Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
2.
Nat Med ; 11(8): 845-52, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16041381

RESUMEN

The latent transcription factor Stat3 is activated by gp130, the common receptor for the interleukin (IL)-6 cytokine family and other growth factor and cytokine receptors. Ligand-induced dimerization of gp130 leads to activation of the Stat1, Stat3 and Shp2-Ras-Erk signaling pathways. Here we assess genetically the contribution of exaggerated Stat3 activation to the phenotype of gp130 (Y757F/Y757F) mice, in which a knock-in mutation disrupts the negative feedback mechanism on gp130-dependent Stat signaling. Compared to gp130 (Y757F/Y757F) mice, reduced Stat3 activation in gp130 (Y757F/Y757F) Stat3(+/-) mice increased their lifespan, prevented splenomegaly, normalized exaggerated hepatic acute-phase response and lymphocyte trafficking, and suppressed the growth of spontaneously arising gastric adenomas in young mice. These lesions share histological features of gastric polyps in aging mice with monoallelic null mutations in Smad4, which encodes the common transducer for transforming growth factor (TGF)-beta signaling. Indeed, hyperactivation of Stat3 desensitizes gp130 (Y757F/Y757F) cells to the cytostatic effect of TGF-beta through transcriptional induction of inhibitory Smad7, thereby providing a novel link for cross-talk between Stat and Smad signaling in gastric homeostasis.


Asunto(s)
Adenoma/metabolismo , Receptor gp130 de Citocinas/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/fisiología , Neoplasias Gástricas/metabolismo , Activación Transcripcional/fisiología , Factor de Crecimiento Transformador beta/metabolismo , Adenoma/fisiopatología , Animales , Receptor gp130 de Citocinas/genética , Técnicas Histológicas , Immunoblotting , Ratones , Ratones Mutantes , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína smad7/metabolismo , Neoplasias Gástricas/fisiopatología
3.
J Clin Invest ; 118(5): 1727-38, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18431520

RESUMEN

Deregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates an antiapoptotic, proangiogenic, and proproliferative environment for neoplastic cells, the molecular mechanisms leading to STAT3 hyperactivation remain poorly understood. Using the gp130(Y757F/Y757F) mouse model of gastric cancer, which carries a mutated gp130 cytokine receptor signaling subunit that cannot bind the negative regulator of cytokine signaling SOCS3 and is characterized by hyperactivation of the signaling molecules STAT1 and STAT3, we have provided genetic evidence that IL-11 promotes chronic gastric inflammation and associated tumorigenesis. Expression of IL-11 was increased in gastric tumors in gp130(Y757F/Y757F) mice, when compared with unaffected gastric tissue in wild-type mice, while gp130(Y757F/Y757F) mice lacking the IL-11 ligand-binding receptor subunit (IL-11Ralpha) showed normal gastric STAT3 activation and IL-11 expression and failed to develop gastric tumors. Furthermore, reducing STAT3 activity in gp130(Y757F/Y757F) mice, either genetically or by therapeutic administration of STAT3 antisense oligonucleotides, normalized gastric IL-11 expression and alleviated gastric tumor burden. Surprisingly, the genetic reduction of STAT1 expression also reduced gastric tumorigenesis in gp130(Y757F/Y757F) mice and coincided with reduced gastric inflammation and IL-11 expression. Collectively, our data have identified IL-11 as a crucial cytokine promoting chronic gastric inflammation and associated tumorigenesis mediated by excessive activation of STAT3 and STAT1.


Asunto(s)
Receptor gp130 de Citocinas/inmunología , Inflamación/metabolismo , Interleucina-11/inmunología , Factor de Transcripción STAT1/inmunología , Factor de Transcripción STAT3/inmunología , Neoplasias Gástricas/metabolismo , Animales , Receptor gp130 de Citocinas/genética , Mucosa Gástrica/metabolismo , Humanos , Interleucina-11/genética , Interleucina-6/inmunología , Ratones , Ratones Noqueados , Ratones Transgénicos , Oligonucleótidos Antisentido/genética , Oligonucleótidos Antisentido/metabolismo , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT3/genética , Transducción de Señal/fisiología , Estómago/anatomía & histología , Estómago/patología , Neoplasias Gástricas/patología
4.
Nat Med ; 8(10): 1089-97, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12219085

RESUMEN

The intracellular signaling mechanisms that specify tissue-specific responses to the interleukin-6 (IL-6) family of cytokines are not well understood. Here, we evaluated the functions of the two major signaling pathways, the signal transducers and activators of transcription 1 and 3 (STAT1/3) and the Src-homology tyrosine phosphatase 2 (SHP2)-Ras-ERK, emanating from the common signal transducer, gp130, in the gastrointestinal tract. Gp130(757F) mice, with a 'knock-in' mutation abrogating SHP2-Ras-ERK signaling, developed gastric adenomas by three months of age. In contrast, mice harboring the reciprocal mutation ablating STAT1/3 signaling (gp130(Delta STAT)), or deficient in IL-6-mediated gp130 signaling (IL-6(-/-) mice), showed impaired colonic mucosal wound healing. These gastrointestinal phenotypes are highly similar to the phenotypes exhibited by mice deficient in trefoil factor 1 (pS2/TFF1) and intestinal trefoil factor (ITF)/TFF3, respectively, and corresponded closely with the capacity of the two pathways to stimulate transcription of the genes encoding pS2/TFF1 and ITF/TFF3. We propose a model whereby mucosal wound healing depends solely on activation of STAT1/3, whereas gastric hyperplasia ensues when the coordinated activation of the STAT1/3 and SHP2-Ras-ERK pathways is disrupted.


Asunto(s)
Antígenos CD/metabolismo , Proteínas de Unión al ADN/metabolismo , Fenómenos Fisiológicos del Sistema Digestivo , Sustancias de Crecimiento/genética , Homeostasis , Glicoproteínas de Membrana/metabolismo , Mucinas , Proteínas Musculares , Neuropéptidos , Péptidos/genética , Proteínas Tirosina Fosfatasas/metabolismo , Transactivadores/metabolismo , Adenoma/metabolismo , Adenoma/patología , Animales , Antígenos CD/genética , Línea Celular , Colon/metabolismo , Colon/patología , Receptor gp130 de Citocinas , Mucosa Gástrica/metabolismo , Regulación de la Expresión Génica , Sustancias de Crecimiento/metabolismo , Interleucina-11/metabolismo , Interleucina-6/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Péptidos y Proteínas de Señalización Intracelular , Glicoproteínas de Membrana/genética , Ratones , Ratones Transgénicos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Péptidos/metabolismo , Proteína Fosfatasa 2 , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteínas/genética , Proteínas/metabolismo , Factor de Transcripción STAT1 , Transducción de Señal/fisiología , Bazo/citología , Bazo/metabolismo , Estómago/citología , Estómago/patología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Activación Transcripcional , Factor Trefoil-2 , Factor Trefoil-3 , Cicatrización de Heridas
5.
J Immunol ; 181(3): 2189-95, 2008 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-18641358

RESUMEN

The successful resolution of inflammation is dependent upon the coordinated transition from the initial recruitment of neutrophils to a more sustained population of mononuclear cells. IL-6, which signals via the common receptor subunit gp130, represents a crucial checkpoint regulator of neutrophil trafficking during the inflammatory response by orchestrating chemokine production and leukocyte apoptosis. However, the relative contribution of specific IL-6-dependent signaling pathways to these processes remains unresolved. To define the receptor-mediated signaling events responsible for IL-6-driven neutrophil trafficking, we used a series of gp130 knockin mutant mice displaying altered IL-6-signaling capacities in an experimental model of acute peritoneal inflammation. Hyperactivation of STAT1 and STAT3 in gp130(Y757F/Y757F) mice led to a more rapid clearance of neutrophils, and this coincided with a pronounced down-modulation in production of the neutrophil-attracting chemokine CXCL1/KC. By contrast, the proportion of apoptotic neutrophils in the inflammatory infiltrate remained unaffected. In gp130(Y757F/Y757F) mice lacking IL-6, neutrophil trafficking and CXCL1/KC levels were normal, and this corresponded with a reduction in the level of STAT1/3 activity. Furthermore, monoallelic ablation of Stat3 in gp130(Y757F/Y757F) mice specifically reduced STAT3 activity and corrected both the rapid clearance of neutrophils and impaired CXCL1/KC production. Conversely, genetic deletion of Stat1 in gp130(Y757F/Y757F) mice failed to rescue the altered responses observed in gp130(Y757F/Y757F) mice. Collectively, these data genetically define that IL-6-driven signaling via STAT3, but not STAT1, limits the inflammatory recruitment of neutrophils, and therefore represents a critical event for the termination of the innate immune response.


