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1.
Nat Immunol ; 24(8): 1295-1307, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37474652

RESUMO

The transcription factor ThPOK (encoded by Zbtb7b) is well known for its role as a master regulator of CD4 lineage commitment in the thymus. Here, we report an unexpected and critical role of ThPOK as a multifaceted regulator of myeloid lineage commitment, differentiation and maturation. Using reporter and knockout mouse models combined with single-cell RNA-sequencing, progenitor transfer and colony assays, we show that ThPOK controls monocyte-dendritic cell versus granulocyte lineage production during homeostatic differentiation, and serves as a brake for neutrophil maturation in granulocyte lineage-specified cells through transcriptional regulation of lineage-specific transcription factors and RNA via altered messenger RNA splicing to reprogram intron retention.


Assuntos
Regulação da Expressão Gênica , Timo , Animais , Camundongos , Diferenciação Celular , Linhagem da Célula , Proteínas de Ligação a DNA , Camundongos Knockout , RNA , Fatores de Transcrição/genética , Antígenos CD4
2.
Immunity ; 53(2): 303-318.e5, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32579887

RESUMO

Granulocyte-monocyte progenitors (GMPs) have been previously defined for their potential to generate various myeloid progenies such as neutrophils and monocytes. Although studies have proposed lineage heterogeneity within GMPs, it is unclear if committed progenitors already exist among these progenitors and how they may behave differently during inflammation. By combining single-cell transcriptomic and proteomic analyses, we identified the early committed progenitor within the GMPs responsible for the strict production of neutrophils, which we designate as proNeu1. Our dissection of the GMP hierarchy led us to further identify a previously unknown intermediate proNeu2 population. Similar populations could be detected in human samples. proNeu1s, but not proNeu2s, selectively expanded during the early phase of sepsis at the expense of monocytes. Collectively, our findings help shape the neutrophil maturation trajectory roadmap and challenge the current definition of GMPs.


Assuntos
Células Precursoras de Granulócitos/citologia , Monócitos/citologia , Mielopoese/fisiologia , Neutrófilos/citologia , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Célula Única
3.
Nature ; 590(7846): 457-462, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33568812

RESUMO

In contrast to nearly all other tissues, the anatomy of cell differentiation in the bone marrow remains unknown. This is owing to a lack of strategies for examining myelopoiesis-the differentiation of myeloid progenitors into a large variety of innate immune cells-in situ in the bone marrow. Such strategies are required to understand differentiation and lineage-commitment decisions, and to define how spatial organizing cues inform tissue function. Here we develop approaches for imaging myelopoiesis in mice, and generate atlases showing the differentiation of granulocytes, monocytes and dendritic cells. The generation of granulocytes and dendritic cells-monocytes localizes to different blood-vessel structures known as sinusoids, and displays lineage-specific spatial and clonal architectures. Acute systemic infection with Listeria monocytogenes induces lineage-specific progenitor clusters to undergo increased self-renewal of progenitors, but the different lineages remain spatially separated. Monocyte-dendritic cell progenitors (MDPs) map with nonclassical monocytes and conventional dendritic cells; these localize to a subset of blood vessels expressing a major regulator of myelopoiesis, colony-stimulating factor 1 (CSF1, also known as M-CSF)1. Specific deletion of Csf1 in endothelium disrupts the architecture around MDPs and their localization to sinusoids. Subsequently, there are fewer MDPs and their ability to differentiate is reduced, leading to a loss of nonclassical monocytes and dendritic cells during both homeostasis and infection. These data indicate that local cues produced by distinct blood vessels are responsible for the spatial organization of definitive blood cell differentiation.


