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1.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360821

RESUMO

Dexamethasone (Dexa), frequently used as an anti-inflammatory agent, paradoxically leads to muscle inflammation and muscle atrophy. Receptor for advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR4) lead to nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome formation through nuclear factor-κB (NF-κB) upregulation. NLRP3 inflammasome results in pyroptosis and is associated with the Murf-1 and atrogin-1 upregulation involved in protein degradation and muscle atrophy. The effects of Ecklonia cava extract (ECE) and dieckol (DK) on attenuating Dexa-induced muscle atrophy were evaluated by decreasing NLRP3 inflammasome formation in the muscles of Dexa-treated animals. The binding of AGE or high mobility group protein 1 to RAGE or TLR4 was increased by Dexa but significantly decreased by ECE or DK. The downstream signaling pathways of RAGE (c-Jun N-terminal kinase or p38) were increased by Dexa but decreased by ECE or DK. NF-κB, downstream of RAGE or TLR4, was increased by Dexa but decreased by ECE or DK. The NLRP3 inflammasome component (NLRP3 and apoptosis-associated speck-like), cleaved caspase -1, and cleaved gasdermin D, markers of pyroptosis, were increased by Dexa but decreased by ECE and DK. Interleukin-1ß/Murf-1/atrogin-1 expression was increased by Dexa but restored by ECE or DK. The mean muscle fiber cross-sectional area and grip strength were decreased by Dexa but restored by ECE or DK. In conclusion, ECE or DK attenuated Dexa-induced muscle atrophy by decreasing NLRP3 inflammasome formation and pyroptosis.


Assuntos
Benzofuranos/farmacologia , Dexametasona/efeitos adversos , Glucocorticoides/efeitos adversos , Inflamassomos/efeitos dos fármacos , Atrofia Muscular , Piroptose/efeitos dos fármacos , Animais , Inflamassomos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Extratos Vegetais/farmacologia
2.
Nutrients ; 13(7)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34371919

RESUMO

Besides its well-known psychoactive effects, caffeine has a broad range of actions. It regulates several physiological mechanisms as well as modulates both native and adaptive immune responses by various ways. Although caffeine is assumed to be a negative regulator of inflammation, the effect on the secretion of pro- and anti-inflammatory cytokines is highly controversial. Macrophages are major mediators of inflammatory responses; however, the various subpopulations develop different effects ranging from the initiation to the resolution of inflammation. Here we report a comparative analysis of the effect of caffeine on two subpopulations of human monocyte-derived macrophages differentiated in the presence of macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF), resulting in M-MΦs and GM-MΦs, respectively. We showed that although TNF-α secretion was downregulated in both LPS-activated MΦ subtypes by caffeine, the secretion of IL-8, IL-6, and IL-1ß as well as the expression of Nod-like receptors was enhanced in M-MΦs, while it did not change in GM-MΦs. We showed that caffeine (1) altered adenosine receptor expression, (2) changed Akt/AMPK/mTOR signaling pathways, and (3) inhibited STAT1/IL-10 signaling axis in M-MΦs. We hypothesized that these alterations play an important modulatory role in the upregulation of NLRP3 inflammasome-mediated IL-1ß secretion in LPS-activated M-MΦs following caffeine treatment.


Assuntos
Cafeína/farmacologia , Citocinas/metabolismo , Fatores Imunológicos/farmacologia , Inflamassomos/metabolismo , Mediadores da Inflamação/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Células Cultivadas , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Fenótipo , Receptor A2A de Adenosina/metabolismo , Receptor A2B de Adenosina/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
3.
Nat Commun ; 12(1): 4794, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373456

RESUMO

The cellular NLRP3 protein level is crucial for assembly and activation of the NLRP3 inflammasome. Various posttranslational modifications (PTMs), including phosphorylation and ubiquitination, control NLRP3 protein degradation and inflammasome activation; however, the function of small ubiquitin-like modifier (SUMO) modification (called SUMOylation) in controlling NLRP3 stability and subsequent inflammasome activation is unclear. Here, we show that the E3 SUMO ligase tripartite motif-containing protein 28 (TRIM28) is an enhancer of NLRP3 inflammasome activation by facilitating NLRP3 expression. TRIM28 binds NLRP3, promotes SUMO1, SUMO2 and SUMO3 modification of NLRP3, and thereby inhibits NLRP3 ubiquitination and proteasomal degradation. Concordantly, Trim28 deficiency attenuates NLRP3 inflammasome activation both in vitro and in vivo. These data identify a mechanism by which SUMOylation controls the cellular NLRP3 level and inflammasome activation, and reveal correlations and interactions of NLRP3 SUMOylation and ubiquitination during inflammasome activation.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Sumoilação/fisiologia , Proteína 28 com Motivo Tripartido/metabolismo , Animais , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Proteólise , Proteína SUMO-1/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação/genética , Proteína 28 com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Ubiquitinas/metabolismo
4.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360684

RESUMO

The outbreak of the coronavirus disease 2019 (COVID-19) began at the end of 2019. COVID-19 is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patients with COVID-19 may exhibit poor clinical outcomes. Some patients with severe COVID-19 experience cytokine release syndrome (CRS) or a cytokine storm-elevated levels of hyperactivated immune cells-and circulating pro-inflammatory cytokines, including interleukin (IL)-1ß and IL-18. This severe inflammatory response can lead to organ damage/failure and even death. The inflammasome is an intracellular immune complex that is responsible for the secretion of IL-1ß and IL-18 in various human diseases. Recently, there has been a growing number of studies revealing a link between the inflammasome and COVID-19. Therefore, this article summarizes the current literature regarding the inflammasome complex and COVID-19.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Inflamassomos/imunologia , Inflamassomos/metabolismo , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Imunidade Adaptativa/imunologia , Animais , COVID-19/complicações , COVID-19/tratamento farmacológico , Síndrome da Liberação de Citocina/tratamento farmacológico , Síndrome da Liberação de Citocina/etiologia , Síndrome da Liberação de Citocina/imunologia , Humanos , Insuficiência de Múltiplos Órgãos/tratamento farmacológico , Insuficiência de Múltiplos Órgãos/etiologia , Insuficiência de Múltiplos Órgãos/imunologia
5.
Cell Rep ; 36(8): 109614, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34433041

RESUMO

Zoonotic pathogens, such as COVID-19, reside in animal hosts before jumping species to infect humans. The Carnivora, like mink, carry many zoonoses, yet how diversity in host immune genes across species affect pathogen carriage is poorly understood. Here, we describe a progressive evolutionary downregulation of pathogen-sensing inflammasome pathways in Carnivora. This includes the loss of nucleotide-oligomerization domain leucine-rich repeat receptors (NLRs), acquisition of a unique caspase-1/-4 effector fusion protein that processes gasdermin D pore formation without inducing rapid lytic cell death, and the formation of a caspase-8 containing inflammasome that inefficiently processes interleukin-1ß. Inflammasomes regulate gut immunity, but the carnivorous diet has antimicrobial properties that could compensate for the loss of these immune pathways. We speculate that the consequences of systemic inflammasome downregulation, however, can impair host sensing of specific pathogens such that they can reside undetected in the Carnivora.


Assuntos
Carnívoros/metabolismo , Evolução Molecular , Inflamassomos/metabolismo , Zoonoses/patologia , Animais , Caspase 1/genética , Caspase 1/metabolismo , Caspase 8/metabolismo , Caspases Iniciadoras/genética , Caspases Iniciadoras/metabolismo , Morte Celular , Linhagem Celular , Humanos , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas NLR/genética , Proteínas NLR/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Salmonella typhi/patogenicidade , Zoonoses/imunologia , Zoonoses/parasitologia
6.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445481

