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1.
Anticancer Res ; 40(10): 5457-5462, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988867

RESUMO

BACKGROUND/AIM: Several studies have found elevated soluble CD40 Ligand (sCD40L) in the serum of patients with malignancies as well as those with inflammatory bowel disease (IBD). Our goal was to determine the possible causal role of sCD40L in colitis-associated colorectal cancer (CAC) by using the well-established azoxymethane/dextran sulfate sodium (AOM/DSS) protocol. MATERIALS AND METHODS: Twelve wild type (WT) and twelve TLR4 knock out (KO) female C57BL6 mice were divided into 4 experimental groups. Six WT and six TLR4 KO mice were treated with a single intraperitoneal dose (10 mg/kg of body weight) of AOM followed by three 7-day cycles of oral 2.5% DSS. The other two groups included 6 WT and 6 TLR4 KO mice that received only water and served as the control groups. The mice were sacrificed after 84 days. RESULTS: All mice in the AOM/DSS WT group developed CAC while all mice from the AOM/DSS TLR4 KO group were protected from CAC. We measured the serum and pathologic tissue levels of sCD40L with quantitative sandwich enzyme-linked immunoassay (ELISA) and found that serum sCD40L was significantly higher in wild-type mice that developed CAC compared to their healthy counterparts (wild-type and TLR-4 KO controls). In comparison, serum sCD40L levels were comparable between TLR-4 KO mice, which are protected from developing CAC, and their healthy counterparts (wild-type and TLR-4 KO controls). Of note, tissue levels of sCD40L were not affected by the development of CAC. CONCLUSION: Our findings point to the presence of an axis between TLR-4 and sCD40L, which may lead to decreased immunosurveillance and the subsequent development of colitis-associated cancer.


Assuntos
Ligante de CD40/genética , Colite/imunologia , Neoplasias Colorretais/induzido quimicamente , Receptor 4 Toll-Like/genética , Animais , Azoximetano/toxicidade , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Imunidade Inata/genética , Camundongos , Camundongos Knockout
2.
Nat Commun ; 11(1): 3816, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732870

RESUMO

Detection of microbial components such as lipopolysaccharide (LPS) by Toll-like receptor 4 (TLR4) on macrophages induces a robust pro-inflammatory response that is dependent on metabolic reprogramming. These innate metabolic changes have been compared to aerobic glycolysis in tumour cells. However, the mechanisms by which TLR4 activation leads to mitochondrial and glycolytic reprogramming are unknown. Here we show that TLR4 activation induces a signalling cascade recruiting TRAF6 and TBK-1, while TBK-1 phosphorylates STAT3 on S727. Using a genetically engineered mouse model incapable of undergoing STAT3 Ser727 phosphorylation, we show ex vivo and in vivo that STAT3 Ser727 phosphorylation is critical for LPS-induced glycolytic reprogramming, production of the central immune response metabolite succinate and inflammatory cytokine production in a model of LPS-induced inflammation. Our study identifies non-canonical STAT3 activation as the crucial signalling intermediary for TLR4-induced glycolysis, macrophage metabolic reprogramming and inflammation.


Assuntos
Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Fator de Transcrição STAT3/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Expressão Gênica , Glicólise/efeitos dos fármacos , Inflamação/genética , Inflamação/metabolismo , Interleucina-1beta/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Transcrição STAT3/genética , Serina/genética , Serina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fator 6 Associado a Receptor de TNF/genética , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/genética
3.
PLoS Negl Trop Dis ; 14(8): e0008495, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32764765

RESUMO

Melioidosis is an often-severe tropical infection caused by Burkholderia pseudomallei (Bp) with high associated morbidity and mortality. Burkholderia thailandensis (Bt) is a closely related surrogate that does not require BSL-3 conditions for study. Lactoferrin is an iron-binding glycoprotein that can modulate the innate inflammatory response. Here we investigated the impact of lactoferrin on the host immune response in melioidosis. Lactoferrin concentrations were measured in plasma from patients with melioidosis and following ex vivo stimulation of blood from healthy individuals. Bt growth was quantified in liquid media in the presence of purified and recombinant human lactoferrin. Differentiated THP-1 cells and human blood monocytes were infected with Bt in the presence of purified and recombinant human lactoferrin, and bacterial intracellular replication and cytokine responses (tumor necrosis factor-α (TNF-α), interleukin-1ß and interferon-γ) were measured. In a cohort of 49 melioidosis patients, non-survivors to 28 days had significantly higher plasma lactoferrin concentrations compared to survivors (median (interquartile range (IQR)): 326 ng/ml (230-748) vs 144 ng/ml (99-277), p<0.001). In blood stimulated with heat-killed Bp, plasma lactoferrin concentration significantly increased compared to unstimulated blood (median (IQR): 424 ng/ml (349-479) vs 130 ng/ml (91-214), respectively; p<0.001). Neither purified nor recombinant human lactoferrin impaired growth of Bt in media. Lactoferrin significantly increased TNF-α production by differentiated THP-1 cells and blood monocytes after Bt infection. This phenotype was largely abrogated when Toll-like receptor 4 (TLR4) was blocked with a monoclonal antibody. In sum, lactoferrin is produced by blood cells after exposure to Bp and lactoferrin concentrations are higher in 28-day survivors in melioidosis. Lactoferrin induces proinflammatory cytokine production after Bt infection that may be TLR4 dependent.


Assuntos
Infecções por Burkholderia/metabolismo , Infecções por Burkholderia/microbiologia , Burkholderia , Lactoferrina/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Burkholderia pseudomallei , Células Cultivadas , Humanos , Melioidose/metabolismo , Monócitos , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/genética
4.
PLoS One ; 15(8): e0237066, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780740

RESUMO

TLR4 is a member of the toll-like receptors (TLR) immune family, which are activated by lipopolysaccharide, ethanol or damaged tissue, among others, by triggering proinflammatory cytokines release and inflammation. Lack of TLR4 protects against inflammatory processes and neuroinflammation linked with several neuropathologies. By considering that miRNAs are key post-transcriptional regulators of the proteins involved in distinct cellular processes, including inflammation, this study aimed to assess the impact of the miRNAs profile in mice cortices lacking the TLR4 response. Using mice cerebral cortices and next-generation sequencing (NGS), the findings showed that lack of TLR4 significantly reduced the quantity and diversity of the miRNAs expressed in WT mice cortices. The results also revealed a significant down-regulation of the miR-200 family, while cluster miR-99b/let-7e/miR-125a was up-regulated in TLR4-KO vs. WT. The bioinformatics and functional analyses demonstrated that TLR4-KO presented the systematic depletion of many pathways closely related to the immune system response, such as cytokine and interleukin signaling, MAPK and ion Channels routes, MyD88 pathways, NF-κß and TLR7/8 pathways. Our results provide new insights into the molecular and biological processes associated with the protective effects of TLR-KO against inflammatory damage and neuroinflammation, and reveal the relevance of the TLR4 receptors response in many neuropathologies.


Assuntos
Córtex Cerebral/metabolismo , MicroRNAs/genética , Receptor 4 Toll-Like/genética , Animais , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica/genética , Inflamação/genética , Inflamação/metabolismo , Lipopolissacarídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo , Transcriptoma/genética
5.
PLoS One ; 15(7): e0232741, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649699

RESUMO

INTRODUCTION: Inflammation plays a major role in the development of atherosclerosis and cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. Toll-like receptor-4 (TLR4) is a major receptor for lipopolysaccharides (endotoxin) and other ligands involved in the pathogenesis of inflammation. We determined whether endotoxin levels and the presence of TLR4 polymorphisms are associated with markers of inflammation and atherosclerosis among South African CKD patients. MATERIALS AND METHODS: Endotoxin, lipopolysaccharide binding protein (LBP), serum CD14 (sCD14), interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and carotid intima media thickness (CIMT) were measured in 160 participants (120 CKD patients and 40 controls). Associations between endotoxins and CIMT in the presence of sCD14, IL-8 and MCP-1, were assessed using odds ratios. Participants were screened for the presence of Asp299Gly and Thr399Ile TLR4 polymorphisms, and CIMT and inflammatory markers were compared between subjects with and without TLR4 polymorphisms. RESULTS: Endotoxin levels correlated with sCD14 (r = 0.441, p<0.001) and MCP-1 (r = 0.388, p<0.001) levels while increased CIMT was associated with MCP-1 (r = 0.448, p<0.001), sCD14 levels (r = 0.476, p<0.001), LBP (r = 0.340, p<0.001), and IL-8 (r = 0.395, p<0.001). Atherosclerosis was associated with endotoxin levels (odds ratio: 4.95; 95% confidence interval: 2.52-9.73; p<0.001), and was predicted by higher serum levels of inflammatory markers. Analysis of patients with TLR4 polymorphisms showed reduced serum levels of inflammatory markers and CIMT values compared with the patients carrying the wild type TLR4 alleles. CONCLUSION: The study demonstrated associations between circulating endotoxaemia, systemic inflammation and accelerated atherosclerosis among South African CKD patients, and showed that the atherogenic predictive power of endotoxaemia was significantly increased by the presence of elevated levels of inflammatory markers. Additional findings, which must be confirmed, suggest that TLR4 polymorphisms are associated with low levels of inflammatory markers and CIMT values.


Assuntos
Grupo com Ancestrais do Continente Africano/estatística & dados numéricos , Aterosclerose/complicações , Grupos Populacionais/estatística & dados numéricos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Adulto , Espessura Intima-Media Carotídea , Estudos de Coortes , Suscetibilidade a Doenças , Feminino , Genótipo , Humanos , Inflamação/complicações , Masculino , Polimorfismo Genético , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/metabolismo , Risco , Receptor 4 Toll-Like/genética
6.
Arterioscler Thromb Vasc Biol ; 40(9): 2279-2292, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32611241