Asunto(s)
Movimiento Celular/inmunología , Interleucina-6/inmunología , Interleucina-6/metabolismo , Neutrófilos/citología , Neutrófilos/metabolismo , Factor de Transcripción STAT3/metabolismo , Enfermedad Aguda , Animales , Apoptosis , Receptor gp130 de Citocinas/genética , Receptor gp130 de Citocinas/inmunología , Receptor gp130 de Citocinas/metabolismo , Regulación de la Expresión Génica , Genotipo , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/patología , Interleucina-6/deficiencia , Interleucina-6/genética , Ratones , Ratones Transgénicos , Neutrófilos/inmunología , Transducción de Señal
6.
J Cell Biol ; 158(1): 115-25, 2002 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-12093790

RESUMEN

Downstream of kinase (Dok)-related protein (DokR, also known as p56(dok)/FRIP/Dok-R) is implicated in cytokine and immunoreceptor signaling in myeloid and T cells. Tyrosine phosphorylation induces DokR to bind the signal relay molecules, RasGTPase-activating protein (RasGAP) and Nck. Here, we have examined the function of DokR during hematopoietic development and the requirement for RasGAP and Nck binding sites in its biological function. Retroviral-mediated expression of DokR in bone marrow cells dramatically inhibited their capacity to form colonies in vitro in response to the cytokines macrophage colony-stimulating factor and stem cell factor, whereas responses to interleukin-3 and granulocyte macrophage colony-stimulating factor were only weakly affected. When introduced into lethally irradiated mice, hematopoietic cells expressing DokR showed a drastically reduced capacity to repopulate lymphoid tissues. Most notably, DokR dramatically reduced repopulation of the thymus, in part by reducing the number of T cell precursors seeding in the thymus, but equally, through inhibiting the transition of CD4(-)CD8(-) to CD4(+)CD8(+) T cells. Consequently, the number of mature peripheral T cells was markedly reduced. In contrast, a minimal effect on B cell and myeloid lineage development was observed. Importantly, functional RasGAP and Nck binding sites were found to be essential for the biological effects of DokR in vitro and in vivo.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Portadoras/fisiología , Proteínas de Unión al GTP Monoméricas/metabolismo , Proteínas Oncogénicas/metabolismo , Fosfoproteínas/fisiología , Linfocitos T/citología , Animales , Linfocitos B/metabolismo , Sitios de Unión , Células de la Médula Ósea/metabolismo , Antígenos CD4/biosíntesis , Antígenos CD8/biosíntesis , División Celular , Linaje de la Célula , Separación Celular , Femenino , Citometría de Flujo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Proteínas Fluorescentes Verdes , Células Madre Hematopoyéticas/metabolismo , Immunoblotting , Interleucina-3/metabolismo , Proteínas Luminiscentes/metabolismo , Ratones , Ratones Endogámicos C57BL , Mutación , Fenotipo , Fosforilación , Pruebas de Precipitina , Retroviridae/genética , Linfocitos T/metabolismo , Timo/citología , Tirosina/metabolismo
7.
Mol Cell Biol ; 25(6): 2441-9, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15743836

RESUMEN

Vascular endothelial growth factor receptor 3 (Vegfr-3) is a tyrosine kinase that is expressed on the lymphatic endothelium and that signals for the growth of the lymphatic vessels (lymphangiogenesis). Vegf-d, a secreted glycoprotein, is one of two known activating ligands for Vegfr-3, the other being Vegf-c. Vegf-d stimulates lymphangiogenesis in tissues and tumors; however, its role in embryonic development was previously unknown. Here we report the generation and analysis of mutant mice deficient for Vegf-d. Vegf-d-deficient mice were healthy and fertile, had normal body mass, and displayed no pathologic changes consistent with a defect in lymphatic function. The lungs, sites of strong Vegf-d gene expression during embryogenesis in wild-type mice, were normal in Vegf-d-deficient mice with respect to tissue mass and morphology, except that the abundance of the lymphatics adjacent to bronchioles was slightly reduced. Dye uptake experiments indicated that large lymphatics under the skin were present in normal locations and were functional. Smaller dermal lymphatics were similar in number, location, and function to those in wild-type controls. The lack of a profound lymphatic phenotype in Vegf-d-deficient mice suggests that Vegf-d does not play a major role in lymphatic development or that Vegf-c or another, as-yet-unknown activating Vegfr-3 ligand can compensate for Vegf-d during development.