Assuntos
Rastreamento de Células/métodos , Células Mieloides/citologia , Mielopoese , Coloração e Rotulagem/métodos , Animais , Atlas como Assunto , Vasos Sanguíneos/citologia , Vasos Sanguíneos/metabolismo , Linhagem da Célula , Autorrenovação Celular , Células Dendríticas/citologia , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Feminino , Granulócitos/citologia , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Fator Estimulador de Colônias de Macrófagos/deficiência , Fator Estimulador de Colônias de Macrófagos/genética , Fator Estimulador de Colônias de Macrófagos/metabolismo , Masculino , Camundongos , Monócitos/citologia , Células Mieloides/metabolismo
4.
Immunity ; 47(5): 890-902.e4, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29166589

RESUMO

Granulocyte-monocyte progenitors (GMPs) and monocyte-dendritic cell progenitors (MDPs) produce monocytes during homeostasis and in response to increased demand during infection. Both progenitor populations are thought to derive from common myeloid progenitors (CMPs), and a hierarchical relationship (CMP-GMP-MDP-monocyte) is presumed to underlie monocyte differentiation. Here, however, we demonstrate that mouse MDPs arose from CMPs independently of GMPs, and that GMPs and MDPs produced monocytes via similar but distinct monocyte-committed progenitors. GMPs and MDPs yielded classical (Ly6Chi) monocytes with gene expression signatures that were defined by their origins and impacted their function. GMPs produced a subset of "neutrophil-like" monocytes, whereas MDPs gave rise to a subset of monocytes that yielded monocyte-derived dendritic cells. GMPs and MDPs were also independently mobilized to produce specific combinations of myeloid cell types following the injection of microbial components. Thus, the balance of GMP and MDP differentiation shapes the myeloid cell repertoire during homeostasis and following infection.


Assuntos
Células Dendríticas/fisiologia , Células Precursoras de Granulócitos/fisiologia , Monócitos/fisiologia , Células Progenitoras Mieloides/fisiologia , Animais , Antígenos Ly/análise , Diferenciação Celular , Leucossialina/análise , Camundongos , Análise de Sequência de RNA , Transcriptoma
5.
Nature ; 582(7810): 109-114, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494068

RESUMO

Advances in genetics and sequencing have identified a plethora of disease-associated and disease-causing genetic alterations. To determine causality between genetics and disease, accurate models for molecular dissection are required; however, the rapid expansion of transcriptional populations identified through single-cell analyses presents a major challenge for accurate comparisons between mutant and wild-type cells. Here we generate mouse models of human severe congenital neutropenia (SCN) using patient-derived mutations in the GFI1 transcription factor. To determine the effects of SCN mutations, we generated single-cell references for granulopoietic genomic states with linked epitopes1, aligned mutant cells to their wild-type equivalents and identified differentially expressed genes and epigenetic loci. We find that GFI1-target genes are altered sequentially, as cells go through successive states of differentiation. These insights facilitated the genetic rescue of granulocytic specification but not post-commitment defects in innate immune effector function, and underscore the importance of evaluating the effects of mutations and therapy within each relevant cell state.


Assuntos
Modelos Animais de Doenças , Células Precursoras de Granulócitos/patologia , Mutação , Neutropenia/genética , Neutropenia/patologia , Neutrófilos/patologia , Animais , Candida albicans/imunologia , Candida albicans/patogenicidade , Linhagem da Célula , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imunidade Inata , Masculino , Camundongos , Camundongos Transgênicos , Neutropenia/congênito , Neutropenia/imunologia , Neutrófilos/imunologia , Fatores de Transcrição/genética
6.
Nature ; 569(7755): E3, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31019298

RESUMO

In this Letter, the first name of author Virendra K. Chaudhri was incorrectly spelled 'Viren'; author Meenakshi Venkatasubramanian should also be associated with 'Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, Ohio 45221, USA'; authors Bruce J. Aronow, Nathan Salomonis, Harinder Singh and H. Leighton Grimes should also be associated with 'Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, USA'. The Letter has not been corrected online.

