Hematopoietic stem cells (HSCs) and lymphoid-primed multi-potential progenitors (LMPPs) are able to initiate both lymphoid and myeloid differentiation. We show here that the transcriptional repressor Gfi1 (growth factor independence 1) implements a specific gene expression program in HSCs and LMPPs that is critical for their survival and lymphoid differentiation potential. We present evidence that Gfi1 is required to maintain expression of genes involved in lymphoid development such as Flt-3, IL7R, Ebf1, Rag1, CCR9 and Notch1 and controls myeloid lineage commitment by regulating expression of genes such as Hoxa9 or M-CSFR. Gfi1 also inhibits apoptosis in HSCs by repressing pro-apoptotic genes such as Bax or Bak. As a consequence, Gfi1-/- mice show defects in self renewal, survival and both myeloid and lymphoid development of HSCs and LMPPs. Co-expression of a Bcl-2 transgene can partially restore the function of HSCs in Gfi1-/- mice, but not the defects in early lymphoid development. Of interest, Gfi1-/- x Bcl-2 transgenic mice show an accelerated expansion of myeloid cells and succumb to a fatal myeloproliferative disease resembling chronic myelomonocytic leukemia (CMML). Our data show that Gfi1 protects HSCs against apoptosis, ensures the proper development of LMPPs and plays a role in the development of myeloid leukemia.
Growth factor independence 1 protects hematopoietic stem cells against apoptosis but also prevents the development of a myeloproliferative-like disease.
Specimen part
View SamplesUsing Gfi1b conditional mice, deletion of gfi1b in the hematopietic system was induced by injecting MxCre tg Gfi1bfl/fl mice with pIpC. 30 days after injection, Cd150 pos, Cd 48 neg, Lin neg Sca and c-kit pos stem cells were sortrted from Gfi1bfl/fl and Mxcre tg Gfi1bfl/fl mice and analysed. We used the mouse Affymetrix Gene ST Array.
Evidence that growth factor independence 1b regulates dormancy and peripheral blood mobilization of hematopoietic stem cells.
No sample metadata fields
View SamplesThe proliferation and survival of hematopoietic stem cells (HSCs) has to be strictly coordinated to ensure the timely production of all blood cells. Here we report that the splice factor and RNA binding protein hnRNP L (heterogeneous nuclear ribonucleoprotein L) is required for hematopoiesis, since its genetic ablation in mice reduces almost all blood cell lineages and causes premature death of the animals. In agreement with this, we observed that hnRNP L deficient HSCs lack both the ability to self-renew and foster hematopoietic differentiation in transplanted hosts. They also display mitochondrial dysfunction, elevated levels of ?H2AX, are Annexin V positive and incorporate propidium iodide indicating that they undergo cell death. Lin(-)c-Kit(+) fetal liver cells from hnRNP L deficient mice show high p53 protein levels and up-regulation of p53 target genes. In addition, cells lacking hnRNP L up-regulated the expression of the death receptors TrailR2 and CD95/Fas and show Caspase-3, Caspase-8 and Parp cleavage. Treatment with the pan-caspase inhibitor Z-VAD-fmk, but not the deletion of p53, restored cell survival in hnRNP L deficient cells. Our data suggest that hnRNP L is critical for the survival and functional integrity of HSCs by restricting the activation of caspase-dependent death receptor pathways. Overall design: fetal liver cells from either hnRNPL wild-type or hnRNPL KO embryos were analysed for differential expression and alternative splicing by RNA-Seq. RNA-Seq was carried out in biological triplicate for each sample type. Each sample is a single embryo.
Heterogeneous Nuclear Ribonucleoprotein L is required for the survival and functional integrity of murine hematopoietic stem cells.
No sample metadata fields
View SamplesRoberts syndrome (RBS) is a human developmental disorder caused by mutations in the cohesin acetyltransferase ESCO2. We previously reported that mTORC1 was inhibited and overall translation was reduced in RBS cells. Treatment of RBS cells with L-leucine partially rescued mTOR function and protein synthesis, correlating with increased cell division. In this study, we use RBS as a model for mTOR inhibition and analyze transcription and translation with ribosome profiling to determine genome-wide effects of L-leucine. The translational efficiency of many genes is increased with Lleucine in RBS cells including genes involved in ribosome biogenesis, translation, and mitochondrial function. snoRNAs are strongly upregulated in RBS cells, but decreased with L-leucine. Imprinted genes, including H19 and GTL2, are differentially expressed in RBS cells consistent with contribution to mTORC1 control. This study reveals dramatic effects of L-leucine stimulation of mTORC1 and supports that ESCO2 function is required for normal gene expression and translation. Overall design: 42 samples of human fibroblast cell lines with various genotypes (wt, corrected, and esco2 mutants) are treated with l-leucine or d-leucine (control) for 3 or 24 hours. Biological replicates are present.
Improved transcription and translation with L-leucine stimulation of mTORC1 in Roberts syndrome.