Asunto(s)
Endotelio Linfático/citología , Linfangiogénesis/genética , Factor D de Crecimiento Endotelial Vascular/fisiología , Receptor 3 de Factores de Crecimiento Endotelial Vascular/fisiología , Animales , Endotelio Linfático/química , Endotelio Linfático/metabolismo , Marcación de Gen , Pulmón/química , Pulmón/citología , Pulmón/metabolismo , Linfangiogénesis/fisiología , Ratones , Ratones Mutantes , Mutación/genética , Factor D de Crecimiento Endotelial Vascular/genética , Receptor 3 de Factores de Crecimiento Endotelial Vascular/análisis
8.
Mol Cell Biol ; 24(4): 1453-63, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14749363

RESUMEN

The mechanisms by which interleukin-6 (IL-6) family cytokines, which utilize the common receptor signaling subunit gp130, influence monocyte/macrophage development remain unclear. Here we have utilized macrophages devoid of either gp130-dependent STAT1/3 (gp130(Delta STAT/Delta STAT)) or extracellular signal-regulated kinases 1 and 2 (ERK1/2) mitogen-activated protein (MAP) kinase (gp130(Y757F/Y757F)) activation to assess the individual contribution of each pathway to macrophage formation. While the inhibition by IL-6 of macrophage colony-stimulating factor (M-CSF)-induced colony formation observed in gp130(wt/wt) mice was abolished in gp130(Delta STAT/Delta STAT) mice, inhibition of macrophage colony formation was enhanced in gp130(Y757F/Y757F) mice. In gp130(Delta STAT/Delta STAT) bone marrow-derived macrophages (BMMs), both IL-6- and M-CSF-induced ERK1/2 tyrosine phosphorylation was enhanced. By contrast, tyrosine phosphorylation of ERK1/2 in response to M-CSF was reduced in gp130(Y757F/Y757F) BMMs, and the pattern of ERK1/2 activation in gp130 mutant BMMs correlated with their opposing responsiveness to M-CSF-induced proliferation. When compared to the level of expression in gp130(wt/wt) BMMs, c-fms expression was elevated in gp130(Delta STAT/Delta STAT) BMMs but reduced in gp130(Y757F/Y757F) BMMs. Finally, an ERK1/2 inhibitor suppressed M-CSF-induced BMM proliferation, and this result corresponded to a reduction in c-fms expression. Collectively, these results provide a functional and causal correlation between gp130-dependent ERK MAP kinase signaling and c-fms gene activation, a finding that provides a potential mechanism underlying the inhibition of M-CSF-dependent macrophage development by IL-6 family cytokines in mice.


Asunto(s)
Antígenos CD/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Genes fms/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor Estimulante de Colonias de Macrófagos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Glicoproteínas de Membrana/metabolismo , Animales , Antígenos CD/genética , División Celular/efectos de los fármacos , Línea Celular , Receptor gp130 de Citocinas , Proteínas de Unión al ADN/metabolismo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Humanos , Interleucina-6/farmacología , Péptidos y Proteínas de Señalización Intracelular , Macrófagos/citología , Glicoproteínas de Membrana/genética , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Mutación , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteínas Tirosina Fosfatasas/metabolismo , Factor de Transcripción STAT3 , Transactivadores/metabolismo , Activación Transcripcional
9.
Mol Cell Biol ; 23(12): 4371-85, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12773577

RESUMEN

The type III transforming growth factor beta (TGFbeta) receptor (TbetaRIII) binds both TGFbeta and inhibin with high affinity and modulates the association of these ligands with their signaling receptors. However, the significance of TbetaRIII signaling in vivo is not known. In this study, we have sought to determine the role of TbetaRIII during development. We identified the predominant expression sites of TbetaRIII mRNA as liver and heart during midgestation and have disrupted the murine TbetaRIII gene by homologous recombination. Beginning at embryonic day 13.5, mice with mutations in TbetaRIII developed lethal proliferative defects in heart and apoptosis in liver, indicating that TbetaRIII is required during murine somatic development. To assess the effects of the absence of TbetaRIII on the function of its ligands, primary fibroblasts were generated from TbetaRIII-null and wild-type embryos. Our results indicate that TbetaRIII deficiency differentially affects the activities of TGFbeta ligands. Notably, TbetaRIII-null cells exhibited significantly reduced sensitivity to TGFbeta2 in terms of growth inhibition, reporter gene activation, and Smad2 nuclear localization, effects not observed with other ligands. These data indicate that TbetaRIII is an important modulator of TGFbeta2 function in embryonic fibroblasts and that reduced sensitivity to TGFbeta2 may underlie aspects of the TbetaRIII mutant phenotype.