RESUMO

Ischemia/reperfusion (I/R) injury is characterized by a limited blood supply to organs, followed by the restoration of blood flow and reoxygenation. In addition to ischemia, blood flow recovery can also lead to very harmful injury, especially inflammatory injury. Autophagy refers to the transport of cellular materials to the lysosomes for degradation, leading to the conversion of cellular components and offering energy and macromolecular precursors. It can maintain the balance of synthesis, decomposition and reuse of the intracellular components, and participate in many physiological processes and diseases. Inflammasomes are a kind of protein complex. Under physiological and pathological conditions, as the cellular innate immune signal receptors, inflammasomes sense pathogens to trigger an inflammatory response. TheNLRP3 inflammasome is the most deeply studied inflammasome and is composed of NLRP3, the adaptor apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and pro-caspase-1. Its activation triggers the cleavage of pro-interleukin (IL)-1ß and pro-IL-18 mediated by caspase-1 and promotes a further inflammatory process. Studies have shown that autophagy and the NLRP3 inflammasome play an important role in the process of I/R injury, but the relevant mechanisms have not been fully explained, especially how the interaction between autophagy and the NLRP3 inflammasome participates in I/R injury, which remains to be further studied. Therefore, we reviewed the recent studies about the interplay between autophagy and the NLRP3 inflammasome in I/R injury and analyzed the mechanisms to provide the theoretical references for further research in the future.


Assuntos
Autofagia , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Humanos , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/metabolismo
7.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445484

RESUMO

In response to diverse pathogenic and danger signals, the cytosolic activation of the NLRP3 (NOD-, LRR-, and pyrin domain-containing (3)) inflammasome complex is a critical event in the maturation and release of some inflammatory cytokines in the state of an inflammatory response. After activation of the NLRP3 inflammasome, a series of cellular events occurs, including caspase 1-mediated proteolytic cleavage and maturation of the IL-1ß and IL-18, followed by pyroptotic cell death. Therefore, the NLRP3 inflammasome has become a prime target for the resolution of many inflammatory disorders. Since NLRP3 inflammasome activation can be triggered by a wide range of stimuli and the activation process occurs in a complex, it is difficult to target the NLRP3 inflammasome. During the activation process, various post-translational modifications (PTM) of the NLRP3 protein are required to form a complex with other components. The regulation of ubiquitination and deubiquitination of NLRP3 has emerged as a potential therapeutic target for NLRP3 inflammasome-associated inflammatory disorders. In this review, we discuss the ubiquitination and deubiquitination system for NLRP3 inflammasome activation and the inhibitors that can be used as potential therapeutic agents to modulate the activation of the NLRP3 inflammasome.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Citosol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Ubiquitinação/efeitos dos fármacos
8.
Viruses ; 13(8)2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34452484

RESUMO

Given the impact of pandemics due to viruses of bat origin, there is increasing interest in comparative investigation into the differences between bat and human immune responses. The practice of comparative biology can be enhanced by computational methods used for dynamic knowledge representation to visualize and interrogate the putative differences between the two systems. We present an agent based model that encompasses and bridges differences between bat and human responses to viral infection: the comparative biology immune agent based model, or CBIABM. The CBIABM examines differences in innate immune mechanisms between bats and humans, specifically regarding inflammasome activity and type 1 interferon dynamics, in terms of tolerance to viral infection. Simulation experiments with the CBIABM demonstrate the efficacy of bat-related features in conferring viral tolerance and also suggest a crucial role for endothelial inflammasome activity as a mechanism for bat systemic viral tolerance and affecting the severity of disease in human viral infections. We hope that this initial study will inspire additional comparative modeling projects to link, compare, and contrast immunological functions shared across different species, and in so doing, provide insight and aid in preparation for future viral pandemics of zoonotic origin.


Assuntos
Quirópteros/imunologia , Imunidade Inata , Viroses/imunologia , Viroses/veterinária , Animais , Quirópteros/virologia , Simulação por Computador , Endotélio/fisiologia , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Índice de Gravidade de Doença , Estresse Fisiológico , Zoonoses Virais , Viroses/virologia , Fenômenos Fisiológicos Virais , Eliminação de Partículas Virais
9.
Oxid Med Cell Longev ; 2021: 6614574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34457117

