Hypoxia regulates microRNA expression
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Sundaram Ramakrishnan
PROVIDER: E-GEOD-17944 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Our genome wide analyses of microRNA expression profiles involve the hybridization of fluorescently labeled RNA samples to custom made, DNA microarrays based on the GAPSII coated slides. We describe a simple and effective method to regenerate such custom microarrays. Our protocol entails the use of a very low concentration of sodium hydroxide in a low salt buffer to strip RNA molecules from the arrays. The solution is also capable of removing DNA molecules hybridized to the slides, while preserving the slide coating and printed DNA probes. Slides can be stripped and reused at least twice without significantly sacrificing data quality. Keywords: expression study, new vs. stripped array comparison There are two stripping conditions in this study (1mM NaOH and 2mM NaOH in SSC buffer). For 1mM NaOH treatment, new, once-, twice-, and triple-stripped arrays are studies. For 2mM NaOH treatment, new and once-stripped arrays are measured.
2010-05-19 | E-GEOD-10305 | biostudies-arrayexpress
Project description:Our genome wide analyses of microRNA expression profiles involve the hybridization of fluorescently labeled RNA samples to custom made, DNA microarrays based on the GAPSII coated slides. We describe the differences in genome wide miRNA expressions between wild type 293 T mammalian cells and Ago2 transformed stable cell lines. Keywords: Expression Comparing one control and three Ago2-overexpressing stable cell lines (A, B, C). One replicate per array.
2010-05-19 | E-GEOD-11168 | biostudies-arrayexpress
Project description:We examined the differential expression of miRNAs in vinyl carbamate (VC)-induced lung tumors in A/J mice and assessed if the chemopreventive agent indole-3-carbinol (I3C) reversed the effects of the carcinogen. Microarray studies revealed some up-regulated microRNAs, but down-regulation of several microRNAs in carcinogen-treated mice relative to vehicle-treated mice. Keywords: Expression micro and control RNA from control treated (3 replicates), vinyl carbamate treated (4 replicates) and vinyl carbamate and indole-3-carbinol treated mice was hybridized versus synthetic human DNA to a custom multi-organism oligonucleotide array.
2010-05-18 | E-GEOD-16490 | biostudies-arrayexpress
Project description:To study the relationship between microRNAs and μ-opioid receptor (MOR) signaling, we examined microRNA expression after chronic morphine or fentanyl treatment in rat primary hippocampal neurons and in mouse hippocampus. Mouse cerebellum region was also tested as a negative control to eliminate microRNA expression changes unrelated to MOR signaling, as the cerebellum is essentially devoid of MOR. We identified a number of microRNAs that altered their expression upon treatment with both morphine and fentanyl in the rat and mouse systems. There were, however, some microRNAs that changed in response to morphine, or fentanyl, but not both. Keywords: Expression profiling There are up to three biological replicates (indicated by 1, 2, and 3) of primary hippocampal neurons from new born rats and the cerebellum and hippocampus regions from adult mice treated for three days (control, morphine, and fentanyl). The biological replicates were from experiments performed on different dates. Each biological replicate contained cells or tissues collected from multiple animals so that enough RNA could be extracted for RNA analysis. RNA was labelled with a green dye, mixed with a reference DNA sample labelled with a red dye. The reference DNA contained a number of synthetic DNA oligos with mature microRNA sequences that served to verify microarray hybridization. RNA signals were in ch1, DNA signals ch2.
2010-05-19 | E-GEOD-14268 | biostudies-arrayexpress
Project description:The high rates of mortality associated with epithelial ovarian cancer (EOC) are a direct consequence of its metastatic nature. Metastasis is dependent on many factors, among which activation of angiogenesis is most significant. Angiogenesis is, in turn, contingent upon the cellular response to hypoxia within the tumor microenvironment. Hypoxia-inducible factor 1 (HIF1) is a transcription factor composed of HIF1alpha and HIF1beta subunits and is the master regulator of the hypoxic response. It is therefore a critical mediator of tumor angiogenesis and metastasis. Regulation of HIF1 is primarily at the level of protein. In normoxia, the HIF1alpha subunit is hydroxylated via an oxygen- and iron-dependent mechanism and targeted for destruction. In hypoxia, low oxygen levels preclude hydroxylation and HIF1alpha is stabilized, allowing for its association with constitutively expressed HIF1beta to form bioactive HIF1. We have identified a novel mechanism of HIF1alpha regulation in EOC cells that involves microRNAs (miRs), ~22 nucleotide, non-coding RNA molecules that repress translation of target mRNAs by binding their 3’ untranslated regions (UTRs). Using microarray and qPCR analysis, we found that levels of miR-199a-1, a miR that is predicted in silico to target the HIF1alpha 3’ UTR, were reduced under hypoxia in EOC cells. We further demonstrated that miR-199a-1 directly targets the HIF1alpha 3’ UTR and overexpression of miR-199a-1 suppresses HIF1alpha protein levels and HIF1-driven gene expression. Moreover, cells stably overexpressing miR-199a-1 exhibit marked defects in migratory ability. These data were corroborated by our in vivo findings, which demonstrated that overexpression of miR-199a-1 causes significant reductions in tumor vessel density and tumor burden in nude mice. These findings provide insight into non-canonical, miR- and iron-based mechanisms of HIF1 regulation that may have important implications in the progression of EOC. miRNA expression analysis of A2780 epithelial ovarian cancer cells by microarrays
2011-09-23 | E-GEOD-32313 | biostudies-arrayexpress
Project description:Our analyses of microRNA expression profiles involve the hybridization of fluorescently labeled miRNA samples to custom made, DNA microarrays based on the GAPSII coated slides. We hybridized different amounts of microRNAs from the mirVana miRNA Reference Panel v9.1 to microarrays. Keywords: Expression Three different concentrations of miRNAs from the commercial standrads were labelled and hybridized to three microarrays.