RESUMO

OBJECTIVE: Recruitment of neutrophils and formation of neutrophil extracellular traps (NETs) contribute to lethality in acute mesenteric infarction. To study the impact of the gut microbiota in acute mesenteric infarction, we used gnotobiotic mouse models to investigate whether gut commensals prime the reactivity of neutrophils towards formation of neutrophil extracellular traps (NETosis). Approach and Results: We applied a mesenteric ischemia-reperfusion (I/R) injury model to germ-free (GF) and colonized C57BL/6J mice. By intravital imaging, we quantified leukocyte adherence and NET formation in I/R-injured mesenteric venules. Colonization with gut microbiota or monocolonization with Escherichia coli augmented the adhesion of leukocytes, which was dependent on the TLR4 (Toll-like receptor-4)/TRIF (TIR-domain-containing adapter-inducing interferon-ß) pathway. Although neutrophil accumulation was decreased in I/R-injured venules of GF mice, NETosis following I/R injury was significantly enhanced compared with conventionally raised mice or mice colonized with the minimal microbial consortium altered Schaedler flora. Also ex vivo, neutrophils from GF and antibiotic-treated mice showed increased LPS (lipopolysaccharide)-induced NETosis. Enhanced TLR4 signaling in GF neutrophils was due to elevated TLR4 expression and augmented IRF3 (interferon regulatory factor-3) phosphorylation. Likewise, neutrophils from antibiotic-treated conventionally raised mice had increased NET formation before and after ischemia. Increased NETosis in I/R injury was abolished in conventionally raised mice deficient in the TLR adaptor TRIF. In support of the desensitizing influence of enteric LPS, treatment of GF mice with LPS via drinking water diminished LPS-induced NETosis in vitro and in the mesenteric I/R injury model. CONCLUSIONS: Collectively, our results identified that the gut microbiota suppresses NETing neutrophil hyperreactivity in mesenteric I/R injury, while ensuring immunovigilance by enhancing neutrophil recruitment.


Assuntos
Armadilhas Extracelulares/metabolismo , Microbioma Gastrointestinal , Isquemia Mesentérica/metabolismo , Mesentério/irrigação sanguínea , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Traumatismo por Reperfusão/metabolismo , Vênulas/metabolismo , Animais , Bacillus subtilis/patogenicidade , Adesão Celular , Células Cultivadas , Modelos Animais de Doenças , Escherichia coli/patogenicidade , Armadilhas Extracelulares/microbiologia , Feminino , Vida Livre de Germes , Interações Hospedeiro-Patógeno , Migração e Rolagem de Leucócitos , Leucócitos/metabolismo , Leucócitos/microbiologia , Masculino , Isquemia Mesentérica/microbiologia , Isquemia Mesentérica/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismo por Reperfusão/microbiologia , Traumatismo por Reperfusão/patologia , Transdução de Sinais , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Vênulas/microbiologia , Vênulas/patologia
7.
Biomed Environ Sci ; 33(5): 331-337, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32553077

RESUMO

Objective: Hyperbaric oxygen treatment (HBOT) has demonstrated efficacy in improving hearing levels of patients with idiopathic sudden sensorineural hearing loss (ISSHL); however, the underlying mechanisms are not well understood. HBOT alleviates the inflammatory response, which is mediated by Toll-like receptor (TLR) 4 and nuclear factor (NF)-κB. In this study we investigated whether HBOT attenuates inflammation in ISHHL patients via alteration of TLR4 and NF-κB expression. Methods: ISHHL patients ( n = 120) and healthy control subjects ( n = 20) were enrolled in this study. Patients were randomly divided into medicine group treated with medicine only ( n = 60) and HBO group receiving both HBOT and medicine ( n = 60). Audiometric testing was performed pre- and post-treatment. TLR4, NF-кB, and TNF-α expression in peripheral blood of ISSHL patients and healthy control subjects was assessed by ELISA before and after treatment. Results: TLR4, NF-κB, and TNF-α levels were upregulated in ISSHL patients relative to healthy control subjects; the levels were decreased following treatment and were lower in the HBO group than that in the medicine group post-treatment ( P < 0.05 and P < 0.01). Conclusion: HBOT alleviates hearing loss in ISSHL patients by suppressing the inflammatory response induced by TLR4 and NF-κB signaling.


Assuntos
Perda Auditiva Neurossensorial/terapia , Perda Auditiva Súbita/terapia , Oxigenação Hiperbárica , Inflamação/terapia , Subunidade p50 de NF-kappa B/genética , Receptor 4 Toll-Like/genética , Adolescente , Adulto , Idoso , China , Feminino , Humanos , Inflamação/genética , Masculino , Pessoa de Meia-Idade , Subunidade p50 de NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Adulto Jovem
8.
PLoS One ; 15(6): e0233643, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479555

RESUMO

Chronic subdural hematoma (CSDH) is an angiogenic and inflammatory disease. Toll-like receptors (TLRs) transduce intracellular signals, resulting in the activation of nuclear factor κB (NF-κB), which leads to the production of inflammatory cytokines. High-mobility group box 1 (HMGB1) functions as a mediator of inflammatory responses through TLRs. In this study, we examined the expression of HMGB1 and components of the Toll-like receptor and NF-κB signaling pathways in the outer membrane of CSDH. Eight patients whose outer membrane was successfully obtained during trepanation surgery were included in this study. The expression of TLR4, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase 4 (IRAK4), TNF receptor-associated factor 6 (TRAF6), TGFß-activated kinase 1 (Tak1), interferon regulatory factors 3 (IRF3), IκB kinase ß (IKKß), IKKγ, IκBε, IκBα, NF-κB/p65 and ß-actin was examined by Western blot analysis. The expression of TLR4, NF-κB/p65 and interleukin-6 (IL-6) was also examined by immunohistochemistry. The concentrations of HMGB1 and IL-6 in CSDH fluids were measured using ELISA kits. Above-mentioned molecules were detected in all cases. In addition, TLR4, NF-κB/p65 and IL-6 were localized in the endothelial cells of vessels within CSDH outer membranes. The concentrations of HMGB1 and IL-6 in CSDH fluids were significantly higher than that in the CSF and serum. There existed a correlation between the concentrations of HMGB1 and IL-6 in CSDH fluids. Our data suggest that HMGB1 in CSDH fluids produces the inflammatory cytokine IL-6 in endothelial cells through the Toll-like receptor and NF-κB signaling pathways. Anti-HMGB1 therapy might be a useful method to treat the growth of CSDH.