7.
Blood ; 140(14): 1621-1634, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-35862735

RESUMO

The erythroblastic island (EBI), composed of a central macrophage surrounded by maturing erythroblasts, is the erythroid precursor niche. Despite numerous studies, its precise composition is still unclear. Using multispectral imaging flow cytometry, in vitro island reconstitution, and single-cell RNA sequencing of adult mouse bone marrow (BM) EBI-component cells enriched by gradient sedimentation, we present evidence that the CD11b+ cells present in the EBIs are neutrophil precursors specifically associated with BM EBI macrophages, indicating that erythro-(myelo)-blastic islands are a site for terminal granulopoiesis and erythropoiesis. We further demonstrate that the balance between these dominant and terminal differentiation programs is dynamically regulated within this BM niche by pathophysiological states that favor granulopoiesis during anemia of inflammation and favor erythropoiesis after erythropoietin stimulation. Finally, by molecular profiling, we reveal the heterogeneity of EBI macrophages by cellular indexing of transcriptome and epitope sequencing of mouse BM EBIs at baseline and after erythropoietin stimulation in vivo and provide a searchable online viewer of these data characterizing the macrophage subsets serving as hematopoietic niches. Taken together, our findings demonstrate that EBIs serve a dual role as niches for terminal erythropoiesis and granulopoiesis and the central macrophages adapt to optimize production of red blood cells or neutrophils.


Assuntos
Eritropoese , Eritropoetina , Animais , Camundongos , Epitopos , Eritroblastos , Eritropoese/fisiologia
8.
Nature ; 537(7622): 698-702, 2016 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-27580035

RESUMO

Delineating hierarchical cellular states, including rare intermediates and the networks of regulatory genes that orchestrate cell-type specification, are continuing challenges for developmental biology. Single-cell RNA sequencing is greatly accelerating such research, given its power to provide comprehensive descriptions of genomic states and their presumptive regulators. Haematopoietic multipotential progenitor cells, as well as bipotential intermediates, manifest mixed-lineage patterns of gene expression at a single-cell level. Such mixed-lineage states may reflect the molecular priming of different developmental potentials by co-expressed alternative-lineage determinants, namely transcription factors. Although a bistable gene regulatory network has been proposed to regulate the specification of either neutrophils or macrophages, the nature of the transition states manifested in vivo, and the underlying dynamics of the cell-fate determinants, have remained elusive. Here we use single-cell RNA sequencing coupled with a new analytic tool, iterative clustering and guide-gene selection, and clonogenic assays to delineate hierarchical genomic and regulatory states that culminate in neutrophil or macrophage specification in mice. We show that this analysis captured prevalent mixed-lineage intermediates that manifested concurrent expression of haematopoietic stem cell/progenitor and myeloid progenitor cell genes. It also revealed rare metastable intermediates that had collapsed the haematopoietic stem cell/progenitor gene expression programme, instead expressing low levels of the myeloid determinants, Irf8 and Gfi1 (refs 9, 10, 11, 12, 13). Genetic perturbations and chromatin immunoprecipitation followed by sequencing revealed Irf8 and Gfi1 as key components of counteracting myeloid-gene-regulatory networks. Combined loss of these two determinants 'trapped' the metastable intermediate. We propose that mixed-lineage states are obligatory during cell-fate specification, manifest differing frequencies because of their dynamic instability and are dictated by counteracting gene-regulatory networks.


Assuntos
Diferenciação Celular/genética , Linhagem da Célula/genética , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Macrófagos/citologia , Neutrófilos/citologia , Análise de Célula Única/métodos , Animais , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/metabolismo , Feminino , Fatores Reguladores de Interferon/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Células Progenitoras Mieloides/citologia , Células Progenitoras Mieloides/metabolismo , Neutrófilos/metabolismo , Análise de Sequência de RNA , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Cytometry A ; 93(5): 556-562, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29533508

RESUMO

The advent of facile genome engineering technologies has made the generation of knock-in gene-expression or fusion-protein reporters more tractable. Fluorescent protein labeling of specific genes combined with surface marker profiling can more specifically identify a cell population. However, the question of which fluorescent proteins to utilize to generate reporter constructs is made difficult by the number of candidate proteins and the lack of updated experimental data on newer fluorescent proteins. Compounding this problem, most fluorescent proteins are designed and tested for use in microscopy. To address this, we cloned and characterized the detection sensitivity, spectral overlap, and spillover spreading of 13 monomeric fluorescent proteins to determine utility in multicolor panels. We identified a group of five fluorescent proteins with high signal to noise ratio, minimal spectral overlap, and low spillover spreading making them compatible for multicolor experiments. Specifically, generating reporters with combinations of three of these proteins would allow efficient measurements even at low-level expression. Because the proteins are monomeric, they could function either as gene-expression or as fusion-protein reporters. Additionally, this approach can be generalized as new fluorescent proteins are developed to determine their usefulness in multicolor panels. © 2018 International Society for Advancement of Cytometry.


