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1.
Life Sci ; 284: 119941, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34508761

RESUMO

Chronic liver diseases (CLD) are among the major cause of mortality and morbidity worldwide. Despite current achievements in the area of hepatitis virus, chronic alcohol abuse and high-fat diet are still fueling an epidemic of severe liver disease, for which, an effective therapy has yet not been discovered. In particular, the therapeutic regimens that could prevent the progression of fibrosis and, in turn, aid cirrhotic liver to develop a robust regenerative capability are intensively needed. To this context, a better understanding of the signaling pathways regulating hepatic disease development may be of critical value. In general, the liver responds to various insults with an orchestrated healing process involving variety of signaling pathways. One such pathway is the TLR2 signaling pathway, which essentially regulates adult liver pathogenesis and thus has emerged as an attractive target to treat liver disease. TLR2 is expressed by different liver cells, including Kupffer cells (KCs), hepatocytes, and hepatic stellate cells (HSCs). From a pathologic perspective, the crosstalk between antigens and TLR2 may preferentially trigger a distinctive set of signaling mechanisms in these liver cells and, thereby, induce the production of inflammatory and fibrogenic cytokines that can initiate and prolong liver inflammation, ultimately leading to fibrosis. In this review, we summarize the currently available evidence regarding the role of TLR2 signaling in hepatic disease progression. We first elaborate its pathological involvement in liver-disease states, such as inflammation, fibrosis, and cirrhosis. We then discuss how therapeutic targeting of this pathway may help to alleviate its disease-related functioning.


Assuntos
Fígado/metabolismo , Fígado/fisiopatologia , Transdução de Sinais , Receptor 2 Toll-Like/metabolismo , Animais , Hepatócitos/metabolismo , Humanos , Hepatopatias/metabolismo , Processamento de Proteína Pós-Traducional
2.
Nat Commun ; 12(1): 5382, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508096

RESUMO

Pathways to control the spreading of α-synuclein (α-syn) and associated neuropathology in Parkinson's disease (PD), multiple system atrophy (MSA) and dementia with Lewy bodies (DLB) are unclear. Here, we show that preformed α-syn fibrils (PFF) increase the association between TLR2 and MyD88, resulting in microglial activation. The TLR2-interaction domain of MyD88 (wtTIDM) peptide-mediated selective inhibition of TLR2 reduces PFF-induced microglial inflammation in vitro. In PFF-seeded A53T mice, the nasal administration of the wtTIDM peptide, NEMO-binding domain (wtNBD) peptide, or genetic deletion of TLR2 reduces glial inflammation, decreases α-syn spreading, and protects dopaminergic neurons by inhibiting NF-κB. In summary, α-syn spreading depends on the TLR2/MyD88/NF-κB pathway and it can be reduced by nasal delivery of wtTIDM and wtNBD peptides.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Microglia/patologia , alfa-Sinucleína/metabolismo , Animais , Células Cultivadas , Modelos Animais de Doenças , Neurônios Dopaminérgicos/imunologia , Humanos , Doença por Corpos de Lewy/genética , Doença por Corpos de Lewy/patologia , Camundongos , Camundongos Knockout , Microglia/imunologia , Microglia/metabolismo , Atrofia de Múltiplos Sistemas/genética , Atrofia de Múltiplos Sistemas/patologia , Mutagênese Sítio-Dirigida , Mutação , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/patologia , Cultura Primária de Células , Regiões Promotoras Genéticas , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , alfa-Sinucleína/genética
3.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360835

RESUMO

Defective intestinal tight junction (TJ) barrier is a hallmark in the pathogenesis of inflammatory bowel disease (IBD). To date, there are no effective therapies that specifically target the intestinal TJ barrier. Among the various probiotic bacteria, Bifidobacterium, is one of the most widely studied to have beneficial effects on the intestinal TJ barrier. The main purpose of this study was to identify Bifidobacterium species that cause a sustained enhancement in the intestinal epithelial TJ barrier and can be used therapeutically to target the intestinal TJ barrier and to protect against or treat intestinal inflammation. Our results showed that Bifidobacterium bifidum caused a marked, sustained enhancement in the intestinal TJ barrier in Caco-2 monolayers. The Bifidobacterium bifidum effect on TJ barrier was strain-specific, and only the strain designated as BB1 caused a maximal enhancement in TJ barrier function. The mechanism of BB1 enhancement of intestinal TJ barrier required live bacterial cell/enterocyte interaction and was mediated by the BB1 attachment to Toll-like receptor-2 (TLR-2) at the apical membrane surface. The BB1 enhancement of the intestinal epithelial TJ barrier function was mediated by the activation of the p38 kinase pathway, but not the NF-κB signaling pathway. Moreover, the BB1 caused a marked enhancement in mouse intestinal TJ barrier in a TLR-2-dependent manner and protected against dextran sodium sulfate (DSS)-induced increase in mouse colonic permeability, and treated the DSS-induced colitis in a TJ barrier-dependent manner. These studies show that probiotic bacteria BB1 causes a strain-specific enhancement of the intestinal TJ barrier through a novel mechanism involving BB1 attachment to the enterocyte TLR-2 receptor complex and activation of p38 kinase pathway.


