RNA-sequencing of primary mouse hematopoietic stem progenitors
Ontology highlight
ABSTRACT: Mechanisms of translational regulation are poorly understood in somatic stem cells. We used polysome profiling, RNA-sequencing, and proteomic approaches to examine translational regulation in hematopoietic stem cell (HSC)-enriched (LSK; Lin-Sca-1+c-Kit+) cells and committed myeloid progenitors (MP). Our studies show that polysomal RNA expression changes more robustly predict changes in protein expression than total RNA and that LSKs preferentially translate transcripts that support HSC maintenance. Collectively, our data reveal that translation is highly regulated during the earliest steps in normal hematopoiesis.
Project description:Ubiquitination is a post-translational mechanism of control of diverse cellular processes. We focus here on the ubiquitin ligase Fbw7, a recently identified hematopoietic tumor suppressor that can target for degradation several important oncogenes including Notch1, c-Myc and cyclin E. We have generated conditional Fbw7 knock-out animals and inactivated the gene in hematopoietic stem cells (HSC) and their differentiated progeny. Deletion of Fbw7 specifically and rapidly affects the HSC compartment in a cell-autonomous manner. Fbw7-/- HSCs show defective maintenance of quiescence, leading to impaired self-renewal and a severe loss of competitive repopulating capacity. Furthermore, Fbw7-/- HSC are unable to colonize the thymus leading to a profound depletion of T cell progenitors. Deletion of Fbw7 in bone marrow stem cells and progenitors leads to the stabilization of c-Myc, a transcription factor previously implicated in HSC self-renewal. On the other hand, neither Notch1 nor cyclin E are stabilized in the bone marrow of Fbw7 deficient mice. Genome-wide transcriptome studies of Fbw7-/- HSC and hematopoietic progenitors indicate that Fbw7 controls, through the regulation of HSC cell cycle entry, the global transcriptional âsignatureâ that is associated with the quiescent, self-renewing HSC phenotype. Transcriptional consequences of inactivating Fbw7 in LKS cells. Experiment Overall Design: Four samples were analyzed: wild-type (WT) control and Fbw7-deficient (FBW7) Lin-ckit+Sca1+ (LSK) cells, as well as Lin-ckit+Sca1- myeloid progenitor (MP) cells, which served as a control for LSK-enriched/specific genes. Total bone marrow cells were pooled from three WT and three FBW7 mice before sorting LSK and MP populations.
Project description:Analysis of gene expression profile of LSK (Lin-Sca-1+ c-Kit+) isolated from Jmjd1c f/f Vav1Cre or Vav1Cre controls. Loss of Jmjd1c minimally affected HSC in homeostatsis while impiars HSC function in response to stree such as transplantation and 5-Fu treatment. These results provide insight into the role of Jmjd1c in normal hematopoiesis.
Project description:We found that iron chelation restored functional defects in aged HSC, including engraftment potential and platelet bias. To gain molecular insights into iron-dependent mechanism for sustaining HSC identity during aging, we performed Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) with lineage (Lin)− Sca-1+ cKit+ (LSK) cells isolated from aged mice after long-term regimens with iron chelator Deferoxamine or vehicle control.
Project description:The Hedgehog (Hh) signaling pathway is a developmentally conserved regulator of stem cell function. Several reports suggested that Hh signaling is an important regulator of hematopoietic stem cell (HSC) maintenance and differentiation. Here we test this hypothesis in vivo using both gain- and loss-of-function Hh genetic models. Surprisingly, our studies demonstrate that conditional Smoothened (Smo) deletion or over-activation has no significant effects on adult HSC self-renewal and function. Moreover, they indicate a lack of synergism between the Notch and Hh pathways in HSC function, as RBPJ- and Smo-deficiency do not affect hematopoiesis. In agreement with this notion, detailed genome-wide transcriptome analysis reveals that silencing of Hh signaling does not significantly alter the HSC-specific gene expression âsignatureâ. Our studies demonstrate that the Hh signaling pathway is dispensable for adult HSC function and suggest that the Hh pathway can be targeted in future clinical trials addressing the effect of Hh inhibition on leukemia-initiating cell maintenance. Transcriptional consequences of inactivating Smo (hh loss-of-function) in LKS cells. Experiment Overall Design: Four samples were analyzed: wild-type (WT) control and Smo-deficient (SMO) Lin-ckit+Sca1+ (LSK) cells, as well as Lin-ckit+Sca1- myeloid progenitor (MP) cells, which served as a control for LSK-enriched/specific genes. Total bone marrow cells were pooled from four WT and four SMO mice before sorting LSK and MP populations.
