signals including growth factor signaling, inflammation, oxidative stress and nutrient availability, to substantially alter the program of gene expression and modulate cell survival, cell cycle progression, and many cell-type specific responses yet to be unraveled. Naive antigen-specific CD8+ T cells undergo a rapid expansion and arming of effector function within days of pathogen exposure, but in addition, by the peak of expansion, they form precursors to memory T cells capable of self-renewal and indefinite survival.
Differentiation of CD8 memory T cells depends on Foxo1.
Specimen part
View SamplesMicroarrays were used to detail the global program of gene expression underlying differences in the organisation of inflammatory cells classified by the expression of the CD21L and IL-17A genes. Synovia were defined by the expression of the CD21L and IL-17A genes as determined by semi-quantitative PCR.
Co-expression of CD21L and IL17A defines a subset of rheumatoid synovia, characterised by large lymphoid aggregates and high inflammation.
Specimen part, Disease, Disease stage, Subject
View SamplesThe long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting programming effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes.
Intermittent neonatal hypoxia elicits the upregulation of inflammatory-related genes in adult male rats through long-lasting programming effects.
Sex
View SamplesDeficiencies in the ATM gene are the underlying cause for ataxia telangiectasia, a congenital syndrome characterized by neurological, motor and immunological defects, as well as a predisposition to cancer risks. MicroRNAs (miRNAs) are small regulators of post-transcriptional gene expression and a useful tool for cancer diagnosis, staging, and prediction of therapeutic responses to clinical regimens. In particular, miRNAs have been used to develop signatures for breast cancer profiling. We are interested in the consequences of ATM deficiency on miRNA expression in breast epithelial cells and the potential contribution to cancer predisposition. In this study we investigate the effects of ATM loss on the miRNA expression and related gene expression changes in normal human mammary epithelial cells (HME-CC). We have identified 81 significantly differently expressed miRNAs in the ATM-deficient HME-CCs using small RNA sequencing. Many of these differentially expressed miRNAs have been described and implicated in tumorigenesis and proliferation. These changes include down-regulation of tumor suppressor miRNAs, such as hsa-miR-29c and hsa-miR-16, as well as the over-expression of pro-oncogenic miRNAs hsa-miR-93 and hsa-mir-221. All 81 miRNAs were combined with genome wide gene expression profiles to investigate possible targets of miRNA regulation. We identified messenger RNA (mRNA) targets of these miRNAs that were also significantly regulated after the depletion of ATM. Predicted targets included many genes implicated in cancer formation and progression, including SOCS1 and the proto-oncogene MAF. Integrated analysis of miRNA and mRNA expression allows us to build a more complete understanding of the pathways and networks involved in the breast cancer predisposition observed in individuals deficient in ATM. This study highlights miRNA and predicted mRNA target expression changes in ATM-deficient HME-CCs and suggests a mechanism for the breast cancer-prone phenotype seen in ATM deficient cells and patients. Additionally, this study provides preliminary data for defining miRNA profiles that may be used prognostic biomarkers for breast cancer predisposition. Overall design: Examination of small RNA population in human mammary epithelial cell lines. Each condition was preformed in triplicate.
Genome-wide small RNA sequencing and gene expression analysis reveals a microRNA profile of cancer susceptibility in ATM-deficient human mammary epithelial cells.
Specimen part, Cell line, Subject
View SamplesIdentification of AP-2d target genes in the midbrain of E15 mouse embryos
AP-2δ is a crucial transcriptional regulator of the posterior midbrain.
Specimen part
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