Assuntos
Bifidobacterium bifidum/fisiologia , Colite/microbiologia , Mucosa Intestinal/microbiologia , Transdução de Sinais , Junções Íntimas , Receptor 2 Toll-Like/metabolismo , Animais , Células CACO-2 , Colite/prevenção & controle , Humanos , Mucosa Intestinal/metabolismo , Camundongos , NF-kappa B , Permeabilidade , Probióticos
4.
Exp Eye Res ; 210: 108716, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34352266

RESUMO

PURPOSE: To evaluate the role of Toll-like receptor 2 (TLR2) signaling in retinal neovascularization in a mouse model of oxygen-induced retinopathy (OIR). MATERIALS AND METHODS: The OIR model was established in C57BL/6J wild type (WT) mice and TLR2-/- mice. Retinal neovascularization in the OIR model was measured by counting new vascular cell nuclei above the internal limiting membrane and analyzing flat-mounted retinas perfused with fluorescein dextran and immunostained with Griffonia Simplicifolia (GS) isolectin. The expression of TLR2 and VEGF in the retina was detected by immunofluorescence. Expression of TGF- ß1, b-FGF, and IL-6 mRNA in the retina was measured by quantitative real-time PCR. RESULTS: Compared to WT OIR mice, retinal neovascularization was attenuated in TLR2-/- OIR mice. The co-expressions of TLR2 and VEGF were remarkably and consistently increased in WT OIR mice; however, there was no expression of TLR2 and a significant decrease in VEGF expression in TLR2-/- OIR mice. These results suggest that TLR2 plays a central role in OIR model angiogenesis. Expression of TGF- ß1, b-FGF, and IL-6 mRNA were reduced in the TLR2-/- OIR mice, suggesting that the inflammatory response induced by TLR2 relates to angiogenesis. CONCLUSION: TLR2 signaling in the retina is associated with neovascularization in mice. Inflammation contributes to the activation of angiogenesis and is partially mediated through the TLR2-VEGF retinal signaling pathway.


Assuntos
Modelos Animais de Doenças , Oxigênio/toxicidade , Neovascularização Retiniana/metabolismo , Retinopatia da Prematuridade/metabolismo , Transdução de Sinais/fisiologia , Receptor 2 Toll-Like/metabolismo , Animais , Citocinas/genética , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Neovascularização Retiniana/genética , Neovascularização Retiniana/patologia , Retinopatia da Prematuridade/genética , Retinopatia da Prematuridade/patologia , Receptor 2 Toll-Like/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Int J Mol Sci ; 22(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34281154

RESUMO

Staphylococcal aureus (S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria-bacteria and bacteria-host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.


Assuntos
Vesículas Extracelulares/imunologia , Lipoproteínas/metabolismo , Staphylococcus aureus/metabolismo , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Inflamação/imunologia , Lipoproteínas/fisiologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/patogenicidade , Receptor 2 Toll-Like/metabolismo
6.
J Immunol ; 207(3): 966-973, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34290104

RESUMO

Neutrophils, polymorphonuclear leukocytes (PMN), play a critical role in the innate immune response to Staphylococcus aureus, a pathogen that continues to be associated with significant morbidity and mortality. Neutrophil extracellular trap (NET) formation is involved in ensnaring and killing of S. aureus, but this host-pathogen interaction also leads to host tissue damage. Importantly, NET components including neutrophil proteases are under consideration as therapeutic targets in a variety of disease processes. Although S. aureus lipoproteins are recognized to activate cells via TLRs, specific mechanisms of interaction with neutrophils are poorly delineated. We hypothesized that a lipoprotein-containing cell membrane preparation from methicillin-resistant S. aureus (MRSA-CMP) would elicit PMN activation, including NET formation. We investigated MRSA-CMP-elicited NET formation, regulated elastase release, and IL-8 production in human neutrophils. We studied PMN from healthy donors with or without a common single-nucleotide polymorphism in TLR1, previously demonstrated to impact TLR2/1 signaling, and used cell membrane preparation from both wild-type methicillin-resistant S. aureus and a mutant lacking palmitoylated lipoproteins (lgt). MRSA-CMP elicited NET formation, elastase release, and IL-8 production in a lipoprotein-dependent manner. TLR2/1 signaling was involved in NET formation and IL-8 production, but not elastase release, suggesting that MRSA-CMP-elicited elastase release is not mediated by triacylated lipoproteins. MRSA-CMP also primed neutrophils for enhanced NET formation in response to a subsequent stimulus. MRSA-CMP-elicited NET formation did not require Nox2-derived reactive oxygen species and was partially dependent on the activity of peptidyl arginine deiminase (PAD). In conclusion, lipoproteins from S. aureus mediate NET formation via TLR2/1 with clear implications for patients with sepsis.