Asunto(s)
Corazón/embriología , Hígado/embriología , Proteoglicanos/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Animales , Northern Blotting , Southern Blotting , Núcleo Celular/metabolismo , Relación Dosis-Respuesta a Droga , Fibroblastos/metabolismo , Citometría de Flujo , Genes Reporteros , Immunoblotting , Inmunohistoquímica , Concentración 50 Inhibidora , Ligandos , Ratones , Ratones Noqueados , Microscopía Fluorescente , Modelos Genéticos , Miocardio/metabolismo , Fenotipo , ARN Mensajero/metabolismo , Recombinación Genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Transducción de Señal , Factores de Tiempo
10.
Exp Hematol ; 30(11): 1248-56, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12423677

RESUMEN

OBJECTIVE: Studies on mice lacking the common receptor subunit gp130 reveal that activation of gp130-dependent signaling pathways is essential for normal fetal and adult hematopoiesis. However, the extent to which hematopoiesis is dependent upon activation of a particular gp130 signaling pathway, namely STAT1/3 or SHP2/MAPK, is unknown. This study examined the specific contribution of gp130-mediated STAT1/3 signaling to the regulation of hematopoiesis. MATERIALS AND METHODS: Hematopoiesis was examined at various developmental stages in mice homozygous for a targeted carboxy-terminal truncation mutation in gp130 (gp130(delta)/(delta)) that deletes all STAT1/3 binding sites, thereby abolishing gp130-mediated STAT1/3 activation. RESULTS: Adult gp130(delta)/(delta) mice have increased numbers of immature colony-forming unit spleen progenitor cells in the bone marrow and spleen, elevated numbers of committed myeloid progenitor cells in the spleen and peripheral blood, and leukocytosis. Increased progenitor cell production was observed in gp130(delta)/(delta) fetal livers from 14 days of gestation onward. In contrast, the circulating platelet count was reduced by 30% in gp130(delta)/(delta) mice, without any corresponding decrease in the number of bone marrow and splenic megakaryocytes. In liquid cultures, megakaryocytes from gp130(delta)/(delta) mice are smaller than those from wild-type mice and do not increase in size upon stimulation with interleukin-6 or interleukin-11. Administration of either interleukin-6 or interleukin-11 to gp130(delta)/(delta) mice failed to increase platelet numbers, despite an increase in the production of megakaryocytes. CONCLUSIONS: Collectively, these results reveal that gp130-mediated STAT1/3 activation is required to maintain the normal balance of hematopoietic progenitors during fetal and adult hematopoiesis. Furthermore, they suggest two distinct roles for gp130-mediated STAT1/3 activation in hematopoiesis, one restricting the production of immature hematopoietic progenitor cells and the other promoting the functional maturation of megakaryocytes to produce platelets.


Asunto(s)
Antígenos CD/fisiología , Proteínas de Unión al ADN/fisiología , Hematopoyesis/fisiología , Células Madre Hematopoyéticas/patología , Glicoproteínas de Membrana/fisiología , Transducción de Señal/fisiología , Transactivadores/fisiología , Factores de Edad , Animales , Antígenos CD/genética , Sitios de Unión , Médula Ósea/patología , Recuento de Células , Diferenciación Celular/fisiología , Tamaño de la Célula , Ensayo de Unidades Formadoras de Colonias , Receptor gp130 de Citocinas , Resistencia a Medicamentos , Inhibidores de Crecimiento/farmacología , Inhibidores de Crecimiento/uso terapéutico , Células Madre Hematopoyéticas/efectos de los fármacos , Sistema Hematopoyético/embriología , Sistema Hematopoyético/crecimiento & desarrollo , Interleucina-11/farmacología , Interleucina-11/uso terapéutico , Interleucina-6/farmacología , Interleucina-6/uso terapéutico , Factor Inhibidor de Leucemia , Linfocinas/farmacología , Linfocinas/uso terapéutico , Megacariocitos/efectos de los fármacos , Megacariocitos/patología , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Madre Multipotentes/efectos de los fármacos , Células Madre Multipotentes/patología , Proteínas Recombinantes/farmacología , Factor de Transcripción STAT1 , Factor de Transcripción STAT3 , Eliminación de Secuencia , Bazo/patología , Trombocitopenia/tratamiento farmacológico , Trombocitopenia/genética
11.
Growth Factors ; 26(1): 23-34, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18365876

