Transfection of dsDNA into many mammalian cell types indues the production of type I interferons and interferon-stimulated genes. We performed an siRNA screen to identify genes involved in this innate immune response, and identified Abcf1.
Identification of regulators of the innate immune response to cytosolic DNA and retroviral infection by an integrative approach.
Specimen part
View SamplesWe used microarrays to determine which genes are upregulated by IFNbeta stimulation in 293T cells.
Identification of regulators of the innate immune response to cytosolic DNA and retroviral infection by an integrative approach.
Specimen part, Cell line, Treatment
View SamplesCSL is a key transcription factor, mostly acting as a repressor. While known as main effector of Notch signaling, it can also play Notch-independent functions. Despite the wide interest in CSL, the mechanisms responsible for its own regulation have been little studied. We recently showed that CSL down-modulation in human dermal fibroblasts (HDFs) leads to conversion into cancer associated fibroblasts, which promote keratinocyte tumor development. We show here that levels of CSL gene transcription differ among HDF strains derived from many different individuals, with negative correlation with genes involved in DNA damage/repair. CSL expression in all tested strains is negatively regulated by stress / DNA damaging insults caused by UVA, Reactive Oxygen Species (ROS), smoke extract and doxorubicin treatment. p53, a key effector of the DNA damage response, functions as common negative regulator of CSL gene transcription, through both suppression of CSL promoter activity and, indirectly, through increased p21 expression. CSL was previously shown to bind p53 suppressing its activity. The present findings indicate that p53, in turn, decreases CSL expression, which can serve to enhance p53 activity in the acute response of cells to DNA damaging cancer-threatening conditions. Overall design: RNA sequencing of 46 human foreskin fibroblasts
Negative control of CSL gene transcription by stress/DNA damage response and p53.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Activation of GCN2 kinase by ribosome stalling links translation elongation with translation initiation.
Age
View SamplesRibosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of B6J-nmf205-/- mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA Arg(UCU) tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2 (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2 kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in B6J-nmf205-/- mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress.
Activation of GCN2 kinase by ribosome stalling links translation elongation with translation initiation.
No sample metadata fields
View SamplesMaize LEAFBLADELESS1 (LBL1) and Arabidopsis SUPPRESSOR OF GENE SILENCING3 (SGS3) play orthologous roles in the biogenesis of 21 nucleotide trans-acting short-interfering RNAs (tasiRNAs). The phenotypes conditioned by mutation of lbl1 and SGS3 are, however, strikingly different, suggesting that the activities of these small RNA biogenesis components, or the tasiRNAs and their targets might not be entirely conserved. To investigate the basis for this phenotypic variation, we compared the small RNA content between wild-type and lbl1 seedling apices. We show that LBL1 affects all major classes of small RNAs, and reveal unexpected crosstalk between tasiRNA biogenesis and other small RNA pathways regulating miRNAs, retrotransposons, and DNA transposons. We further identified genomic regions generating phased siRNAs, including numerous loci generating 22-nt phased small RNAs from long hairpin RNAs or overlapping antisense transcripts not previously described in other plant species. By combining both analyses, we identified nine TAS loci, all belonging to the conserved TAS3 family. Contrary to other plant species, no TAS loci targeted by a single miRNA were identified. Information from target prediction, RNAseq, and PARE analyses identified the tasiARFs as the major functional tasiRNAs in the maize vegetative apex where they regulate expression of ARF3 homologs. As such, divergence in TAS pathways is unlikely to account for the distinct phenotypes of tasiRNA biogenesis mutants in Arabidopsis and maize. Instead, the data suggests variation in the spatiotemporal regulation of ARF3, or divergence in its function, as a plausible basis for the dramatic phenotypic differences observed upon mutation of SGS3/lbl1 in Arabidopsis and maize. Overall design: An analysis of tasiRNA biogenesis, activity, and contribution to developmental phenotypes in the maize leaf. Data generated includes small RNA sequencing data and mRNA sequencing data. All data was generated in both wild type and lbl1 mutant maize leaf apices. Three replicates were generated for each genotype for the small RNA data. Two of these replicates were also used for the RNA-seq data.
Genome-wide analysis of leafbladeless1-regulated and phased small RNAs underscores the importance of the TAS3 ta-siRNA pathway to maize development.