Assuntos
Membrana Celular/metabolismo , Armadilhas Extracelulares/metabolismo , Lipoproteínas/metabolismo , Staphylococcus aureus Resistente à Meticilina/metabolismo , Neutrófilos/imunologia , Proteína-Arginina Desiminase do Tipo 1/metabolismo , Infecções Estafilocócicas/imunologia , Células Cultivadas , Humanos , Interleucina-8/metabolismo , Lipoproteínas/genética , Lipoilação , Staphylococcus aureus Resistente à Meticilina/genética , Mutação/genética , Elastase Pancreática/metabolismo , Polimorfismo de Nucleotídeo Único , Transdução de Sinais/genética , Receptor 1 Toll-Like/genética , Receptor 1 Toll-Like/metabolismo , Receptor 2 Toll-Like/metabolismo
7.
Front Immunol ; 12: 609615, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34322115

RESUMO

Background: Rosacea, a chronic inflammatory skin disorder etiologically associated with immune cells and the antibacterial peptide cathelicidin LL-37, can be effectively treated by oral carvedilol administration. Objective: To investigate the molecular mechanisms underlying carvedilol efficacy in rosacea treatment. Methods: Skin samples of patients with rosacea were subjected to histopathological (hematoxylin and eosin) and immunohistochemical (CD68, Toll-like receptor 2 (TLR2), kallikrein 5, cathelicidin, TNF-α, and IL-1ß) evaluation. An in vivo murine rosacea-like inflammation model was established by LL-37 intradermal injection with or without carvedilol gavage-based pretreatment. Erythema proportion (Image J) and skin redness (L*a*b colorimetry) were quantified. Murine skin samples underwent pathological examination for inflammatory status and immunofluorescence staining. Murine skin and lipopolysaccharide-stimulated RAW 264.7 cells with or without carvedilol pretreatment were evaluated by quantitative reverse transcription-polymerase chain reaction and western blotting. Clinical facial images of patients were obtained using the VISIA skin analysis system before, 4, and 6 months following oral carvedilol administration. Results: Rosacea skin lesions exhibited more pronounced inflammatory cell infiltration than peripheral areas, with profound macrophage infiltration and inflammatory cytokines (TLR2, kallikrein 5, cathelicidin, TNF-α, and IL-1ß). In vivo, carvedilol alleviated inflammation in LL-37 mice, down-regulating TLR2, KLK5, and cathelicidin expression. In vitro, carvedilol decreased TLR2 expression in RAW 264.7 cells, further reducing KLK5 secretion and LL-37 expression and ultimately inhibiting rosacea-like inflammatory reactions. Clinical manifestations and facial redness obviously improved during 6-month follow-up with systemic carvedilol administration. Conclusion: Carvedilol is effective against rosacea, with inhibition of macrophage TLR2 expression as a novel anti-inflammatory mechanism.


Assuntos
Anti-Inflamatórios/uso terapêutico , Carvedilol/uso terapêutico , Macrófagos/efeitos dos fármacos , Rosácea/tratamento farmacológico , Pele/efeitos dos fármacos , Receptor 2 Toll-Like/antagonistas & inibidores , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Calicreínas/genética , Calicreínas/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Rosácea/imunologia , Rosácea/metabolismo , Rosácea/patologia , Pele/imunologia , Pele/metabolismo , Pele/patologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Resultado do Tratamento
8.
Front Immunol ; 12: 650779, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34194428

RESUMO

Listeria monocytogenes (L.m) is efficiently controlled by several cells of the innate immunity, including the Mast Cell (MC). MC is activated by L.m inducing its degranulation, cytokine production and microbicidal mechanisms. TLR2 is required for the optimal control of L.m infection by different cells of the immune system. However, little is known about the MC receptors involved in recognizing this bacterium and whether these interactions mediate MC activation. In this study, we analyzed whether TLR2 is involved in mediating different MC activation responses during L.m infection. We found that despite MC were infected with L.m, they were able to clear the bacterial load. In addition, MC degranulated and produced ROS, TNF-α, IL-1ß, IL-6, IL-13 and MCP-1 in response to bacterial infection. Interestingly, L.m induced the activation of signaling proteins: ERK, p38 and NF-κB. When TLR2 was blocked, L.m endocytosis, bactericidal activity, ROS production and mast cell degranulation were not affected. Interestingly, only IL-6 and IL-13 production were affected when TLR2 was inhibited in response to L.m infection. Furthermore, p38 activation depended on TLR2, but not ERK or NF-κB activation. These results indicate that TLR2 mediates only some MC activation pathways during L.m infection, mainly those related to IL-6 and IL-13 production.


