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1.
BMC Complement Altern Med ; 19(1): 310, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718640

RESUMO

BACKGROUND: Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R. METHODS: The cytotoxicity of HM-R against RAW264.7 cells was evaluated using MTT assay. The inhibition of NO and PGE2 production by HM-R was evaluated using Griess reagent and Prostaglandin E2 ELISA Kit, respectively. The changes in mRNA or protein level following HM-R treatment were assessed by RT-PCR and Western blot analysis, respectively. RESULTS: HM-R dose-dependently blocked LPS-induced NO and PGE2 production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, IL-1ß and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound. CONCLUSIONS: These results indicate that HM-R may exert anti-inflammatory activity by inhibiting NF-κB and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. These findings suggest that HM-R has a potential as a natural material for the development of anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Heme Oxigenase-1/imunologia , Heracleum/química , Fator 2 Relacionado a NF-E2/imunologia , NF-kappa B/imunologia , Espécies Reativas de Oxigênio/imunologia , Animais , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/imunologia , Heme Oxigenase-1/genética , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/genética , Raízes de Plantas/química , Células RAW 264.7
2.
Parasit Vectors ; 12(1): 475, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31610797

RESUMO

BACKGROUND: Inflammation-induced dysfunction of hepatic stellate cells (HSCs) is involved in schistosomiasis-associated liver fibrosis, and soluble egg antigen (SEA) is a crucial pathogen-associated molecular pattern associated with liver injury in schistosomiasis. In addition, numerous studies have shown that caspase-1-mediated pyroptosis participates in the development of multiple inflammation-related diseases. However, whether pyroptotic cell death of HSCs is involved in SEA-mediated liver damage is not well understood. METHODS: Primary cultured HSCs and Schistosoma japonicum-infected mouse liver tissue were analysed for histological changes and caspase-1 activation, and the role of pyroptosis in the mechanisms underlying SEA-induced HSC death was investigated. Accumulation of reactive oxygen species (ROS) in infected livers and SEA-stimulated HSCs was measured by flow cytometry and immunofluorescence. RESULTS: Caspase-1 activity was elevated in both liver tissues and HSCs of S. japonicum-infected mice. Furthermore, SEA stimulation increased the proportion of pyroptotic HSCs, as shown by lactate dehydrogenase (LDH) release assays and by flow cytometric analysis of propidium iodide (PI) and caspase-1 double staining in cells. In addition, ROS generation was elevated in infected liver tissues and SEA-stimulated HSCs, and ROS inhibition downregulated SEA-induced caspase-1 activation and pyroptosis in HSCs. CONCLUSIONS: Our present study demonstrates that pyroptotic cell death in HSCs induced by SEA via ROS-mediated caspase-1 activation may serve as a significant mechanism to initiate the inflammatory response and thereby exacerbate liver injury during S. japonicum infection.


Assuntos
Antígenos de Helmintos/fisiologia , Células Estreladas do Fígado/fisiologia , Piroptose/fisiologia , Espécies Reativas de Oxigênio/imunologia , Schistosoma japonicum/imunologia , Análise de Variância , Animais , Caspase 1/genética , Caspase 1/metabolismo , Feminino , Imunofluorescência , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/enzimologia , Células Estreladas do Fígado/metabolismo , Imuno-Histoquímica , Fígado/enzimologia , Fígado/metabolismo , Fígado/parasitologia , Fígado/patologia , Cirrose Hepática/enzimologia , Cirrose Hepática/patologia , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Schistosoma japonicum/metabolismo , Esquistossomose Japônica/enzimologia , Esquistossomose Japônica/etiologia , Esquistossomose Japônica/patologia , Caramujos/parasitologia
3.
J Agric Food Chem ; 67(40): 11230-11235, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31523955

RESUMO

Ochratoxin A (OTA) is a mycotoxin which could cause strong immunosuppressive toxicological effects in animals and humans. Heterophil extracellular traps (HETs) as a novel defense of chicken heterophils play an important role against pathogen infection. It has been reported that OTA can weaken the phagocytosis function of neutrophils. However, whether or not OTA shows immunosuppressive effects on HET release remains unclear. In the present study, we aim to first investigate the effects of OTA on HET release and then try to clarify the mechanisms in this process. OTA-induced HET structures were observed and analyzed by fluorescence confocal microscopy. The quantitative determination of OTA-induced HETs was measured by PicoGreen and a fluorescence microplate. The results clearly showed that OTA obviously induced the release of HET-like structures in heterophils, and these extracellular networks were composed by chromatin decorated with histones and neutrophil elastase. Reactive oxygen species (ROS) production was also increased in the process of OTA-induced HET formation. Furthermore, the inhibitors of NADPH oxidase, ERK [Formula: see text], and p38 MAPK signaling pathways significantly decreased OTA-induced HET formation. The abovementioned results suggest that OTA-induced HET formation is related to ROS production dependent on the activation of NADPH oxidase, ERK [Formula: see text], and p38 MAPK signaling pathways. Taken together, this study first shows that OTA possesses the ability to trigger HET formation, which provides our understanding of the host that continuously suffered OTA exposure leading to the hyporeactivity of the immune system against infection.


Assuntos
Galinhas/imunologia , MAP Quinases Reguladas por Sinal Extracelular/imunologia , Armadilhas Extracelulares/imunologia , NADPH Oxidases/imunologia , Neutrófilos/efeitos dos fármacos , Ocratoxinas/toxicidade , Espécies Reativas de Oxigênio/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Animais , Galinhas/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , Armadilhas Extracelulares/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , NADPH Oxidases/genética , Neutrófilos/enzimologia , Neutrófilos/imunologia , Fagocitose , Proteínas Quinases p38 Ativadas por Mitógeno/genética
4.
J Med Microbiol ; 68(11): 1629-1640, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31553301

RESUMO

Introduction. ML1899 is conserved in all mycobacterium sp. and is a middle member of mle-ML1898 operon involved in mycolic acid modification.Aim. In the present study attempts were made to characterize ML1899 in detail.Methodology. Bioinformatics tools were used for prediction of active-site residues, antigenic epitopes and a three-dimensional model of protein. The gene was cloned, expressed and purified as His-tagged protein in Escherichia coli for biophysical/biochemical characterization. Recombinant protein was used to treat THP-1 cells to study change in production of nitric oxide (NO), reactive oxygen species (ROS), cytokines and chemokines using flowcytometry/ELISA.Results. In silico analysis predicted ML1899 as a member of α/ß hydrolase family with GXSXG-motif and Ser126, His282, Asp254 as active-site residues that were confirmed by site-directed mutagensis. ML1899 exhibited esterase activity. It hydrolysed pNP-butyrate as optimum substrate at pH 8.0 and 50 °C with 5.56 µM-1 min-1 catalytic efficiency. The enzyme exhibited stability up to 60 °C temperature and between pH 6.0 to 9.0. K m, V max and specific activity of ML1899 were calculated to be 400 µM, 40 µmoles min-1 ml-1 and 27 U mg- 1, respectively. ML1899 also exhibited phospholipase activity. The protein affected the survival of macrophages when treated at higher concentration. ML1899 enhanced ROS/NO production and up-regulated pro-inflammatory cytokines and chemokine including TNF-α, IFN-γ, IL-6 and IL-8 in macrophages. ML1899 was also observed to elicit humoral response in 69 % of leprosy patients.Conclusion. These results suggested that ML1899, an esterase could up-regulate the immune responses in favour of macrophages at a low concentration but kills the THP-1 macrophages cells at a higher concentration.


Assuntos
Proteínas de Bactérias/imunologia , Esterases/imunologia , Hanseníase/microbiologia , Mycobacterium leprae/enzimologia , Sequência de Aminoácidos , Anticorpos Antibacterianos/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Citocinas/genética , Citocinas/imunologia , Estabilidade Enzimática , Esterases/química , Esterases/genética , Feminino , Humanos , Concentração de Íons de Hidrogênio , Cinética , Hanseníase/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Mycobacterium leprae/química , Mycobacterium leprae/genética , Mycobacterium leprae/imunologia , Óxido Nítrico/imunologia , Espécies Reativas de Oxigênio/imunologia , Alinhamento de Sequência
5.
J Helminthol ; 94: e72, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412958

RESUMO

Schistosomiasis is an inflammatory disease that occurs when schistosome species eggs are deposited in the liver, resulting in fibrosis and portal hypertension. Schistosomes can interact with host inflammasomes to elicit host immune responses, leading to mitochondrial damage, generation of high levels of reactive oxygen species (ROS) and activation of apoptosis during inflammation. This study aims to examine whether ROS and NF-κB (p65) expression elicited other types of inflammasome activation in Schistosoma mansoni-infected mouse livers. We examine the relationship between inflammasome activation, mitochondrial damage and ROS production in mouse livers infected with S. mansoni. We demonstrate a significant release of ROS and superoxides and increased NF-κB (p65) in S. mansoni-infected mouse livers. Moreover, activation of the NLRP3 and AIM2 inflammasomes was triggered by S. mansoni infection. Stimulation of HuH-7 hepatocellular carcinoma cells with soluble egg antigen induced activation of the AIM2 inflammasome pathway. In this study, we demonstrate that S. mansoni infection promotes both NLRP3 and AIM2 inflammasome activation.


Assuntos
Proteínas de Ligação a DNA/genética , Inflamassomos/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Esquistossomose mansoni/imunologia , Animais , Apoptose , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/imunologia , Modelos Animais de Doenças , Inflamassomos/imunologia , Inflamação , Fígado/parasitologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Espécies Reativas de Oxigênio/imunologia , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia
6.
Int Immunopharmacol ; 75: 105821, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31437787

RESUMO

Mounting evidence has demonstrated that acute pancreatitis (AP) is one of the causes of multiple organ damage. NADPH (nicotinamide adenine dinucleotide phosphate) act as a substrate of NADPH oxidase (NOX) to generate reactive oxygen species (ROS), but the role NADPH oxidase signaling pathway plays in AP-induced acute lung injury remains unclear. Apocynin, an inhibitor of NOX, is highly effective in suppressing the production of ROS. Here, we used rat model of severe acute pancreatitis (SAP) to explore whether the NOX inhibitor apocynin produced protective effects in against SAP-induced lung injury via inhibition of inflammation and oxidation. We observed that apocynin significantly attenuated severe acute pancreatitis-induced increase of NOX2, NOX4 and ROS expressions in lung tissues. In addition, the phosphorylation and degradation of IκBα, and the nuclear localization of NF-κB p65 in SAP-induced lung injury were also inhibited after using apocynin. Simultaneously, down-regulation of NOX suppressed the levels of inflammasome proteins including NLRP3, ASC, pro-Caspase-1 and cleaved-Caspase-1 in the lung. Serum levels of TNF-α, interleukin (IL)-1ß and IL-6 were also reduced. Our findings suggest that beyond anti-oxidative effects, apocynin may also have anti-inflammatory effects by suppressing NLRP3 inflammasome activation and NF-κB signaling in acute pancreatitis. Therefore, apocynin may have therapeutic potential in the treatment of SAP and SAP-induced lung injury.


Assuntos
Acetofenonas/farmacologia , Lesão Pulmonar Aguda/imunologia , Anti-Inflamatórios/farmacologia , Inflamassomos/imunologia , NF-kappa B/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Pancreatite/imunologia , Acetofenonas/uso terapêutico , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/patologia , Animais , Anti-Inflamatórios/uso terapêutico , Citocinas/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Masculino , Pâncreas/efeitos dos fármacos , Pâncreas/imunologia , Pâncreas/patologia , Pancreatite/complicações , Pancreatite/tratamento farmacológico , Pancreatite/patologia , Ratos Wistar , Espécies Reativas de Oxigênio/imunologia , Transdução de Sinais/efeitos dos fármacos
7.
Int Immunopharmacol ; 75: 105822, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31437793

RESUMO

Metformin, the most widely used medicine for type 2 diabetes, displays anti-inflammatory functions via activating AMP-activated protein kinase (AMPK). Circulating autoantibodies and disequilibrium of helper T cells and regulatory T cells are pathological hallmarks of myasthenia gravis (MG). Rectify the imbalance of different T cell populations has become an important therapeutic strategy to treat MG. In this study, we assessed the effect of metformin on the development of autoimmunity using an experimental autoimmune myasthenia gravis (EAMG) rat model. We first provided evidence that oral administration of metformin attenuated the onset of EAMG. This effect was accompanied by a substantial decrease of circulating auto-antibody levels with no effect on blood glucose level. While metformin treatment in vitro showed little effect on inducible Treg, metformin strongly inhibited Th17 cell differentiation through the increase of reactive oxygen species and AMPK. Furthermore, an attenuation of antigen-induced IgG2b antibody production by two different doses of metformin was also observed in the AChR-specific recall response. In conclusion, the above results indicate that metformin may have therapeutic value for the clinical treatment of MG.


