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 SamplesThis SuperSeries is composed of the SubSeries listed below.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
View SamplesDifferentiation of hematopoietic stem cells (HSCs) is regulated by a concert of different transcription factors (TFs). A disturbed function of TFs can be the basis of (pre)malignancies such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Growth Factor Independence 1b (Gfi1b) is a repressing TF with a key role in quiescence of HSCs and emergence and maturation of erythrocytes and platelets. Here, we show that low expression of GFI1B in blast cells is associated with inferior prognosis of MDS and AML patients. Using mouse models with either reduced expression or conditional deletion of Gfi1b, crossed with a mouse model reflecting human MDS or AML, we demonstrate that AML development was accelerated with heterozygous loss of Gfi1b, and latency was further decreased when Gfi1b was conditionally deleted. Loss of Gfi1b significantly enhanced stemness of leukemic cells with upregulation of genes fundamentally involved in leukemia development. On a molecular level, we found that loss of Gfi1b not only increased the levels of reactive oxygen species (ROS) but also induced gene expression changes of key AML pathways such as the p38/AKT pathway. These results demonstrate that Gfi1b functions as an oncosuppressor in MDS/AML development.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
View SamplesFOXE3 is a lens specific transcription factor that has been associated with anterior segment ocular dysgenesis. To determine the transcriptional target(s) of FOXE3 that are indispensable for the anterior segment development, we examined the transcriptome and the proteome of cells expressing truncated FOXE3 responsible for Peters anomaly identified through linkage-coupled next-generation whole exome sequencing. We found that DNAJB1, an autophagy-associated protein, was the only candidate exhibiting differential expression in both screens. We confirmed the candidacy of DNAJB1 through chromatin immunoprecipitation and luciferase assays while knockdown of DNAJB1 in human lens epithelial cells resulted in mitotic arrest. Subsequently, we targeted dnajb1a in zebrafish through injection of a splice-blocking morpholino. The dnajb1a morphants exhibited underdeveloped cataractous lenses with persistent apoptotic nuclei. In conclusion, we have identified DNAJB1 as a transcriptional target of FOXE3 in a novel pathway that is crucial for development of the anterior segment of the eye. Overall design: Human Embryonic Kidney (HEK293FT) cells were transfected with the expression vector (pT-RexTM-DEST30) harboring either the wild type or the mutant (C240*) FOXE3 ORF (open reading frame). The experimental design included a total of eight biological replicates of cells expressing the wild type and eight replicates of mutant FOXE3 along with eight non-transfected controls. Cells were harvested 24-hour post-transfection and subjected to total RNA isolation for the preparation of whole transcriptome next-generation sequencing libraries. Initially, we examined the quality of transcriptome libraries on a MiSeq genome analyzer. Subsequent to confirmation of the quality, all libraries were paired-end sequenced (2 x 100 bp) using Illumina TruSeq Cluster V3 flow cell at a concentration of 13.0 pM in two separate lanes (12 bar-coded mRNA pooled libraries in each lane) on a HiSeq 2000 genome analyzer.
FOXE3 contributes to Peters anomaly through transcriptional regulation of an autophagy-associated protein termed DNAJB1.
No sample metadata fields
View SamplesCommitted preadipocyte fibroblasts were genetically labelled in transgenic mice by expressing GFP under the control of the locus for Zfp423, a gene controlling preadipocyte determination. These mice are herein referred to as Zfp423-GFP mice. The overall goal was to identify genes differentially expressed between adipogenic GFP+ firboblasts and non-adipogenic GFP- fibroblasts from either inguinal or epididymal fat stromal vascular cultures obtained from Zfp423-GFP mice.
Zfp423 expression identifies committed preadipocytes and localizes to adipose endothelial and perivascular cells.
Sex, Specimen part
View SamplesThis study analyzes gene expression in beta-thalassemic fetal liver erythroblasts in the Th3 murine model. FACS-purified wild-type, heterozygous, and homozygous stage-matched erythroblasts from E14.5 fetal livers are compared.
Integrated protein quality-control pathways regulate free α-globin in murine β-thalassemia.
Specimen part
View SamplesTo better understand the mechanistic basis of aging and its relationship with retinal degeneration, we examined gene expression changes in aging rod photoreceptors. Rod photoreceptor cell death is a feature of normal retinal aging and is accelerated in many retinal degenerative diseases, including AMD, the leading cause of untreatable adult blindness in the United States and other western countries. To our knowledge, the examination of age-related gene expression changes in a specific neuronal cell-type is novel, and it has allowed us to identify significant age-related changes with better resolution than is possible with whole retina samples. We used flow cytometry and a transgenic mouse with GFP-tagged rod photoreceptors to purify this specific cell population, and gene expression changes were evaluated at three time points using microarrays and quantitative RT-PCR. Our results suggest that aging is progressive, beginning even in young adult mice. Although rod photoreceptors are highly specialized neurons, our analyses revealed changes in consensus pathways of aging, including oxidative phosphorylation and stress responses affecting transcription and inflammation. In addition, we identified stress response processes that may be especially relevant for the aging retina and retinal diseases, such as angiogenesis and nuclear receptor signaling pathways that affect retinoid and lipid metabolism.
Distinct signature of altered homeostasis in aging rod photoreceptors: implications for retinal diseases.
Age, Specimen part
View SamplesThe study aims to define gene expression changes associated with mithramycin treatment of Ewing Sarcoma cell lines.
Identification of an inhibitor of the EWS-FLI1 oncogenic transcription factor by high-throughput screening.
Cell line, Treatment
View SamplesThis dataset contains Affymetrix Mouse Genome 430 2.0 Array data obtained from K7M2 cells over-expressing ezrinT567A and the wild-type
Dysregulation of ezrin phosphorylation prevents metastasis and alters cellular metabolism in osteosarcoma.
Cell line
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