Project description:The study was a comparison of gene expression using RNA-seq. We analyzed the stem and progenitor cells from WT and Vav-cre+ Tet2fl/fl Flt3-ITD (T2F3) mice. We isolated stem cells LSK (lin- sca+ kit+) and granulocyte-macrophage progenitors GMP (lin- sca- kit+ fcgr+ cd34+) cells from bone marrow. Comparisons were made across genotypes WT vs. T2F3 and cell types LSK vs. GMP.
Project description:To identify pathways and processes driving the observed hematopoietic stem cell (HSC) aging-like phenotypes in miR-146a-/- vs. WT, we performed RNA-seq gene expression profiling of Lin- Sca-1+ c-Kit+ (LSK) cells isolated from miR-146a-/- or WT mouse bone marrow (BM). Differential expression analysis and EnrichmentMap network analysis identified cytokine signalling and immune pathways as potential drivers of aging-like alterations in miR-146a-/- HSC proliferation and differentiation.
Project description:Hematopoietic stem cells (HSCs) must ensure adequate blood cell production following distinct external stressors. A comprehensive understanding of in vivo heterogeneity and specificity of HSC responses to external stimuli is currently lacking. We performed single-cell RNA sequencing (scRNA-Seq) on functionally validated mouse HSCs and LSK (Lin-, c-Kit+,Sca1+) progenitors after in vivo pharmacological perturbation of niche signals interferon, granulocyte-colony stimulating factor (G-CSF), and prostaglandin. We identified six HSC states that are characterized by enrichment but not exclusive expression of marker genes. External signals induced rapid transitions between HSC states but transcriptional response varied both between external stimulants and within the HSC population for a given perturbation. In contrast to LSK progenitors, HSCs were characterized by a greater link between molecular signatures at baseline and in response to external stressors. Chromatin analysis of unperturbed HSCs and LSKs by scATAC-Seq suggested some HSC-specific, cell intrinsic predispositions to niche signals. We compiled a comprehensive resource of HSC- and LSK progenitor-specific chromatin and transcriptional features that represent determinants of signal receptiveness and regenerative potential during stress hematopoiesis.
Project description:To gain insight into how miR-142 deficit drives a BC-like transformation, we performed RNA-seq on bone marrow (BM) Lin-Sca-1+c-Kit+ cells (LSKs) harvested from normal miR-142+/+ (wt) and miR-142−/− (miR-142 KO) mice, as well as from leukemic miR-142+/+ BCR-ABL (CP CML) and miR-142−/− BCR-ABL (BC CML) mice, two weeks after BCR-ABL induction. We then performed gene expression profiling analysis using data obtained from RNA-seq of 24 samples of LSK cells from 4 mouse strains (KO vs WT, KO CML vs CML).
Project description:The biology of chronic myeloid leukemia (CML)-stem cells is still incompletely understood. Therefore, we previously developed an inducible transgenic mouse model in which stem cell targeted induction of BCR-ABL expression leads to chronic phase CML-like disease. Here, we now demonstrate that the disease is transplantable using BCR-ABL positive LSK cells (lin-Sca-1+c-kit+). Interestingly, the phenotype is enhanced when unfractionated bone marrow (BM) cells are transplanted. However, neither progenitor cells (lin-Sca-1-c-kit+) nor mature granulocytes (CD11b+Gr-1+), or potential stem cell niche cells were able to transmit the disease or alter the phenotype. The phenotype was largely independent of BCR ABL priming prior to transplant. However, BCR-ABL abrogated the potential of LSK cells to induce full blown disease in secondary recipients. Subsequently, we found that BCR-ABL increased the fraction of multipotent progenitor cells (MPP) at the expense of long term HSC (LT-HSC) in the BM. Microarray analyses of LSK cells revealed that BCR-ABL alters the expression of genes involved in proliferation, survival, and hematopoietic development. Our results suggest that BCR-ABL induces differentiation of LT-HSC and decreases their self renewal capacity. Furthermore, reversion of BCR-ABL eradicates mature cells while leukemic stem cells persist, giving rise to relapsed CML upon re-induction of BCR-ABL.
Project description:We performed ATAC-sequencing in LSK cells (Lin(neg)/c-Kit(+)/Sca-1(+)) from shRNA mice carrying an shRNA for either Renilla or Stag2.