2009-07-30 | E-GEOD-11176 | biostudies-arrayexpress
Project description:Long noncoding RNAs (lncRNAs) are non-protein coding RNAs regulating gene expression. Although for some lncRNAs a relevant role in hypoxic endothelium has been shown, the regulation and function of lncRNAs is still largely unknown in the vascular physio-pathology. Taking advantage of next-generation sequencing techniques, transcriptomic changes induced by endothelial cell exposure to hypoxia were investigated. Paired-end sequencing of polyadenylated RNA derived from human umbilical vein endothelial cells (HUVECs) exposed to 1% O2 or normoxia was performed. Bioinformatics analysis identified â 2000 differentially expressed genes, including 122 lncRNAs. Extensive validation was performed by both microarray and qPCR. Among the validated lncRNAs, H19, MIR210HG, MEG9, MALAT1 and MIR22HG were also induced in a mouse model of hindlimb ischemia. To test the functional relevance of lncRNAs in endothelial cells, knockdown of H19 expression was performed. H19 inhibition decreased HUVEC growth, inducing their accumulation in G1 phase of the cell cycle; accordingly, p21 (CDKN1A) expression was increased. Additionally, H19 knockdown also diminished HUVEC ability to form capillary like structures when plated on matrigel. In conclusion, a high-confidence signature of lncRNAs modulated by hypoxia in HUVEC was identified and a significant impact of H19 lncRNA was shown Total RNA was extracted from two independent experiments with different time-points of hypoxia exposure (1% oxygen). HUVEC were exposed to 24h normoxia and 24h hypoxia or to 24h normoxia and 48h hypoxia. Each experiment was performed in duplicate.
2016-08-25 | E-GEOD-76743 | biostudies-arrayexpress
Project description:Ago2 binds mature microRNAs (miRNAs) to regulate gene expression. A mutant Ago2 is constructed to render it unable to bind miRNAs and inhibit mRNA translation. Human 293T cells were transiently transfected with a plasmid that encoded a FLAG-tagged wildtype human Ago2 or mutant Ago2. FLAG IP was preformed, and assoicated RNA was isolated and subjected miRNA microarray analysis.
2013-03-01 | E-GEOD-37941 | biostudies-arrayexpress
Project description:Endotoxin/LPS tolerance is a tightly regulated phenomenon, which, during infection, prevents systemic hyper-inflammation. Here we report for the first time that morphine reversal of endotoxin tolerance resulting in persistent inflammation thus contributing to septicemia and septic shock. We further report that this regulation is mediated by LPS-induced down-regulation of microRNAs 146a and 155. However, only over-expression of miR-146a, but not miR-155 abrogates morphine mediated hyper-inflammation, while antagonizing miR-146a (but not miR-155) augments morphine mediated hyper-inflammation. Hence, miR-146a could be the potential therapeutic target for morphine-mediated abrogation of endotoxin tolerance. All treatments done in vivo. Morphine implanted subcuteniously, LPS administered as intraperitoneal injection.
2013-08-01 | E-GEOD-42506 | biostudies-arrayexpress
Project description:Long noncoding RNAs (lncRNAs) are non-protein coding RNAs regulating gene expression. Although for some lncRNAs a relevant role in hypoxic endothelium has been shown, the regulation and function of lncRNAs is still largely unknown in the vascular physio-pathology. Taking advantage of next-generation sequencing techniques, transcriptomic changes induced by endothelial cell exposure to hypoxia were investigated. Paired-end sequencing of polyadenylated RNA derived from human umbilical vein endothelial cells (HUVECs) exposed to 1% O2 or normoxia was performed. Bioinformatics analysis identified â 2000 differentially expressed genes, including 122 lncRNAs. Extensive validation was performed by both microarray and qPCR. Among the validated lncRNAs, H19, MIR210HG, MEG9, MALAT1 and MIR22HG were also induced in a mouse model of hindlimb ischemia. To test the functional relevance of lncRNAs in endothelial cells, knockdown of H19 expression was performed. H19 inhibition decreased HUVEC growth, inducing their accumulation in G1 phase of the cell cycle; accordingly, p21 (CDKN1A) expression was increased. Additionally, H19 knockdown also diminished HUVEC ability to form capillary like structures when plated on matrigel. In conclusion, a high-confidence signature of lncRNAs modulated by hypoxia in HUVEC was identified and a significant impact of H19 lncRNA was shown. HUVEC were exposed to normoxia or 24 and 48 hours of hypoxia (1% oxygen). For each time point and condition was performed in duplicate was produced Total RNAs of six samples were extracted and analysed.
2016-08-25 | E-GEOD-76739 | biostudies-arrayexpress