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1.
J Biol Chem ; 298(2): 101501, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34929172

RESUMO

Activated macrophages undergo metabolic reprogramming, which not only supports their energetic demands but also allows for the production of specific metabolites that function as signaling molecules. Several Krebs cycles, or Krebs-cycle-derived metabolites, including succinate, α-ketoglutarate, and itaconate, have recently been shown to modulate macrophage function. The accumulation of 2-hydroxyglutarate (2HG) has also been well documented in transformed cells and more recently shown to play a role in T cell and dendritic cell function. Here we have found that the abundance of both enantiomers of 2HG is increased in LPS-activated macrophages. We show that L-2HG, but not D-2HG, can promote the expression of the proinflammatory cytokine IL-1ß and the adoption of an inflammatory, highly glycolytic metabolic state. These changes are likely mediated through activation of the transcription factor hypoxia-inducible factor-1α (HIF-1α) by L-2HG, a known inhibitor of the HIF prolyl hydroxylases. Expression of the enzyme responsible for L-2HG degradation, L-2HG dehydrogenase (L-2HGDH), was also found to be decreased in LPS-stimulated macrophages and may therefore also contribute to L-2HG accumulation. Finally, overexpression of L-2HGDH in HEK293 TLR4/MD2/CD14 cells inhibited HIF-1α activation by LPS, while knockdown of L-2HGDH in macrophages boosted the induction of HIF-1α-dependent genes, as well as increasing LPS-induced HIF-1α activity. Taken together, this study therefore identifies L-2HG as a metabolite that can regulate HIF-1α in macrophages.


Assuntos
Glutaratos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Lipopolissacarídeos , Macrófagos , Glutaratos/metabolismo , Células HEK293 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lipopolissacarídeos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Macrófagos/metabolismo
2.
Trends Immunol ; 41(2): 93-94, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31948874

RESUMO

Metabolic reprogramming in macrophages supports effector functions and differs depending on the activating stimulus. Lauterbach et al. now show that early metabolic alterations in macrophages driven by LPS signaling serve to increase the acetyl-CoA pool via citrate metabolism by the ATP-citrate lyase (ACLY), leading to histone acetylation and regulation of TLR-driven gene expression.


Assuntos
ATP Citrato (pro-S)-Liase , Histonas , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Acetilação , Trifosfato de Adenosina , Código das Histonas , Histonas/metabolismo , Humanos , Macrófagos/metabolismo , Complexos Multienzimáticos , Oxo-Ácido-Liases , Receptores Toll-Like
3.
Respir Res ; 22(1): 133, 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33926483

RESUMO

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.


Assuntos
Imunidade Adaptativa , Asma/imunologia , Doenças Transmissíveis/imunologia , Imunidade Inata , Pulmão/imunologia , Metais/imunologia , Microbiota , Estado Nutricional , Doença Pulmonar Obstrutiva Crônica/imunologia , Animais , Asma/microbiologia , Asma/fisiopatologia , Asma/virologia , Doenças Transmissíveis/microbiologia , Doenças Transmissíveis/fisiopatologia , Doenças Transmissíveis/virologia , Interações Hospedeiro-Patógeno , Humanos , Pulmão/microbiologia , Pulmão/fisiopatologia , Pulmão/virologia , Metais/metabolismo , Prognóstico , Doença Pulmonar Obstrutiva Crônica/microbiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/virologia
4.
Proc Natl Acad Sci U S A ; 114(32): E6480-E6489, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28739909

RESUMO

MyD88 adaptor-like (MAL) is a critical protein in innate immunity, involved in signaling by several Toll-like receptors (TLRs), key pattern recognition receptors (PRRs). Crystal structures of MAL revealed a nontypical Toll/interleukin-1 receptor (TIR)-domain fold stabilized by two disulfide bridges. We therefore undertook a structural and functional analysis of the role of reactive cysteine residues in the protein. Under reducing conditions, the cysteines do not form disulfides, but under oxidizing conditions they are highly amenable to modification. The solution structure of the reduced form of the MAL TIR domain, determined by NMR spectroscopy, reveals a remarkable structural rearrangement compared with the disulfide-bonded structure, which includes the relocation of a ß-strand and repositioning of the functionally important "BB-loop" region to a location more typical for TIR domains. Redox measurements by NMR further reveal that C91 has the highest redox potential of all cysteines in MAL. Indeed, mass spectrometry revealed that C91 undergoes glutathionylation in macrophages activated with the TLR4 ligand lipopolysaccharide (LPS). The C91A mutation limits MAL glutathionylation and acts as a dominant negative, blocking the interaction of MAL with its downstream target MyD88. The H92P mutation mimics the dominant-negative effects of the C91A mutation, presumably by preventing C91 glutathionylation. The MAL C91A and H92P mutants also display diminished degradation and interaction with interleukin-1 receptor-associated kinase 4 (IRAK4). We conclude that in the cell, MAL is not disulfide-bonded and requires glutathionylation of C91 for signaling.


