RESUMO
Recent interest in the biology and function of peritoneal tissue resident macrophages (pMΦ) has led to a better understanding of their cellular origin, programming, and renewal. The programming of pMΦ is dependent on microenvironmental cues and tissue-specific transcription factors, including GATA6. However, the contribution of microRNAs remains poorly defined. We conducted a detailed analysis of the impact of GATA6 deficiency on microRNA expression in mouse pMΦ. Our data suggest that for many of the pMΦ, microRNA composition may be established during tissue specialization and that the effect of GATA6 knockout is largely unable to be rescued in the adult by exogenous GATA6. The data are consistent with GATA6 modulating the expression pattern of specific microRNAs, directly or indirectly, and including miR-146a, miR-223, and miR-203 established by the lineage-determining transcription factor PU.1, to achieve a differentiated pMΦ phenotype. Lastly, we showed a significant dysregulation of miR-708 in pMΦ in the absence of GATA6 during homeostasis and in response to LPS/IFN-γ stimulation. Overexpression of miR-708 in mouse pMΦ in vivo altered 167 mRNA species demonstrating functional downregulation of predicted targets, including cell immune responses and cell cycle regulation. In conclusion, we demonstrate dependence of the microRNA transcriptome on tissue-specific programming of tissue macrophages as exemplified by the role of GATA6 in pMΦ specialization.
Assuntos
Fator de Transcrição GATA6 , Macrófagos Peritoneais , MicroRNAs , Transcriptoma , Animais , Camundongos , Fator de Transcrição GATA6/metabolismo , Fator de Transcrição GATA6/genética , Regulação da Expressão Gênica , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/metabolismo , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Especificidade de Órgãos , Proteínas Proto-Oncogênicas , Transativadores/genética , Transativadores/metabolismoRESUMO
The alarm cytokine interleukin-1ß (IL-1ß) is a potent activator of the inflammatory cascade following pathogen recognition. IL-1ß production typically requires two signals: first, priming by recognition of pathogen-associated molecular patterns leads to the production of immature pro-IL-1ß; subsequently, inflammasome activation by a secondary signal allows cleavage and maturation of IL-1ß from its pro-form. However, despite the important role of IL-1ß in controlling local and systemic inflammation, its overall regulation is still not fully understood. Here we demonstrate that peritoneal tissue-resident macrophages use an active inhibitory pathway, to suppress IL-1ß processing, which can otherwise occur in the absence of a second signal. Programming by the transcription factor Gata6 controls the expression of prostacyclin synthase, which is required for prostacyclin production after lipopolysaccharide stimulation and optimal induction of IL-10. In the absence of secondary signal, IL-10 potently inhibits IL-1ß processing, providing a previously unrecognized control of IL-1ß in tissue-resident macrophages.
Assuntos
Epoprostenol/imunologia , Interleucina-10/imunologia , Interleucina-1beta/imunologia , Macrófagos Peritoneais/imunologia , Animais , Epoprostenol/genética , Fator de Transcrição GATA6/genética , Fator de Transcrição GATA6/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interleucina-10/genética , Interleucina-1beta/genética , Macrófagos Peritoneais/patologia , Camundongos , Camundongos TransgênicosRESUMO
A disintegrin and metalloproteinase (ADAM) 17 has been implicated in many shedding processes. Major substrates of ADAM17 are TNF-α, IL-6R, and ligands of the epidermal growth factor receptor. The essential role of the protease is emphasized by the fact that ADAM17 deficiency is lethal in mice. To study ADAM17 function in vivo, we generated viable hypomorphic ADAM17 mice called ADAM17ex/ex mice. Recent studies indicated regulation of proteolytic ADAM17 activity by cellular processes such as cytoplasmic phosphorylation and removal of the prodomain by furin cleavage. Maturation and thus activation of ADAM17 is not fully understood. So far, studies of ADAM17 maturation have been mainly limited to mouse embryonic fibroblasts or transfected cell lines relying on nonphysiologic stimuli such as phorbol esters, thus making interpretation of the results difficult in a physiologic context. In this article, we present a robust cell system to study ADAM17 maturation and function in primary cells of the immune system. To this end, HoxB8 conditionally immortalized macrophage precursor cell lines were derived from bone marrow of wild-type and hypomorphic ADAM17ex/ex mice, which are devoid of measurable ADAM17 activity. ADAM17 mutants were stably expressed in macrophage precursor cells, differentiated to macrophages under different growth factor conditions (M-CSF versus GM-CSF), and analyzed for cellular localization, proteolytic activity, and podosome disassembly. Our study reveals maturation and activity of ADAM17 in a more physiological-immune cell system. We show that this cell system can be further exploited for genetic modifications of ADAM17 and for studying its function in immune cells.
Assuntos
Proteína ADAM17/química , Proteína ADAM17/metabolismo , Técnicas de Cultura de Células/métodos , Células Dendríticas/enzimologia , Macrófagos/enzimologia , Animais , Linhagem Celular , Proteínas de Homeodomínio , CamundongosRESUMO
The inflammatory activation and recruitment of defined myeloid populations is essential for controlling the bridge between innate and adaptive immunity and shaping the immune response to microbial challenge. However, these cells exhibit significant functional heterogeneity and the inflammatory signals that differentially influence their effector characteristics are poorly characterized. In this study, we defined the phenotype of discrete subsets of effective antigen-presenting cells (APCs) in the peritoneal cavity during peritonitis. When the functional properties of these cells were compared to inflammatory monocyte-derived macrophages we noted differential responses to the immune-modulatory cytokine IL-10. In contrast to the suppressive actions of IL-10 on inflammatory macrophages, the recruitment of APCs was relatively refractory and we found no evidence for selective inhibition of APC differentiation. This differential response of myeloid cell subsets to IL-10 may thus have limited impact on development of potentially tissue-damaging adaptive immune responses, while restricting the magnitude of the inflammatory response. These findings may have clinical relevance in the context of peritoneal dialysis patients, where recurrent infections are associated with immune-mediated membrane dysfunction, treatment failure, and increased morbidity.
Assuntos
Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Interleucina-10/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Apresentação de Antígeno/imunologia , Células Apresentadoras de Antígenos/patologia , Biomarcadores , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Imunomodulação , Imunofenotipagem , Inflamação/patologia , Interleucina-10/genética , Macrófagos/patologia , Camundongos , Camundongos Knockout , Peritonite/imunologia , Peritonite/metabolismo , Peritonite/patologia , Fenótipo , Receptores CCR2/metabolismoRESUMO
BACKGROUND: There are several studies that indicate that cancer development may be conditioned by the activation of some biological systems that involve the interaction of different biomolecules, such as adenosine and vascular endothelial growth factor. These biomolecules have been targeted of some drugs for treat of cancer; however, there is little information on the interaction of purine derivatives with adenosine and vascular endothelial growth factor receptor (VEGF-R1). OBJECTIVE: The aim of this research was to determine the possible interaction of purine (1: ) and their derivatives (2-31: ) with A1, A2-adenosine receptors, and VEGF-R1. METHODS: Theoretical interaction of purine and their derivatives with A1, A2-adenosine receptors and VEGF-R1 was carried out using the 5uen, 5mzj and 3hng proteins as theoretical tools. Besides, adenosine, cgs-15943, rolofylline, cvt-124, wrc-0571, luf-5834, cvt-6883, AZD-4635, cabozantinib, pazopanib, regorafenib, and sorafenib drugs were used as controls. RESULTS: The results showed differences in the number of aminoacid residues involved in the interaction of purine and their derivatives with 5uen, 5mzj and 3hng proteins compared with the controls. Besides, the inhibition constants (Ki) values for purine and their derivatives 5: , 9: , 10: , 14: , 15: , 16: , and 20: were lower compared with the controls CONCLUSIONS: Theoretical data suggest that purine and their derivatives 5: , 9: , 10: , 14: , 15: , 16: , and 20: could produce changes in cancer cell growth through inhibition of A1, A2-adenosine receptors and VEGFR-1 inhibition. These data indicate that these purine derivatives could be a therapeutic alternative to treat some types of cancer.
RESUMO
The mannose receptor (MR) is an endocytic type I membrane molecule with a broad ligand specificity that is involved in both hemostasis and pathogen recognition. Membrane-anchored MR is cleaved by a metalloproteinase into functional soluble MR (sMR) composed of the extracellular domains of intact MR. Although sMR production was initially considered a constitutive process, enhanced MR shedding has been observed in response to the fungal pathogen Pneumocystis carinii. In this work, we have investigated the mechanism mediating enhanced MR shedding in response to fungi. We show that other fungal species, including Candida albicans and Aspergillus fumigatus, together with zymosan, a preparation of the cell wall of Saccharomyces cerevisiae, mimic the effect of P. carinii on sMR production and that this effect takes place mainly through ß-glucan recognition. Additionally, we demonstrate that MR cleavage in response to C. albicans and bioactive particulate ß-glucan requires expression of dectin-1. Our data, obtained using specific inhibitors, are consistent with the canonical Syk-mediated pathway triggered by dectin-1 being mainly responsible for inducing MR shedding, with Raf-1 being partially involved. As in the case of steady-state conditions, MR shedding in response to C. albicans and ß-glucan particles requires metalloprotease activity. The induction of MR shedding by dectin-1 has clear implications for the role of MR in fungal recognition, as sMR was previously shown to retain the ability to bind fungal pathogens and can interact with numerous host molecules, including lysosomal hydrolases. Thus, MR cleavage could also impact on the magnitude of inflammation during fungal infection.
Assuntos
Fungos/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos Peritoneais/metabolismo , Lectinas de Ligação a Manose/metabolismo , Proteínas de Membrana/metabolismo , Micoses/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Fungos/imunologia , Lectinas Tipo C/imunologia , Macrófagos Peritoneais/imunologia , Receptor de Manose , Lectinas de Ligação a Manose/imunologia , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Micoses/imunologia , Proteínas do Tecido Nervoso/imunologia , Receptores de Superfície Celular/imunologiaRESUMO
In this Viewpoint, we concentrate on the aspects of macrophage biology that we believe are fundamental for an appropriate contextual understanding of macrophage function during acute inflammation. These are the different origins of macrophage populations (and the implications of this for the renewal of these populations in the adult); and the impact of specific homeostatic or disease-associated microenvironments upon cellular heterogeneity, activation and effector functions.
Assuntos
Macrófagos/imunologia , Doença Aguda , Adulto , Animais , Diferenciação Celular/imunologia , Homeostase/imunologia , Humanos , Inflamação , Ativação de Macrófagos , Regeneração/imunologiaRESUMO
We have examined the potential to generate bona fide macrophages (MØ) from conditionally immortalised murine bone marrow precursors. MØ can be derived from Hoxb8 conditionally immortalised macrophage precursor cell lines (MØP) using either M-CSF or GM-CSF. When differentiated in GM-CSF (GM-MØP) the resultant cells resemble GM-CSF bone marrow-derived dendritic cells (BMDC) in morphological phenotype, antigen phenotype and functional responses to microbial stimuli. In spite of this high similarity between the two cell types and the ability of GM-MØP to effectively present antigen to a T-cell hybridoma, these cells are comparatively poor at priming the expansion of IFN-γ responses from naïve CD4(+) T cells. The generation of MØP from transgenic or genetically aberrant mice provides an excellent opportunity to study the inflammatory role of GM-MØP, and reduces the need for mouse colonies in many studies. Hence differentiation of conditionally immortalised MØPs in GM-CSF represents a unique in vitro model of inflammatory monocyte-like cells, with important differences from bone marrow-derived dendritic cells, which will facilitate functional studies relating to the many 'sub-phenotypes' of inflammatory monocytes.
Assuntos
Diferenciação Celular/imunologia , Células Dendríticas/citologia , Proteínas de Homeodomínio/genética , Macrófagos/citologia , Células Precursoras de Monócitos e Macrófagos/citologia , Animais , Apresentação de Antígeno/imunologia , Antígenos de Superfície/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Transformada , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Interferon gama/metabolismo , Interleucina-2/metabolismo , Lectinas Tipo C , Lipopeptídeos/farmacologia , Lipopolissacarídeos/farmacologia , Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Knockout , Células Precursoras de Monócitos e Macrófagos/efeitos dos fármacos , Células Precursoras de Monócitos e Macrófagos/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Óxido Nítrico/metabolismo , Ovalbumina/imunologia , Transdução Genética , Zimosan/farmacologia , beta-Glucanas/farmacologiaRESUMO
Macrophage (MØ) biology is routinely modelled in the peritoneal cavity, a vascular tissue readily infiltrated by leukocytes during inflammation. After several decades of study, no consensus has emerged regarding the importance of in situ proliferation versus peripheral monocyte recruitment for the maintenance of tissue resident MØs. By applying specific measures of mitosis, we have monitored tissue MØ proliferation during newborn development, adulthood and acute resolving inflammation in young adult mice. Despite the vascular nature of the tissue and ease of peripheral leukocyte entry, tissue MØs in the newborn increase in number by local proliferation. On the contrary, in the adult, tissue MØ proliferation is considerably reduced and most likely provides homeostatic control of cell numbers. Importantly, during an acute inflammatory response, when substantial numbers of inflammatory MØs are recruited from the circulation, tissue-resident MØs survive and then undergo a transient and intense proliferative burst in situ to repopulate the tissue. Our data indicate that local proliferation is a general mechanism for the self-sufficient renewal of tissue MØs during development and acute inflammation and not one restricted to non-vascular tissues, which has implications for the therapeutic modulation of MØ activity during the resolution of inflammation.
Assuntos
Proliferação de Células , Homeostase/imunologia , Macrófagos/imunologia , Peritonite/imunologia , Doença Aguda , Animais , Ciclo Celular/imunologia , Sobrevivência Celular/imunologia , Células Cultivadas , DNA/imunologia , DNA/metabolismo , Feminino , Citometria de Fluxo , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Cavidade Peritoneal/patologia , Peritonite/metabolismo , Peritonite/patologia , Fatores de TempoRESUMO
Mature neutrophils are notoriously short-lived immune cells that cannot be genetically manipulated. Analysis of gene function therefore requires genetically modified animals, which is expensive, time-consuming, and costly in animal life. Analysis of gene function in neutrophils in a physiologically relevant context thus represents a significant problem in the field. We sought to overcome this obstruction in the field by developing a strategy for the analysis of gene function in neutrophils in a physiologically relevant context. Here, we demonstrate the functional relevance of in vitro conditional-Hoxb8 immortalized precursor-derived neutrophils. In vitro-derived neutrophils functionally resembled primary neutrophils, but critically, neutrophils generated in this way can be adoptively transferred into live animals and tracked during inflammatory responses using single-cell analysis to define functional attributes. We have validated this approach using CD11b-deficient neutrophils and replicated the key findings observed in gene-targeted animals and in naturally CD11b-deficient humans. Furthermore, we show that by retroviral transduction, one can generate stable alterations in the precursor cell lines and thus a continuous supply of functionally altered neutrophils. This novel technological advance offers for the first time the possibility of applying higher-throughput genetic modification and in vivo functional analysis to the neutrophil-lineage.
Assuntos
Alternativas ao Uso de Animais , Engenharia Genética/métodos , Neutrófilos/citologia , Neutrófilos/fisiologia , Animais , Antígeno CD11b/genética , Antígeno CD11b/metabolismo , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Linhagem Celular , Regulação da Expressão Gênica/fisiologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mutação , Transdução Genética/métodos , LevedurasRESUMO
Oxylipins are potent biological mediators requiring strict control, but how they are removed en masse during infection and inflammation is unknown. Here we show that lipopolysaccharide (LPS) dynamically enhances oxylipin removal via mitochondrial ß-oxidation. Specifically, genetic or pharmacological targeting of carnitine palmitoyl transferase 1 (CPT1), a mitochondrial importer of fatty acids, reveal that many oxylipins are removed by this protein during inflammation in vitro and in vivo. Using stable isotope-tracing lipidomics, we find secretion-reuptake recycling for 12-HETE and its intermediate metabolites. Meanwhile, oxylipin ß-oxidation is uncoupled from oxidative phosphorylation, thus not contributing to energy generation. Testing for genetic control checkpoints, transcriptional interrogation of human neonatal sepsis finds upregulation of many genes involved in mitochondrial removal of long-chain fatty acyls, such as ACSL1,3,4, ACADVL, CPT1B, CPT2 and HADHB. Also, ACSL1/Acsl1 upregulation is consistently observed following the treatment of human/murine macrophages with LPS and IFN-γ. Last, dampening oxylipin levels by ß-oxidation is suggested to impact on their regulation of leukocyte functions. In summary, we propose mitochondrial ß-oxidation as a regulatory metabolic checkpoint for oxylipins during inflammation.
Assuntos
Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Metabolismo dos Lipídeos/genética , Mitocôndrias/efeitos dos fármacos , Oxilipinas/metabolismo , Peritonite/genética , Sepse/genética , Acil-CoA Desidrogenase de Cadeia Longa/sangue , Acil-CoA Desidrogenase de Cadeia Longa/genética , Animais , Carnitina O-Palmitoiltransferase/sangue , Carnitina O-Palmitoiltransferase/genética , Coenzima A Ligases/sangue , Coenzima A Ligases/genética , Feminino , Regulação da Expressão Gênica , Humanos , Recém-Nascido , Interferon gama/farmacologia , Lipidômica/métodos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Subunidade beta da Proteína Mitocondrial Trifuncional/sangue , Subunidade beta da Proteína Mitocondrial Trifuncional/genética , Oxirredução , Peritonite/sangue , Peritonite/induzido quimicamente , Peritonite/patologia , Células RAW 264.7 , Sepse/sangue , Sepse/patologiaRESUMO
Resident tissue macrophages are activated by the fungal pathogen Candida albicans to release eicosanoids, which are important modulators of inflammation and immune responses. Our objective was to identify the macrophage receptors engaged by C. albicans that mediate activation of group IVA cytosolic phospholipase A(2) (cPLA(2)α), a regulatory enzyme that releases arachidonic acid (AA) for production of prostaglandins and leukotrienes. A comparison of peritoneal macrophages from wild type and knock-out mice demonstrates that the ß-glucan receptor Dectin-1 and MyD88 regulate early release of AA and eicosanoids in response to C. albicans. However, cyclooxygenase 2 (COX2) expression and later phase eicosanoid production are defective in MyD88(-/-) but not Dectin-1(-/-) macrophages. Furthermore, C. albicans-stimulated activation of MAPK and phosphorylation of cPLA(2)α on Ser-505 are regulated by MyD88 and not Dectin-1. In contrast, Dectin-1 mediates MAPK activation, cPLA(2)α phosphorylation, and COX2 expression in response to particulate ß-glucan suggesting that other receptors engaged by C. albicans preferentially mediate these responses. Results also implicate the mannan-binding receptor Dectin-2 in regulating cPLA(2)α. C. albicans-stimulated MAPK activation and AA release are blocked by d-mannose and Dectin-2-specific antibody, and overexpression of Dectin-2 in RAW264.7 macrophages enhances C. albicans-stimulated MAPK activation, AA release, and COX2 expression. In addition, calcium mobilization is enhanced in RAW264.7 macrophages overexpressing Dectin-1 or -2. The results demonstrate that C. albicans engages both ß-glucan and mannan-binding receptors on macrophages that act with MyD88 to regulate the activation of cPLA(2)α and eicosanoid production.
Assuntos
Candida albicans , Candidíase/enzimologia , Eicosanoides/biossíntese , Fosfolipases A2 do Grupo IV/metabolismo , Sistema de Sinalização das MAP Quinases , Macrófagos Peritoneais/enzimologia , Animais , Candidíase/genética , Candidíase/microbiologia , Linhagem Celular , Ciclo-Oxigenase 2/biossíntese , Ciclo-Oxigenase 2/genética , Eicosanoides/genética , Ativação Enzimática/genética , Regulação Enzimológica da Expressão Gênica/genética , Fosfolipases A2 do Grupo IV/genética , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Macrófagos Peritoneais/microbiologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fosforilação/genéticaRESUMO
Dectin-1 is the archetypal signaling, non-Toll-like pattern recognition receptor that plays a protective role in immune defense to Candida albicans as the major leukocyte receptor for beta-glucans. Dectin-1-deficiency is associated with impaired recruitment of inflammatory leukocytes and inflammatory mediator production at the site of infection. In this study, we have used mice to define the mechanisms that regulate the dectin-1-mediated inflammatory responses. Myeloid cell activation by dectin-1 is controlled by inherent cellular programming, with distinct macrophage and dendritic cell populations responding differentially to the engagement of this receptor. The inflammatory response is further modulated by the progression of the phagocytosis, with "frustrated phagocytosis" resulting in dramatically augmented inflammatory responses. These studies demonstrate that dectin-1 in isolation is sufficient to drive a potent inflammatory response in a context-dependent manner. This has implications for the mechanism by which myeloid cells are activated during fungal infections and the processes involved in the therapeutic manipulation of the immune system via exogenous dectin-1 stimulation or blockade.
Assuntos
Inflamação/etiologia , Proteínas de Membrana/fisiologia , Células Mieloides/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Fagocitose , Animais , Candida albicans/imunologia , Células Dendríticas , Lectinas Tipo C , Macrófagos , Proteínas de Membrana/deficiência , Camundongos , Camundongos Knockout , Micoses/imunologia , Proteínas do Tecido Nervoso/deficiência , beta-Glucanas/imunologiaRESUMO
The peritoneal macrophage (Mphi) is the site of greatest 12/15-lipoxygenase (12/15-LOX) expression in the mouse; however, its immunoregulatory role in this tissue has not been explored. Herein, we show that 12/15-LOX is expressed by 95% of resident peritoneal CD11b(high) cells, with the remaining 5% being 12/15-LOX(-). 12/15-LOX(+) cells are phenotypically defined by high F4/80, SR-A, and Siglec1 expression, and enhanced IL-10 and G-CSF generation. In contrast, 12/15-LOX(-) cells are a dendritic cell population. Resident peritoneal Mphi numbers were significantly increased in 12/15-LOX(-/-) mice, suggesting alterations in migratory trafficking or cell differentiation in vivo. In vitro, Mphi from 12/15-LOX(-/-) mice exhibit multiple abnormalities in the regulation of cytokine/growth factor production both basally and after stimulation with Staphylococcus epidermidis cell-free supernatant. Resident adherent cells from 12/15-LOX(-/-) mice generate more IL-1, IL-3, GM-CSF, and IL-17, but less CCL5/RANTES than do cells from wild-type mice, while Staphylococcus epidermidis cell-free supernatant-elicited 12/15-LOX(-/-) adherent cells release less IL-12p40, IL-12p70, and RANTES, but more GM-CSF. This indicates a selective effect of 12/15-LOX on peritoneal cell cytokine production. In acute sterile peritonitis, 12/15-LOX(+) cells and LOX products were cleared, then reappeared during the resolution phase. The peritoneal lavage of 12/15-LOX(-/-) mice showed elevated TGF-beta1, along with increased immigration of monocytes/Mphi, but decreases in several cytokines including RANTES/CCL5, MCP-1/CCL2, G-CSF, IL-12-p40, IL-17, and TNF-alpha. No changes in neutrophil or lymphocyte numbers were seen. In summary, endogenous 12/15-LOX defines the resident MPhi population and regulates both the recruitment of monocytes/Mphi and cytokine response to bacterial products in vivo.
Assuntos
Araquidonato 12-Lipoxigenase/fisiologia , Araquidonato 15-Lipoxigenase/fisiologia , Citocinas/biossíntese , Mediadores da Inflamação/fisiologia , Peritonite/enzimologia , Peritonite/microbiologia , Infecções Estafilocócicas/enzimologia , Infecções Estafilocócicas/patologia , Staphylococcus epidermidis/imunologia , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/biossíntese , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/fisiologia , Doença Aguda , Animais , Araquidonato 12-Lipoxigenase/biossíntese , Araquidonato 12-Lipoxigenase/deficiência , Araquidonato 15-Lipoxigenase/biossíntese , Araquidonato 15-Lipoxigenase/deficiência , Células Cultivadas , Citocinas/metabolismo , Citocinas/fisiologia , Ácidos Hidroxieicosatetraenoicos/biossíntese , Ácidos Hidroxieicosatetraenoicos/fisiologia , Imunofenotipagem , Mediadores da Inflamação/metabolismo , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/microbiologia , Macrófagos Peritoneais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peritonite/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus epidermidis/metabolismoRESUMO
Tissue factor (TF) is critical for the activation of blood coagulation. TF function is regulated by the amount of externalised phosphatidylserine (PS) and phosphatidylethanolamine (PE) on the surface of the cell in which it is expressed. We investigated the role PS and PE in fibroblast TF function. Fibroblasts expressed 6-9 x 104 TF molecules/cell but had low specific activity for FXa generation. We confirmed that this was associated with minimal externalized PS and PE and characterised for the first time the molecular species of PS/PE demonstrating that these differed from those found in platelets. Mechanical damage of fibroblasts, used to simulate vascular injury, increased externalized PS/PE and led to a 7-fold increase in FXa generation that was inhibited by annexin V and an anti-TF antibody. Platelet-derived extracellular vesicles (EVs), that did not express TF, supported minimal FVIIa-dependent FXa generation but substantially increased fibroblast TF activity. This enhancement in fibroblast TF activity could also be achieved using synthetic liposomes comprising 10% PS without TF. In conclusion, despite high levels of surface TF expression, healthy fibroblasts express low levels of external-facing PS and PE limiting their ability to generate FXa. Addition of platelet-derived TF-negative EVs or artificial liposomes enhanced fibroblast TF activity in a PS dependent manner. These findings contribute information about the mechanisms that control TF function in the fibroblast membrane.
Assuntos
Vesículas Extracelulares/metabolismo , Fibroblastos/metabolismo , Tromboplastina/metabolismo , Coagulação Sanguínea , Plaquetas/metabolismo , Linhagem Celular , Humanos , Lipossomos/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilserinas/metabolismo , Tromboplastina/genéticaRESUMO
Hemostatic defects are treated using coagulation factors; however, clot formation also requires a procoagulant phospholipid (PL) surface. Here, we show that innate immune cell-derived enzymatically oxidized phospholipids (eoxPL) termed hydroxyeicosatetraenoic acid-phospholipids (HETE-PLs) restore hemostasis in human and murine conditions of pathological bleeding. HETE-PLs abolished blood loss in murine hemophilia A and enhanced coagulation in factor VIII- (FVIII-), FIX-, and FX-deficient human plasma . HETE-PLs were decreased in platelets from patients after cardiopulmonary bypass (CPB). To explore molecular mechanisms, the ability of eoxPL to stimulate individual isolated coagulation factor/cofactor complexes was tested in vitro. Extrinsic tenase (FVIIa/tissue factor [TF]), intrinsic tenase (FVIIIa/FIXa), and prothrombinase (FVa/FXa) all were enhanced by both HETE-PEs and HETE-PCs, suggesting a common mechanism involving the fatty acid moiety. In plasma, 9-, 15-, and 12-HETE-PLs were more effective than 5-, 11-, or 8-HETE-PLs, indicating positional isomer specificity. Coagulation was enhanced at lower lipid/factor ratios, consistent with a more concentrated area for protein binding. Surface plasmon resonance confirmed binding of FII and FX to HETE-PEs. HETE-PEs increased membrane curvature and thickness, but not surface charge or homogeneity, possibly suggesting increased accessibility to cations/factors. In summary, innate immune-derived eoxPL enhance calcium-dependent coagulation factor function, and their potential utility in bleeding disorders is proposed.
Assuntos
Fatores de Coagulação Sanguínea/metabolismo , Hemorragia/enzimologia , Hemorragia/metabolismo , Fosfolipídeos/metabolismo , Trombina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Coagulação Sanguínea , Fatores de Coagulação Sanguínea/genética , Plaquetas , Ponte Cardiopulmonar/efeitos adversos , Proteínas de Transporte , Cisteína Endopeptidases , Fator IX/genética , Fator VIII/genética , Fator VIIa/metabolismo , Fator X/genética , Hemofilia A , Hemorragia/prevenção & controle , Hemostasia , Humanos , Ácidos Hidroxieicosatetraenoicos , Lipoproteínas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Proteínas de Neoplasias , Ressonância de Plasmônio de Superfície , Tromboplastina/antagonistas & inibidores , Tromboplastina/metabolismoRESUMO
Interleukin (IL)-5 is a hematopoietic cytokine able to regulate differentiation, survival, and effector functions of eosinophils. It binds specifically to its receptor, which is composed of a cytokine-specific alpha-chain and a beta-chain shared with the receptors for IL-3 and the granulocyte macrophage-colony stimulating factor. The molecular mechanisms by which IL-5 modulates eosinophil survival remain unclear. In this study, we demonstrate that IL-5 withdrawal induces eosinophil apoptosis through a mitochondria-dependent pathway, independently of Fas receptor activation. The lipid kinase phosphatidylinositol-3 kinase plays a crucial role in the maintenance of eosinophil survival, as inhibition of its activity results in apoptosis. IL-5 induces phosphorylation and thus, inhibition of the Forkhead transcription factor FOXO3a and glycogen synthase kinase 3 (GSK-3). We analyzed expression of FOXO3a-dependent transcriptional targets: Fas ligand or Bim (a proapoptotic Bcl-2 family member), but neither was detected in apoptotic eosinophils. We further show that GSK-3 is activated after IL-5 withdrawal, and inhibition of its activity rescues eosinophils from apoptosis. beta-catenin, a direct GSK-3 substrate, is present in the nucleus of IL-5-stimulated eosinophils, but it is translocated to the plasma membrane in the absence of cytokine in a GSK-3-dependent manner. This is the first report describing a potential role for GSK-3 and beta-catenin in regulating eosinophil survival and suggests a novel mechanism by which IL-5 inhibits the constitutive apoptotic program in these cells.
Assuntos
Eosinófilos/imunologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Interleucina-5/fisiologia , beta Catenina/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Eosinófilos/efeitos dos fármacos , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/antagonistas & inibidores , Fatores de Transcrição Forkhead/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Interleucina-5/farmacologia , Mitocôndrias/metabolismo , Fosforilação/efeitos dos fármacos , Relação Estrutura-Atividade , beta Catenina/efeitos dos fármacosRESUMO
Phosphatidylinositol 3-kinase (PI3K) and its effector protein kinase B (PKB/c-akt) have been implicated as critical mediators of cytokine-induced survival signals. In this study, we have utilized an IL-5 dependent hematopoietic cell line (TF-1) to investigate the signaling events involved in cytokine-dependent erythroblast survival. We demonstrate that IL-5 rescues TF-1 cells from apoptosis through a PI3K/PKB-dependent signaling pathway. Cytokine-withdrawal leads to activation of the Forkhead transcription factor FOXO3a and subsequent expression of the pro-apoptotic Bcl-2 family member Bim. Bim is itself sufficient to induce apoptosis in these cells. Importantly, activation of an inducible active FOXO3a mutant is alone sufficient for upregulation of Bim expression and induction of apoptosis. These data define a mechanism by which survival factors inhibit the default apoptotic pathway and can regulate TF-1 erythroblast survival.
Assuntos
Apoptose , Proteínas de Transporte/metabolismo , Eritroblastos/metabolismo , Interleucina-5/fisiologia , Proteínas de Membrana/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Reguladoras de Apoptose , Proteína 11 Semelhante a Bcl-2 , Caspase 3 , Caspase 7 , Caspases/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead , Quinase 3 da Glicogênio Sintase/fisiologia , Humanos , Mutação/genética , Fosforilação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Tissue-resident macrophages are heterogeneous as a consequence of anatomical niche-specific functions. Many populations self-renew independently of bone marrow in the adult, but the molecular mechanisms of this are poorly understood. We determined a transcriptional profile for the major self-renewing population of peritoneal macrophages in mice. These cells specifically expressed the transcription factor Gata6. Selective deficiency of Gata6 in myeloid cells caused substantial alterations in the transcriptome of peritoneal macrophages. Gata6 deficiency also resulted in dysregulated peritoneal macrophage proliferative renewal during homeostasis and in response to inflammation, which was associated with delays in the resolution of inflammation. Our investigations reveal that the tissue macrophage phenotype is under discrete tissue-selective transcriptional control and that this is fundamentally linked to the regulation of their proliferation renewal.
Assuntos
Proliferação de Células , Fator de Transcrição GATA6/fisiologia , Macrófagos Peritoneais/imunologia , Animais , Fator de Transcrição GATA6/genética , Inflamação/imunologia , Camundongos , Camundongos Knockout , Células Mieloides/imunologia , FenótipoRESUMO
INTRODUCTION: Activation of the inflammasome has been implicated in the pathology of various autoinflammatory and autoimmune diseases. While the NLRP3 inflammasome has been linked to arthritis progression, little is known about its synovial regulation or contribution to joint histopathology. Regulators of inflammation activation, such as interleukin (IL)-10, may have the potential to limit the inflammasome-driven arthritic disease course and associated structural damage. Hence, we used IL-10-deficient (IL-10KO) mice to assess NLRP3 inflammasome-driven arthritic pathology. METHODS: Antigen-induced arthritis (AIA) was established in IL-10KO mice and wild-type controls. Using histological and radiographic approaches together with quantitative real-time PCR of synovial mRNA studies, we explored the regulation of inflammasome components. These were combined with selective blocking agents and ex vivo investigative studies in osteoclast differentiation assays. RESULTS: In AIA, IL-10KO mice display severe disease with increased histological and radiographic joint scores. Here, focal bone erosions were associated with increased tartrate-resistant acid phosphatase (TRAP)-positive cells and a localized expression of IL-1ß. When compared to controls, IL-10KO synovium showed increased expression of Il1b, Il33 and NLRP3 inflammasome components. Synovial Nlrp3 and Casp1 expression further correlated with Acp5 (encoding TRAP), while neutralization of IL-10 receptor signaling in control mice caused increased expression of Nlrp3 and Casp1. In ex vivo osteoclast differentiation assays, addition of exogenous IL-10 or selective blockade of the NLRP3 inflammasome inhibited osteoclastogenesis. CONCLUSIONS: These data provide a link between IL-10, synovial regulation of the NLRP3 inflammasome and the degree of bone erosions observed in inflammatory arthritis.