Filters
Technology
Platform
GSE77806
Arabidopsis thaliana
17 Downloadable Samples
Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Selected soil-borne rhizobacteria can trigger an induced systemic resistance (ISR) that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, the root-specific transcription factor MYB72 is required for the onset of ISR, but is also associated with plant survival under conditions of iron deficiency. Here we investigated the role of MYB72 in both processes. To identify MYB72 target genes, we analyzed the root transcriptomes of wild-type Col-0, mutant myb72, and complemented 35S:FLAG-MYB72/myb72 plants in response to ISR-inducing Pseudomonas fluorescens WCS417. Five WCS417-inducible genes were misregulated in myb72 and complemented in 35S:FLAG-MYB72/myb72. Amongst these, we uncovered -glucosidase BGLU42 as a novel component of the ISR signaling pathway. Overexpression of BGLU42 resulted in constitutive disease resistance, whereas bglu42 was defective in ISR. Furthermore, we found 195 genes to be constitutively upregulated in MYB72-overexpressing roots in the absence of WCS417. Many of these encode enzymes involved in the production of iron-mobilizing phenolic metabolites under conditions of iron deficiency. We provide evidence that BGLU42 is required for their release into the rhizosphere. Together, this work highlights a thus far unidentified link between the ability of beneficial rhizobacteria to stimulate systemic immunity and mechanisms induced by iron deficiency in host plants.
Publication Title
β-Glucosidase BGLU42 is a MYB72-dependent key regulator of rhizobacteria-induced systemic resistance and modulates iron deficiency responses in Arabidopsis roots.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 7 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Chromosomal instability in early cancer stages is caused by stress on DNA replication. The molecular basis for replication perturbation in this context is currently unknown. We studied the replication dynamics in cells in which a regulator of S-phase entry and cell proliferation, the Rb-E2F pathway, is aberrantly activated. Aberrant activation of this pathway by HPV-16 E6/E7 or cyclin E oncogenes, significantly decreased the cellular nucleotide levels in the newly transformed cells. Exogenously supplied nucleosides rescued the replication stress and DNA damage, and dramatically decreased oncogene-induced transformation. Increased transcription of nucleotide biosynthesis genes, mediated by expressing the transcription factor c-Myc, increased the nucleotide pool and also rescued the replication-induced DNA damage. Our results suggest a model for early oncogenesis in which uncoordinated activation of factors regulating cell proliferation leads to insufficient nucleotides that fail to support normal replication and genome stability.
Publication Title
Nucleotide deficiency promotes genomic instability in early stages of cancer development.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 5 Downloadable Samples
Illumina HiSeq 2000
Description
Transcriptome of beta-cells isolated from mice expressing p16ink4a and GFP transgenes and of control ß-cells isolated from mice expressing only the GFP transgene Overall design: RNAseq of murine beta-cells sorted based on GFP expression from three Ins-rtTA/tet-GFP/tet-p16ink4a mice and two control Ins-rtTA/tet-GFP mice following 10 days tet-mediated induction.
Publication Title
p16(Ink4a)-induced senescence of pancreatic beta cells enhances insulin secretion.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2000
Description
Argonaute (Ago) proteins mediate post-transcriptional gene repression by binding guide microRNAs (miRNAs) to regulate targeted RNAs. To confidently assess Agobound small RNAs, we adapted a mouse embryonic stem cell system to express a single inducible epitope-tagged Ago protein. Here, we report the small RNA profile of Agodeficient cells and determine Ago-dependent stability is a common feature of mammalian miRNAs. Considering both in vivo Ago-dependence for stability and Ago2 binding as defined by immunopurification, we have identified a novel class of non-canonical miRNAs derived from protein-coding gene promoters, which we name transcriptional start site miRNAs (TSS-miRNAs). A subset of promoter-proximal RNA polymerase II complexes produce hairpin RNAs that are processed in a DGCR8/Drosha-independent, but Dicer-dependent manner. TSS-miRNA activity is detectable endogenously, upon transfection of a mimic or by mRNA overexpression. Finally, we present evidence of differential expression and conservation in humans, suggesting important roles in gene regulation. Overall design: Examination of Ago immunoprecipitations and mESC without Ago proteins
Publication Title
Argonaute-bound small RNAs from promoter-proximal RNA polymerase II.
Sample Metadata Fields
Specimen part, Treatment, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
Target competition (ceRNA crosstalk) within miRNA-regulated gene networks has been proposed to influence biological systems. To assess target competition, we characterize and quantitate miRNA networks in two cell types. Argonaute iCLIP reveals that hierarchical binding of high to low affinity miRNA targets is a key characteristic of in vivo activity. Quantification of cellular miRNA and mRNA/ncRNA target pool levels indicates that miRNA-Target pool ratios and an affinity partitioned target pool accurately predict in vivo Ago binding profiles and miRNA susceptibility to target competition. Using single-cell reporters, we directly test predictions and estimate ~3,000 additional high affinity target sites can affect active miRNA families with low endogenous miRNA-Target ratios, such as miR-92/25. In contrast, the highly expressed miR-294 and let-7 families are not susceptible to increases of nearly 10,000 sites. These results show differential susceptibility based on endogenous miRNA-Target pool ratios and provide a physiological context for ceRNA competition in vivo. Overall design: mRNA seq from TT-FHAgo2 mouse embryonic stem cells or Meschencymal stem cells grown with 2.5 µg/mL Dox to express Ago2 or removed from doxycycline for 96h.