Assuntos
Glutationa/metabolismo , Glicoproteínas de Membrana , Processamento de Proteína Pós-Traducional , Receptores de Interleucina-1 , Transdução de Sinais , Substituição de Aminoácidos , Cisteína/química , Cisteína/genética , Cisteína/metabolismo , Glutationa/química , Glutationa/genética , Células HEK293 , Humanos , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Mutação de Sentido Incorreto , Ressonância Magnética Nuclear Biomolecular , Domínios Proteicos , Estrutura Secundária de Proteína , Receptores de Interleucina-1/química , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/metabolismo , Relação Estrutura-Atividade
5.
JCI Insight ; 8(16)2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37606038

RESUMO

Alveolar epithelial type II (AEC2) cells strictly regulate lipid metabolism to maintain surfactant synthesis. Loss of AEC2 cell function and surfactant production are implicated in the pathogenesis of the smoking-related lung disease chronic obstructive pulmonary disease (COPD). Whether smoking alters lipid synthesis in AEC2 cells and whether altering lipid metabolism in AEC2 cells contributes to COPD development are unclear. In this study, high-throughput lipidomic analysis revealed increased lipid biosynthesis in AEC2 cells isolated from mice chronically exposed to cigarette smoke (CS). Mice with a targeted deletion of the de novo lipogenesis enzyme, fatty acid synthase (FASN), in AEC2 cells (FasniΔAEC2) exposed to CS exhibited higher bronchoalveolar lavage fluid (BALF) neutrophils, higher BALF protein, and more severe airspace enlargement. FasniΔAEC2 mice exposed to CS had lower levels of key surfactant phospholipids but higher levels of BALF ether phospholipids, sphingomyelins, and polyunsaturated fatty acid-containing phospholipids, as well as increased BALF surface tension. FasniΔAEC2 mice exposed to CS also had higher levels of protective ferroptosis markers in the lung. These data suggest that AEC2 cell FASN modulates the response of the lung to smoke by regulating the composition of the surfactant phospholipidome.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Surfactantes Pulmonares , Animais , Camundongos , Ácido Graxo Sintase Tipo II , Ácido Graxo Sintases/genética , Tensoativos , Células Epiteliais , Homeostase , Lipídeos
6.
Elife ; 112022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36173104

RESUMO

Macrophages are a highly adaptive population of innate immune cells. Polarization with IFNγ and LPS into the 'classically activated' M1 macrophage enhances pro-inflammatory and microbicidal responses, important for eradicating bacteria such as Mycobacterium tuberculosis. By contrast, 'alternatively activated' M2 macrophages, polarized with IL-4, oppose bactericidal mechanisms and allow mycobacterial growth. These activation states are accompanied by distinct metabolic profiles, where M1 macrophages favor near exclusive use of glycolysis, whereas M2 macrophages up-regulate oxidative phosphorylation (OXPHOS). Here, we demonstrate that activation with IL-4 and IL-13 counterintuitively induces protective innate memory against mycobacterial challenge. In human and murine models, prior activation with IL-4/13 enhances pro-inflammatory cytokine secretion in response to a secondary stimulation with mycobacterial ligands. In our murine model, enhanced killing capacity is also demonstrated. Despite this switch in phenotype, IL-4/13 trained murine macrophages do not demonstrate M1-typical metabolism, instead retaining heightened use of OXPHOS. Moreover, inhibition of OXPHOS with oligomycin, 2-deoxy glucose or BPTES all impeded heightened pro-inflammatory cytokine responses from IL-4/13 trained macrophages. Lastly, this work identifies that IL-10 attenuates protective IL-4/13 training, impeding pro-inflammatory and bactericidal mechanisms. In summary, this work provides new and unexpected insight into alternative macrophage activation states in the context of mycobacterial infection.


Assuntos
Interleucina-10 , Interleucina-13 , Animais , Citocinas/metabolismo , Glucose/metabolismo , Humanos , Interleucina-10/metabolismo , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Lipopolissacarídeos/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Camundongos , Oligomicinas , Fosforilação Oxidativa
7.
Cells ; 10(11)2021 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-34831186

RESUMO

Macrophage stimulation by pathogen-associated molecular patterns (PAMPs) like lipopolysaccharide (LPS) or lipoteichoic acid (LTA) drives a proinflammatory phenotype and induces a metabolic reprogramming to sustain the cell's function. Nevertheless, the relationship between metabolic shifts and gene expression remains poorly explored. In this context, the metabolic enzyme ATP citrate lyase (ACLY), the producer of citrate-derived acetyl-coenzyme A (CoA), plays a critical role in supporting a proinflammatory response. Through immunocytochemistry and cytosol-nucleus fractionation, we found a short-term ACLY nuclear translocation. Protein immunoprecipitation unveiled the role of nuclear ACLY in NF-κB acetylation and in turn its full activation in human PBMC-derived macrophages. Notably, sepsis in the early hyperinflammatory phase triggers ACLY-mediated NF-κB acetylation. The ACLY/NF-κB axis increases the expression levels of proinflammatory genes, including SLC25A1-which encodes the mitochondrial citrate carrier-and ACLY, thus promoting the existence of a proinflammatory loop involving SLC25A1 and ACLY genes.