RESUMO

Inflammatory reactions mediated by the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome contributes to non-small-cell lung cancer (NSCLC) progression, particularly in patients with bacterial infections. Salidroside (SAL) has recently been shown to suppress lipopolysaccharide- (LPS-) induced NSCLC proliferation and migration, but its mechanism of action remains unclear. It has been shown that SAL improves metabolic inflammation in diabetic rodents through AMP-activated protein kinase- (AMPK-) dependent inhibition of the NLRP3 inflammasome. However, whether the NLRP3 inflammasome is regulated by SAL in NSCLC cells and how its underlying mechanism(s) can be determined require clarification. In this study, human lung alveolar basal carcinoma epithelial (A549) cells were treated with LPS, and the effects of SAL on cell proliferation, migration, AMPK activity, reactive oxygen species (ROS) production, and NLRP3 inflammasome activation were investigated. We found that LPS induction increases the proliferation and migration of A549 cells which was suppressed by SAL. Moreover, SAL protected A549 cells against LPS-induced AMPK inhibition, ROS production, and NLRP3 inflammasome activation. Blocking AMPK using Compound C almost completely suppressed the beneficial effects of SAL. In summary, these results indicate that SAL suppresses the proliferation and migration of human lung cancer cells through AMPK-dependent NLRP3 inflammasome regulation.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Glucosídeos/farmacologia , Inflamassomos/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Apoptose , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Movimento Celular , Proliferação de Células , Humanos , Inflamassomos/metabolismo , Lipopolissacarídeos/farmacologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Transdução de Sinais , Células Tumorais Cultivadas
10.
FASEB J ; 35(9): e21837, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34383985

RESUMO

Overwhelming evidence indicates that excessive stimulation of innate immune receptors of the NOD-like receptor (NLR) family causes significant damage to multiple tissues, yet the role of these proteins in bone metabolism is not well known. Here, we studied the interaction between the NLRP3 and NLRC4 inflammasomes in bone homeostasis and disease. We found that loss of NLRP3 or NLRC4 inflammasome attenuated osteoclast differentiation in vitro. At the tissue level, lack of NLRP3, or NLRC4 to a lesser extent, resulted in higher baseline bone mass compared to wild-type (WT) mice, and conferred protection against LPS-induced inflammatory osteolysis. Bone mass accrual in mutant mice correlated with lower serum IL-1ß levels in vivo. Unexpectedly, the phenotype of Nlrp3-deficient mice was reversed upon loss of NLRC4 as bone mass was comparable between WT mice and Nlrp3;Nlrc4 knockout mice. Thus, although bone homeostasis is perturbed to various degrees by the lack of NLRP3 or NLRC4, this tissue appears to function normally upon compound loss of the inflammasomes assembled by these receptors.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Reabsorção Óssea/metabolismo , Osso e Ossos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Diferenciação Celular/fisiologia , Homeostase/fisiologia , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoclastos/metabolismo , Osteólise/metabolismo
11.
Nat Commun ; 12(1): 4664, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34341353

RESUMO

Excessive inflammatory responses induced upon SARS-CoV-2 infection are associated with severe symptoms of COVID-19. Inflammasomes activated in response to SARS-CoV-2 infection are also associated with COVID-19 severity. Here, we show a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation. N protein facilitates maturation of proinflammatory cytokines and induces proinflammatory responses in cultured cells and mice. Mechanistically, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates NLRP3 inflammasome assembly. More importantly, N protein aggravates lung injury, accelerates death in sepsis and acute inflammation mouse models, and promotes IL-1ß and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production are blocked by MCC950 (a specific inhibitor of NLRP3) and Ac-YVAD-cmk (an inhibitor of caspase-1). Therefore, this study reveals a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation and induces excessive inflammatory responses.


Assuntos
COVID-19/metabolismo , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Inflamassomos/metabolismo , Inflamação/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , SARS-CoV-2/metabolismo , Animais , COVID-19/virologia , Células Cultivadas , Citocinas/metabolismo , Células HEK293 , Humanos , Inflamassomos/genética , Lesão Pulmonar/genética , Lesão Pulmonar/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fosfoproteínas/metabolismo , Ligação Proteica , SARS-CoV-2/fisiologia , Células THP-1
12.
Commun Biol ; 4(1): 824, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193972

RESUMO

Demand for a cure of liver fibrosis is rising with its increasing morbidity and mortality. Therefore, it is an urgent issue to investigate its therapeutic candidates. Liver fibrosis progresses following 'multi-hit' processes involving hepatic stellate cells, macrophages, and hepatocytes. The NOD-like receptor protein 3 (NLRP3) inflammasome is emerging as a therapeutic target in liver fibrosis. Previous studies showed that the anti-rheumatic agent auranofin inhibits the NLRP3 inflammasome; thus, this study evaluates the antifibrotic effect of auranofin in vivo and explores the underlying molecular mechanism. The antifibrotic effect of auranofin is assessed in thioacetamide- and carbon tetrachloride-induced liver fibrosis models. Moreover, hepatic stellate cell (HSC), bone marrow-derived macrophage (BMDM), kupffer cell, and hepatocyte are used to examine the underlying mechanism of auranofin. Auranofin potently inhibits activation of the NLRP3 inflammasome in BMDM and kupffer cell. It also reduces the migration of HSC. The underlying molecular mechanism was inhibition of cystine-glutamate antiporter, system Xc. Auranofin inhibits system Xc activity and instantly induced oxidative burst, which mediated inhibition of the NLRP3 inflammasome in macrophages and HSCs. Therefore, to the best of our knowledge, we propose the use of auranofin as an anti-liver fibrotic agent.


Assuntos
Sistema y+ de Transporte de Aminoácidos/metabolismo , Auranofina/farmacologia , Inflamassomos/efeitos dos fármacos , Cirrose Hepática/prevenção & controle , Fígado/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Apoptose/efeitos dos fármacos , Tetracloreto de Carbono , Células Cultivadas , Humanos , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Macrófagos do Fígado/efeitos dos fármacos , Macrófagos do Fígado/metabolismo , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Piroptose/efeitos dos fármacos , Tioacetamida
13.
Arterioscler Thromb Vasc Biol ; 41(9): 2509-2511, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34261329
14.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202702

RESUMO

Inflammation is a key underlying factor of age-related macular degeneration (AMD) and inflammasome activation has been linked to disease development. Induced pluripotent stem-cell-derived retinal pigment epithelial cells (iPSC-RPE) are an attractive novel model system that can help to further elucidate disease pathways of this complex disease. Here, we analyzed the effect of dysfunctional protein clearance on inflammation and inflammasome activation in iPSC-RPE cells generated from a patient suffering from age-related macular degeneration (AMD) and an age-matched control. We primed iPSC-RPE cells with IL-1α and then inhibited both proteasomal degradation and autophagic clearance using MG-132 and bafilomycin A1, respectively, causing inflammasome activation. Subsequently, we determined cell viability, analyzed the expression levels of inflammasome-related genes using a PCR array, and measured the levels of pro-inflammatory cytokines IL-1ß, IL-6, IL-8, and MCP-1 secreted into the medium. Cell treatments modified the expression of 48 inflammasome-related genes and increased the secretion of mature IL-1ß, while reducing the levels of IL-6 and MCP-1. Interestingly, iPSC-RPE from an AMD donor secreted more IL-1ß and expressed more Hsp90 prior to the inhibition of protein clearance, while MCP-1 and IL-6 were reduced at both protein and mRNA levels. Overall, our results suggest that cellular clearance mechanisms might already be dysfunctional, and the inflammasome activated, in cells with a disease origin.


Assuntos
Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Células-Tronco Pluripotentes Induzidas/metabolismo , Inflamassomos/genética , Degeneração Macular/etiologia , Epitélio Pigmentado da Retina/metabolismo , Biomarcadores , Linhagem Celular , Células Cultivadas , Citocinas/metabolismo , Suscetibilidade a Doenças , Perfilação da Expressão Gênica , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Inflamassomos/metabolismo , Mediadores da Inflamação/metabolismo , Degeneração Macular/metabolismo , Epitélio Pigmentado da Retina/citologia
15.
Chem Biol Interact ; 345: 109573, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34217685