Assuntos
Proteína HMGB1/metabolismo , Hematoma Subdural Crônico/metabolismo , Interleucina-6/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Idoso , Idoso de 80 Anos ou mais , Endotélio Vascular/metabolismo , Feminino , Proteína HMGB1/genética , Humanos , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-6/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Masculino , Pessoa de Meia-Idade , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/genética , Transdução de Sinais , Receptor 4 Toll-Like/genética
9.
PLoS Genet ; 16(5): e1008773, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32469896

RESUMO

Principal component analysis (PCA) is a key tool for understanding population structure and controlling for population stratification in genome-wide association studies (GWAS). With the advent of large-scale datasets of genetic variation, there is a need for methods that can compute principal components (PCs) with scalable computational and memory requirements. We present ProPCA, a highly scalable method based on a probabilistic generative model, which computes the top PCs on genetic variation data efficiently. We applied ProPCA to compute the top five PCs on genotype data from the UK Biobank, consisting of 488,363 individuals and 146,671 SNPs, in about thirty minutes. To illustrate the utility of computing PCs in large samples, we leveraged the population structure inferred by ProPCA within White British individuals in the UK Biobank to identify several novel genome-wide signals of recent putative selection including missense mutations in RPGRIP1L and TLR4.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Biologia Computacional/métodos , Grupo com Ancestrais do Continente Europeu/genética , Mutação de Sentido Incorreto , Receptor 4 Toll-Like/genética , Algoritmos , Bancos de Espécimes Biológicos , Genética Populacional , Estudo de Associação Genômica Ampla/métodos , Humanos , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Reino Unido/etnologia
10.
Life Sci ; 254: 117762, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32437795

RESUMO

AIMS: Patients with nonalcoholic fatty liver disease (NAFLD) have less tolerance to ischemia-reperfusion injury (IRI) of the liver than those with the healthy liver; hence have a higher incidence of severe complications after surgery. This study aimed to investigate the dynamics of the liver and mitochondrial damage and the impact of TLR4 knockout (TLR4KO) on Mfn2 expression in the composite model of NAFLD and IRI. MAIN METHODS: We performed high-fat diet (HFD) feeding and ischemia reperfusion (IR) on wild type (WT) and TLR4 knockout TLR4KO mice. KEY FINDINGS: The degree of structural and functional injuries to the liver and mitochondria (NAFLD and IRI) is greater than that caused by a single factor (NAFLD or IRI) or a simple superposition of both. The IL-6 and TNF-α expressions were significantly suppressed (P < .05), while PGC-1α and Mfn2 expressions were up-regulated considerably (P < .05) after TLR4KO. Furthermore, mitochondrial fusion increased, while ATP consumption and ROS production decreased significantly after TLR4KO (P < .05). The degree of reduction of compound injury by TLR4KO is more significant than the reduction degree of single factor injury. Also, TNF-α and IL-6 levels can be used predictive markers for mitochondrial damage and liver tolerance to NAFLD and IRI. SIGNIFICANCE: TLR4KO upregulates the expression of Mfn2 and PGC-1α in the composite model of NAFLD and IRI. This pathway may be related to IL-6 and TNF-α. This evidence provides theoretical and experimental basis for the subsequent Toll-like receptor 4 (TLR4) receptor targeted therapy.


Assuntos
GTP Fosfo-Hidrolases/biossíntese , Fígado/irrigação sanguínea , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/biossíntese , Traumatismo por Reperfusão/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Regulação da Expressão Gênica , Fígado/metabolismo , Fígado/patologia , Transplante de Fígado , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Reperfusão , Traumatismo por Reperfusão/patologia , Transdução de Sinais/fisiologia , Receptor 4 Toll-Like/deficiência , Receptor 4 Toll-Like/genética , Ativação Transcricional , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
11.
Am J Physiol Gastrointest Liver Physiol ; 318(6): G1070-G1087, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32390462

RESUMO

Lipopolysaccharides (LPS) are potent pro-inflammatory molecules that enter the systemic circulation from the intestinal lumen by uncertain mechanisms. We investigated these mechanisms and the effect of exogenous glucagon-like peptide-2 (GLP-2) on LPS transport in the rodent small intestine. Transmucosal LPS transport was measured in Ussing-chambered rat jejunal mucosa. In anesthetized rats, the appearance of fluorescein isothiocyanate (FITC)-LPS into the portal vein (PV) and the mesenteric lymph was simultaneously monitored after intraduodenal perfusion of FITC-LPS with oleic acid and taurocholate (OA/TCA). In vitro, luminally applied LPS rapidly appeared in the serosal solution only with luminal OA/TCA present, inhibited by the lipid raft inhibitor methyl-ß-cyclodextrin (MßCD) and the CD36 inhibitor sulfosuccinimidyl oleate (SSO), or by serosal GLP-2. In vivo, perfusion of FITC-LPS with OA/TCA rapidly increased FITC-LPS appearance into the PV, followed by a gradual increase of FITC-LPS into the lymph. Rapid PV transport was inhibited by the addition of MßCD or by SSO, whereas transport into the lymph was inhibited by chylomicron synthesis inhibition. Intraveous injection of the stable GLP-2 analog teduglutide acutely inhibited FITC-LPS transport into the PV, yet accelerated FITC-LPS transport into the lymph via Nω-nitro-l-arginine methyl ester (l-NAME)- and PG97-269-sensitive mechanisms. In vivo confocal microscopy in mouse jejunum confirmed intracellular FITC-LPS uptake with no evidence of paracellular localization. This is the first direct demonstration in vivo that luminal LPS may cross the small intestinal barrier physiologically during fat absorption via lipid raft- and CD36-mediated mechanisms, followed by predominant transport into the PV, and that teduglutide inhibits LPS uptake into the PV in vivo.NEW & NOTEWORTHY We report direct in vivo confirmation of transcellular lipopolysaccharides (LPS) uptake from the intestine into the portal vein (PV) involving CD36 and lipid rafts, with minor uptake via the canonical chylomicron pathway. The gut hormone glucagon-like peptide-2 (GLP-2) inhibited uptake into the PV. These data suggest that the bulk of LPS absorption is via the PV to the liver, helping clarify the mechanism of LPS transport into the PV as part of the "gut-liver" axis. These data do not support the paracellular transport of LPS, which has been implicated in the pathogenesis of the "leaky gut" syndrome.


Assuntos
Gorduras/metabolismo , Intestino Delgado/metabolismo , Lipopolissacarídeos/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Fármacos Gastrointestinais/farmacologia , Células HEK293 , Humanos , Intestino Delgado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/química , Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
12.
PLoS One ; 15(5): e0233096, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421725

RESUMO

Congenital cytomegalovirus (cCMV) infection is the most common intrauterine infection. A non-specific immune response is the first line of host defense mechanism against human cytomegalovirus (HCMV). There is limited data on associations between Single Nucleotide Polymorphisms (SNPs) in genes involving innate immunity and the risk and clinical manifestation of cCMV infection. The aim of the study was to investigate association between selected SNPs in genes encoding cytokines and cytokine receptors, and predisposition to cCMV infection including symptomatic course of disease and symptoms. A panel of eight SNPs: IL1B rs16944, IL12B rs3212227, IL28B rs12979860, CCL2 rs1024611, DC-SIGN rs735240, TLR2 rs5743708, TLR4 rs4986791, TLR9 rs352140 was analyzed in 233 infants (92 cCMV-infected and 141 healthy controls). Associations between genotyped SNPs and predisposition to cCMV infection and symptoms were analyzed. The association analysis was performed using SNPStats software. No statistically significant association was found between any genotyped SNPs and predisposition to cCMV infection and symptomatic course of disease. In relation to particular symptoms, polymorphism of IL12B rs3212227 was linked to decreased risk of prematurity (OR = 0.37;95%CI,0.14-0.98;p = 0.025), while polymorphism of IL1B rs16944 was linked to reduced risk of splenomegaly (OR = 0.36;95%CI,0.14-0.98; p = 0.034) in infants with cCMV infection. An increased risk of thrombocytopenia was associated with IL28B rs12979860 polymorphism (OR = 2.55;95%CI,1.03-6.32;p = 0.042), while hepatitis was associated with SNP of TLR4rs4986791 (OR = 7.80;95%CI,1.49-40,81; p = 0.024). This is the first study to demonstrate four new associations between SNPs in selected genes (IL1B, IL12B, IL28B, TLR4) and particular symptoms in cCMV disease. Further studies on the role of SNPs in the pathogenesis of cCMV infection and incorporation of selected SNPs in the clinical practice might be considered in the future.


Assuntos
Infecções por Citomegalovirus/genética , Interferons/genética , Interleucina-12/genética , Interleucina-1beta/genética , Polimorfismo de Nucleotídeo Único/genética , Receptor 4 Toll-Like/genética , Adulto , Infecções por Citomegalovirus/virologia , Feminino , Frequência do Gene/genética , Genótipo , Técnicas de Genotipagem , Humanos , Masculino , Trombocitopenia/genética , Trombocitopenia/virologia
13.
Phytomedicine ; 70: 153208, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32283413

RESUMO

Background: Kawasaki disease (KD) is a self-limiting acute systemic vasculitis occur mainly in infants and young children under 5 years old. Although the use of acetylsalicylic acid (AAS) in combination with intravenous immunoglobulin (IVIG) remains the standard therapy to KD, the etiology, genetic susceptibility genes and pathogenic factors of KD are still un-elucidated. Purpose: Current obstacles in the treatment of KD include the lack of standard clinical and genetic markers for early diagnosis, possible severe side effect of AAS (Reye's syndrome), and the refractory KD cases with resistance to IVIG therapy, therefore, this review has focused on introducing the current advances in the identification of genetic susceptibility genes, environmental factors, diagnostic markers and adjuvant pharmacological intervention for KD. Results: With an overall update in the development of KD from different aspects, our current bioinformatics data has suggested CASP3, CD40 and TLR4 as the possible pathogenic factors or diagnostic markers of KD. Besides, a list of herbal medicines which may work as the adjunct therapy for KD via targeting different proposed molecular targets of KD have also been summarized. Conclusion: With the aid of modern pharmacological research and technology, it is anticipated that novel therapeutic remedies, especially active herbal chemicals targeting precise clinical markers of KD could be developed for accurate diagnosis and treatment of the disease.