Assuntos
ATP Citrato (pro-S)-Liase/metabolismo , Núcleo Celular/metabolismo , Regulação da Expressão Gênica , Inflamação/genética , Macrófagos/metabolismo , NF-kappa B/metabolismo , ATP Citrato (pro-S)-Liase/genética , Acetilação/efeitos dos fármacos , Idoso , Núcleo Celular/efeitos dos fármacos , Citosol/efeitos dos fármacos , Citosol/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Sepse/genética , Ácidos Teicoicos/farmacologia , Regulação para Cima/genética , Adulto Jovem
8.
Front Immunol ; 9: 141, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29459863

RESUMO

Metabolism in immune cells is no longer thought of as merely a process for adenosine triphosphate (ATP) production, biosynthesis, and catabolism. The reprogramming of metabolic pathways upon activation is also for the production of metabolites that can act as immune signaling molecules. Activated dendritic cells (DCs) and macrophages have an altered Krebs cycle, one consequence of which is the accumulation of both citrate and succinate. Citrate is exported from the mitochondria via the mitochondrial citrate- carrier. Cytosolic metabolism of citrate to acetyl-coenzyme A (acetyl-CoA) is important for both fatty-acid synthesis and protein acetylation, both of which have been linked to macrophage and DC activation. Citrate-derived itaconate has a direct antibacterial effect and also has been shown to act as an anti-inflammatory agent, inhibiting succinate dehydrogenase. These findings identify citrate as an important metabolite for macrophage and DC effector function.


Assuntos
Ácido Cítrico/imunologia , Ácido Cítrico/metabolismo , Imunidade Inata , Animais , Metabolismo dos Carboidratos , Ciclo do Ácido Cítrico , Células Dendríticas/metabolismo , Ácidos Graxos/metabolismo , Histonas/metabolismo , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Macrófagos/metabolismo , Processamento de Proteína Pós-Traducional
9.
Nat Med ; 22(2): 163-74, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26752519

RESUMO

Chronic obstructive pulmonary disease (COPD) is linked to both cigarette smoking and genetic determinants. We have previously identified iron-responsive element-binding protein 2 (IRP2) as an important COPD susceptibility gene and have shown that IRP2 protein is increased in the lungs of individuals with COPD. Here we demonstrate that mice deficient in Irp2 were protected from cigarette smoke (CS)-induced experimental COPD. By integrating RNA immunoprecipitation followed by sequencing (RIP-seq), RNA sequencing (RNA-seq), and gene expression and functional enrichment clustering analysis, we identified Irp2 as a regulator of mitochondrial function in the lungs of mice. Irp2 increased mitochondrial iron loading and levels of cytochrome c oxidase (COX), which led to mitochondrial dysfunction and subsequent experimental COPD. Frataxin-deficient mice, which had higher mitochondrial iron loading, showed impaired airway mucociliary clearance (MCC) and higher pulmonary inflammation at baseline, whereas mice deficient in the synthesis of cytochrome c oxidase, which have reduced COX, were protected from CS-induced pulmonary inflammation and impairment of MCC. Mice treated with a mitochondrial iron chelator or mice fed a low-iron diet were protected from CS-induced COPD. Mitochondrial iron chelation also alleviated CS-induced impairment of MCC, CS-induced pulmonary inflammation and CS-associated lung injury in mice with established COPD, suggesting a critical functional role and potential therapeutic intervention for the mitochondrial-iron axis in COPD.


Assuntos
Bronquite/genética , Quelantes de Ferro/farmacologia , Proteínas de Ligação ao Ferro/genética , Ferro/metabolismo , Pulmão/metabolismo , Mitocôndrias/metabolismo , Nicotiana , Doença Pulmonar Obstrutiva Crônica/genética , Enfisema Pulmonar/genética , Fumaça/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Remodelação das Vias Aéreas , Animais , Bronquite/etiologia , Modelos Animais de Doenças , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Imuno-Histoquímica , Imunoprecipitação , Proteína 2 Reguladora do Ferro/genética , Proteína 2 Reguladora do Ferro/metabolismo , Ferro da Dieta , Pulmão/efeitos dos fármacos , Lesão Pulmonar/etiologia , Lesão Pulmonar/genética , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Knockout , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Mitocôndrias/efeitos dos fármacos , Depuração Mucociliar/genética , Pneumonia/etiologia , Pneumonia/genética , Doença Pulmonar Obstrutiva Crônica/etiologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Enfisema Pulmonar/etiologia , Reação em Cadeia da Polimerase em Tempo Real , Fumar/efeitos adversos , Frataxina
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