Alu SINEs are the most numerous frequently occurring transcription units in our genome and possess sequence competence for transcription by RNA Pol III. However, through poorly understood mechanisms, the Alu RNA levels are maintained at very low levels in normal somatic cells with obvious benefits of low rates of Alu retrotransposition and energy-economical deployment of RNA Pol III to the tRNA genes which share promoter structure and polymerase requirements with Alu SINEs. Using comparative ChIP sequencing, we unveil that a repeat binding protein, CGGBP1, binds to the transcriptional regulatory regions of Alu SINEs thereby impeding Alu transcription by inhibiting RNA Pol III recruitment. We show that this Alu-silencing depends on growth factor stimulation of cells and subsequent tyrosine phosphorylation of CGGBP1. Importantly, CGGBP1 ensures a sequence-specific discriminative inhibition of RNA Pol III activity at Alu promoters, while sparing the structurally similar tRNA promoters. Our data suggest that CGGBP1 contributes to growth-related transcription by preventing the hijacking of RNA Pol III by Alu SINEs.
Growth signals employ CGGBP1 to suppress transcription of Alu-SINEs.
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View SamplesTranscriptomic profiling of miR-132/212-deficient and WT CD4 T cells isolated from spleens of L donovani infected mice (d28) to determine the effects of miR-132/212 on CD4 T cell activation in vivo. This was combined by transcriptomic analysis of early stage in vitro activated WT and miR-132/212-deficient CD4 T cells to identify direct miR-132/212 targets in CD4 T cells. Overall design: Examination of expression profiles of splenic CD4+ T cells from L. donovani-infected WT (samples 1-4) and miR-132/212-/- mice (samples 5-9) using RNASeq. This was followed by similar RNASeq in naïve CD4+ T-cells in WT and miR-132/212 -/- mice prior to and following 18h of in vitro TCR stimulation under Th1 conditions (samples 10-25).
<i>Malat1</i> Suppresses Immunity to Infection through Promoting Expression of Maf and IL-10 in Th Cells.
Specimen part, Cell line, Subject
View SamplesRNA polymerase III (Pol III) is an essential enzyme responsible for the synthesis of several small non-coding RNAs, a number of which are involved in mRNA translation. Recessive mutations in POLR3A, encoding the largest subunit of Pol III, cause POLR3-related hypomyelinating leukodystrophy (POLR3-HLD), characterized by deficient central nervous system myelination. Identification of the downstream effectors of pathogenic POLR3A mutations has been so far elusive. Here, we used CRISPR-Cas9 to introduce the POLR3A mutation c.2554A>G (p.M852V) into human cell lines and assessed its impact on Pol III biogenesis, nuclear import, DNA occupancy, transcription, and protein levels. Transcriptomic profiling uncovered a subset of transcripts vulnerable to Pol III hypofunction, including a global reduction in tRNA levels. The brain cytoplasmic BC200 RNA (BCYRN1), involved in translation regulation, was consistently affected in all our cellular models, including patient-derived fibroblasts. Genomic BC200 deletion in an oligodendroglial cell line led to major transcriptomic and proteomic changes, having a larger impact than those of POLR3A mutations. Upon differentiation, mRNA levels of the MBP gene, encoding myelin basic protein, were significantly decreased in POLR3A-mutant cells. Our findings provide the first evidence for impaired Pol III transcription in cellular models of POLR3-HLD and identify several candidate effectors, including BC200 RNA, having a potential role in oligodendrocyte biology and involvement in the disease. Overall design: Gene expression profiling of Pol III transcripts in control and POLR3A-mutated cell lines (HEK293 and MO3.13) using RNA-seq and small RNA-seq; ChIP-seq of FLAG-tagged POLR3A-WT and mutated POLR3A-M852V
Leukodystrophy-associated <i>POLR3A</i> mutations down-regulate the RNA polymerase III transcript and important regulatory RNA <i>BC200</i>.
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View SamplesThe expression level of a gene is often used as a proxy for determining whether the protein or RNA product is functional in a cell or tissue. Therefore, it is of fundamental importance to understand the global distribution of gene expression levels, and to be able to interpret it mechanistically and functionally. Here we use RNA sequencing of mouse Th2 cells, coupled with a range of other techniques, to show that all genes can be separated, based on their expression abundance, into two distinct groups: one group comprising of lowly expressed and putatively non-functional mRNAs, and the other of highly expressed mRNAs with active chromatin marks at their promoters. Similar observations are made in other data sets, including sources such as Drosophila. Overall design: RNA-seq data of two biological replicates of murine Th2 cells.
Single-cell RNA sequencing reveals T helper cells synthesizing steroids de novo to contribute to immune homeostasis.
No sample metadata fields
View SamplesmRNA-seq and expression profile of mouse ES OS25 cells Overall design: Gene expression (mRNA-Seq) in mouse ES cells
Polycomb associates genome-wide with a specific RNA polymerase II variant, and regulates metabolic genes in ESCs.
Cell line, Subject
View SamplesAn autochthonous model of pancreatic ductal adenocarcinoma (PDA) permitted the analysis of why immunotherapy is ineffective in this human disease. Despite finding that PDA-bearing mice had cancer cell-specific CD8+ T cells, the mice, like human PDA patients, did not respond to two immunological checkpoint antagonists that promote the function of T cells, a-CTLA-4 and a-PD-L1. Immune control of PDA growth was achieved, however, by depleting carcinoma-associated fibroblasts (CAFs) that express Fibroblast Activation Protein (FAP). The depletion of the FAP+ stromal cell also uncovered the anti-tumor effects of a-CTLA-4 and a-PD-L1, indicating that its immune suppressive activity accounts for the failure of these T cell checkpoint antagonists. Three findings suggested that CXCL12 explained the overriding immunosuppression by the FAP+ cell: T cells were absent from regions of the tumor containing cancer cells; cancer cells were coated with the chemokine, CXCL12; and the FAP+ CAF was the principle source of CXCL12 in the tumor. Administering AMD3100, a CXCL12 receptor (CXCR4) inhibitor, induced rapid T cell accumulation among cancer cells, and acted synergistically with a-PD-L1 to selectively and greatly diminish cancer cells, identified by their loss-of-heterozygosity (LOH) of Trp53. The residual tumor was comprised only of pre-malignant epithelial cells and inflammatory cells. Thus, a single protein, CXCL12, from a single stromal cell type, the FAP+ CAF, may direct tumor immune evasion in a model of human PDA. Overall design: FAP+ cells were sorted from pancreatic ductal adenocarcinoma. Cells were isolated in duplicate experiments and these were analysed separately. These were compared separately to previously published publicly available CD4+ T-cell subset data (C57BL/6 mice and Foxp3-RFP mice (Line 8374) GEO accession GSE20898), and previously published FAP+ cell datasets (transgenic albino (Tyr-/-) C57BL/6 mouse, GEO accession GSE39438).
Targeting CXCL12 from FAP-expressing carcinoma-associated fibroblasts synergizes with anti-PD-L1 immunotherapy in pancreatic cancer.
Specimen part, Disease, Disease stage, Subject
View SamplesFibroblast activation protein-a (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP(+) cells, we find that they reside in most tissues of the adult mouse. FAP(+) cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP(+) cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP(+) stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia. Overall design: FAP+ cells were sorted from two mesenchymal tissues, visceral adipose and skeletal muscle, and from an epithelial organ, the pancreas. These were compared to MEFs. Cells were isolated in duplicate experiments and these were analysed separately. These were compared to previously published publically available CD4+ T-cell subset data.
Depletion of stromal cells expressing fibroblast activation protein-α from skeletal muscle and bone marrow results in cachexia and anemia.
Specimen part, Subject
View SamplesThe liver parenchyma is composed of hepatocytes and bile duct epithelial cells (BECs). Controversy exists regarding the cellular origin of human liver parenchymal tissue generation during embryonic development, homeostasis or repair. Here we report the existence of a hepatobiliary hybrid progenitor (HHyP) population in human fetal liver using single-cell RNA sequencing. HHyPs are anatomically restricted to the ductal plate of fetal liver and maintain a unique transcriptional profile distinct from fetal hepatocytes, mature hepatocytes and mature BECs. In addition, molecular heterogenicity within the EpCAM+ population of freshly isolated fetal and adult human liver reveals diverse gene expression signatures of hepatic and biliary lineage potential. Finally, we FACS isolated fetal HHyPs and confirmed their hybrid progenitor phenotype in vivo. Our study suggests that hepatobiliary progenitor cells previously identified in mice also exist in humans, and can be distinguished from other parenchymal populations, including mature BECs, by distinct gene expression profiles. Overall design: Primary samples from 5 2nd trimester human fetal livers and 3 uninjured adult human livers for single cell RNA sequencing by Smartseq2.
Single cell analysis of human foetal liver captures the transcriptional profile of hepatobiliary hybrid progenitors.
No sample metadata fields
View SamplesBriefly, the well characterized female hES cell line H9 was allowed to differentiate into a clonally purified mortal splanchnopleuric mesodermal somatic cell line EN13. The EN13 line was subsequently virally reprogrammed back to an induced pluripotent state (we term re-H9) using OCT4, SOX2, KLF4 retroviral vectors creating isogenic lines of hESC, hiPSC and mortal cells. Our results reveal several important differences between embryo-derived H9 and the induced re-H9 stem cells. We find a dysregulation of genes involved in imprinting and altered expression of X-chromosome localized genes in re-H9 cells.
Suppression of the imprinted gene NNAT and X-chromosome gene activation in isogenic human iPS cells.
Cell line
View SamplesAnalysis of differences in gene expression between different cell types of the vascular niche. Looking for candidates, that could potentially be up-or downregualted in the different cell types
Pericyte-expressed Tie2 controls angiogenesis and vessel maturation.
Specimen part
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