No sample metadata fields
View SamplesClassically activated (M1) macrophages protect from infection but can cause inflammatory disease and tissue damage while alternatively activated (M2) macrophages reduce inflammation and promote tissue repair. Modulation of macrophage phenotype may be therapeutically beneficial and requires further understanding of the molecular programs that control macrophage differentiation. A potential mechanism by which macrophages differentiate may be through microRNA (miRNA), which bind to messenger RNA and post-transcriptionally modify gene expression, cell phenotype and function. The inflammation-associated miRNA, miR-155, was rapidly up-regulated over 100-fold in M1, but not M2, macrophages. Inflammatory M1 genes and proteins iNOS, IL-1b and TNF-a were reduced up to 72% in miR-155 knockout mouse macrophages, but miR-155 deficiency did not affect expression of genes associated with M2 macrophages (e.g., Arginase-1). Additionally, a miR-155 oligonucleotide inhibitor efficiently suppressed iNOS and TNF-a gene expression in wild-type M1 macrophages. Comparative transcriptional profiling of unactivated (M0) and M1 macrophages derived from wild-type and miR-155 knockout (KO) mice revealed an M1 signature of approximately 1300 genes, half of which were dependent on miR-155. Real-Time PCR of independent datasets validated miR-155's contribution to induction of iNOS, IL-1b, TNF-a, IL-6 and IL-12, as well as suppression of miR-155 targets Inpp5d, Tspan14, Ptprj and Mafb. Overall, these data indicate that miR-155 plays an essential role in driving the differentiation and effector potential of inflammatory M1 macrophages.
Control of the Inflammatory Macrophage Transcriptional Signature by miR-155.
Specimen part, Treatment
View SamplesPurpose:We have the first-reported set of glial-specific transcripts utilizing the Ribotag model. We use this model to explore glial changes in DNBS-induced inflammation and neurokinin-2 receptor (NK2R) antagonism. Methods: Actively translated mRNA profiles of the distal colon myeneteric plexi of Rpl22(+/-)Sox10(+/-) male and female mice 8-10 weeks old were obtained utilizing the HA-tagged ribosomal immunoprecipitation and downstream RNA extraction. Samples meeting RNA quality standards by 18S and 28S rRNA peaks by 2100 Bioanalyzer and RNA 6000 Nano LabChip Kit (Agilent) were deep sequenced with the Illumina HiSeq 4000. Results: We mapped approximately 30-50 millions reads per sample to the mouse genome (v88) and identified approximately 100K ribosome-associated transcripts, with Tuxedo workflow, in distal colon glial cells with DNBS-induced inflammation and NK2R antagonism and their respective controls. Of these transcripts, changes in biological processes associated with inflammation and other important enteric nervous system communications between samples have been identified. Conclusions: Our study demonstrates the first use of the Ribotag model to provide glial cell-specific actively-translated mRNA changes in DNBS-induced inflammation with and without functional NK2R signalling. Overall design: Distal colon glial mRNA samples from Ribotag Rpl22(+/-)Sox10(+/-) mice administered either saline or DNBS and DMSO vehicle or NK2R antagonism.
Communication Between Enteric Neurons, Glia, and Nociceptors Underlies the Effects of Tachykinins on Neuroinflammation.
Sex, Specimen part, Cell line, Subject
View SamplesA microarray time series was generated to identify cyclic genes of the segmentation clock in the mouse. The right posterior half presomitic mesoderms (PSM) from 17 mouse embryos were dissected while the contralateral side of the embryo containing the left PSM was immediately fixed to be analyzed by in situ hybridization using a Lfng probe to order the samples along the segmentation clock oscillation cycle. Probes were produced from RNA extracted from the 17 dissected posterior half PSMs using a two-step amplification protocol and were hybridized to Affymetrix GeneChip MOE430A. The reproducibility of the amplification procedure was initially assessed by comparing array data generated from the right and the left posterior PSM from the same embryo. Because of the symmetry of the paraxial mesoderm along the left-right axis, left and right samples are expected to show overtly similar gene expression. RNA was amplified from three such sample pairs (1, a and b; 2, a and b; 3, a and b) and hybridized on Murine Genome U74Av2 array (MG-U74Av2)
A complex oscillating network of signaling genes underlies the mouse segmentation clock.
Age, Specimen part, Subject, Time
View SamplesWe have used surgical specimens to perform a differential analysis of the transcriptome of human retinal tissues following detachment.
Transcriptomic analysis of human retinal detachment reveals both inflammatory response and photoreceptor death.
Subject
View SamplesPurpose: To understand the molecular mechanisms underlying NPM1c-mediated tumorigenesis by comparing the transcriptome of de novo generated bulk human leukemic cells and leukemic stem cells Overall design: Human hematopoietic stem/progenitor cells (HSPC) are transduced with lentiviruses expressing a mutated form of Nucleophosmin (NPM1c). Following engraftment into immunodeficient mice, transduced HSPCs give rise to human myeloid leukemia whereas untransduced HSPCs give rise to human immune cells in the same mice. The de novo AML, with CD123+ leukemic stem cells (LSC), resembles NPM1c+ AML from patients.
Induction and Therapeutic Targeting of Human NPM1c<sup>+</sup> Myeloid Leukemia in the Presence of Autologous Immune System in Mice.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Poised RNA polymerase II changes over developmental time and prepares genes for future expression.
Specimen part, Cell line, Treatment, Time
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