Assuntos
Síndrome de Linfonodos Mucocutâneos/diagnóstico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Síndrome de Linfonodos Mucocutâneos/genética , Fitoterapia/métodos , Adjuvantes Imunológicos/uso terapêutico , Adjuvantes Farmacêuticos/uso terapêutico , Aspirina/uso terapêutico , Antígenos CD40/genética , Caspase 3/genética , Criança , Pré-Escolar , Marcadores Genéticos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Lactente , Japão/epidemiologia , Síndrome de Linfonodos Mucocutâneos/epidemiologia , Receptor 4 Toll-Like/genética
14.
J Immunol Res ; 2020: 9602576, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211445

RESUMO

The leishmanin skin test (LST) is an in vivo technique commonly used to evaluate the Leishmania-specific cellular immune response in dogs. However, information regarding the local immune response in LST-positive reactions is scarce. We examined the pattern of toll-like receptor 2 (TLR2), TLR4, TLR7, interleukin- (IL-) 10, interferon gamma (IFN-γ), and (program death ligand) PD-L1 gene expression in LST-positive reactions and paired normal-looking skin of nine infected Ibizan hound dogs. Healthy skin from ten seronegative dogs from a nonendemic area was analysed as a negative control. Immune gene expressions were examined by quantitative PCR (qPCR) analysis. LST-positive reactions presented significant upregulation of TLR2, TLR4, IL-10, IFN-γ, and PD-L1 and downregulation of TLR7 when compared with healthy skin of seronegative control dogs from a nonendemic area. All transcripts but TLR7 were significantly higher in LST-positive reaction than in paired normal-looking skin of Ibizan hound. The expression profile of immune genes in LST-positive reactions was similar to that previously observed in clinically lesioned skin of mildly diseased dogs with papular dermatitis due to Leishmania infantum infection. This data provide additional support for the important role of TLRs in canine leishmaniosis.


Assuntos
Antígeno B7-H1/metabolismo , Cães/imunologia , Interferon gama/metabolismo , Interleucina-10/metabolismo , Leishmania infantum/fisiologia , Leishmaniose/diagnóstico , Pele/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Receptor 7 Toll-Like/metabolismo , Animais , Anticorpos Antiprotozoários/metabolismo , Antígenos de Protozoários/metabolismo , Antígeno B7-H1/genética , Interferon gama/genética , Interleucina-10/genética , Testes Cutâneos , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Receptor 7 Toll-Like/genética , Regulação para Cima
15.
Curr Med Sci ; 40(1): 130-137, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32166675

RESUMO

Sinomenine (SN) has been used in the clinical treatment of systemic lupus erythematosus and rheumatoid arthritis for many years. Studies showed that SN held protective effects such as anti-inflammation, scavenging free radicals and suppressing immune response in many autoimmune diseases. The purpose of the present study is to explore the mechanism of anti-inflammation of SN on lipopolysaccharide (LPS)-induced macrophages activation and investigate whether the TLR4/NF-κB signaling pathway participated in. Macrophages isolated from mouse peritoneal cavity were stimulated by 1 µg/mL LPS for 24 h. And then the cells were treated with various concentrations of SN, TLR4 inhibitor respectively for additional 48 h. Drug toxicity was detected by MTT assay and Transwell experiment was used to assess chemotaxis. Furthermore, TLR4 and MyD88 mRNA levels were detected by real-time PCR. Western blotting was used to examine TLR4, MyD88 and phosphorylated IκB protein expression in macrophages. Immunofluorescence assay was applied to observe p65 NF-κB protein expression in macrophage nucleus. We extracted macrophages with high purity and activity from the abdominal cavity of mice. SN remarkably inhibited the chemotaxis and secretion function of LPS-stimulated macrophages. It also down-regulated both the protein levels of inflammatory cytokines (TNF-α, IL-1ß and IL-6) and the RNA and protein levels of the key factors (TLR4, MyD88, P-IκB) in TLR4 pathway. The expression of p65 NF-κB protein in nuclei was down-regulated, which was correlated with a similar decrease in P-IκB protein level. In conclusion, SN can inhibit the LPS induced immune responses in macrophages by blocking the activated TLR4/NF-κB signaling pathway. These results may provide a therapeutic approach to regulate inflammatory responses.