RESUMEN

Neutrophils play an important role in the host's defense against infection with various pathogenic organisms. Granulocyte colony stimulating factor (G-CSF) is regarded as a major regulator of neutrophil production and function. Mice lacking G-CSF or its receptor are neutropenic. IL-6 is another cytokine that has been shown to promote neutrophil production and modulate the function of many types of immune cells. We have analyzed G-CSF/IL-6 double deficient (G-CSF(- / - )/IL-6(- / - )) mice to gain an insight into the possible contribution of IL-6 to the residual granulopoiesis in G-CSF-deficient (G-CSF(- / - )) mice. Furthermore, we have evaluated the ability of G-CSF(- / - )/IL-6(- / - ) mice to combat an experimental infection with Candida albicans. Our data shows that IL-6 plays a role in granulopoiesis during early post natal period but it is dispensable for steady-state granulopoiesis in adult mice. However, adult G-CSF(- / - )/IL-6(- / - ) mice are more susceptible to Candida infection than similarly infected G-CSF(- / - ) mice. Although, the candidacidal function of neutrophils of G-CSF(- / - )/IL-6(- / - ) mice is deficient, the ability to produce IFN-gamma and TNF-alpha in response to Candida infection is not compromised. Similarly, nitric oxide production by peritoneal macrophages from G-CSF(- / - )/IL-6(- / - ) mice in response to Candida is comparable to G-CSF(- / - ) mice.


Asunto(s)
Candida albicans/metabolismo , Candidiasis/metabolismo , Factor Estimulante de Colonias de Granulocitos/genética , Factor Estimulante de Colonias de Granulocitos/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Neutrófilos/metabolismo , Animales , Células de la Médula Ósea/citología , Candidiasis/microbiología , Supervivencia Celular , Interferón gamma/metabolismo , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Modelos Biológicos , Factor de Necrosis Tumoral alfa/metabolismo
12.
Blood ; 109(6): 2380-8, 2007 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-17082315

RESUMEN

We have previously demonstrated that STAT3 hyperactivation via the interleukin 6 (IL-6) cytokine family receptor gp130 in gp130 (Y757F/Y757F) mice leads to numerous hematopoietic and lymphoid pathologies, including neutrophilia, thrombocytosis, splenomegaly, and lymphadenopathy. Because IL-6 and IL-11 both signal via a gp130 homodimer, we report here a genetic approach to dissect their individual roles in these pathologies. Neutrophilia and thrombocytosis were absent in gp130 (Y757F/Y757F) mice lacking either IL-6 (gp130 (Y757F/Y757F): IL-6 (-/-)) or the IL-11 receptor alpha subunit (gp130 (Y757F/Y757F): IL-11Ralpha1 (-/-)), and this was associated with a normalized bone marrow compartment. The elevated myelopoiesis and megakaryopoiesis in bone marrow of gp130 (Y757F/Y757F) mice was attributable to an increase by either IL-6 or IL-11 in the STAT3-driven impairment of transforming growth factor beta (TGF-beta) signaling, which is a suppressor of these lineages. In contrast, the absence of IL-6, but not IL-11 signaling, prevented the splenomegaly, abnormal lymphopoiesis, and STAT3 hyperactivation in lymphoid organs of gp130 (Y757F/Y757F) mice. Furthermore, hyperactivation of STAT3 in lymphoid organs was associated with increased expression of IL-6Ralpha, and IL-6Ralpha expression was reduced in gp130 (Y757F/Y757F): Stat3 (+/-) mice displaying normal levels of STAT3 activity. Collectively, these data genetically define distinct roles of IL-6 and IL-11 in driving pathologic hematopoietic and lymphoid responses mediated by STAT3 hyperactivation.


Asunto(s)
Hematopoyesis , Interleucina-11/metabolismo , Interleucina-6/metabolismo , Linfocitos/citología , Linfocitos/metabolismo , Factor de Transcripción STAT3/metabolismo , Alelos , Animales , Receptor gp130 de Citocinas/genética , Receptor gp130 de Citocinas/metabolismo , Regulación de la Expresión Génica , Interleucina-11/farmacología , Interleucina-6/deficiencia , Interleucina-6/genética , Enfermedades Linfáticas/genética , Enfermedades Linfáticas/metabolismo , Enfermedades Linfáticas/patología , Ratones , Ratones Transgénicos , Receptores de Interleucina-11/metabolismo , Transducción de Señal , Esplenomegalia/genética , Esplenomegalia/metabolismo , Esplenomegalia/patología , Trombocitosis/genética , Trombocitosis/metabolismo , Trombocitosis/patología , Factor de Crecimiento Transformador beta1/metabolismo
13.
Hepatology ; 45(2): 486-94, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17256754