Assuntos
Interleucina-13/imunologia , Interleucina-6/imunologia , Listeria monocytogenes/imunologia , Mastócitos/imunologia , Receptor 2 Toll-Like/imunologia , Animais , Degranulação Celular/imunologia , Degranulação Celular/fisiologia , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Ativação Enzimática/imunologia , Interações Hospedeiro-Patógeno/imunologia , Interleucina-13/metabolismo , Interleucina-6/metabolismo , Listeria monocytogenes/fisiologia , Mastócitos/microbiologia , Mastócitos/fisiologia , Camundongos Endogâmicos C57BL , NF-kappa B/imunologia , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Receptor 2 Toll-Like/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
9.
Front Immunol ; 12: 660065, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234775

RESUMO

Toll-like receptors (TLRs) play a crucial role in the recognition of pathogen-derived components as a first line of defense against infections. It has been suggested that depending on the nature of the pathogens, TLRs activation induce a distinct cytokine profile that may contribute to the polarization of the acquired immune response. Here, we investigated the early MAPK signaling activation via TLR4 and TLR2 receptors and its impact in differential cytokine profile by macrophages. We found that TLR2 ligands activated MAPKs p38 and ERK earlier compared to the TLR4 ligand LPS in macrophages. Higher IL-10/IL-12 and IL-10/TNF-α ratios were also observed at later time points in response to TLR2 ligands compared to LPS. The results also indicate an earlier activation of the phosphatase MKP-1 and that MKP-1 KO macrophages show a prolongation in p38 phosphorylation in response to TLR2 stimulation. Furthermore, p38 is critical for IL-10 expression in response to TLR2 ligands, which triggers the macrophage change to a M2 and regulatory phenotype in contrast to the M1 phenotype induced by TLR4 activation. Therefore, the early TLR2-mediated p38 induction contributes for the high IL-10 production, likely as a virulence strategy to suppress host Th1 response against certain types of pathogens.


Assuntos
Fosfatase 1 de Especificidade Dupla/imunologia , Interleucina-10/imunologia , Macrófagos/imunologia , Receptor 2 Toll-Like/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Animais , Células Cultivadas , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Diglicerídeos/farmacologia , Fosfatase 1 de Especificidade Dupla/genética , Fosfatase 1 de Especificidade Dupla/metabolismo , Ativação Enzimática/imunologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Interleucina-10/genética , Interleucina-10/metabolismo , Lipopeptídeos/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oligopeptídeos/farmacologia , Fosforilação/efeitos dos fármacos , Células RAW 264.7 , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
10.
Nutrients ; 13(5)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34068838

RESUMO

Changes in intestinal microbiome and barrier function are critical in the development of alcohol-related liver disease (ALD). Here, we determined the effects of a one-week alcohol withdrawal on parameters of intestinal barrier function in heavy drinkers with ALD in comparison to healthy non-drinkers (controls). In serum samples of 17 controls (m = 10/f = 7) and 37 age-matched ALD patients (m = 26/f = 11) undergoing a one-week alcohol withdrawal, markers of liver health and intestinal barrier function were assessed. Liver damage, e.g., fibrosis and hepatic steatosis, were assessed using FibroScan. Before alcohol withdrawal, markers of liver damage, lipopolysaccharide binding protein (LBP) and overall TLR4/TLR2 ligands in serum were significantly higher in ALD patients than in controls, whereas intestinal fatty acid binding protein (I-FABP) and zonulin protein concentrations in serum were lower. All parameters, with the exception of LBP, were significantly improved after alcohol withdrawal; however, not to the level of controls. Our data suggest that one-week of abstinence improves markers of intestinal barrier function and liver health in ALD patients.


Assuntos
Alcoolismo , Biomarcadores/sangue , Microbioma Gastrointestinal/fisiologia , Intestinos/microbiologia , Hepatopatias Alcoólicas/metabolismo , Fígado/metabolismo , Proteínas de Fase Aguda , Adulto , Toxinas Bacterianas/efeitos adversos , Toxinas Bacterianas/sangue , Proteínas de Transporte , Endotoxinas/sangue , Fígado Gorduroso/metabolismo , Feminino , Células HEK293 , Humanos , Cirrose Hepática , Masculino , Glicoproteínas de Membrana , Pessoa de Meia-Idade , Permeabilidade , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
11.
PLoS Biol ; 19(5): e3000939, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34014921