RESUMO

Pyroptosis plays an important role in the pathogenesis of numerous infectious, autoimmune, and inflammatory diseases, which makes it a promising target for intervention. In this study, the effect of luteolin on pyroptosis and the underlying mechanism were investigated using the canonical NLRP3 inflammasome in THP-1 macrophages induced by LPS/ATP. The results showed that luteolin exhibited a potent preventive effect on THP-1 macrophage pyroptosis, as evidenced by the increase in cell viability and the decrease in LDH release. Moreover, luteolin was found to significantly reduce the expression of NLRP3, pro-CASP-1 and CASP-1, which are the key components of NLRP3 inflammasome, as well as the expression of N-GSDMD and IL-1ß, and we proved that the inhibition of luteolin on NLRP3 inflammasome activation is ROS-dependent. Furthermore, it was demonstrated that luteolin promoted Nrf2 nuclear translocation, thereby increasing the expression of HO-1 that reduces ROS production, while the anti-pyroptotic effect of luteolin was reversed by a specific Nrf2 inhibitor. Additionally, luteolin inhibited NF-κB p65 phosphorylation and nuclear translocation. In summary, we conclude that luteolin prevents THP-1 macrophage pyroptosis by suppressing ROS production via Nrf2 activation as well as NF-κB inactivation. These results support luteolin as a potential bioactive chemical against pyroptosis-related inflammatory diseases.


Assuntos
Luteolina/farmacologia , Macrófagos/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Piroptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamassomos/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo
16.
Chem Biol Interact ; 345: 109572, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34217687

RESUMO

Oxidized low-density lipoprotein (ox-LDL) not only causes hyperlipidemia and contributes to atherosclerosis but also induces the endothelial dysfunction that leads to cardiovascular diseases. The nuclear factor-kappa B (NF-κB) pathway plays a key role in many chronic disorders and is a transcriptional factor in various inflammatory responses. The present study aimed to investigate the synergistic effects of pelargonic acid vanillylamide (PAVA) and rosuvastatin (RSV) on ox-LDL-induced inflammatory responses in human vascular endothelial cells (HUV-EC-C). HUV-EC-C were pretreated with PAVA or RSV and their combination for 2 h followed by ox-LDL for 24 h. The MTT assay was used to measure mitochondrial function. The DCFH-DA assay was used to evaluate oxidative phosphorylation, and western blotting was used to measured NF-κB/NLRP3 and related signaling pathways in HUV-EC-C. Ox-LDL induced lectin-type oxidized LDL receptor 1 (LOX-1) expression, NADPH oxidase 4 activation, and the overexpression of reactive oxygen species, which were inhibited by pretreatment with the combination of PAVA and RSV. Moreover, PAVA and RSV inhibited ox-LDL-induced NF-κBp65 activation. Ox-LDL induced NF-κB/NLRP3 pathway activation by inducing C-reactive protein expression, NLRP3 activation, caspase-1 activation, and IL-1ß secretion, which were inhibited by pretreatment with the combination of PAVA and RSV. The combination of PAVA and RSV reduced ox-LDL-induced recruitment of monocytes to the site of inflammation, inhibited activation of the NLRP3 inflammasome, and ameliorated the impairment of cell-cell junctions through the NF-κB pathway. Our results suggest that the synergistic effects of PAVA and RSV provide a novel mechanism for the treatment of cardiovascular diseases.


Assuntos
Benzilaminas/farmacologia , Citoproteção/efeitos dos fármacos , Ácidos Graxos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Junções Intercelulares/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Caspase 1/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Inflamassomos/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
Nat Commun ; 12(1): 4546, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315884

RESUMO

The NLRP3 inflammasome mediates the production of proinflammatory cytokines and initiates inflammatory cell death. Although NLRP3 is essential for innate immunity, aberrant NLRP3 inflammasome activation contributes to a wide variety of inflammatory diseases. Understanding the pathways that control NLRP3 activation will help develop strategies to treat these diseases. Here we identify WNK1 as a negative regulator of the NLRP3 inflammasome. Macrophages deficient in WNK1 protein or kinase activity have increased NLRP3 activation and pyroptosis compared with control macrophages. Mice with conditional knockout of WNK1 in macrophages have increased IL-1ß production in response to NLRP3 stimulation compared with control mice. Mechanistically, WNK1 tempers NLRP3 activation by balancing intracellular Cl- and K+ concentrations during NLRP3 activation. Collectively, this work shows that the WNK1 pathway has a critical function in suppressing NLRP3 activation and suggests that pharmacological inhibition of this pathway to treat hypertension might have negative clinical implications.


