RESUMO
Vitamin D plays a crucial role in preventing atherosclerosis and in the regulation of macrophage function. This review aims to provide a comprehensive summary of the clinical evidence regarding the impact of vitamin D on atherosclerotic cardiovascular disease, atherosclerotic cerebrovascular disease, peripheral arterial disease, and associated risk factors. Additionally, it explores the mechanistic studies investigating the influence of vitamin D on macrophage function in atherosclerosis. Numerous findings indicate that vitamin D inhibits monocyte or macrophage recruitment, macrophage cholesterol uptake, and esterification. Moreover, it induces autophagy of lipid droplets in macrophages, promotes cholesterol efflux from macrophages, and regulates macrophage polarization. This review particularly focuses on analyzing the molecular mechanisms and signaling pathways through which vitamin D modulates macrophage function in atherosclerosis. It claims that vitamin D has a direct inhibitory effect on the formation, adhesion, and migration of lipid-loaded monocytes, thus exerting anti-atherosclerotic effects. Therefore, this review emphasizes the crucial role of vitamin D in regulating macrophage function and preventing the development of atherosclerosis.
Assuntos
Aterosclerose , Macrófagos , Vitamina D , Aterosclerose/prevenção & controle , Humanos , Vitamina D/farmacologia , Vitamina D/fisiologia , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Macrófagos/metabolismo , Animais , Transdução de Sinais , Colesterol/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/fisiologia , Autofagia/efeitos dos fármacosRESUMO
Cerebral malaria (CM) pathogenesis is described as a multistep mechanism. In this context, monocytes have been implicated in CM pathogenesis by increasing the sequestration of infected red blood cells to the brain microvasculature. In disease, endothelial activation is followed by reduced monocyte rolling and increased adhesion. Nowadays, an important challenge is to identify potential pro-inflammatory stimuli that can modulate monocytes behavior. Our group have demonstrated that bradykinin (BK), a pro-inflammatory peptide involved in CM, is generated during the erythrocytic cycle of P. falciparum and is detected in culture supernatant (conditioned medium). Herein we investigated the role of BK in the adhesion of monocytes to endothelial cells of blood brain barrier (BBB). To address this issue human monocytic cell line (THP-1) and human brain microvascular endothelial cells (hBMECs) were used. It was observed that 20% conditioned medium from P. falciparum infected erythrocytes (Pf-iRBC sup) increased the adhesion of THP-1 cells to hBMECs. This effect was mediated by BK through the activation of B2 and B1 receptors and involves the increase in ICAM-1 expression in THP-1 cells. Additionally, it was observed that angiotensin-converting enzyme (ACE) inhibitor, captopril, enhanced the effect of both BK and Pf-iRBC sup on THP-1 adhesion. Together these data show that BK, generated during the erythrocytic cycle of P. falciparum, could play an important role in adhesion of monocytes in endothelial cells lining the BBB.
Assuntos
Barreira Hematoencefálica , Bradicinina , Adesão Celular , Malária Cerebral , Malária Falciparum , Plasmodium falciparum , Humanos , Bradicinina/metabolismo , Adesão Celular/fisiologia , Meios de Cultivo Condicionados/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Eritrócitos/parasitologia , Malária Cerebral/metabolismo , Malária Cerebral/parasitologia , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Monócitos/fisiologia , Plasmodium falciparum/fisiologia , Barreira Hematoencefálica/fisiopatologiaRESUMO
Immune-derived hunger hormones restore tissue after infection.
Assuntos
Infecções Bacterianas , Grelina , Leptina , Neovascularização Fisiológica , Animais , Humanos , Camundongos , Infecções Bacterianas/fisiopatologia , Grelina/fisiologia , Leptina/fisiologia , Microscopia Intravital , Neutrófilos/fisiologia , Monócitos/fisiologiaRESUMO
Macrophages have previously been characterized based on phenotypical and functional differences into suggested simplified subtypes of MØ, M1, M2a and M2c. These macrophage subtypes can be generated in a well-established primary monocyte culture model that produces cells expressing accepted subtype surface markers. To determine how these subtypes retain functional similarities and better understand their formation, we generated all four subtypes from the same donors. Comparative whole-cell proteomics confirmed that four distinct macrophage subtypes could be induced from the same donor material, with > 50% of 5435 identified proteins being significantly altered in abundance between subtypes. Functional assessment highlighted that these distinct protein expression profiles are primed to enable specific cell functions, indicating that this shifting proteome is predictive of meaningful changes in cell characteristics. Importantly, the 2552 proteins remained consistent in abundance across all macrophage subtypes examined, demonstrating maintenance of a stable core proteome that likely enables swift polarity changes. We next explored the cross-polarization capabilities of preactivated M1 macrophages treated with dexamethasone. Importantly, these treated cells undergo a partial repolarization toward the M2c surface markers but still retain the M1 functional phenotype. Our investigation of polarized macrophage subtypes therefore provides evidence of a sliding scale of macrophage functionality, with these data sets providing a valuable benchmark resource for further studies of macrophage polarity, with relevance for cell therapy development and drug discovery.
Assuntos
Proteoma , Proteômica , Proteoma/metabolismo , Células Cultivadas , Macrófagos/metabolismo , Monócitos/fisiologiaRESUMO
Inflammation is a host defense response to various invading stimuli, but an excessive and persistent inflammatory response can cause tissue injury, which can lead to irreversible organ damage and dysfunction. Excessive inflammatory responses are believed to link to most human diseases. A specific type of leukocyte infiltration into invaded tissues is required for inflammation. Historically, the underlying molecular mechanisms of this process during inflammation were an enigma, compromising research in the fields of inflammation, immunology, and pathology. However, the pioneering discovery of chemotactic cytokines (chemokines), monocyte-derived neutrophil chemotactic factor (MDNCF; interleukin [IL]-8, CXCL8) and monocyte chemotactic and activating factor (MCAF; monocyte chemotactic factor 1 [MCP-1], CCL2) in the late 1980s finally enabled us to address this issue. In this review, we provide a historical overview of chemokine research over the last 35 years.
Assuntos
Quimiocina CCL2 , Interleucina-8 , Humanos , Quimiocinas , Citocinas , Inflamação/patologia , Interleucina-8/fisiologia , Monócitos/patologia , Monócitos/fisiologiaRESUMO
PURPOSE OF REVIEW: Recent technological advances have identified distinct subpopulations and roles of the cardiac innate immune cells, specifically macrophages and neutrophils. Studies on distinct metabolic pathways of macrophage and neutrophil in cardiac injury are expanding. Here, we elaborate on the roles of cardiac macrophages and neutrophils in concomitance with their metabolism in normal and diseased hearts. RECENT FINDINGS: Single-cell techniques combined with fate mapping have identified the clusters of innate immune cell subpopulations present in the resting and diseased hearts. We are beginning to know about the presence of cardiac resident macrophages and their functions. Resident macrophages perform cardiac homeostatic roles, whereas infiltrating neutrophils and macrophages contribute to tissue damage during cardiac injury with eventual role in repair. Prior studies show that metabolic pathways regulate the phenotypes of the macrophages and neutrophils during cardiac injury. Profiling the metabolism of the innate immune cells, especially of resident macrophages during chronic and acute cardiac diseases, can further the understanding of cardiac immunometabolism.
Assuntos
Traumatismos Cardíacos , Macrófagos , Humanos , Macrófagos/fisiologia , Monócitos/fisiologia , Coração , Neutrófilos/fisiologia , Traumatismos Cardíacos/metabolismo , Imunidade InataRESUMO
Generalized status epilepticus (SE) triggers a robust neuroinflammatory response involving reactive astrocytosis, activation of brain-resident microglia, and brain infiltration of CCR2+ monocytes. Multiple lines of evidence indicate that quenching SE-induced neuroinflammation can alleviate the adverse consequences of SE, including neuronal damage and cognitive impairments. Our recent findings show that blocking monocyte brain entry after SE, via global Ccr2 KO, rescues several SE-induced adverse effects including blood-brain barrier (BBB) erosion, microgliosis and neuronal damage while enhancing weight regain. The goals of the present study were to determine if CCR2 antagonism with a small molecule after SE replicates the effects of the CCR2 knockout. Male Ccr2+/rfp heterozygous mice were subject to intraperitoneal injection of kainic acid, scored for seizure severity, weight recovery, and nest building capability. Surviving mice were randomized into CCR2 antagonist and vehicle groups. The CCR2 antagonist, or vehicle, was administered 24- and 48-h post-SE via oral gavage, and mice were sacrificed three days post-SE. Mice subject to the CCR2 antagonist displayed faster weight recovery between one- and three-days post-SE and modestly enhanced ability to build a nest on the third day after SE when compared to vehicle-treated controls. CCR2 antagonism limited monocyte recruitment to the hippocampus and reduced numbers of Iba1+ macrophages. The mRNA levels of inflammatory mediators were depressed by 47%, and glial markers were reduced by 30% in mice treated with the CCR2 antagonist compared to controls. Astrocytosis was reduced in four brain regions. Neuroprotection was observed in the hippocampus, and erosion of the BBB was lessened in mice subject to the antagonist. Our findings provide proof-of-concept that brief CCR2 antagonism beginning one day after SE can alleviate multiple adverse SE-induced effects, including functional impairment, and identify circulating CCR2+ monocytes as a viable therapeutic target.
Assuntos
Gliose , Estado Epiléptico , Camundongos , Masculino , Animais , Gliose/tratamento farmacológico , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/tratamento farmacológico , Monócitos/fisiologia , Macrófagos , Convulsões , Inflamação , Receptores de Quimiocinas , Receptores CCR2/genética , Camundongos Endogâmicos C57BLRESUMO
Inflammatory stimuli cause a state of emergency myelopoiesis leading to neutrophil-like monocyte expansion. However, their function, the committed precursors, or growth factors remain elusive. In this study we find that Ym1+Ly6Chi monocytes, an immunoregulatory entity of neutrophil-like monocytes, arise from progenitors of neutrophil 1 (proNeu1). Granulocyte-colony stimulating factor (G-CSF) favors the production of neutrophil-like monocytes through previously unknown CD81+CX3CR1lo monocyte precursors. GFI1 promotes the differentiation of proNeu2 from proNeu1 at the cost of producing neutrophil-like monocytes. The human counterpart of neutrophil-like monocytes that also expands in response to G-CSF is found in CD14+CD16- monocyte fraction. The human neutrophil-like monocytes are discriminated from CD14+CD16- classical monocytes by CXCR1 expression and the capacity to suppress T cell proliferation. Collectively, our findings suggest that the aberrant expansion of neutrophil-like monocytes under inflammatory conditions is a process conserved between mouse and human, which may be beneficial for the resolution of inflammation.
Assuntos
Monócitos , Neutrófilos , Camundongos , Animais , Humanos , Monócitos/fisiologia , Mielopoese , Diferenciação Celular , Fator Estimulador de Colônias de GranulócitosRESUMO
Fluorescent nanodiamonds (FNDs) with negative nitrogen-vacancy (NV- ) defect centers are great probes for biosensing applications, with potential to act as biomarkers for cell differentiation. To explore this concept, uptake of FNDs (≈120 nm) by THP-1 monocytes and monocyte-derived M0-macrophages is studied. The time course analysis of FND uptake by monocytes confirms differing FND-cell interactions and a positive time-dependence. No effect on cell viability, proliferation, and differentiation potential into macrophages is observed, while cells saturated with FNDs, unload the FNDs completely by 25 cell divisions and subsequently take up a second dose effectively. FND uptake variations by THP-1 cells at early exposure-times indicate differing phagocytic capability. The cell fraction that exhibits relatively enhanced FND uptake is associated to a macrophage phenotype which derives from spontaneous monocyte differentiation. In accordance, chemical-differentiation of the THP-1 cells into M0-macrophages triggers increased and homogeneous FND uptake, depleting the fraction of cells that were non-responsive to FNDs. These observations imply that FND uptake allows for distinction between the two cell subtypes based on phagocytic capacity. Overall, FNDs demonstrate effective cell labeling of monocytes and macrophages, and are promising candidates for sensing biological processes that involve cell differentiation.
Assuntos
Técnicas Biossensoriais , Corantes Fluorescentes , Macrófagos , Monócitos , Nanodiamantes , Fagocitose , Nanodiamantes/química , Nanodiamantes/toxicidade , Nitrogênio/química , Corantes Fluorescentes/química , Corantes Fluorescentes/toxicidade , Humanos , Linhagem Celular , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/fisiologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Fagocitose/efeitos dos fármacosRESUMO
Macro-autophagy is a highly conserved catabolic process among eukaryotes affecting macrophages. This work studies the genetic regulatory network involving the interplay between autophagy and macrophage polarization (activation). Autophagy-related genes (Atgs) and differentially expressed genes (DEGs) of macrophage polarization (M1-M2) were predicted, and their regulatory networks constructed. Naïve (M0) mouse bone marrow-derived monocytes were differentiated into M1 and M2a. Validation of the targets of Smad1, LC3A and LC3B, Atg16L1, Atg7, IL-6, CD68, Arg-1, and Vamp7 was performed in vitro. Immunophenotyping by flow cytometry revealed three macrophage phenotypes: M0 (IL-6 + /CD68 +), M1 (IL-6 + /CD68 + /Arg-1 +), and M2a (CD68 + /Arg-1). Confocal microscopy revealed increased autophagy in both M1 and M2a and a significant increase in the pre-autophagosomes size and number. Bafilomycin A increased the expression of CD68 and Arg-1 in all cell lineages. In conclusion, our approach predicted the protein targets mediating the interplay between autophagy and macrophage polarization. We suggest that autophagy reprograms macrophage polarization via CD68, arginase 1, Atg16L1-1, and Atg16L1-3. The current findings provide a foundation for the future use of macrophages in immunotherapy of different autoimmune disorders.
Assuntos
Autofagia , Redes Reguladoras de Genes , Ativação de Macrófagos , Macrófagos , Animais , Camundongos , Autofagia/genética , Autofagia/imunologia , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Ativação de Macrófagos/genética , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Macrófagos/fisiologia , Monócitos/imunologia , Monócitos/fisiologiaRESUMO
OBJECTIVE: To comprehensively characterize monocyte and neutrophil responses to E. coli and its product [lipopolysaccharide (LPS) or endotoxin] in vitro during pregnancy. MATERIAL OR SUBJECTS: Peripheral blood was collected from pregnant women during the third trimester (n = 20) and from non-pregnant women (n = 20). METHODS: The number, phagocytic activity, and reactive oxygen species (ROS) production of peripheral monocytes and neutrophils were investigated using flow cytometry. The phenotypes of peripheral monocytes and neutrophils after acute or chronic LPS stimulation were also determined using flow cytometry. Cytokine profiles were quantified for LPS-stimulated peripheral blood mononuclear cells (PBMCs) and a whole blood TruCulture® system using a multiplex immunoassay. RESULTS: Increased number, phagocytic activity, and ROS production capacity of monocytes and neutrophils were found in pregnant compared to non-pregnant women. Additionally, specific subsets of pro-inflammatory monocytes (IL-6+CD14+ or MIP-1α+CD14+ cells) and neutrophils (IL-1ß+CD15+ or MIP-1ß+CD15+ cells) were increased in pregnant women in response to acute LPS stimulation. Moreover, distinct subsets of intermediate-activated monocytes expressing CD142, IL-6, and IL-1RA were increased in pregnant women upon chronic LPS stimulation. Last, pregnant women displayed a different cytokine profile than non-pregnant women in LPS-stimulated PBMCs and in whole blood. CONCLUSIONS: Pregnancy tailors the immune responses of circulating monocytes and neutrophils to endotoxin, a Gram-negative bacterial product.
Assuntos
Endotoxinas , Monócitos , Neutrófilos , Gravidez , Endotoxinas/farmacologia , Escherichia coli , Feminino , Humanos , Interleucina-6 , Lipopolissacarídeos/farmacologia , Monócitos/imunologia , Monócitos/fisiologia , Neutrófilos/imunologia , Neutrófilos/fisiologia , Gravidez/sangue , Gravidez/imunologia , Gravidez/fisiologia , Espécies Reativas de OxigênioRESUMO
BACKGROUND: The CCL2 (CC-chemokine ligand 2)/CCR2 (CC-chemokine receptor 2) axis governs monocyte recruitment to atherosclerotic lesions. Genetic and epidemiological studies show strong associations of CCL2 levels with atherosclerotic disease. Still, experimental studies testing pharmacological inhibition of CCL2 or CCR2 in atheroprone mice apply widely different approaches and report variable results, thus halting clinical translation. METHODS: We systematically searched the literature for studies employing pharmacological CCL2/CCR2 blockade in atheroprone mice and meta-analyzed their effects on lesion size and morphology. RESULTS: In a meta-analysis of 14 studies testing 11 different agents, CCL2/CCR2 blockade attenuated atherosclerotic lesion size in the aortic root or arch (g=-0.75 [-1.17 to -0.32], P=6×10-4; N=171/171 mice in experimental/control group), the carotid (g=-2.39 [-4.23 to -0.55], P=0.01; N=24/25), and the femoral artery (g=-2.38 [-3.50 to -1.26], P=3×10-5; N=10/10). Furthermore, CCL2/CCR2 inhibition reduced intralesional macrophage accumulation and increased smooth muscle cell content and collagen deposition. The effects of CCL2/CCR2 inhibition on lesion size correlated with reductions in plaque macrophage accumulation, in accord with a prominent role of CCL2/CCR2 signaling in monocyte recruitment. Subgroup analyses showed comparable efficacy of different CCL2- and CCR2-inhibitors in reducing lesion size and intralesional macrophages. The quality assessment revealed high risk of detection bias due to lack of blinding during outcome assessment, as well as evidence of attrition and reporting bias. CONCLUSIONS: Preclinical evidence suggests that pharmacological targeting of CCL2 or CCR2 might lower atherosclerotic lesion burden, but the majority of existing studies suffer major quality issues that highlight the need for additional high-quality research.
Assuntos
Aterosclerose , Quimiocina CCL2 , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/genética , Aterosclerose/prevenção & controle , Quimiocina CCL2/genética , Quimiocinas , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/fisiologia , Receptores CCR2/genéticaRESUMO
During inflammation, Ly6Chi monocytes are rapidly mobilized from the bone marrow (BM) and are recruited into inflamed tissues, where they undergo monocyte-to-phagocyte transition (MTPT). The in vivo developmental trajectories of the MTPT and the contribution of individual cytokines to this process remain unclear. Here, we used a murine model of neuroinflammation to investigate how granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-γ (IFNγ), two type 1 cytokines, controlled MTPT. Using genetic fate mapping, gene targeting and high-dimensional single-cell multiomics analyses, we found that IFNγ was essential for the gradual acquisition of a mature inflammatory phagocyte phenotype in Ly6Chi monocytes, while GM-CSF was required to license interleukin-1ß (IL-1ß) production, phagocytosis and oxidative burst. These results suggest that the proinflammatory cytokine environment guided MTPT trajectories in the inflamed central nervous system (CNS) and indicated that GM-CSF was the most prominent target for the disarming of monocyte progenies during neuroinflammation.
Assuntos
Diferenciação Celular/fisiologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Interferon gama/metabolismo , Monócitos/metabolismo , Doenças Neuroinflamatórias/metabolismo , Fagócitos/metabolismo , Animais , Citocinas/metabolismo , Feminino , Macrófagos/metabolismo , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monócitos/fisiologia , Doenças Neuroinflamatórias/fisiopatologia , Fagócitos/fisiologiaRESUMO
Cerebrovascular diseases are a leading cause of death and neurologic disability. Further understanding of disease mechanisms and therapeutic strategies requires a deeper knowledge of cerebrovascular cells in humans. We profiled transcriptomes of 181,388 cells to define a cell atlas of the adult human cerebrovasculature, including endothelial cell molecular signatures with arteriovenous segmentation and expanded perivascular cell diversity. By leveraging this reference, we investigated cellular and molecular perturbations in brain arteriovenous malformations, which are a leading cause of stroke in young people, and identified pathologic endothelial transformations with abnormal vascular patterning and the ontology of vascularly derived inflammation. We illustrate the interplay between vascular and immune cells that contributes to brain hemorrhage and catalog opportunities for targeting angiogenic and inflammatory programs in vascular malformations.
Assuntos
Vasos Sanguíneos/citologia , Encéfalo/irrigação sanguínea , Malformações Arteriovenosas Intracranianas/patologia , Transcriptoma , Adulto , Vasos Sanguíneos/patologia , Vasos Sanguíneos/fisiologia , Vasos Sanguíneos/fisiopatologia , Células Cultivadas , Córtex Cerebral/irrigação sanguínea , Hemorragia Cerebral/patologia , Hemorragia Cerebral/fisiopatologia , Circulação Cerebrovascular , Células Endoteliais/citologia , Células Endoteliais/patologia , Células Endoteliais/fisiologia , Fibroblastos/citologia , Fibroblastos/fisiologia , Humanos , Inflamação , Malformações Arteriovenosas Intracranianas/metabolismo , Monócitos/citologia , Monócitos/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiologia , Pericitos/citologia , Pericitos/fisiologia , RNA-Seq , Análise de Célula ÚnicaRESUMO
Pyrophosphate-containing calcium phosphate implants promote osteoinduction and bone regeneration. The role of pyrophosphate for inflammatory cell-mesenchymal stem cell (MSC) cross-talk during osteogenesis is not known. In the present work, the effects of lipopolysaccharide (LPS) and pyrophosphate (PPi) on primary human monocytes and on osteogenic gene expression in human adipose-derived MSCs were evaluated in vitro, using conditioned media transfer as well as direct effect systems. Direct exposure to pyrophosphate increased nonadherent monocyte survival (by 120% without LPS and 235% with LPS) and MSC viability (LDH) (by 16-19% with and without LPS). Conditioned media from LPS-primed monocytes significantly upregulated osteogenic genes (ALP and RUNX2) and downregulated adipogenic (PPAR-γ) and chondrogenic (SOX9) genes in recipient MSCs. Moreover, the inclusion of PPi (250 µM) resulted in a 1.2- to 2-fold significant downregulation of SOX9 in the recipient MSCs, irrespective of LPS stimulation or culture media type. These results indicate that conditioned media from LPS-stimulated inflammatory monocytes potentiates the early MSCs commitment towards the osteogenic lineage and that direct pyrophosphate exposure to MSCs can promote their viability and reduce their chondrogenic gene expression. These results are the first to show that pyrophosphate can act as a survival factor for both human MSCs and primary monocytes and can influence the early MSC gene expression. Graphical abstract.
Assuntos
Difosfatos/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Monócitos/fisiologia , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/genética , Regeneração Óssea/fisiologia , Comunicação Celular/efeitos dos fármacos , Comunicação Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Meios de Cultivo Condicionados , Regulação para Baixo/efeitos dos fármacos , Humanos , Lipopolissacarídeos/farmacologia , Teste de Materiais , Osteogênese/genética , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Circulating monocytes are functionally heterogeneous and can be divided into classical (CMo), intermediate (IMo), and non-CMo/patrolling monocyte (PMo) subsets. CMo can differentiate into PMo through IMo. PMos have been shown to inhibit cancer metastasis but the role of IMo is unclear. To date, no strategy has been developed to inhibit cancer metastasis through enhancing PMo/IMo differentiation. METHODS: We screened multiple inflammatory cytokines/chemokines activity of modulating PMo/IMo associated cell markers expression using human monocyte in vitro culture system. We tested our candidate cytokine activity in vivo using multiple mice models. We identified critical key factors and cytokines for our candidate cytokine activity by using gene-knockout mice and neutralization antibodies. RESULTS: We identified IFN-γ as a candidate inflammatory cytokine in the regulation of human IMo/PMo marker expression. Our in vivo data demonstrated that IMo expansion was induced by short-term (3 days) IFN-γ treatment through increasing CMo-IMo differentiation and blocking IMo-PMo differentiation. The IMo induced by IFN-γ (IFN-IMo), but not IFN-γ activated CMo (IFN-CMo), inhibited cancer metastasis by 90%. Surprizing, the effect of IFN-γ is greater in PMo deficiency mice, indicating the effect of IFN-IMo is not mediated through further differentiation into PMo. We also found that IFN-IMos induced by short-term IFN-γ treatment robustly boosted NK cell expansion for threefold and promoted NK differentiation and function through IL-27 and CXCL9. Furthermore, we identified that FOXO1, a key molecule controlling cellular energy metabolism, mediated the effect of IFN-γ induced IL-27 expression, and that NR4A1, a key molecule controlling PMo differentiation and inhibiting cancer metastasis, inhibited the pro-NK cell and anti-metastasis activity of IFN-IMo by suppressing CXCL9 expression. CONCLUSIONS: We have discovered the antimetastasis and pro-NK cell activity of IFN-IMo, identified FOXO1 as a key molecule for IFN-γ driven monocyte differentiation and function, and found NR4A1 as an inhibitory molecule for IFN-IMo activity. Our study has not only shown novel mechanisms for a classical antitumor cytokine but also provided potential target for developing superior monocytic cell therapy against cancer metastasis.
Assuntos
Proteína Forkhead Box O1/fisiologia , Interferon gama/farmacologia , Interleucina-27/fisiologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Monócitos/efeitos dos fármacos , Metástase Neoplásica/prevenção & controle , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/fisiologia , Fator de Transcrição STAT1/fisiologiaRESUMO
Aging is characterized by an increased vulnerability to infection and the development of inflammatory diseases, such as atherosclerosis, frailty, cancer and neurodegeneration. Here, we find that aging is associated with the loss of diurnally rhythmic innate immune responses, including monocyte trafficking from bone marrow to blood, response to lipopolysaccharide and phagocytosis. This decline in homeostatic immune responses was associated with a striking disappearance of circadian gene transcription in aged compared to young tissue macrophages. Chromatin accessibility was significantly greater in young macrophages than in aged macrophages; however, this difference did not explain the loss of rhythmic gene transcription in aged macrophages. Rather, diurnal expression of Kruppel-like factor 4 (Klf4), a transcription factor (TF) well established in regulating cell differentiation and reprogramming, was selectively diminished in aged macrophages. Ablation of Klf4 expression abolished diurnal rhythms in phagocytic activity, recapitulating the effect of aging on macrophage phagocytosis. Examination of individuals harboring genetic variants of KLF4 revealed an association with age-dependent susceptibility to death caused by bacterial infection. Our results indicate that loss of rhythmic Klf4 expression in aged macrophages is associated with disruption of circadian innate immune homeostasis, a mechanism that may underlie age-associated loss of protective immune responses.
Assuntos
Relógios Circadianos/genética , Macrófagos/fisiologia , Envelhecimento , Animais , Aterosclerose/genética , Diferenciação Celular/genética , Regulação da Expressão Gênica/genética , Imunidade Inata/genética , Inflamação/genética , Fator 4 Semelhante a Kruppel/genética , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/fisiologia , Fagocitose/genéticaRESUMO
Nonphlogistic migration of macrophages contributes to the clearance of pathogens and apoptotic cells, a critical step for the resolution of inflammation and return to homeostasis. Angiotensin-(1-7) [Ang-(1-7)] is a heptapeptide of the renin-angiotensin system that acts through Mas receptor (MasR). Ang-(1-7) has recently emerged as a novel proresolving mediator, yet Ang-(1-7) resolution mechanisms are not fully determined. Herein, Ang-(1-7) stimulated migration of human and murine monocytes/macrophages in a MasR-, CCR2-, and MEK/ERK1/2-dependent manner. Pleural injection of Ang-(1-7) promoted nonphlogistic mononuclear cell influx alongside increased levels of CCL2, IL-10, and macrophage polarization toward a regulatory phenotype. Ang-(1-7) induction of CCL2 and mononuclear cell migration was also dependent on MasR and MEK/ERK. Of note, MasR was upregulated during the resolution phase of inflammation, and its pharmacological inhibition or genetic deficiency impaired mononuclear cell recruitment during self-resolving models of LPS pleurisy and E. coli peritonitis. Inhibition/absence of MasR was associated with reduced CCL2 levels, impaired phagocytosis of bacteria, efferocytosis, and delayed resolution of inflammation. In summary, we have uncovered a potentially novel proresolving feature of Ang-(1-7), namely the recruitment of mononuclear cells favoring efferocytosis, phagocytosis, and resolution of inflammation. Mechanistically, cell migration was dependent on MasR, CCR2, and the MEK/ERK pathway.
Assuntos
Angiotensina I , Macrófagos , Monócitos , Fragmentos de Peptídeos , Fagocitose , Proto-Oncogene Mas/metabolismo , Angiotensina I/metabolismo , Angiotensina I/farmacologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Humanos , Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Monócitos/efeitos dos fármacos , Monócitos/fisiologia , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Peritonite , Fagocitose/efeitos dos fármacos , Fagocitose/fisiologia , Fenótipo , Receptores CCR2/metabolismoRESUMO
Endothelial inflammation is a crucial event in the initiation of atherosclerosis. Here, we identify Ataxin-10 protein as a novel negative modulator of endothelial activation by suppressing IRF-1 transcription activity. The protein level of Ataxin-10 is relatively higher in human vascular endothelial cells, which can be significantly suppressed by TNF-α in both HUVECs and HLMECs. Overexpression of Ataxin-10 markedly inhibited the mRNA expressions of VCAM-1 and several cytokines including MCP-1, CXCL-1, CCL-5, and TNF-α; thus, it can also suppress monocyte adhesion to endothelial cells. Accordingly, Ataxin-10 silencing promoted endothelial inflammation. However, Ataxin-10 did not affect the MAPK/NF-κB signaling pathway stimulated by TNF-α in HUVECs. Using the yeast two-hybrid assay, we found that Ataxin-10 can directly bind to interferon regulatory factor-1 (IRF-1). Upon TNF-α stimulation, Ataxin-10 promoted the cytoplasmic localization of IRF-1, which inhibited the transcription of VCAM-1. Moreover, knockdown of IRF-1 can eliminate the effect of Ataxin-10 on the expression of VCAM-1 in HUVECs induced by TNF-α. Taken together, these results indicate that Ataxin-10 inhibits endothelial cell activation and may serve as a promising therapeutic target for some vascular inflammatory-related diseases such as atherosclerosis.
Assuntos
Ataxina-10/fisiologia , Células Endoteliais/efeitos dos fármacos , Inflamação/prevenção & controle , Fator Regulador 1 de Interferon/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologia , Aterosclerose/etiologia , Células Cultivadas , Células Endoteliais/fisiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Monócitos/fisiologia , NF-kappa B/fisiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Molécula 1 de Adesão de Célula Vascular/análise , Molécula 1 de Adesão de Célula Vascular/genéticaRESUMO
This study investigated the effects of l-glutamine (Gln) and/or l-leucine (Leu) administration on sepsis-induced skeletal muscle injuries. C57BL/6J mice were subjected to cecal ligation and puncture to induce polymicrobial sepsis and then given an intraperitoneal injection of Gln, Leu, or Gln plus Leu beginning at 1 h after the operation with re-injections every 24 h. All mice were sacrificed on either day 1 or day 4 after the operation. Blood and muscles were collected for analysis of inflammation and oxidative damage-related biomolecules. Results indicated that both Gln and Leu supplementation alleviated sepsis-induced skeletal muscle damage by reducing monocyte infiltration, calpain activity, and mRNA expression levels of inflammatory cytokines and hypoxia-inducible factor-1α. Furthermore, septic mice treated with Gln had higher percentages of blood anti-inflammatory monocytes and muscle M2 macrophages, whereas Leu treatment enhanced the muscle expressions of mitochondrion-related genes. However, there were no synergistic effects when Gln and Leu were simultaneously administered. These findings suggest that both Gln and Leu had prominent abilities to attenuate inflammation and degradation of skeletal muscles in the early and/or late phases of sepsis. Moreover, Gln promoted the switch of leukocytes toward an anti-inflammatory phenotype, while Leu treatment maintained muscle bioenergetic function.