RESUMO
Epithelial-to-mesenchymal-transition (EMT) is critical for normal embryogenesis and effective postnatal wound healing, but is also associated with cancer metastasis. SNAIL, ZEB, and TWIST families of transcription factors are key modulators of the EMT process, but their precise roles in adult hematopoietic development and homeostasis remain unclear. Here we report that genetic inactivation of Zeb2 results in increased frequency of stem and progenitor subpopulations within the bone marrow (BM) and spleen and that these changes accompany differentiation defects in multiple hematopoietic cell lineages. We found no evidence that Zeb2 is critical for hematopoietic stem cell self-renewal capacity. However, knocking out Zeb2 in the BM promoted a phenotype with several features that resemble human myeloproliferative disorders, such as BM fibrosis, splenomegaly, and extramedullary hematopoiesis. Global gene expression and intracellular signal transduction analysis revealed perturbations in specific cytokine and cytokine receptor-related signaling pathways following Zeb2 loss, especially the JAK-STAT and extracellular signal-regulated kinase pathways. Moreover, we detected some previously unknown mutations within the human Zeb2 gene (ZFX1B locus) from patients with myeloid disease. Collectively, our results demonstrate that Zeb2 controls adult hematopoietic differentiation and lineage fidelity through widespread modulation of dominant signaling pathways that may contribute to blood disorders.
Assuntos
Citocinas/genética , Transição Epitelial-Mesenquimal/genética , Hematopoese Extramedular/genética , Proteínas de Homeodomínio/genética , Mielofibrose Primária/genética , Proteínas Repressoras/genética , Esplenomegalia/genética , Adulto , Animais , Sequência de Bases , Medula Óssea/metabolismo , Medula Óssea/patologia , Diferenciação Celular , Linhagem da Célula/genética , Citocinas/metabolismo , Regulação da Expressão Gênica , Humanos , Janus Quinases/genética , Janus Quinases/metabolismo , Camundongos , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação , Mielofibrose Primária/metabolismo , Mielofibrose Primária/patologia , Proteínas Repressoras/deficiência , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Baço/metabolismo , Baço/patologia , Esplenomegalia/metabolismo , Esplenomegalia/patologia , Células-Tronco/metabolismo , Células-Tronco/patologia , Transcrição Gênica , Homeobox 2 de Ligação a E-box com Dedos de ZincoRESUMO
Natural killer (NK) cell maturation is a tightly controlled process that endows NK cells with functional competence and the capacity to recognize target cells. Here, we found that the transcription factor (TF) Zeb2 was the most highly induced TF during NK cell maturation. Zeb2 is known to control epithelial to mesenchymal transition, but its role in immune cells is mostly undefined. Targeted deletion of Zeb2 resulted in impaired NK cell maturation, survival, and exit from the bone marrow. NK cell function was preserved, but mice lacking Zeb2 in NK cells were more susceptible to B16 melanoma lung metastases. Reciprocally, ectopic expression of Zeb2 resulted in a higher frequency of mature NK cells in all organs. Moreover, the immature phenotype of Zeb2(-/-) NK cells closely resembled that of Tbx21(-/-) NK cells. This was caused by both a dependence of Zeb2 expression on T-bet and a probable cooperation of these factors in gene regulation. Transgenic expression of Zeb2 in Tbx21(-/-) NK cells partially restored a normal maturation, establishing that timely induction of Zeb2 by T-bet is an essential event during NK cell differentiation. Finally, this novel transcriptional cascade could also operate in human as T-bet and Zeb2 are similarly regulated in mouse and human NK cells.
Assuntos
Proteínas de Homeodomínio/imunologia , Células Matadoras Naturais/imunologia , Melanoma Experimental/imunologia , Proteínas Repressoras/imunologia , Proteínas com Domínio T/imunologia , Animais , Medula Óssea/imunologia , Medula Óssea/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Citometria de Fluxo , Expressão Gênica/imunologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Células Matadoras Naturais/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de ZincoRESUMO
Early T-cell precursor leukaemia (ETP-ALL) is a high-risk subtype of human leukaemia that is poorly understood at the molecular level. Here we report translocations targeting the zinc finger E-box-binding transcription factor ZEB2 as a recurrent genetic lesion in immature/ETP-ALL. Using a conditional gain-of-function mouse model, we demonstrate that sustained Zeb2 expression initiates T-cell leukaemia. Moreover, Zeb2-driven mouse leukaemia exhibit some features of the human immature/ETP-ALL gene expression signature, as well as an enhanced leukaemia-initiation potential and activated Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signalling through transcriptional activation of IL7R. This study reveals ZEB2 as an oncogene in the biology of immature/ETP-ALL and paves the way towards pre-clinical studies of novel compounds for the treatment of this aggressive subtype of human T-ALL using our Zeb2-driven mouse model.