RESUMEN

UNLABELLED: Gp130-mediated IL-6 signaling may play a role in oval cell proliferation in vivo. Levels of IL-6 are elevated in livers of mice treated with a choline-deficient ethionine-supplemented (CDE) diet that induces oval cells, and there is a reduction of oval cells in IL-6 knockout mice. The CDE diet recapitulates characteristics of chronic liver injury in humans. In this study, we determined the impact of IL-6 signaling on oval cell-mediated liver regeneration in vivo. Signaling pathways downstream of gp130 activation were also dissected. Numbers of A6(+ve) liver progenitor oval cells (LPCs) in CDE-treated murine liver were detected by immunohistochemistry and quantified. Levels of oval cell migration and proliferation were compared in CDE-treated mouse strains that depict models of gp130-mediated hyperactive ERK-1/2 signaling (gp130(deltaSTAT)), hyperactive STAT-3 signaling (gp130(Y757F) and Socs-3(-/deltaAlb)) or active ERK-1/2 as well as active STAT-3 signaling (wild-type). The A6(+ve) LPC numbers were increased with IL-6 treatment in vivo. The gp130(Y757F) mice displayed increased A6(+ve) LPCs numbers compared with wild-type and gp130(deltaSTAT) mice. Numbers of A6(+ve) LPCs were also increased in the livers of CDE treated Socs-3(-/deltaAlb) mice compared with their control counterparts. Lastly, inhibition of ERK-1/2 activation in cultured oval cells increased hyper IL-6-induced cell growth. For the first time, we have dissected the gp130-mediated signaling pathways, which influence liver progenitor oval cell proliferation. CONCLUSION: Hyperactive STAT-3 signaling results in enhanced oval cell numbers, whereas ERK-1/2 activation suppresses oval cell proliferation.


Asunto(s)
Movimiento Celular/fisiología , Proliferación Celular , Receptor gp130 de Citocinas/fisiología , Interleucina-6/fisiología , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Factor de Transcripción STAT3/fisiología , Transducción de Señal/fisiología , Células Madre/fisiología , Animales , Línea Celular , Humanos , Hígado/citología , Hígado/metabolismo , Regeneración Hepática/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/metabolismo
14.
Blood ; 105(9): 3512-20, 2005 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-15650055

RESUMEN

The interleukin-6 (IL-6) cytokine family plays an important role in regulating cellular responses during hematopoiesis. We report here that mice homozygous for a knock-in mutation in the IL-6 cytokine family receptor signaling subunit glycoprotein (gp) 130 (gp130(Y757F/Y757F)) that leads to gp130-dependent signal transducers and activators of transcription (STAT) 1/3 hyperactivation develop a broad spectrum of hematopoietic abnormalities, including splenomegaly, lymphadenopathy, and thrombocytosis. To determine whether STAT3 hyperactivation was responsible for the perturbed hematopoiesis in gp130(Y757F/Y757F) mice, we generated gp130(Y757F/Y757F) mice on a Stat3 heterozygous (Stat3(+/-)) background to specifically reduce gp130-dependent activation of STAT3, but not STAT1. Normal hematopoiesis was observed in gp130(Y757F/Y757F):Stat3(+/-) bone marrow and spleen, with no evidence of the splenomegaly and thrombocytosis displayed by gp130(Y757F/Y757F) mice. The perturbed cellular composition of thymus and lymph nodes in gp130(Y757F/Y757F) mice was also alleviated in gp130(Y757F/Y757F): Stat3(+/-) mice. Furthermore, we show that hematopoietic cells from gp130(Y757F/Y757F) mice exhibited increased survival and proliferation in response to IL-6 family cytokines. Collectively, these data provide genetic evidence that gp130-dependent STAT3 hyperactivation during hematopoiesis has pathological consequences affecting multiple organs, and therefore identify the threshold of STAT3 signaling elicited by IL-6 family cytokines as a critical determinant for hematopoietic homeostasis.


Asunto(s)
Antígenos CD/fisiología , Proteínas de Unión al ADN/fisiología , Hematopoyesis , Glicoproteínas de Membrana/fisiología , Transducción de Señal/fisiología , Transactivadores/fisiología , Animales , Antígenos CD/genética , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Receptor gp130 de Citocinas , Genotipo , Células Madre Hematopoyéticas/citología , Glicoproteínas de Membrana/genética , Ratones , Ratones Mutantes , Mutación Missense , Factor de Transcripción STAT3 , Esplenomegalia/genética , Trombocitosis/genética
15.
Gastroenterology ; 129(3): 1005-18, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16143138