Assuntos
Anti-Inflamatórios/farmacologia , Lipopolissacarídeos/efeitos adversos , Macrófagos/citologia , Morfinanos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quimiotaxia/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
16.
Gene ; 741: 144539, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32160960

RESUMO

microRNAs (miRNAs) are involved in the physiological and pathophysiological processes of diabetes and its microvascular and macrovascular complications. Hence, the aim of the study was to investigate whether miR-499-3p played an important role in diabetic retinopathy. Diabetic retinopathy was developed in rats by intraperitoneal injection of streptozocin (STZ), followed by collection of retinal tissues and preparation of retinal cells. Immunohistochemical staining was used to detect expression of interferon alpha 2 (IFNA2). RT-qPCR was used to determine the expression of miR-499-3p. Bioinformatics website and dual luciferase reporter gene assay were used to validate the targeting relationship between miR-499-3p and IFNA2. Gain- and loss-of-function assays were performed to explore the functional roles of aberrantly expressed miR-499-3p and IFNA2 in retinal cell proliferation by MTT, and apoptosis by flow cytometry. In retinal tissues and cells of diabetic rats, IFNA2 expression was reduced, and miR-499-3p expression increased to activate the toll-like receptor 4 (TLR4) signaling pathway. IFNA2 was a target gene of miR-499-3p and negatively regulated by miR-499-3p. Further, downregulated miR-499-3p promoted retinal cell proliferation while suppressing apoptosis to alleviate diabetic retinopathy. All in all, miR-499-3p promoted retinopathy by enhancing activation of the TLR4 signaling pathway, which provides a new therapeutic target for diabetic retinopathy.


Assuntos
Retinopatia Diabética/genética , Interferon-alfa/genética , MicroRNAs/genética , Receptor 4 Toll-Like/genética , Animais , Apoptose/genética , Proliferação de Células/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Ratos , Retina/metabolismo , Retina/patologia , Transdução de Sinais/genética
17.
PLoS Pathog ; 16(3): e1008435, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32210480

RESUMO

A striking feature of human visceral leishmaniasis (VL) is chronic inflammation in the spleen and liver, and VL patients present increased production levels of multiple inflammatory mediators, which contribute to tissue damage and disease severity. Here, we combined an experimental model with the transcriptional profile of human VL to demonstrate that the TLR4-IFN-ß pathway regulates the chronic inflammatory process and is associated with the asymptomatic form of the disease. Tlr4-deficient mice harbored fewer parasites in their spleen and liver than wild-type mice. TLR4 deficiency enhanced the Th1 immune response against the parasite, which was correlated with an increased activation of dendritic cells (DCs). Gene expression analyses demonstrated that IRF1 and IFN-ß were expressed downstream of TLR4 after infection. Accordingly, IRF1- and IFNAR-deficient mice harbored fewer parasites in the target organs than wild-type mice due to having an increased Th1 immune response. However, the absence of TLR4 or IFNAR increased the serum transaminase levels in infected mice, indicating the presence of liver damage in these animals. In addition, IFN-ß limits IFN-γ production by acting directly on Th1 cells. Using RNA sequencing analysis of human samples, we demonstrated that the transcriptional signature for the TLR4 and type I IFN (IFN-I) pathways was positively modulated in asymptomatic subjects compared with VL patients and thus provide direct evidence demonstrating that the TLR4-IFN-I pathway is related to the nondevelopment of the disease. In conclusion, our results demonstrate that the TLR4-IRF1 pathway culminates in IFN-ß production as a mechanism for dampening the chronic inflammatory process and preventing immunopathology development.


Assuntos
Fator Regulador 1 de Interferon/imunologia , Interferon beta/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Células Th1/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Fator Regulador 1 de Interferon/genética , Interferon beta/genética , Leishmaniose Visceral/genética , Leishmaniose Visceral/patologia , Camundongos , Camundongos Knockout , Células Th1/patologia , Receptor 4 Toll-Like/genética
18.
World Neurosurg ; 138: 535-540.e8, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32113992

RESUMO

BACKGROUND: Cerebral cavernous malformations (CCMs) are vascular capillary anomalies with a dysfunctional endothelial adherent junction profile, depicting hemorrhage and epilepsy as the main clinical features. With the advent of an increasingly personalized medicine, better comprehension of genetic mechanisms behind CCM represents an important key in the management of the patients and risk rating in relatives. In this context, genetic factors that might influence clinical expressiveness of CCM need to be identified. CASE DESCRIPTION: A 33-year-old woman harboring multiple CCM lesions with a CCM1 mutational profile already being treated conservatively for a right mesial temporal lobe CCM presented with refractory seizures. Magnetic resonance imaging showed no bleeding in the lesion, and the patient was submitted to complete resection of the CCM. Histopathology of the CCM samples depicted an extensive inflammatory reaction and colocalization of CD20+ and CD68+ cells. Genetic analyses of the patient and her mother demonstrated a novel CCM1 (KRIT1) frameshift mutation (c.1661_1662insT; p.Leu554PhefsTer14). Furthermore, variants in CD14 (rs778588), TLR-4 (rs10759930), SOD2 (rs4880), APEX1 (rs1130409), and OGG1 (rs1052133), known as polymorphisms related to disease aggressiveness, were detected in the patient and not in her oligosymptomatic mother harboring the same CCM1 mutation. CONCLUSIONS: Heterogeneity of clinical manifestations among individuals with familial CCM with the same genotype adds mechanistic involvement of modifier factors as phenotypic markers. We describe a novel CCM1/KRIT1 familial mutation in which the coexistence of genetic variants in inflammation and oxidative stress may be related to variable expressiveness of the disease.


