Preterm infants are susceptible to neonatal inflammatory/infective diseases requiring drug therapy. The present study hypothesized that mRNA expression in the blood may be modulated by signaling pathways during treatment. The current study aimed to explore changes in global gene expression in the blood from preterm infants with the objective of identifying patterns or pathways of potential relevance to drug therapy. The infants involved were selected based on maternal criteria indicating increased risk for therapeutic intervention. Global mRNA expression was measured in 107 longitudinal whole blood samples using Affymetrix Human Genome U133 Plus 2.0 arrays; samples were obtained from 20 preterm infants. Unsupervised clustering revealed a distinct homogeneous gene expression pattern in 13 samples derived from seven infants undergoing continuous oxygen therapy. At these sampling times, all but one of the seven infants exhibited severe drops in peripheral capillary saturation levels below 60%. The infants were reoxygenated with 100% inspired oxygen concentration. The other samples (n=94) represented the infants from the cohort at time points when they did not undergo continuous oxygen therapy. Comparing these two sets of samples identified a distinct gene expression pattern of 5,986 significantly differentially expressed genes, of which 5,167 genes exhibited reduced expression levels during transient hypoxia. This expression pattern was reversed when the infants became stable, i.e., when they were not continuously oxygenated and had no events of hypoxia. To identify signaling pathways involved in gene regulation, the Database for Annotation, Visualization and Integrated Discovery online tool was used. Mitogen activated protein kinases, which are normally induced by oxidative stress, exhibited reduced gene expression during hypoxia. In addition, nuclear factor erythroid 2 related factor 2 antioxidant response element target genes involved in oxidative stress protection were also expressed at lower levels, suggesting reduced transcription of this pathway. The findings of the present study suggest that oxidative stress dependent signaling is reduced during hypoxia. Understanding the molecular response in preterm infants during continuous oxygenation may aid in refining therapeutic strategies for oxygen therapy.
Gene expression profiles in preterm infants on continuous long‑term oxygen therapy suggest reduced oxidative stress‑dependent signaling during hypoxia.
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View SamplesThe contrasting dose of sex chromosomes in males and females potentially introduces a large-scale imbalance in levels of gene expression between sexes. In many organisms dosage compensation has thus evolved to equalize sex-linked gene expression in males and females1,2, in mammals achieved by X chromosome inactivation and in flies and worms by up- or down-regulation of X-linked expression, respectively. Another form of dosage compensation ensures that expression levels on the X chromosome and on autosomes are balanced3,4. While otherwise widespread in systems with heteromorphic sex chromosomes, the case of dosage compensation in birds (males ZZ, females ZW) remains an unsolved enigma5,6. Here we use a microarray approach to show that male day 18 chicken embryos generally express higher levels of Z-linked genes than female birds, both in soma and in gonads. The distribution of male-to-female fold-change values for Z chromosome genes is wide and has a mean of 1.4-1.6, which is consistent with absence of dosage compensation and sex-specific feedback regulation of gene expression at individual loci2. Intriguingly, without global dosage compensation, female chicken has significantly lower expression levels of Z-linked compared to autosomal genes, which is not the case in male birds. The pronounced sex difference in gene expression is likely to contribute to sexual dimorphism among birds, and potentially has implication to avian sex determination.
Faced with inequality: chicken do not have a general dosage compensation of sex-linked genes.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene copy number aberrations are associated with survival in histologic subgroups of non-small cell lung cancer.
Specimen part
View SamplesHypothesis: Non-small cell lung cancer (NSCLC) is characterized by a multitude of genetic aberrations with unknown clinical impact. In this study, we aimed to identify gene copy number changes that correlate with clinical outcome in NSCLC. To maximize the chance to identify clinically relevant events, we applied a strategy involving two prognostically extreme patient groups.
Gene copy number aberrations are associated with survival in histologic subgroups of non-small cell lung cancer.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
Specimen part, Cell line
View SamplesMicroRNAs are a class of small non-coding RNAs that regulate mRNA expression at the post-transcriptional level and thereby many fundamental biological processes. A number of methods, such as multiplex polymerase chain reaction, microarrays have been developed for profiling levels of known miRNAs. These methods lack ability to identify novel miRNAs and accurately determine expression at a range of concentration. Deep or massively parallel sequencing methods are providing suitable platforms for genome wide transcriptome analysis and have the ability to identify novel transcripts. The results of analysis of small RNA sequences obtained by Solexa technology of normal peripheral blood mononuclear cells, tumor cell lines K562 (chronic myelogenous leukemia) and HL60 (acute promyelogenous leukemia) are presented. Custom computation pipelines were used to generate expression profiles of known and for identification of novel miRNAs. Some of the highly expressed miRNAs in the leukocytes include several members of the let 7 family, mir-21, 103, 185, 191 and 320a. Comparison of the miRNA profiles of normal versus K562 cells or HL60 revealed a specific set of differentially expressed molecules. Correlation of the miRNA with that of mRNA expression profiles, obtained by microarray, revealed a set of target genes showing inverse correlation with miRNA levels. Our computational pipeline also predicted a number of novel miRNAs. Some of the predictions were validated by realtime RT-PCR and or RNAase protection assay. Overall design: The small RNA population from four samples - Two Normal Peripheral blood mononuclear cells (PBMC) samples, K562 cell line (This cell line is used as a model to study Chronic Myelogenous Leukemia), HL60 (This cell line is used to study acute promyelogenous leukemia) was sequenced using Solexa technology.
Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
No sample metadata fields
View SamplesWe did microarray to compare the gene expression profile of peripheral blood mononuclear cells (PBMC from normal volunteer) and two leukemic cell lines that is K562 (Chronic myelogenous leukemia cell line), HL60 (Promyelocytic leukemia cell line) in order to find differentially expressed genes in these samples.
Analysis of microRNA transcriptome by deep sequencing of small RNA libraries of peripheral blood.
Specimen part, Cell line
View SamplesWe report RNA-Seq data of S.cerevisiae PPN1 knock-out yeast strain and PPN1 overproducing transformant yeast strain grown to logarithmic stage in control medium and in the medium containing 5mM manganese. Overall design: Yeast were grown to logarithmic growth stage in control YPD medium and in YPD medium with 5 mM MnSO4.
The Reduced Level of Inorganic Polyphosphate Mobilizes Antioxidant and Manganese-Resistance Systems in <i>Saccharomyces cerevisiae</i>.
Cell line, Subject
View SamplesGene expression profiling was performed on biopsies of affected and unaffected psoriatic skin and normal skin from seven Japanese patients to obtain insights into the pathways that control this disease. U95A Affymetrix DNA chips that contain oligonucleotide arrays of approximately 12,000 well-characterized human genes were used in the study. The statistical analysis of the Affymetrix data, based on the ranking of the Student-test statistic, revealed a complex regulation of molecular stress and immune gene responses. The majority of the 266 induced-genes in affected and unaffected psoriatic skin were involved with interferon mediation, immunity, cell-adhesion, cytoskeleton restructuring, protein trafficking and degradation, RNA regulation and degradation, signaling transduction, apoptosis and atypical epidermal cellular proliferation and differentiation. The disturbances in the normal protein degradation equilibrium of skin were reflected by the significant increase in the gene expression of various protease inhibitors and proteinases including the induced components of the ATP/ubiquitin-dependent non-lysosomal proteolytic pathway that is involved with peptide processing and presentation to T-cells. Some of the upregulated genes, such as TGM1, IVL, CSTA, FABP5 and SPRR, are well known psoriatic markers involved in atypical epidermal cellular organization and differentiation. In the comparison between the affected and unaffected psoriatic skin, the transcription factor JUNB was found at the top of the statistical rankings for the 51 significantly upregulated genes in affected skin, suggesting that it has an important but as yet undefined role in psoriasis. Our gene expression data and analysis suggest that psoriasis is a chronic IFN and T-cell-mediated immune disease of the skin where the imbalance in epidermal cellular structure, growth and differentiation arises from the molecular antiviral stress signals initiating inappropriate immune responses.
Gene expression profiling of Japanese psoriatic skin reveals an increased activity in molecular stress and immune response signals.
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View SamplesMicroRNAs (miRNAs) are small non-protein-coding RNAs that are incorporated into the RNA-induced silencing complex (RISC) and inhibit gene expression by regulating the stability and/or the translational efficiency of target mRNAs. Previously, we demonstrated that miR-210 is a key player of endothelial cell (EC) response to hypoxia, modulating EC survival, migration and ability to form capillary like-structures. Moreover, the receptor tyrosine kinase ligand Ephrin-A3 was identified as one functionally relevant target. Since each miRNA regulates hundreds of mRNAs, different approaches were combined to identify new miR-210 targets: a Using target prediction software, 32 new miR-210 potential targets were identified. b The proteomic profiling of miR-210 over-expressing ECs identified 11 proteins that were specifically inhibited by miR-210, either directly or indirectly. c Affymetrix based gene expression profiles identified 51 genes that were both down-modulated by miR-210 over-expression and de-repressed when miR-210 was blocked. Surprisingly, only few genes identified either by proteomics or transcriptomics were recognized as miR-210 targets by target prediction algorithms. However, a low-stringency pairing research revealed enrichment for miR-210 putative binding sites, raising the possibility that these genes were targeted via non-canonical recognition sequences. To clarify this issue, miR-210-loaded RISC was purified by immuno-precipitation along with its mRNA targets. The presence of Ephrin-A3 mRNA in the complex validated this approach. We found that 32 potential targets were indeed enriched in miR-210-loaded RISC, and thus can be considered as genuine miR-210 targets. In keeping with this conclusion, we were able to further validate a sub-set of them by 3UTR-reporter assays. Gene ontology analysis of the targets confirmed the known miR-210 activity in differentiation and cell cycle regulation, highlighting new functions such as involvement in RNA processing, DNA binding, development, membrane trafficking and amino acid catabolism. In conclusion, we validated a multidisciplinary approach for miRNAs target identification and indicated novel molecular mechanisms underpinning miR-210 role in EC response to hypoxia.
An integrated approach for experimental target identification of hypoxia-induced miR-210.
Cell line
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