RESUMEN

BACKGROUND & AIMS: We have shown that mice with a mutation in gp130 (gp130(757F/F)), the signal transducing receptor for interleukin (IL)-6 family cytokines, have chronic gastric inflammation and develop distal stomach tumors associated with deregulated phosphorylated STAT3 expression. This model recapitulates many characteristics of intestinal-type gastric cancer in humans. METHODS: To evaluate the role of IL-6 and IL-11 as ligands regulating tumor growth and submucosal invasion, we compared tumor characteristics of gp130(757F/F) mice with gp130(757F/F) mice lacking IL-6 or mature T and B cells. RESULTS: As a result of the gp130(757F/F) mutation, expression of IL-6 and IL-11 was greatly up-regulated concomitant with activation of STAT3 and development of tumors. However, the lack of IL-6 or T and B cells did not impact on tumor growth. While IL-6 did not regulate tumor growth or tumor vascularization, gp130(757F/F)/IL-6(-/-) mice showed approximately 10-20-fold more submucosal tumor invasion, reduced mononuclear inflammatory cell infiltrate, and greater IL-11 and matrix metalloproteinase (MMP)-13 and MMP-9 synthesis than gp130(757F/F) mice. Expression of MMP-13 was largely restricted to tumor-associated stroma, but MMP-9 was also expressed in polymorphonuclear cells and a subset of epithelial cells. In addition, treatment with recombinant IL-11 stimulated expression of MMP-13 and MMP-9 in stomachs of wild-type mice. CONCLUSIONS: Increased submucosal invasion in gp130(757F/F)/IL-6(-/-) mice could not be explained by increased vascularization or reduced immunosurveillance but was most likely facilitated by augmented metalloproteinase activity driven by elevated IL-11 levels.


Asunto(s)
Antígenos CD/fisiología , Citocinas/farmacología , Glicoproteínas de Membrana/fisiología , Neoplasias Gástricas/patología , Animales , Antígenos CD/efectos de los fármacos , Antígenos CD/genética , Apoptosis , Secuencia de Bases , Receptor gp130 de Citocinas , Cartilla de ADN , Proteínas de Unión al ADN/genética , Mucosa Gástrica/inmunología , Mucosa Gástrica/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Hibridación in Situ , Interleucina-11/genética , Interleucina-11/farmacología , Interleucina-6/genética , Interleucina-6/farmacología , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/efectos de los fármacos , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutagénesis Sitio-Dirigida , Reacción en Cadena de la Polimerasa , Factor de Transcripción STAT3 , Transducción de Señal/efectos de los fármacos , Neoplasias Gástricas/genética , Transactivadores/genética
16.
Proc Natl Acad Sci U S A ; 102(27): 9589-94, 2005 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-15976028

RESUMEN

Interleukin (IL)-6 signaling through its soluble receptor (IL-6 transsignaling) directs transition between innate and acquired immune responses by orchestrating the chemokine-directed attraction and apoptotic clearance of leukocytes. Through analysis of mononuclear cell infiltration in WT and IL-6-deficient mice during peritoneal inflammation, we now report that IL-6 selectively governs T cell infiltration by regulating chemokine secretion (CXCL10, CCL4, CCL5, CCL11, and CCL17) and chemokine receptor (CCR3, CCR4, CCR5, and CXCR3) expression on the CD3+ infiltrate. Although blockade of IL-6 trans-signaling prevented chemokine release, chemokine receptor expression remained unaltered suggesting that this response is regulated by IL-6 itself. To dissect the signaling events promoting T cell migration, inflammation was established in knock-in mice expressing mutated forms of the universal signal-transducing element for IL-6-related cytokines gp130. In mice (gp130Y757F/Y757F) deficient in SHP2 and SOCS3 binding, but presenting hyperactivation of STAT1/3, T cell recruitment and CCL5 expression was enhanced. Conversely, both of these parameters were suppressed in mice with ablated gp130-mediated STAT1/3 activation (gp130DeltaSTAT/DeltaSTAT). T cell migration was related to STAT3 activity, because monoallelic deletion of Stat3 in gp130(Y757F/Y757F) mice (gp130Y757F/Y757F:Stat3+/-) corrected the exaggerated responses observed in gp130Y757F/Y757F mice. Consequently, STAT3 plays a defining role in IL-6-mediated T cell migration.


Asunto(s)
Movimiento Celular/inmunología , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica/inmunología , Inflamación/inmunología , Interleucina-6/metabolismo , Transducción de Señal/inmunología , Linfocitos T/inmunología , Transactivadores/metabolismo , Animales , Anticuerpos Antibacterianos/inmunología , Western Blotting , Quimiocinas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Inflamación/microbiología , Ratones , Ratones Noqueados , Peritoneo/microbiología , Receptores de Quimiocina/metabolismo , Factor de Transcripción STAT3 , Staphylococcus epidermidis/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA