Circular RNAs (circRNAs) are a class of noncoding RNAs produced by a non-canonical form of alternative splicing called back-splicing. To investigate a potential role of circRNAs in the p53 pathway, we analyzed RNA-seq data from colorectal cancer cell lines (HCT116, RKO and SW48) in the presence or absence of DNA damage. Surprisingly, unlike the strong p53-dependent induction of hundreds of p53-induced mRNAs, only a few circRNAs were induced from the p53-induced genes. Circ-MDM2, an annotated circRNA from the MDM2 locus, was one of the handful of circRNAs that originated from a p53-induced gene. Given the central role of MDM2 in suppressing p53 protein levels and p53 activity, we investigated the function of circ-MDM2. Knocking down circ-MDM2 with siRNAs that targeted the circ-MDM2 junction and had no effect on linear MDM2 mRNA, resulted in increased basal p53 levels and growth defects in vitro and in vivo. Consistent with these results, transcriptome profiling showed increased expression of several direct p53 targets, reduced Rb phosphorylation and defects in G1-S progression upon silencing circ-MDM2. Our results reveal the role of a novel circRNA by which the MDM2 locus suppresses p53 levels and cell cycle progression.
A Circular RNA from the <i>MDM2</i> Locus Controls Cell Cycle Progression by Suppressing p53 Levels.
Treatment
View SamplesComparison of mRNA expression showed widespread changes in the circulating CD8+ but not CD4+ T-cells from patients with severe asthma. No changes were observed in the CD4+ and CD8+ T-cells in non-severe asthmatics versus healthy controls. Bioinformatics analysis showed that the changes in CD8+ T-cell mRNA expression were associated with multiple pathways involved in T-cell activation. As with mRNAs, we also observed widespread changes in expression of non-coding RNA species including natural antisense, pseudogenes, intronic long ncRNAs and long intergenic long ncRNAs in CD8+ T-cells from severe asthmatics. Measurement of the miRNA expression profile showed selective down-regulation of miR-28-5p in CD8+ T-cells and reduction of miR-146a and miR-146b in both CD4+ and CD8+ T-cells.
Transcriptome analysis shows activation of circulating CD8+ T cells in patients with severe asthma.
Sex, Age, Specimen part, Subject
View SamplesWe examined the brain''s choroid plexus and myeloid cell populations isolated from the brain of 5XFAD Alzheimer''s disease transgenic mice following PD-1 blockade Overall design: Choroid plexus samples and myeloid cell populations were isolated from the brain of 5XFAD mice following PD-1 blockade, and sequenced. For choroid plexus samples, 5 mice were treated with anti-PD-1, 5 with IgG control, and 4 were left untreated. For the myeloid cells samples, myeloid cells sorted from the brains of 5XFAD mice according to a gating strategy that seperate microglia (CD11b+CD45-low) and monocytes-derived macrophages (CD11b+CD45-high).
PD-1 immune checkpoint blockade reduces pathology and improves memory in mouse models of Alzheimer's disease.
Specimen part, Cell line, Treatment, Subject
View SamplesAlzheimer's disease (AD) is a heterogeneous disorder with multiple etiologies. Harnessing the immune system by blocking the programmed cell death receptor (PD)-1 pathway in an amyloid beta mouse model was shown to evoke a sequence of immune responses that lead to disease modification. Here, blocking PD-L1, a PD-1 ligand, was found to have similar efficacy to that of PD-1 blocking in disease modification, in both animal models of AD and of tauopathy. Targeting PD-L1 in a tau-driven disease model resulted in increased immunomodulatory monocyte-derived macrophages within the brain parenchyma. Single cell RNA-seq revealed that the homing macrophages expressed unique scavenger molecules including macrophage scavenger receptor 1 (MSR1), which was shown here to be required for the effect of PD-L1 blockade in disease modification. Overall, our results demonstrate that immune checkpoint blockade targeting the PD-1/PD-L1 pathway leads to modification of common factors that go awry in AD and dementia, and thus can potentially provide an immunotherapy to help combat these diseases. Overall design: Cell populations were sorted with FACSAriaIII (BD Biosciences, San Jose, CA). Prior to sorting, all samples were filtered through a 40-µm nylon mesh. For the isolation of monocytes-derived macrophages, samples were gated for CD45high and CD11bhigh (Brilliant-violet-421, 1:150, 30-F11, Biolegend Inc. San Diego, CA; APC CD11b, 1:100, M1/70, eBioscience), while excluding doublets. Isolated cells were single cell sorted into 384-well cell capture plates containing 2?µL of lysis solution and barcoded poly(T) reverse-transcription (RT) primers for single-cell RNA-seq84. Four empty wells were designated in each 384-well plate as a no-cell control during data analysis. Immediately after sorting, each plate was spun down to ensure cell immersion into the lysis solution, snap frozen on dry ice, and stored at -80?°C until processing. Single-cell libraries were prepared as previously described73. In brief, mRNA from cells sorted into cell capture plates was barcoded, converted into cDNA, and pooled using an automated pipeline. The pooled sample was then linearly amplified by T7 in vitro transcription, and the resulting RNA was fragmented and converted into a sequencing-ready library by tagging the samples with pooled barcodes and Illumina sequences during ligation, RT, and PCR. Each pool of cells was tested for library quality, and concentration was assessed, as described73.
PD-1/PD-L1 checkpoint blockade harnesses monocyte-derived macrophages to combat cognitive impairment in a tauopathy mouse model.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesRNA-Seq data of micoglia isolated from brains of indicated mouse types. Overall design: Microglia were collected from perfused brains of mice based on FACS markers CD11b+ CD45int to lysis buffer
Mef2C restrains microglial inflammatory response and is lost in brain ageing in an IFN-I-dependent manner.
Specimen part, Cell line, Treatment, Subject
View SamplesThe differentiated state of somatic cells provides barriers for the efficient derivation of induced pluripotent stem cells (iPSCs). To address why some cell types reprogram more readily than others, we studied the effect of combined modulation of cellular signaling pathways. This revealed that inhibition of TGF together with activation of Wnt signaling in presence of ascorbic acid allows >80% of murine fibroblasts to acquire pluripotency after one week of reprogramming factor expression. In contrast, hepatic progenitors and blood progenitors predominantly required only TGF inhibition or canonical Wnt activation, respectively, to reprogram at efficiencies approaching 100%. Strikingly, blood progenitors reactivated endogenous pluripotency loci in a highly synchronous manner. We further demonstrate that expression of specific chromatin-modifying enzymes and reduced TGF/MAP kinase activity are intrinsic properties associated with the unique reprogramming response of these cells. Together, our observations define novel cell type-specific requirements for the rapid and synchronous reprogramming of somatic cells.
Combinatorial modulation of signaling pathways reveals cell-type-specific requirements for highly efficient and synchronous iPSC reprogramming.
Specimen part, Time
View SamplesCharacterization of the transcriptome of normal and abnormal embryos. Overall design: Gene expression profiling of every mono and trisomy.
Human blastocysts of normal and abnormal karyotypes display distinct transcriptome profiles.
Specimen part, Subject
View SamplesThe regional specificity and timing of gene activation following chemotherapy, and how this relates to subsequent mucositis development is currently unknown. The aim of the study was therefore to determine the early time course of gene expression changes along the gastrointestinal tract (GIT) of the DA rat following irinotecan treatment, so as to provide an insight into the genetic component of mucositis.
Gene expression analysis of multiple gastrointestinal regions reveals activation of common cell regulatory pathways following cytotoxic chemotherapy.
Sex, Age
View SamplesThe human steroid receptor RNA activator (SRA) gene encodes both non-coding RNAs (ncRNAs) and protein-generating isoforms. However, the breadth of endogenous target genes that might be regulated by SRA RNAs remains largely unknown. To address this, we depleted SRA RNA in two human cancer cell lines (HeLa and MCF-7) with small interfering RNAs, then assayed for changes in gene expression by microarray analyses using Affymetrix HGU133+2 arrays. We also tested if SRA depletion affects estradiol-regulated genes in MCF-7 breast cancer cells.
Research resource: expression profiling reveals unexpected targets and functions of the human steroid receptor RNA activator (SRA) gene.
Cell line
View SamplesSimilar to the bone marrow, the mammary gland contains a distinct population of Hoechst-effluxing side population cells, MG-SPs. To better characterize MG-SPs, their microarray gene profiles were compared to the remaining cells, which retain Hoechst dye (MG-NSPs). For analysis, gene ontology (GO) that describes genes in terms of biological processes and ontology traverser (OT) that performs enrichment analysis were utilized. OT showed that MG-SP specific genes were enriched in the GO categories of cell cycle regulation and checkpoints, multi-drug resistant transporters, organogenesis, and vasculogenesis. The MG-NSP upregulated genes were enriched in the GO category of cellular organization and biogenesis which includes basal epithelial markers, p63, smooth muscle actin (SMA), myosin, alpha-6 integrin, cytokeratin (CK) 14, as well as luminal markers, CK8 and CD24. Additional studies showed that a higher percentage of MG-SPs exist in the G1 phase of the cell cycle compared to the MG-NSPs. G1 cell cycle block of MG-SPs may be explained by higher expression of cell cycle negative regulatory genes such as TGF-beta2 (transforming growth factor-beta2), IGFBP-5 (insulin like growth factor binding protein-5), P18 INK4C and Wnt-5a (wingless-5a). Accordingly, a smaller percentage of MG-SPs expressed nuclear b-catenin, possibly as a consequence of the higher expression of Wnt-5a. In conclusion, microarray gene profiling suggests that MG-SPs are a lineage deficient mammary gland sub-population expressing key genes involved in cell cycle regulation, development and angiogenesis.
Transcriptional profiling of mammary gland side population cells.
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