Age, Specimen part, Subject
View SamplesBackground: Long non-coding RNAs (lncRNAs) are increasingly implicated as gene regulators and may ultimately be more numerous than protein-coding genes in the human genome. Despite large numbers of reported lncRNAs, reference annotations are likely incomplete due to their lower and tighter tissue-specific expression compared to mRNAs. An unexplored factor potentially confounding lncRNA identification is inter-individual expression variability. Here, we characterize lncRNA natural expression variability in human primary granulocytes. Results: We annotate granulocyte lncRNAs and mRNAs in RNA-seq data from ten healthy individuals, identifying multiple lncRNAs absent from reference annotations, and use this to investigate three known features (higher tissue-specificity, lower expression, and reduced splicing efficiency) of lncRNAs relative to mRNAs. Expression variability was examined in seven individuals sampled three times at one or more than one month intervals. We show that lncRNAs display significantly more inter-individual expression variability compared to mRNAs. We confirm this finding in 2 independent human datasets by analyzing multiple tissues from the GTEx project and lymphoblastoid cell lines from the GEUVADIS project. Using the latter dataset we also show that including more human donors into the transcriptome annotation pipeline allows identification of an increasing number of lncRNAs, but minimally affects mRNA gene number. Conclusions: A comprehensive annotation of lncRNAs is known to require an approach that is sensitive to low and tight tissue-specific expression. Here we show that increased inter-individual expression variability is an additional general lncRNA feature to consider when creating a comprehensive annotation of human lncRNAs or proposing their use as prognostic or disease markers. Overall design: We used PolyA+ RNA-seq data from human primary granulocytes of 10 healthy individuals to de novo annotate lncRNAs and mRNAs in this cell type and ribosomal depleted (total) RNA-seq data from seven of these individuals sampled three times to analyze lncRNA amd mRNA expression variability
Long non-coding RNAs display higher natural expression variation than protein-coding genes in healthy humans.
No sample metadata fields
View SamplesBone is a frequent target of lung cancer metastasis, which is associated with significant morbidity and a dismal prognosis. To identify and functionally characterize genes involved in the mechanisms of osseous metastasis we developed a murine lung cancer model. Comparative transcriptomic analysis identified genes encoding signaling molecules (such as TCF4 and PRKD3), and cell anchorage related proteins (MCAM, and SUSD5), some of which were basally modulated by TGFbeta in tumor cells and in conditions mimicking tumor-stroma interactions. Triple gene combinations induced not only high osteoclastogenic activity but also a marked enhancement of global metalloproteolytic activities in vitro. These effects were strongly associated with robust bone colonization in vivo, whereas this gene subset was ineffective in promoting local tumor growth and cell homing activity to bone. Interestingly, global inhibition of metalloproteolytic activities and simultaneous TGFbeta blockade in vivo led to increased survival and a remarkable attenuation of bone tumor burden and osteolytic metastasis. Thus, this metastatic gene signature mediates bone-matrix degradation by a dual mechanism of induction of TGFbeta-dependent osteoclastogenic bone resorption and enhancement of stroma-dependent metalloproteolytic activities. Our findings suggest the cooperative contribution of host-derived and cell-autonomous effects directed by a small subset of genes in mediating aggressive osseous colonization.
A novel lung cancer signature mediates metastatic bone colonization by a dual mechanism.
No sample metadata fields
View SamplesIt is currently unclear whether tissue changes surrounding multifocal epithelial tumors are a cause or consequence of cancer. Here, we provide evidence that loss of mesenchymal Notch/CSL signaling causes tissue alterations, including stromal atrophy and inflammation, which precede and are potent triggers for epithelial tumors. Mice carrying a mesenchymal-specific deletion of CSL/RBP-JK, a key Notch effector, exhibit spontaneous multifocal keratinocyte tumors that develop after dermal atrophy and inflammation. CSL-deficient dermal fibroblasts promote increased tumor cell proliferation through up-regulation of c-Jun and c-Fos expression and consequently higher levels of diffusible growth factors, inflammatory cytokines, and matrix remodeling enzymes. In human skin samples, stromal fields adjacent to cutaneous squamous cell carcinomas and multifocal premalignant actinic keratosis lesions exhibit decreased Notch/CSL signaling and associated molecular changes. Importantly, these changes in gene expression are also induced by UVA, a known environmental cause of cutaneous field cancerization and skin cancer.
Multifocal epithelial tumors and field cancerization from loss of mesenchymal CSL signaling.
Specimen part
View SamplesIn this study we analyzed the myeloma cell contact-mediated changes on the transcriptome of skeletal precursor cells. Therefore, human mesenchymal stem cells (MSC) and osteogenic precursor cells (OPC) were co-cultured with the representative myeloma cell line INA-6 for 24 h. Afterwards, MSC and OPC were separated from INA-6 cells by fluorescence activated cell sorting. Total RNA of MSC and OPC fractions was used for whole genome array analysis.
Contact of myeloma cells induces a characteristic transcriptome signature in skeletal precursor cells -Implications for myeloma bone disease.
Sex, Age, Specimen part, Disease stage
View Samples