RESUMO

Inflammation is implicated in the onset and progression of various diseases, including cerebral pathologies. Here, we report that DJ-1, which plays a role within cells as an antioxidant protein, functions as a damage-associated molecular pattern (DAMP) and triggers inflammation if released from dead cells into the extracellular space. We first found that recombinant DJ-1 protein induces the production of various inflammatory cytokines in bone marrow-derived macrophages (BMMs) and dendritic cells (BMDCs). We further identified a unique peptide sequence in the αG and αH helices of DJ-1 that activates Toll-like receptor 2 (TLR2) and TLR4. In the ischemic brain, DJ-1 is released into the extracellular space from necrotic neurons within 24 h after stroke onset and makes direct contact with TLR2 and TLR4 in infiltrating myeloid cells. Although DJ-1 deficiency in a murine model of middle cerebral artery occlusion did not attenuate neuronal injury, the inflammatory cytokine expression in infiltrating immune cells was significantly decreased. Next, we found that the administration of an antibody to neutralize extracellular DJ-1 suppressed cerebral post-ischemic inflammation and attenuated ischemic neuronal damage. Our results demonstrate a previously unknown function of DJ-1 as a DAMP and suggest that extracellular DJ-1 could be a therapeutic target to prevent inflammation in tissue injuries and neurodegenerative diseases.


Assuntos
Isquemia Encefálica/metabolismo , Proteína Desglicase DJ-1/metabolismo , Alarminas/metabolismo , Animais , Encéfalo/metabolismo , Isquemia Encefálica/fisiopatologia , Citocinas/imunologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/imunologia , Infarto da Artéria Cerebral Média/patologia , Inflamação , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Proteína Desglicase DJ-1/fisiologia , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/fisiopatologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
12.
Nat Immunol ; 22(7): 829-838, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963333

RESUMO

The innate immune response is critical for recognizing and controlling infections through the release of cytokines and chemokines. However, severe pathology during some infections, including SARS-CoV-2, is driven by hyperactive cytokine release, or a cytokine storm. The innate sensors that activate production of proinflammatory cytokines and chemokines during COVID-19 remain poorly characterized. In the present study, we show that both TLR2 and MYD88 expression were associated with COVID-19 disease severity. Mechanistically, TLR2 and Myd88 were required for ß-coronavirus-induced inflammatory responses, and TLR2-dependent signaling induced the production of proinflammatory cytokines during coronavirus infection independent of viral entry. TLR2 sensed the SARS-CoV-2 envelope protein as its ligand. In addition, blocking TLR2 signaling in vivo provided protection against the pathogenesis of SARS-CoV-2 infection. Overall, our study provides a critical understanding of the molecular mechanism of ß-coronavirus sensing and inflammatory cytokine production, which opens new avenues for therapeutic strategies to counteract the ongoing COVID-19 pandemic.


Assuntos
COVID-19/imunologia , Proteínas do Envelope de Coronavírus/metabolismo , Síndrome da Liberação de Citocina/imunologia , SARS-CoV-2/imunologia , Receptor 2 Toll-Like/metabolismo , Animais , COVID-19/complicações , COVID-19/diagnóstico , COVID-19/tratamento farmacológico , COVID-19/virologia , Chlorocebus aethiops , Síndrome da Liberação de Citocina/diagnóstico , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Imunidade Inata/efeitos dos fármacos , Leucócitos Mononucleares , Macrófagos , Masculino , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Cultura Primária de Células , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Índice de Gravidade de Doença , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/antagonistas & inibidores , Receptor 2 Toll-Like/genética , Células Vero
13.
Phytomedicine ; 87: 153569, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33985878

