Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA147335 | ENA |
REPOSITORIES: ENA
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Project description:We investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion. Flt3-Lin-Sca1+cKit+ cells were flow sorted from mice containing homozygous floxed alleles for exon 6 of the Raptor gene in the presence (MT group) or absence (WT group) of the MxCre transgene, which was induced with injections of mice with pIpC 5 weeks before cell isolation.
2012-09-19 | E-GEOD-32265 | biostudies-arrayexpress
Project description:We investigated the role of mTORC1 in murine hematopoiesis by conditionally deleting the Raptor gene in murine hematopoietic stem cells. We observed mutliple alterations evoked by Raptor loss in hematopoiesis and profiled gene-expression alterations induced by raptor loss in Flt3-Lin-Sca1+cKit+ hematopoietic stem and progenitor enriched cell populations, 5 weeks post Raptor deletion.
2012-09-19 | GSE32265 | GEO
Project description:Hematopoietic cell fate decisions such as self-renewal and differentiation are highly regulated through multiple molecular pathways. One pathway, the ubiquitin proteasome system (UPS), controls protein levels by tagging them with polyubiquitin chains and promoting their degradation through the proteasome. Ubiquitin E3 ligases serve as the substrate-recognition component of the UPS. Through investigating the FBOX family of E3 ligases, we discovered that Fbxo21 was highly expressed in the hematopoietic stem and progenitor cell (HSPC) population, and showed low to no expression in mature myeloid populations. To determine the role of FBXO21 on HSPC maintenance, self-renewal, and differentiation, we generated shRNAs against FBXO21 and a hematopoietic specific Fbxo21 conditional knockout (cKO) mouse model. We found that silencing FBXO21 in HSPCs led to a loss in colony formation and an increase in cell differentiation in vitro. Additionally, stressing the HSPC populations in our Fbxo21 cKO mouse with 5-FU injections resulted in a decrease in survival, despite these populations showing minimal alterations during steady-state hematopoiesis. Although FBXO21 has previously been proposed to regulate cytokine signaling via ASK and p38, our results show that depletion of FBXO21 led to altered ERK signaling in vitro. Together, these findings suggest ubiquitin E3 ligase FBXO21 regulates HSPCs through cytokine mediated pathways.
2022-11-11 | PXD035283 | Pride
Project description:The mechanistic target of rapamycin mTORC1 is a key regulator of cell metabolism and autophagy. Despite widespread clinical use of mTOR inhibitors, the role of mTORC1 in renal tubular function and kidney homeostasis remains elusive. By utilizing constitutive and inducible deletion of conditional Raptor alleles in renal tubular epithelial cells, we discovered that mTORC1 deficiency caused a marked concentrating defect, loss of tubular cells and slowly progressive renal fibrosis. Transcriptional profiling revealed that mTORC1 maintains renal tubular homeostasis by controlling mitochondrial metabolism and biogenesis as well as transcellular transport processes involved in counter-current multiplication and urine concentration. Although mTORC2 partially compensated the loss of mTORC1, exposure to ischemia and reperfusion injury exaggerated the tubular damage in mTORC1-deficient mice, and caused pronounced apoptosis, diminished proliferation rates and delayed recovery. These findings identify mTORC1 as an essential regulator of tubular energy metabolism and as a crucial component of ischemic stress responses. Pharmacological inhibition of mTORC1 likely affects tubular homeostasis, and may be particularly deleterious if the kidney is exposed to acute injury. Furthermore, the combined inhibition of mTORC1 and mTORC2 may increase the susceptibility to renal damage. Raptor fl/fl*KspCre and Raptor fl/fl animals were sacrificed at P14 before the development of an overt functional phenotype. Kidneys were split in half and immediately snap frozen in liquid nitrogen.
2014-06-09 | E-GEOD-54417 | biostudies-arrayexpress
Project description:Naïve T cells respond to antigen stimulation by exiting from quiescence into clonal expansion and functional differentiation, but the control mechanism is elusive. Here we describe that Raptor/mTORC1-dependent metabolic reprogramming is a central determinant of this transitional process. Loss of Raptor abrogates T cell priming and Th2 cell differentiation, although Raptor function is less important for continuous proliferation of actively cycling cells. mTORC1 coordinates multiple metabolic programs in T cells including glycolysis, lipid synthesis and oxidative phosphorylation to mediate antigen-triggered exit from quiescence. mTORC1 further links glucose metabolism to the initiation of Th2 differentiation by orchestrating cytokine receptor expression and cytokine responsiveness. Activation of Raptor/mTORC1 integrates T cell receptor (TCR) and CD28 co-stimulatory signals in antigen-stimulated T cells. Our studies identify a Raptor/mTORC1-dependent pathway linking signal-dependent metabolic reprogramming to quiescence exit, and this in turn coordinates lymphocyte activation and fate decisions in adaptive immunity. We used microarrays to explore the gene expression profiles differentially expressed in CD4+ T-cells from wild-type (WT) and CD4(cre) x Raptor(fl/fl) mice before and after stimulation with anti CD3/CD28 antibodies.
2014-01-27 | E-GEOD-51668 | biostudies-arrayexpress
Project description:Bone marrow mesenchymal stromal cells (MSCs) are a major source of secreted factors that control hematopoietic stem and progenitor cell (HSPC) function. We previously reported the generation of revitalized MSCs (rMSCs), which support functional HSCs in culture more effectively than control MSCs. In a secretomic screen using rMSCs, we identified semaphorin 3A (SEM3A) as a secreted factor upregulated as part of a pro-inflammatory signature that may underly HSPC expansion by rMSCs. Similarly, SEM3A expression is upregulated by BM-MSCs in vivo in response to hematopoietic stress. Recombinant SEM3A directly promotes HSPC quiescence ex vivo. Analysis of a SEM3A loss of function mutation in vivo revealed hematopoietic progenitor expansion and accelerated recovery after myeloablation, consistent with a role for SEM3A in regulating the HSPC stress response. This work highlights proteomic screening using rMSCs as a method to identify novel secreted niche factors and uncovers a novel role for SEM3A in promoting HSPC quiescence in stress hematopoiesis.
2025-07-11 | PXD065232 | Pride
Project description:The purpose of the experiment was to define the heterogeneity of hematopoietic stem and progenitor cells (HSPC) at emergence and initial maturation using scRNA-Seq of enriched blood populations from transgenic fluorescent zebrafish (30 and 52 hpf). Results provide insight into the different HSPC populations in heamtopoietic development.
2021-08-23 | GSE182213 | GEO
Project description:Preeclampsia (PE) has been associated with placental dysfunction, resulting in foetal hypoxia, accelerated erythropoiesis and increased erythroblast count in the umbilical cord blood (UCB). Although the detailed effects remain unknown, placental dysfunction can also cause inflammation, nutritional and oxidative stress in the fetus that can affect erythropoiesis. Here, we compared the expression of surface adhesion molecules and erythroid differentiation capacity of UCB hematopoietic stem/ progenitor cells (HSPCs), UCB erythroid profiles along with transcriptome and proteome of these cells between male and female foetuses from PE and normotensive pregnancies. While no significant differences were observed in UCB HSPC migration/ homing and in vitro erythroid colony differentiation, the UCB HSPC transcriptome and the proteomic profile of the in vitro differentiated erythroid cells differed between PE vs normotensive samples. Accordingly, despite absence of significant differences in the UCB erythroid populations in male or female foetuses from PE or normotensive pregnancies, transcriptional changes were observed during erythropoiesis, particularly affecting male foetuses. Pathway analysis suggested deregulation in mTORC1/AMPK signaling pathways controlling cell cycle, differentiation and protein synthesis. These results associate PE with transcriptional and proteomic changes in foetal HSPCs and erythroid cells that may underlie the higher erythroblast count in the UCB in PE.
2019-06-20 | PXD010364 | Pride
Project description:The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct T cell fate decisions1. Activation of mTOR, comprised of mTORC1 and mTORC2 complexes, delivers an obligatory signal for proper activation and differentiation of effector CD4+ T cells2,3, whereas in the regulatory T cell (Treg) compartment, the Akt-mTOR axis is widely acknowledged as a crucial negative regulator of Treg de novo differentiation4-8 and population expansion9. However, whether mTOR signaling affects the homeostasis and function of Tregs remains largely unexplored. Here we show that mTORC1 signaling is a pivotal positive determinant of Treg function. Tregs have elevated steady-state mTORC1 activity compared to naïve T cells. Signals via T cell receptor (TCR) and IL-2 provide major inputs for mTORC1 activation, which in turn programs suppressive function of Tregs. Disruption of mTORC1 through Treg-specific deletion of the essential component Raptor leads to a profound loss of Treg suppressive activity in vivo and development of a fatal early-onset inflammatory disorder. Mechanistically, Raptor/mTORC1 signaling in Tregs promotes cholesterol/lipid metabolism, with the mevalonate pathway particularly important for coordinating Treg proliferation and upregulation of suppressive molecules CTLA-4 and ICOS to establish Treg functional competency. In contrast, mTORC1 does not directly impact the expression of Foxp3 or anti- and pro-inflammatory cytokines in Tregs, suggesting a non-conventional mechanism for Treg functional regulation. Lastly, we provide evidence that mTORC1 maintains Treg function partly through inhibiting the mTORC2 pathway. Our results demonstrate that mTORC1 acts as a fundamental ‘rheostat’ in Tregs to link immunological signals from TCR and IL-2 to lipogenic pathways and functional fitness, and highlight a central role of metabolic programming of Treg suppressive activity in immune homeostasis and tolerance. We used microarrays to explore the gene expression profiles differentially expressed in regulatory T-cells from wild-type and CD4(cre) x Raptor(fl/fl) mice
2013-06-24 | E-GEOD-46693 | biostudies-arrayexpress
Project description:Advances in pluripotent stem cell and reprogramming technologies have given hope of generating hematopoietic stem cells (HSC) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that glycophosphatidylinositol-anchored surface protein GPI-80 (Vanin 2) defines a distinct subpopulation of human fetal hematopoietic stem/progenitor cells (HSPC) with self-renewal ability. CD34+CD90+CD38-GPI-80+ HSPC were the sole population that maintained proliferative potential and undifferentiated state in bone marrow stroma co-culture, and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSC migration between human fetal hematopoietic niches. The most highly enriched surface protein in GPI-80+ HSPC as compared to their progeny was Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of either GPI-80 or ITGAM was sufficient to perturb undifferentiated HSPC in stroma co-culture. These findings indicate that human fetal HSC utilize common mechanisms with leukocytes for cell-cell interactions governing HSC self-renewal. We used microarrays to identify genes enriched in the GPI-80+ hematopoietic stem and progenitor population in fetal liver. RNA was extracted from enriched fetal liver hematopoietic stem and progenitor cells, and downstream progenitors, for comparison based on Affymetrix arrays.
2015-01-23 | E-GEOD-54315 | biostudies-arrayexpress