Assuntos
Citometria de Fluxo/métodos , Corantes Fluorescentes , Genes Reporter , Animais , Linhagem Celular , Humanos , Camundongos , Microscopia Confocal
10.
Haematologica ; 103(7): 1110-1123, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29650642

RESUMO

SET domain containing 2 (Setd2), encoding a histone methyltransferase, is associated with many hematopoietic diseases when mutated. By generating a novel exon 6 conditional knockout mouse model, we describe an essential role of Setd2 in maintaining the adult hematopoietic stem cells. Loss of Setd2 results in leukopenia, anemia, and increased platelets accompanied by hypocellularity, erythroid dysplasia, and mild fibrosis in bone marrow. Setd2 knockout mice show significantly decreased hematopoietic stem and progenitor cells except for erythroid progenitors. Setd2 knockout hematopoietic stem cells fail to establish long-term bone marrow reconstitution after transplantation because of the loss of quiescence, increased apoptosis, and reduced multiple-lineage terminal differentiation potential. Bioinformatic analysis revealed that the hematopoietic stem cells exit from quiescence and commit to differentiation, which lead to hematopoietic stem cell exhaustion. Mechanistically, we attribute an important Setd2 function in murine adult hematopoietic stem cells to the inhibition of the Nsd1/2/3 transcriptional complex, which recruits super elongation complex and controls RNA polymerase II elongation on a subset of target genes, including Myc Our results reveal a critical role of Setd2 in regulating quiescence and differentiation of hematopoietic stem cells through restricting the NSDs/SEC mediated RNA polymerase II elongation.


Assuntos
Diferenciação Celular/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Histona-Lisina N-Metiltransferase/genética , RNA Polimerase II/metabolismo , Fase de Repouso do Ciclo Celular/genética , Alelos , Animais , Apoptose/genética , Biomarcadores , Biópsia , Linhagem da Célula/genética , Proliferação de Células , Autorrenovação Celular/genética , Técnicas de Silenciamento de Genes , Hematopoese , Histona-Lisina N-Metiltransferase/metabolismo , Imuno-Histoquímica , Imunofenotipagem , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Elongação Traducional da Cadeia Peptídica , Fosforilação
11.
Blood ; 118(6): 1534-43, 2011 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-21670467

RESUMO

Hypoxia is emerging as an important characteristic of the hematopoietic stem cell (HSC) niche, but the molecular mechanisms contributing to quiescence, self-renewal, and survival remain elusive. Vascular endothelial growth factor A (VEGFA) is a key regulator of angiogenesis and hematopoiesis. Its expression is commonly regulated by hypoxia-inducible factors (HIF) that are functionally induced in low-oxygen conditions and that activate transcription by binding to hypoxia-response elements (HRE). Vegfa is indispensable for HSC survival, mediated by a cell-intrinsic, autocrine mechanism. We hypothesized that a hypoxic HSC microenvironment is required for maintenance or up-regulation of Vegfa expression in HSCs and therefore crucial for HSC survival. We have tested this hypothesis in the mouse model Vegfa(δ/δ), where the HRE in the Vegfa promoter is mutated, preventing HIF binding. Vegfa expression was reduced in highly purified HSCs from Vegfa(δ/δ) mice, showing that HSCs reside in hypoxic areas. Loss of hypoxia-regulated Vegfa expression increases the numbers of phenotypically defined hematopoietic stem and progenitor cells. However, HSC function was clearly impaired when assessed in competitive transplantation assays. Our data provide further evidence that HSCs reside in a hypoxic microenvironment and demonstrate a novel way in which the hypoxic niche affects HSC fate, via the hypoxia-VEGFA axis.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Oxigênio/metabolismo , Nicho de Células-Tronco/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Hipóxia Celular , Células Cultivadas , Feminino , Citometria de Fluxo , Expressão Gênica , Genótipo , Lâmina de Crescimento/irrigação sanguínea , Lâmina de Crescimento/crescimento & desenvolvimento , Hematopoese/genética , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Hexoquinase/genética , Hexoquinase/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fígado/citologia , Fígado/embriologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfoglicerato Quinase/genética , Fosfoglicerato Quinase/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Nicho de Células-Tronco/citologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Biochim Biophys Acta ; 1779(10): 590-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18586123