RESUMO

BACKGROUND: Toll-like receptor 2 and Toll-like receptor 4 (TLR2/4) on microglia have been found as important regulators in the inflammatory response during cerebral ischemia/reperfusion (I/R). In China, traditional Chinese medicine Salvia miltiorrhiza (danshen) and its some components are considered to be effective in rescuing cerebral I/R injury through clinical practice. HYPOTHESIS/PURPOSE: Here we examined the effect of Salvianolic acid A (SAA), a monomer compound in the water extract of Salvia miltiorrhiza, on TLR2/4 of microglia and its mediated inflammatory injury during cerebral I/R in vivo and in vitro. STUDY DESIGN: For exploring the effect of SAA on cerebral I/R and TLR2/4, classic middle cerebral artery occlusion (MCAO) model and oxygen glucose deprivation / reoxygenation (OGD/R) model of co-culture with primary hippocampal neurons and microglia in vitro were used. Signal pathway research and gene knockout have been applied to further explain its mechanism. METHODS: The evaluation indexes of I/R injury included infarct size, edema degree and pathology as well as primary hippocampal neurons and microglia culture, ELISA, western, RT-PCR, HE staining, immunofluorescence, flow cytometry, siRNA gene knockout were also employed. RESULTS: SAA significantly improved the degree of brain edema and ischemic area in I/R rats accompanied by decreases in levels of interleukin-1ß (IL-1ß) and tumor necrosis factor-alpha (TNF-α). Pathological staining revealed that SAA could reduce inflammatory cell infiltration and mcirogila activation after reperfusion. Both protein and gene expression of TLR2 and TLR4 in ischemic hemisphere were obviously inhibited by SAA treatment while changes were not found in the non-ischemic hemisphere. In order to further study its mechanism, OGD/R model was used to mimic inflammatory damage of ischemic tissue by co-culturing primary rat hippocampal neurons and microglial cells. It was found that SAA also inhibited the protein and gene expression of TLR2 and TLR4 after OGD/R injury in microglia. After TLR2/4 knockout, the inhibitory effect of SAA on IL-1ß and TNF-α levels in cell supernatant and neuron apoptosis were significantly weakened in each dose group. Moreover, expression levels of myeloid differentiation factor 88 (MyD88), NFκB, IL-1ß and IL-6 in TLR2/4 mediated inflammatory pathway were reduced with SAA treatment. CONCLUSION: SAA could significantly reduce the inflammatory response and injury in cerebral ischemia-reperfusion in vivo and in vitro, and its mechanism may be through the inhibition of TLR2/4 and its related signal pathway.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Ácidos Cafeicos/farmacologia , Lactatos/farmacologia , Microglia/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Isquemia Encefálica/patologia , Ácidos Cafeicos/uso terapêutico , Infarto da Artéria Cerebral Média , Inflamação/metabolismo , Lactatos/uso terapêutico , Masculino , Microglia/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Receptor 2 Toll-Like/antagonistas & inibidores , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/genética
14.
Immunology ; 164(2): 318-331, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34021910

RESUMO

Of the thirteen Toll-like receptors (TLRs) in mice, TLR2 has a unique ability of forming heterodimers with TLR1 and TLR6. Such associations lead to selective cellular signalling and cellular responses such as cytokine expression. One of the signalling intermediates is protein kinase C (PKC); of which, eight isoforms are expressed in macrophages. Leishmania-a protozoan parasite that resides and replicates in macrophages-selectively modulates PKC-α, PKC-ß, PKC-δ and PKC-ζ isoforms in macrophages. As TLR2 plays significant roles in Leishmania infection, we examined whether these PKC isoforms play selective roles in TLR2 signalling and TLR2-induced anti-leishmanial functions. We observed that the TLR2 ligands-Pam3 CSK4 (TLR1/2), PGN (TLR2/2) and FSL (TLR2/6)-differentially phosphorylated and translocated PKC-α, PKC-ß, PKC-δ and PKC-ζ isoforms to cell membrane in uninfected and L. major-infected macrophages. The PKC isoform-specific inhibitors differentially altered IL-10 and IL-12 expression, Th1 and Th2 responses and anti-leishmanial effects in macrophages and in BALB/c mice. While PKC isoforms' inhibitors had insignificant effects on the Pam3CSK4-induced anti-leishmanial functions, PGN-induced pro-leishmanial effects were enhanced by PKC-(α + ß) inhibitors, whereas PKC-(δ + Î¶) inhibitors enhanced the anti-leishmanial effects of FSL. These results indicated that the ligand-induced TLR2 dimerization triggered differential dose-dependent and kinetic profiles of PKC isoform activation and that selective targeting of PKC isoforms using their respective inhibitors in combination significantly modulated TLR2-induced anti-leishmanial functions. To the best of our knowledge, this is the first demonstration of TLR2 dimer signalling through PKC isoforms and TLR2-induced PKC isoform-targeted anti-leishmanial therapy.


Assuntos
Leishmaniose Cutânea/metabolismo , Isoformas de Proteínas/metabolismo , Proteína Quinase C/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Citocinas/metabolismo , Ligantes , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação/fisiologia , Transdução de Sinais/fisiologia
15.
J Med Chem ; 64(11): 7371-7389, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34029463

RESUMO

The previous virtual screening of ten million compounds yielded two novel nonlipopeptide-like chemotypes as TLR2 agonists. Herein, we present the chemical optimization of our initial hit, 1-phenyl-3-(thiophen-2-yl)urea, which resulted in the identification of SMU-C80 (EC50 = 31.02 ± 1.01 nM) as a TLR2-specific agonist with a 370-fold improvement in bioactivity. Mechanistic studies revealed that SMU-C80, through TLR1/2, recruits the adaptor protein MyD88 and triggers the NF-κB pathway to release cytokines such as TNF-α and IL-1ß from human, but not murine, cells. To the best of our knowledge, it is the first species-specific TLR1/2 agonist reported until now. Moreover, SMU-C80 increased the percentage of T, B, and NK cells ex vivo and activated the immune cells, which suppressed cancer cell growth in vitro. In summary, we obtained a highly efficient and specific human TLR1/2 agonist that acts through the MyD88 and NF-κB pathway, facilitating cytokine release and the simultaneous activation of immune cells that in turn affects the apoptosis of cancer cells.