Assuntos
Cloretos/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose , Proteína Quinase 1 Deficiente de Lisina WNK/metabolismo , Animais , Caspase 1/metabolismo , Feminino , Imidazóis/farmacologia , Imunidade Inata/efeitos dos fármacos , Interleucina-1beta/metabolismo , L-Lactato Desidrogenase/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Potássio/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Piroptose/efeitos dos fármacos , Pirrolidinas/farmacologia , Tamoxifeno/farmacologia , Proteína Quinase 1 Deficiente de Lisina WNK/antagonistas & inibidores
18.
EMBO J ; 40(18): e108249, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34296442

RESUMO

SARS-CoV-2 is an emerging coronavirus that causes dysfunctions in multiple human cells and tissues. Studies have looked at the entry of SARS-CoV-2 into host cells mediated by the viral spike protein and human receptor ACE2. However, less is known about the cellular immune responses triggered by SARS-CoV-2 viral proteins. Here, we show that the nucleocapsid of SARS-CoV-2 inhibits host pyroptosis by blocking Gasdermin D (GSDMD) cleavage. SARS-CoV-2-infected monocytes show enhanced cellular interleukin-1ß (IL-1ß) expression, but reduced IL-1ß secretion. While SARS-CoV-2 infection promotes activation of the NLRP3 inflammasome and caspase-1, GSDMD cleavage and pyroptosis are inhibited in infected human monocytes. SARS-CoV-2 nucleocapsid protein associates with GSDMD in cells and inhibits GSDMD cleavage in vitro and in vivo. The nucleocapsid binds the GSDMD linker region and hinders GSDMD processing by caspase-1. These insights into how SARS-CoV-2 antagonizes cellular inflammatory responses may open new avenues for treating COVID-19 in the future.


Assuntos
COVID-19/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Nucleocapsídeo/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Piroptose/fisiologia , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/imunologia , COVID-19/patologia , COVID-19/virologia , Caspase 1/imunologia , Caspase 1/metabolismo , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Camundongos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas de Ligação a Fosfato/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Células THP-1
19.
Immunity ; 54(7): 1363-1365, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34260881

RESUMO

CARD8 senses pathogen-associated protease activity and assembles a pyroptosis-inducing inflammasome, but detailed regulatory mechanisms have remained elusive. In this issue of Immunity, Sharif et al. use cryo-EM and biochemical assays to unveil how DPP9 sequesters the inflammasome-forming C-terminal fragment of CARD8 to suppress its activation.


Assuntos
Proteínas Adaptadoras de Sinalização CARD , Inflamassomos , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Inflamassomos/metabolismo , Proteínas de Neoplasias/metabolismo , Piroptose
20.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299198

RESUMO

An inflammasome is an intracellular protein complex that is activated in response to a pathogenic infection and cellular damage. It triggers inflammatory responses by promoting inflammatory cell death (called pyroptosis) and the secretion of pro-inflammatory cytokines, interleukin (IL)-1ß and IL-18. Many types of inflammasomes have been identified and demonstrated to play a central role in inducing inflammatory responses, leading to the onset and progression of numerous inflammatory diseases. Methylation is a biological process by which methyl groups are transferred from methyl donors to proteins, nucleic acids, and other cellular molecules. Methylation plays critical roles in various biological functions by modulating gene expression, protein activity, protein localization, and molecular stability, and aberrant regulation of methylation causes deleterious outcomes in various human diseases. Methylation is a key determinant of inflammatory responses and diseases. This review highlights the current understanding of the functional relationship between inflammasome regulation and methylation of cellular molecules in inflammatory responses and diseases.


Assuntos
Metilação de DNA , Inflamassomos/metabolismo , Inflamação/metabolismo , Metiltransferases/metabolismo , Animais , Humanos , Inflamação/enzimologia , Inflamação/genética , Inflamação/patologia , Piroptose
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