Publication Title
Endogenous miRNA and target concentrations determine susceptibility to potential ceRNA competition.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 59 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Integrated ordination of miRNA and mRNA expression profiles.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 29 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Several studies have shown that negative and positive miRNA-mRNA correlations are symmetrically distributed. While negative correlations are consistent with a faster degradation of miRNA targets, the presence of positive correlations suggests bidirectional interactions between the two classes of molecules. However, a comprehensive study of miRNA and mRNA correlations is lacking. A homogeneous map of miRNA and mRNA relationships was obtained by multidimensional scaling (MDS) applied to a single matrix including both heterologous (miRNA-mRNA) and homologous (miRNA-miRNA and mRNA-mRNA) correlations.
Publication Title
Integrated ordination of miRNA and mRNA expression profiles.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
A variety of airborne pathogens can induce inflammatory responses in airway epithelial cells, which is a crucial component of host defence. However, excessive inflammatory responses and chronic inflammation also contribute to different diseases in the respiratory system. We hypothesized that the activation of protein kinase C (PKC) is one of the essential mechanisms of inflammatory responses in airway epithelial cells. In the present study, we stimulated human bronchial lung epithelial (BEAS-2B) cells with phorbol ester Phorbol 12, 13-dibutyrate (PDBu), and examined gene expression profile with microarray analysis. Bioinformatics suggested that PKC activation induced dramatic changes in gene expression related to multiple cellular functions. The top two functional networks of genes were centered on NFB and TNF-, which are two commonly known pathways for cell death and inflammation. Subsequent tests confirmed the decrease in cell viability and increase in the production of various cytokines. Interestingly, each of the increased cytokines was differentially regulated at mRNA and/or protein levels by different sub-class of PKC isozymes. We conclude that many pathogen-induced cell death and cytokine production in airway epithelial cells may be mediated through PKC related signaling pathways. These findings suggest that PKCs can be new targets for treatments of lung diseases.
Publication Title
PKC activation induces inflammatory response and cell death in human bronchial epithelial cells.
Sample Metadata Fields
Specimen part, Cell line, Treatment, Time
View Samples- Rattus norvegicus
- 111 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Mdr1a-, Bcrp-, and Mrp2-knockout rats are a more practical species for ADME studies than murine models and previously demonstrated expected alterations in pharmacokinetics of various probe substrates. At present, gene expression and pathology changes were systematically studied in small intestine, liver, kidney, and brain tissue from male SAGE Mdr1a-, Bcrp-, and Mrp2-knockout rats versus wild-type Sprague Dawley controls. Gene expression data supported the relevant knockout genotype. As expected, Mrp2-knockout rats were hyperbilirubinemic and exhibited upregulation of hepatic Mrp3. Overall, few alterations were observed within 137 ADME-relevant genes. The two most consequential changes were upregulation of intestinal carboxylesterase in Mdr1a-knockouts and catechol-O-methyltransferase in all tissues of Bcrp-knockout rats. Previously reported upregulation of hepatic Mdr1b P-glycoprotein in proprietary Wistar Mdr1a-knockout rats was not observed in the SAGE counterpart investigated herein. Relative liver and kidney weights were 22-53% higher in all three knockouts, with microscopic increases in hepatocyte size in Mdr1a- and Mrp2-knockout rats, and glomerular size in Bcrp- and Mrp2-knockouts. Increased relative weight of clearing organs is quantitatively consistent with reported increases in clearance of drugs that are not substrates of the knocked-out transporter. Overall, SAGE knockout rats demonstrated modest compensatory changes, which do not preclude their general application to study transporter-mediated pharmacokinetics. However until future studies elucidate the magnitude of functional change, caution is warranted in rare instances of extensive metabolism by catechol-O-methyltransferase in Bcrp-knockouts and intestinal carboxylesterase in Mdr1a-knockout rats, specifically for molecules with free catechol groups and esters subject to gut wall hydrolysis.
Publication Title
Minor compensatory changes in SAGE Mdr1a (P-gp), Bcrp, and Mrp2 knockout rats do not detract from their utility in the study of transporter-mediated pharmacokinetics.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2000
Description
Argonaute (Ago) proteins, which act in post-transcriptional gene regulation directed by small RNAs, are vital for normal stem cell biology. Here we report the genomic characterization of stable Ago-deficient mouse embryonic stem cells (mESC) and determine the direct, primary and system level response to loss of Ago-mediated regulation. We find mESCs lacking all four Ago proteins are viable, do not repress microRNA (miRNA)-targeted cellular RNAs, and show distinctive gene network signatures. Profiling of RNA expression and epigenetic activity in an Ago mutant genetic series indicates that early responses to Ago loss are driven by transcriptional regulatory networks, in particular the Tgf-ß/Smad transcriptional network. This finding is confirmed using a time course analysis of Ago depletion and Ago rescue experiments. Detailed analysis places Tgf-ß/Smad activation upstream of cell cycle regulator activation, such as Cdkn1a, and repression of the c-Myc transcriptional network. The Tgf-ß/Smad pathway is directly controlled by multiple low-affinity miRNA interactions with Tgf-ß/Activin receptor mRNAs and receptor-mediated activation is required for Tgf-ß/Smad target induction with Ago loss. Our characterization reveals the interplay of post-transcriptional regulatory pathways with transcriptional networks in maintaining cell state and likely coordinating cell state transitions. Overall design: mRNA seq from stable genetic Dicer and Dgcr8 mutant mouse embryonic stem cells.
Publication Title
Temporal Control of the TGF-β Signaling Network by Mouse ESC MicroRNA Targets of Different Affinities.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples