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Frontiers in Immunology 2021Inhaled allergens promote inflammatory response, tissue damage, and airway hyperresponsiveness in the lungs, leading to allergic asthma. NLRP3, as an immune sensor of...
Inhaled allergens promote inflammatory response, tissue damage, and airway hyperresponsiveness in the lungs, leading to allergic asthma. NLRP3, as an immune sensor of infections and cellular stress, is associated with the development and exacerbation of asthma. However, the mechanism by which NLRP3 affects asthma requires further investigation. Here, we showed that inhaled house dust mite (HDM) promotes NLRP3 inflammasome activation in the lungs and specifically induces the maturation of caspase-1 and IL-1β in alveolar macrophages (AMs). Using -mutant mice, we found that NLRP3 promotes the inflammatory response and pathogenesis in HDM-induced allergic asthma in an inflammasome-dependent manner. Treatment with RRx-001, an NLRP3 inhibitor, significantly reduced inflammatory cell infiltration and mucus secretion in the airway. Our results showed that NLRP3 in myeloid cells promoted the development and progression of allergic asthma in an inflammasome-dependent manner. Small molecules targeting the NLRP3 inflammasome may provide new treatment options for this disease.
Topics: Allergens; Animals; Asthma; Biomarkers; Disease Models, Animal; Disease Susceptibility; Immunohistochemistry; Inflammasomes; Macrophage Activation; Macrophages, Alveolar; Mice; Mice, Knockout; NLR Family, Pyrin Domain-Containing 3 Protein; Pyroglyphidae
PubMed: 34413860
DOI: 10.3389/fimmu.2021.718779 -
Cell Death & Disease Apr 2021Exosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the...
Exosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.
Topics: Animals; Autophagy; Exosomes; Glioma; Humans; Macrophage Activation; Male; Mice; Transfection; Tumor Microenvironment
PubMed: 33828078
DOI: 10.1038/s41419-021-03664-1 -
Journal of Innate Immunity 2022Macrophages, the central mediators of innate immune responses, being in the first-line of defense, they have to readily respond to pathogenic or tissue damage signals to... (Review)
Review
Macrophages, the central mediators of innate immune responses, being in the first-line of defense, they have to readily respond to pathogenic or tissue damage signals to initiate the inflammatory cascade. Such rapid responses require energy to support orchestrated production of pro-inflammatory mediators and activation of phagocytosis. Being a cell type that is present in diverse environments and conditions, macrophages have to adapt to different nutritional resources. Thus, macrophages have developed plasticity and are capable of utilizing energy at both normoxic and hypoxic conditions and in the presence of varying concentrations of glucose or other nutrients. Such adaptation is reflected on changes in signaling pathways that modulate responses, accounting for the different activation phenotypes observed. Macrophage metabolism has been tightly associated with distinct activation phenotypes within the range of M1-like and M2-like types. In the context of diseases, systemic changes also affect macrophage metabolism, as in diabetes and insulin resistance, which results in altered metabolism and distinct activation phenotypes in the adipose tissue or in the periphery. In the context of solid tumors, tumor-associated macrophages adapt in the hypoxic environment, which results in metabolic changes that are reflected on an activation phenotype that supports tumor growth. Coordination of environmental and pathogenic signals determines macrophage metabolism, which in turn shapes the type and magnitude of the response. Therefore, modulating macrophage metabolism provides a potential therapeutic approach for inflammatory diseases and cancer.
Topics: Adipose Tissue; Humans; Immunity, Innate; Inflammation; Insulin Resistance; Macrophage Activation; Macrophages
PubMed: 34247159
DOI: 10.1159/000516780 -
Immunity May 2017Recognition of pathogens by innate and adaptive immune cells instructs rapid alterations of cellular processes to promote effective resolution of infection. To... (Review)
Review
Recognition of pathogens by innate and adaptive immune cells instructs rapid alterations of cellular processes to promote effective resolution of infection. To accommodate increased bioenergetic and biosynthetic demands, metabolic pathways are harnessed to maximize proliferation and effector molecule production. In parallel, activation initiates context-specific gene-expression programs that drive effector functions and cell fates that correlate with changes in epigenetic landscapes. Many chromatin- and DNA-modifying enzymes make use of substrates and cofactors that are intermediates of metabolic pathways, providing potential cross talk between metabolism and epigenetic regulation of gene expression. In this review, we discuss recent studies of T cells and macrophages supporting a role for metabolic activity in integrating environmental signals with activation-induced gene-expression programs through modulation of the epigenome and speculate as to how this may influence context-specific macrophage and T cell responses to infection.
Topics: Animals; Cell Differentiation; Cellular Microenvironment; Energy Metabolism; Epigenesis, Genetic; Gene Expression Regulation; Humans; Immunity; Lymphocyte Activation; Macrophage Activation; Macrophages; Metabolic Networks and Pathways; T-Lymphocytes
PubMed: 28514673
DOI: 10.1016/j.immuni.2017.04.016 -
Biochimica Et Biophysica Acta.... Jan 2022Macrophages are professional phagocytes, indispensable for maintenance of tissue homeostasis and integrity. Depending on their resident tissue, macrophages are exposed... (Review)
Review
Macrophages are professional phagocytes, indispensable for maintenance of tissue homeostasis and integrity. Depending on their resident tissue, macrophages are exposed to highly diverse metabolic environments. Adapted to their niche, they can contribute to local metabolic turnover through metabolite uptake, conversion, storage and release. Disturbances in tissue homeostasis caused by infection, inflammation or damage dramatically alter the local milieu, impacting macrophage activation status and metabolism. In the case of persisting stimuli, defective macrophage responses ensue, which can promote tissue damage and disease. Especially relevant herein are disbalances in lipid rich environments, where macrophages are crucially involved in lipid uptake and turnover, preventing lipotoxicity. Lipid uptake is to a large extent facilitated by macrophage expressed scavenger receptors that are dynamically regulated and important in many metabolic diseases. Here, we review the receptors mediating lipid uptake and summarize recent findings on their role in health and disease. We further highlight the underlying pathways driving macrophage lipid acquisition and their impact on myeloid metabolic remodelling.
Topics: Biological Transport; Homeostasis; Humans; Inflammation; Lipids; Macrophage Activation; Macrophages
PubMed: 34626791
DOI: 10.1016/j.bbalip.2021.159066 -
Science Advances Nov 2023BMP15 is a conserved regulator of ovarian development and maintenance in vertebrates. In humans, premature ovarian insufficiency is caused by autoimmunity and genetic...
BMP15 is a conserved regulator of ovarian development and maintenance in vertebrates. In humans, premature ovarian insufficiency is caused by autoimmunity and genetic factors, including mutation of BMP15. The cellular mechanisms underlying ovarian failure caused by BMP15 mutation and immune contributions are not understood. Using zebrafish, we established a causal link between macrophage activation and ovarian failure, which, in zebrafish, causes sex reversal. We define a germline-soma signaling axis that activates macrophages and drives ovarian failure and female-to-male sex reversal. Germline loss of zebrafish Bmp15 impairs oogenesis and initiates this cascade. Single-cell RNA sequencing and genetic analyses implicate ovarian somatic cells that express conserved macrophage-activating ligands as mediators of ovarian failure and sex reversal. Genetic ablation of macrophages or elimination of Csf1Rb ligands, Il34 or Csf1a, delays or blocks premature oocyte loss and sex reversal. The axis identified here provides insight into the cells and pathways governing oocyte and ovary maintenance and potential therapeutic targets to preserve female fertility.
Topics: Humans; Animals; Male; Female; Zebrafish; Macrophage Activation; Oocytes; Primary Ovarian Insufficiency
PubMed: 37992158
DOI: 10.1126/sciadv.adg7488 -
Journal of Visualized Experiments : JoVE Jun 2013The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells...
The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.
Topics: Animals; Bone Marrow Cells; Cell Differentiation; Cell Polarity; Cytological Techniques; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoietic Stem Cells; Macrophage Activation; Macrophage Colony-Stimulating Factor; Macrophages; Mice
PubMed: 23851980
DOI: 10.3791/50323 -
Cellular & Molecular Biology Letters Oct 2022Macrophages are influential members of the innate immune system that can be reversibly polarized by different microenvironment signals. Cell polarization leads to a wide... (Review)
Review
Macrophages are influential members of the innate immune system that can be reversibly polarized by different microenvironment signals. Cell polarization leads to a wide range of features, involving the migration, development, and organization of the cells. There is mounting evidence that macrophage polarization plays a key role in the initiation and development of a wide range of diseases. This study aims to give an overview of macrophage polarization, their different subtypes, and the importance of alternatively activated M2 macrophage and classically activated M1 macrophage in immune responses and pathological conditions. This review provides insight on the role of exosomes in M1/M2-like macrophage polarization and their potential as a promising therapeutic candidate.
Topics: Exosomes; Immunity; Immunomodulation; Macrophage Activation; Macrophages
PubMed: 36192691
DOI: 10.1186/s11658-022-00384-y -
Seminars in Immunology Oct 2016Macrophages are heterogeneous cells that play a key role in inflammatory and tissue reparative responses. Over the past decade it has become clear that shifts in... (Review)
Review
Macrophages are heterogeneous cells that play a key role in inflammatory and tissue reparative responses. Over the past decade it has become clear that shifts in cellular metabolism are important determinants of macrophage function and phenotype. At the same time, our appreciation of macrophage diversity in vivo has also been increasing. Factors such as cell origin and tissue localization are now recognized as important variables that influence macrophage biology. Whether different macrophage populations also have unique metabolic phenotypes has not been extensively explored. In this article, we will discuss the importance of understanding how macrophage origin can modulate metabolic programming and influence inflammatory responses.
Topics: Animals; Energy Metabolism; Gene Expression Regulation; Humans; Immunomodulation; Macrophage Activation; Macrophages; Metabolic Networks and Pathways; Organ Specificity; Phenotype
PubMed: 27771140
DOI: 10.1016/j.smim.2016.10.004 -
Results and Problems in Cell... 2017Macrophages constitute a heterogeneous population of myeloid cells that are essential for maintaining homeostasis and as a first line of innate responders controlling... (Review)
Review
Macrophages constitute a heterogeneous population of myeloid cells that are essential for maintaining homeostasis and as a first line of innate responders controlling and organizing host defenses against pathogens. Monocyte-macrophage lineage cells are among the most functionally diverse and plastic cells of the immune system. They undergo specific activation into functionally distinct phenotypes in response to immune signals and microbial products. In mammals, macrophage functional heterogeneity is defined by two activation states, M1 and M2, which represent two polar ends of a continuum exhibiting pro-inflammatory and tissue repair activities, respectively. While the ancient evolutionary origin of macrophages as phagocytic defenders is well established, the evolutionary roots of the specialized division of macrophages into subsets with polarized activation phenotypes is less well defined. Accordingly, this chapter focuses on recent advances in the understanding of the evolution of macrophage polarization and functional heterogeneity with a focus on ectothermic vertebrates.
Topics: Animals; Cell Lineage; Humans; Macrophage Activation; Macrophages
PubMed: 28455703
DOI: 10.1007/978-3-319-54090-0_1