RESUMO

The leukaemia-associated eight-twenty-one (ETO) family members ETO, MTG16 (Myeloid Translocation Gene on chromosome 16) and MTGR1 (Myeloid Transforming Gene-Related protein1) are putative transcriptional repressor proteins, which form complexes with coregulatory nuclear corepressors such as SIN3 (SWI-Independent) and N-CoR (Nuclear receptor Co Repressor). In acute myeloid leukaemia (AML), fusion proteins involving the transcription factor AML1 and corepressors ETO or MTG16 are recurrently found. We investigated transcriptional repression by the ETO family members ETO and MTG16 with attention to the conserved Nervy Homology Regions (NHRs) and the interacting corepressors human SIN3B (hSIN3B) and N-CoR. Transcriptional repression was examined in a cell line by a GAL4-thymidine kinase luciferase reporter to which the corepressors were tethered through a binding domain. ETO- and MTG16-mediated repression was found to be independent of deletion of the oligomerization NHR2, but deletion of NHR4 and in particular combined deletion of NHR2 and NHR4 lowered the capacity for repression. An interaction was observed between the corepressors hSIN3B and N-CoR and these two proteins cooperated for transcriptional repression independent of co-transfected ETO and MTG16. Transcriptional repression mediated by ETO and MTG16 was only slightly strengthened by coexpression of hSIN3B or N-CoR and was dependent on HDAC activity. Our data indicate that ETO family member-mediated oligomerization and repression can be distinct events and that interaction between ETO family members and hSIN3B or N-CoR may not necessarily strengthen transcriptional repression.


Assuntos
Proteínas Nucleares/metabolismo , Fosfoproteínas/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Repressoras/metabolismo , Proteínas Repressoras/fisiologia , Fatores de Transcrição/fisiologia , Transcrição Gênica/fisiologia , Proteínas Supressoras de Tumor/fisiologia , Células Cultivadas , Dimerização , Regulação para Baixo , Histona Desacetilases/metabolismo , Histona Desacetilases/fisiologia , Humanos , Família Multigênica/fisiologia , Proteínas Nucleares/genética , Correpressor 1 de Receptor Nuclear , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Transgenes , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
13.
Cancer Discov ; 9(8): 1080-1101, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31085557

RESUMO

Aging is associated with functional decline of hematopoietic stem cells (HSC) as well as an increased risk of myeloid malignancies. We performed an integrative characterization of epigenomic and transcriptomic changes, including single-cell RNA sequencing, during normal human aging. Lineage-CD34+CD38- cells [HSC-enriched (HSCe)] undergo age-associated epigenetic reprogramming consisting of redistribution of DNA methylation and reductions in H3K27ac, H3K4me1, and H3K4me3. This reprogramming of aged HSCe globally targets developmental and cancer pathways that are comparably altered in acute myeloid leukemia (AML) of all ages, encompassing loss of 4,646 active enhancers, 3,091 bivalent promoters, and deregulation of several epigenetic modifiers and key hematopoietic transcription factors, such as KLF6, BCL6, and RUNX3. Notably, in vitro downregulation of KLF6 results in impaired differentiation, increased colony-forming potential, and changes in expression that recapitulate aging and leukemia signatures. Thus, age-associated epigenetic reprogramming may form a predisposing condition for the development of age-related AML. SIGNIFICANCE: AML, which is more frequent in the elderly, is characterized by epigenetic deregulation. We demonstrate that epigenetic reprogramming of human HSCs occurs with age, affecting cancer and developmental pathways. Downregulation of genes epigenetically altered with age leads to impairment in differentiation and partially recapitulates aging phenotypes.This article is highlighted in the In This Issue feature, p. 983.