Assuntos
Desenho de Fármacos , Tioureia/análogos & derivados , Receptor 1 Toll-Like/agonistas , Receptor 2 Toll-Like/agonistas , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Imunoterapia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Neoplasias/terapia , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Tioureia/metabolismo , Tioureia/uso terapêutico , Receptor 1 Toll-Like/metabolismo , Receptor 2 Toll-Like/metabolismo
16.
Aging (Albany NY) ; 13(8): 11595-11609, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33872217

RESUMO

Tuberculosis (TB) is a common infectious disease caused by Mycobacterium tuberculosis (M.tb), and macrophages serve as the primary natural host of M.tb. Mesenchymal stem cells (MSCs)-derived exosomes play an essential role in inflammatory responses. This study aimed to determine the role of exosomes derived from M.tb-infected MSCs (Exo-MSCs-M.tb) on macrophages in vitro and in vivo and the underlying mechanisms. Here, we demonstrated that M.tb infection promoted the production of Exo-MSCs-M.tb, but did not influence MSCs proliferation. Exo-MSCs-M.tb were taken up by macrophages and then induced the pro-inflammatory response of macrophages through elevating the production of TNF-α, RANTES, and iNOS. Also, pro-inflammatory response induced by Exo-MSCs-M.tb displayed a time-dependent pattern in macrophages, in which the highest level of inflammatory response was observed at 72 hours post-infection of MSCs. In addition, the effect of Exo-MSCs-M.tb was mediated through TLR2/4 and MyD88 signaling pathways. Furthermore, Exo-MSCs-M.tb could induce the pro-inflammatory response in mice in vivo, and exosomes isolated from Exo-MSCs-M.tb-treated mice could also promote the pro-inflammatory response. Taken together, these results indicate that Exo-MSCs-M.tb induced the pro-inflammatory response of macrophages through TLRs signaling. This study provides new insight into the potential of MSCs-derived exosomes for the treatment of TB.


Assuntos
Comunicação Celular/imunologia , Exossomos/metabolismo , Macrófagos/imunologia , Células-Tronco Mesenquimais/metabolismo , Tuberculose/imunologia , Adulto , Animais , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Exossomos/imunologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Células-Tronco Mesenquimais/imunologia , Camundongos , Camundongos Knockout , Mycobacterium tuberculosis/imunologia , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Cultura Primária de Células , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Tuberculose/microbiologia , Adulto Jovem
17.
Int J Biol Macromol ; 183: 145-157, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33878360

RESUMO

Two novel glucans named MIPB50-W and MIPB50-S-1 were obtained from edible Morchella importuna with molecular weights (Mw) of 939.2 kDa and 444.5 kDa, respectively. MIPB50-W has a backbone of α-(1 → 4)-d-glucan, which was substituted at O-6 position by α-d-Glcp-(1→. Moreover, MIPB50-S-1 has a backbone of α-(1 → 4)-d-glucan, which was substituted at O-6 position by α-d-Glcp-(1 → 6)-α-d-Glcp-(1→. This is the first report about glucan found in Morchella mushrooms. Furthermore, MIPB50-W and MIPB50-S-1 strengthened the phagocytosis function and the promoted secretion of interleukins (IL)-6/tumor necrosis factor-alpha (TNF-α) and nitric oxide (NO), which induced the activation of Toll-like receptor 2 (TLR2), TLR4 as well as mitogen activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways. Interestingly, MIPB50-S-1 performed the better immunomodulatory activity than that of MIPB50-W in almost all tests. Therefore, MIPB50-W and MIPB50-S-1 are potential immune-enhancing components of functional foods.


Assuntos
Ascomicetos/metabolismo , Carpóforos/metabolismo , Glucanos/farmacologia , Fatores Imunológicos/farmacologia , Macrófagos/efeitos dos fármacos , Animais , Glucanos/química , Glucanos/isolamento & purificação , Fatores Imunológicos/química , Fatores Imunológicos/isolamento & purificação , Interleucina-6/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estrutura Molecular , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Fagocitose/efeitos dos fármacos , Células RAW 264.7 , Transdução de Sinais , Relação Estrutura-Atividade , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
18.
Biochem Biophys Res Commun ; 555: 54-60, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33813276

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is the pathological manifestation of metabolic syndrome in liver. Its pathological changes may evolve from the initial simple steatosis to non-alcoholic steatohepatitis, liver fibrosis and even liver cancer. Numerous studies have proved that platelets play a vital role in liver disease and homeostasis. Particularly, anti-platelet therapy can reduce intrahepatic platelet aggregation and improve the inflammation of fatty liver. Previous study has also confirmed that SAA is a gene closely related to high-fat diet (HFD) induced obesity, and SAA1 can promote liver insulin resistance induced by Palmitate or HFD. Here, we found that SAA1 treated platelets presented increased sensitivity of platelet aggregation, enhanced activation and increased adhesion ability, and such function was partly dependent on Toll-Like Receptor (TLR) 2 signaling. In addition, blocking SAA1 expression in vivo not only inhibited platelet aggregation in the liver tissues of NAFLD mice, but also alleviated the inflammation of fatty liver. In conclusion, our findings identify that HFD-induced hepatic overexpressed SAA1 aggravates fatty liver inflammation by promoting intrahepatic platelet aggregation, these results also imply that SAA1 may serve as a potential target for ameliorating NAFLD.