Assuntos
Mutação da Fase de Leitura , Hemangioma Cavernoso do Sistema Nervoso Central/genética , Proteína KRIT1/genética , Adulto , Anticonvulsivantes/uso terapêutico , Brasil , DNA Glicosilases/genética , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/genética , Feminino , Genótipo , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico por imagem , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos , Inflamação/genética , Receptores de Lipopolissacarídeos/genética , Imagem por Ressonância Magnética , Mães , Estresse Oxidativo/genética , Fenótipo , Convulsões/tratamento farmacológico , Convulsões/etiologia , Índice de Gravidade de Doença , Superóxido Dismutase/genética , Receptor 4 Toll-Like/genética
19.
Radiat Res ; 193(4): 383-393, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32097101

RESUMO

The functions and molecular mechanism of circRNAs in the development of radiation-induced liver disease (RILD) remain largely unknown. The goal of this study was to explore the expression and potential role of a new circular RNA, named circTUBD1, in irradiated and lipopolysaccharide (LPS)-stimulated human hepatic stellate cell (HSC) line LX-2 cells. The expression of circTUBD1 was significantly upregulated in irradiated and LPS-stimulated LX-2 cells compared to non-treated LX-2 cells. To explore the functions of circTUBD1, small interfering RNAs targeting circTUBD1 were designed. Silencing circTUBD1 inhibited proliferation, promoted apoptosis of LX-2 cells, and significantly decreased the expression level of pro-inflammatory cytokines, including IL-1ß, IL-6 and TNF-α in irradiated and LPS-stimulated LX-2 cells. Mechanistic analysis suggested that circTUBD1 acted as the miR-146a-5p sponge to affect pro-inflammatory cytokine production through regulating expression of Toll-like receptor 4 (TLR4), interleukin receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor-6 (TRAF6), and phosphorylation of nuclear factor-kappa B (pNF-κB) in irradiated and LPS-stimulated LX-2 cells. To our knowledge, this is the first study to show that circTUBD1 acts as a miR-146a-5p sponge to affect the viability and pro-inflammatory cytokine production of LX-2 cells through the TLR4 pathway, suggesting that circTUBD1 is a potential target for RILD therapy.


Assuntos
Anormalidades Induzidas por Radiação/genética , MicroRNAs/genética , RNA Circular/genética , Receptor 4 Toll-Like/genética , Sobrevivência Celular/efeitos da radiação , Citocinas/biossíntese , Citocinas/genética , Células Estreladas do Fígado/patologia , Células Estreladas do Fígado/efeitos da radiação , Humanos , Fígado/metabolismo , Fígado/patologia , Fígado/efeitos da radiação , Hepatopatias/etiologia , Transdução de Sinais/efeitos da radiação , Tubulina (Proteína)/genética
20.
Am J Physiol Gastrointest Liver Physiol ; 318(4): G736-G747, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32090603

RESUMO

Aging is a risk factor in the development of many diseases, including liver-related diseases. The two aims of the present study were 1) to determine how aging affects liver health in mice in the absence of any interventions and 2) if degenerations observed in relation to blood endotoxin levels are critical in aging-associated liver degeneration. Endotoxin levels and markers of liver damage, mitochondrial dysfunction, insulin resistance, and apoptosis as well as the Toll-like receptor 4 (Tlr-4) signaling cascade were studied in liver tissue and blood, respectively, of 3- and 24-mo-old male C57BL/6J mice. In a second set of experiments, 3- to 4-mo-old and 14-mo-old female lipopolysaccharide-binding protein (LBP)-/- mice and littermates fed standard chow, markers of liver damage, insulin resistance, and mitochondrial dysfunction were assessed. Plasma activity of aspartate aminotransferase and histological signs of hepatic inflammation and fibrosis were significantly higher in old C57BL/6J mice than in young animals. The number of neutrophils, CD8α-positive cells, and mRNA expression of markers of apoptosis were also significantly higher in livers of old C57BL/6J mice compared with young animals, being also associated with a significant induction of hepatic Tlr-4 and LBP expression as well as higher endotoxin levels in peripheral blood. Compared with age-matched littermates, LBP-/- mice display less signs of senescence in liver. Taken together, our data suggest that, despite being fed standard chow, old mice developed liver inflammation and beginning fibrosis and that bacterial endotoxin may play a critical role herein.NEW & NOTEWORTHY Old age in mice is associated with marked signs of liver degeneration, hepatic inflammation, and fibrosis. Aging-associated liver degeneration is associated with elevated bacterial endotoxin levels and an induction of lipopolysaccharide-binding protein (LBP) and Toll-like receptor 4-dependent signaling cascades in liver tissue. Furthermore, in old aged LBP-/- mice, markers of senescence seem to be lessened, supporting the hypothesis that bacterial endotoxin levels might be critical in aging-associated decline of liver.


Assuntos
Proteínas da Fase Aguda/metabolismo , Envelhecimento , Proteínas de Transporte/metabolismo , Endotoxinas/sangue , Cirrose Hepática/patologia , Fígado/patologia , Glicoproteínas de Membrana/metabolismo , Proteínas da Fase Aguda/genética , Animais , Apoptose , Biomarcadores , Proteínas de Transporte/genética , Feminino , Regulação da Expressão Gênica , Glucose/metabolismo , Inflamação/patologia , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Fígado/metabolismo , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
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