Assuntos
Diferenciação Celular/genética , Reprogramação Celular/genética , Senescência Celular/genética , Epigênese Genética , Células-Tronco Hematopoéticas/metabolismo , Leucemia/genética , Leucemia/metabolismo , Citosina/metabolismo , Metilação de DNA , Suscetibilidade a Doenças , Elementos Facilitadores Genéticos , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Histonas/metabolismo , Humanos , Fator 6 Semelhante a Kruppel/genética , Fator 6 Semelhante a Kruppel/metabolismo , Leucemia/patologia , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo
14.
Cancer Discov ; 8(11): 1438-1457, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30139811

RESUMO

Myelodysplastic syndromes (MDS) are heterogeneous hematopoietic disorders that are incurable with conventional therapy. Their incidence is increasing with global population aging. Although many genetic, epigenetic, splicing, and metabolic aberrations have been identified in patients with MDS, their clinical features are quite similar. Here, we show that hypoxia-independent activation of hypoxia-inducible factor 1α (HIF1A) signaling is both necessary and sufficient to induce dysplastic and cytopenic MDS phenotypes. The HIF1A transcriptional signature is generally activated in MDS patient bone marrow stem/progenitors. Major MDS-associated mutations (Dnmt3a, Tet2, Asxl1, Runx1, and Mll1) activate the HIF1A signature. Although inducible activation of HIF1A signaling in hematopoietic cells is sufficient to induce MDS phenotypes, both genetic and chemical inhibition of HIF1A signaling rescues MDS phenotypes in a mouse model of MDS. These findings reveal HIF1A as a central pathobiologic mediator of MDS and as an effective therapeutic target for a broad spectrum of patients with MDS.Significance: We showed that dysregulation of HIF1A signaling could generate the clinically relevant diversity of MDS phenotypes by functioning as a signaling funnel for MDS driver mutations. This could resolve the disconnection between genotypes and phenotypes and provide a new clue as to how a variety of driver mutations cause common MDS phenotypes. Cancer Discov; 8(11); 1438-57. ©2018 AACR. See related commentary by Chen and Steidl, p. 1355 This article is highlighted in the In This Issue feature, p. 1333.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/fisiologia , Histona-Lisina N-Metiltransferase/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Hipóxia/fisiopatologia , Síndromes Mielodisplásicas/patologia , Proteína de Leucina Linfoide-Mieloide/fisiologia , Animais , Regulação Neoplásica da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Metaboloma , Camundongos , Camundongos Knockout , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo
15.
Exp Hematol ; 33(2): 189-98, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15676213

RESUMO

The Eight twenty-one (ETO) homologues are nuclear repressor proteins including ETO, myeloid-transforming gene-related protein 1 (MTGR1), and myeloid-transforming gene chromosome 16 (MTG16). ETO and MTG16 are both part of fusion proteins resulting from chromosomal translocations associated with acute myeloid leukemia. Expression of these chimeras results in a differentiation block that contributes to the onset of leukemia. In order to elucidate the relation between the ETO homologues and hematopoietic differentiation, we determined the expression of the homologues during differentiation of leukemic and normal hematopoietic cells. Our results showed MTGR1 and MTG16 to be ubiquitously expressed in leukemic cell lines, whereas expression of ETO was observed only in an erythroleukemic cell line. The MTGR1 and MTG16 proteins decreased during all trans-retinoic acid-, but not vitamin D(3)-induced differentiation of leukemic cells. The reduction seemed to reflect a decrease in transcript levels as well as in protein stability. MTGR1 transcripts were ubiquitously expressed in human bone marrow cells. The MTG16 transcripts of CD34(+) progenitor cells were rapidly downregulated by cytokine-induced differentiation into myeloid or erythroid lineages. ETO transcripts, present at very low abundance in CD34(+) progenitor cells, were transiently upregulated during erythroid differentiation. In conclusion, the differential expression of the ETO homologues suggests that they may have a potential role in hematopoietic differentiation.


Assuntos
Proteínas de Ligação a DNA/genética , Células-Tronco Hematopoéticas/citologia , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Células da Medula Óssea/citologia , Diferenciação Celular , Linhagem Celular , Linhagem Celular Tumoral , Primers do DNA , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Humanos , Células K562 , Rim , Leucemia , Fosfoproteínas/genética , Reação em Cadeia da Polimerase , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Acetato de Tetradecanoilforbol/farmacologia , Tretinoína/farmacologia , Proteínas Supressoras de Tumor/genética , Células U937
16.
J Clin Invest ; 123(9): 3876-88, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23979164

RESUMO

RUNX1 is generally considered a tumor suppressor in myeloid neoplasms. Inactivating RUNX1 mutations have frequently been found in patients with myelodysplastic syndrome (MDS) and cytogenetically normal acute myeloid leukemia (AML). However, no somatic RUNX1 alteration was found in AMLs with leukemogenic fusion proteins, such as core-binding factor (CBF) leukemia and MLL fusion leukemia, raising the possibility that RUNX1 could actually promote the growth of these leukemia cells. Using normal human cord blood cells and those expressing leukemogenic fusion proteins, we discovered a dual role of RUNX1 in myeloid leukemogenesis. RUNX1 overexpression inhibited the growth of normal cord blood cells by inducing myeloid differentiation, whereas a certain level of RUNX1 activity was required for the growth of AML1-ETO and MLL-AF9 cells. Using a mouse genetic model, we also showed that the combined loss of Runx1/Cbfb inhibited leukemia development induced by MLL-AF9. RUNX2 could compensate for the loss of RUNX1. The survival effect of RUNX1 was mediated by BCL2 in MLL fusion leukemia. Our study unveiled an unexpected prosurvival role for RUNX1 in myeloid leukemogenesis. Inhibiting RUNX1 activity rather than enhancing it could be a promising therapeutic strategy for AMLs with leukemogenic fusion proteins.


Assuntos
Sobrevivência Celular , Subunidade alfa 2 de Fator de Ligação ao Core/fisiologia , Animais , Apoptose , Pontos de Checagem do Ciclo Celular , Proliferação de Células , Células Cultivadas , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Subunidade beta de Fator de Ligação ao Core/metabolismo , Humanos , Leucemia Mieloide Aguda , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Mutação de Sentido Incorreto , Células Mieloides/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Transplante de Neoplasias , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína 1 Parceira de Translocação de RUNX1
17.
Eur J Haematol ; 71(6): 439-47, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14703694

RESUMO

The eight-twenty-one (ETO) homologues, represented by ETO, myeloid transforming gene-related protein 1 (MTGR1) and myeloid transforming gene chromosome 16 (MTG16), are nuclear repressor proteins. ETO is part of the fusion protein acute myeloid leukaemia (AML)1-ETO, resulting from the translocation (8;21). Similarly, MTG16 is disrupted to become part of AML1/MTG16 in t(16;21). The aberrant expression of these chimeras could affect interplay between ETO homologues and contribute to the leukaemogenic process. We investigated possible interactions between the ETO homologues. Ectopic co-expression in COS-cells resulted in heterodimerisation of the various ETO homologues suggesting that they may co-operate. Similarly, the chimeric oncoprotein AML1-ETO interacted with both MTGR1 and MTG16. However, results from cell lines endogenously expressing more than one ETO homologue did not demonstrate co-precipitation. Results from IP-Western and size determination by gel filtration of deletion mutants expressed in COS-cells, indicated an important role of the HHR domain for oligomerisation. A role was also suggested for the Nervy domain in the homologue interactions. Our results suggest that ETO homologues can interact with each other as well as with AML1-ETO, although it is unclear as to what extent these interactions occur in vivo.


Assuntos
Proteínas de Ligação a DNA/química , Fosfoproteínas/química , Proteínas Proto-Oncogênicas , Proteínas Repressoras/química , Fatores de Transcrição/química , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Western Blotting , Células COS , Núcleo Celular/química , Chlorocebus aethiops , Proteínas de Ligação a DNA/análise , Proteínas de Ligação a DNA/genética , Dimerização , Interações Medicamentosas , Deleção de Genes , Expressão Gênica , Técnicas de Imunoadsorção , Leucemia , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Fosfoproteínas/análise , Fosfoproteínas/genética , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/análise , Proteínas Repressoras/genética , Homologia de Sequência , Fatores de Transcrição/análise , Fatores de Transcrição/genética , Transfecção , Células Tumorais Cultivadas
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