Assuntos
Hepatócitos/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Agregação Plaquetária/efeitos dos fármacos , Proteína Amiloide A Sérica/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Feminino , Hepatite/etiologia , Hepatócitos/patologia , Humanos , Camundongos Endogâmicos BALB C , Hepatopatia Gordurosa não Alcoólica/metabolismo , Proteína Amiloide A Sérica/genética , Proteína Amiloide A Sérica/farmacologia , Receptor 2 Toll-Like/metabolismo
19.
Carbohydr Polym ; 264: 117991, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33910729

RESUMO

The mushroom cell wall contains polysaccharides that can activate cells of the innate immune system through receptors such as Toll-like receptors (TLR) and dectin-1. In the present study, Pleurotus eryngii polysaccharide fractions containing a 3-O methylated mannogalactan and (1→3)/(1→6)-ß-d-glucans were isolated and extensively characterized by 2D NMR and methylation analysis. Traces of a (1→3)-α-d-glucan and a (1→2)-α-d-mannan were also observed. Affinity for TLR2, TLR2-TLR6 and dectin-1 using HEK-cells expressing the relevant receptor genes was tested. PeWN, containing the 3-O methylated mannogalactan, was inactive towards TLR2, whereas fraction PeWB, containing more ß-glucan, activated the TLR2-TLR6 heterodimer. Activation of the human ß-glucan receptor dectin-1 correlated with the amount of ß-glucan in each fraction. Nitric oxide and cytokine supernatant levels of D2SC/1 dendritic cells stimulated with the P. eryngii fractions and interferon-γ were low to moderate. The results indicate that the immunomodulatory activity of water-soluble P. eryngii polysaccharide fractions is modest.


Assuntos
Carpóforos/química , Polissacarídeos Fúngicos/metabolismo , Lectinas Tipo C/metabolismo , Pleurotus/química , Receptor 2 Toll-Like/metabolismo , Animais , Linhagem Celular , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Polissacarídeos Fúngicos/imunologia , Humanos , Imunomodulação , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Óxido Nítrico/metabolismo , Polissacarídeos/imunologia , Polissacarídeos/metabolismo , Receptores Toll-Like/metabolismo , Água/química , beta-Glucanas/imunologia , beta-Glucanas/metabolismo
20.
Brain ; 144(7): 2024-2037, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-33792662

RESUMO

Increasing evidence suggests that microglial activation is strongly linked to the initiation and progression of Parkinson's disease. Cell-to-cell propagation of α-synuclein pathology is a highlighted feature of Parkinson's disease, and the focus of such research has been primarily on neurons. However, recent studies as well as the data contained herein suggest that microglia, the primary phagocytes in the brain, play a direct role in the spread of α-synuclein pathology. Recent data revealed that plasma exosomes derived from Parkinson's disease patients (PD-EXO) carry pathological α-synuclein and target microglia preferentially. Hence, PD-EXO are likely a key tool for investigating the role of microglia in α-synuclein transmission. We showed that intrastriatal injection of PD-EXO resulted in the propagation of exosomal α-synuclein from microglia to neurons following microglia activation. Toll-like receptor 2 (TLR2) in microglia was activated by exosomal α-synuclein and acted as a crucial mediator of PD-EXO-induced microglial activation. Additionally, partial microglia depletion resulted in a significant decrease of exogenous α-synuclein in the substantia nigra. Furthermore, exosomal α-synuclein internalization was initiated by binding to TLR2 of microglia. Excessive α-synuclein phagocytosis may induce the inflammatory responses of microglia and provide the seed for microglia-to-neuron transmission. Consistently, TLR2 silencing in microglia mitigated α-synuclein pathology in vivo. Overall, the present data support the idea that the interaction of exosomal α-synuclein and microglial TLR2 contribute to excessive α-synuclein phagocytosis and microglial activation, which lead to the further propagation and spread of α-synuclein pathology, thereby highlighting the pivotal roles of reactive microglia in α-synuclein transmission.


Assuntos
Exossomos/metabolismo , Microglia/metabolismo , Doença de Parkinson/metabolismo , Receptor 2 Toll-Like/metabolismo , alfa-Sinucleína/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/patologia , Doença de Parkinson/patologia , Ratos , Ratos Sprague-Dawley
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