Assuntos
Anti-Inflamatórios/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Miastenia Gravis Autoimune Experimental/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/imunologia , Animais , Anti-Inflamatórios/farmacologia , Anticorpos/sangue , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Glicemia/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Ratos Endogâmicos Lew , Espécies Reativas de Oxigênio/imunologia , Receptores Colinérgicos/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia
8.
Immunity ; 51(3): 443-450.e4, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31422870

RESUMO

The presence of gallstones (cholelithiasis) is a highly prevalent and severe disease and one of the leading causes of hospital admissions worldwide. Due to its substantial health impact, we investigated the biological mechanisms that lead to the formation and growth of gallstones. We show that gallstone assembly essentially requires neutrophil extracellular traps (NETs). We found consistent evidence for the presence of NETs in human and murine gallstones and describe an immune-mediated process requiring activation of the innate immune system for the formation and growth of gallstones. Targeting NET formation via inhibition of peptidyl arginine deiminase type 4 or abrogation of reactive oxygen species (ROS) production, as well as damping of neutrophils by metoprolol, effectively inhibit gallstone formation in vivo. Our results show that after the physicochemical process of crystal formation, NETs foster their assembly into larger aggregates and finally gallstones. These insights provide a feasible therapeutic concept to prevent cholelithiasis in patients at risk.


Assuntos
Armadilhas Extracelulares/imunologia , Cálculos Biliares/imunologia , Neutrófilos/imunologia , Animais , Feminino , Humanos , Imunidade Inata/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/imunologia
9.
Int J Mol Sci ; 20(15)2019 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-31382586

RESUMO

Peroxisomes are ubiquitous organelles with well-defined functions in lipid and reactive oxygen species metabolism, having a significant impact on a large number of important diseases. Growing evidence points to them, in concert with mitochondria, as important players within the antiviral response. In this review we summarize and discuss the recent findings concerning the relevance of peroxisomes within innate immunity. We not only emphasize their importance as platforms for cellular antiviral signaling but also review the current information concerning their role in the control of bacterial infections. We furthermore review the recent data that pinpoints peroxisomes as regulators of inflammatory processes.


Assuntos
Infecções Bacterianas/imunologia , Imunidade Inata , Peroxissomos/imunologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Antivirais/uso terapêutico , Infecções Bacterianas/microbiologia , Infecções Bacterianas/virologia , Humanos , Peroxissomos/microbiologia , Peroxissomos/virologia , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/imunologia
10.
Life Sci ; 234: 116773, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31422095

RESUMO

AIMS: NLRP3 inflammasome activation is essential for the development and prognosis of diabetic cardiomyopathy (DCM). The anti-aging protein Klotho is suggested to modulate tissue inflammatory responses. The aim of the present study was to examine the protective effects of Klotho on DCM. MAIN METHODS: A streptozotocin-induced diabetes mouse model was established to assess the effects of Klotho in vivo, which was administered for 12 weeks. The characteristics of type 1 DCM were evaluated by general status, echocardiography, and histopathology. The expression of associated factors was determined by RT-qPCR and western blotting. Parallel experiments to determine the molecular mechanism through which Klotho prevents DCM were performed using H9C2 cells exposed to high glucose (35 mM). KEY FINDINGS: Diabetes-induced increases in serum creatine kinase-muscle/brain and lactate dehydrogenase levels, cardiac fibrosis, cardiomyocyte apoptosis, and cardiac dysfunction were ameliorated by Klotho. Additionally, Klotho suppressed TXNIP expression, NLRP3 inflammasome activation, and expression of the inflammatory cytokines tumor necrosis factor ɑ, interleukin-1ß, and interleukin-18 in vivo. In high glucose-cultured cardiomyocytes, Klotho and N-acetylcysteine significantly downregulated intracellular reactive oxygen species generation and TXNIP/NLRP3 inflammasome activation. Pretreatment of H9C2 cells with NLRP3 siRNA or Klotho prevented high glucose-induced inflammation and apoptosis in H9C2 cells. SIGNIFICANCE: Our results demonstrate that the protective effect of Klotho on diabetes-induced cardiac injury is associated with inhibition of the NLRP3 inflammasome pathway, suggesting its therapeutic potential for DCM.


Assuntos
Diabetes Mellitus Experimental/imunologia , Cardiomiopatias Diabéticas/imunologia , Glucuronidase/imunologia , Inflamassomos/imunologia , Inflamação/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Animais , Anti-Inflamatórios/imunologia , Anti-Inflamatórios/uso terapêutico , Cardiotônicos/imunologia , Cardiotônicos/uso terapêutico , Linhagem Celular , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/patologia , Glucuronidase/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/etiologia , Inflamação/patologia , Masculino , Camundongos Endogâmicos C57BL , Ratos , Espécies Reativas de Oxigênio/imunologia
11.
Biosens Bioelectron ; 141: 111430, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31299629

RESUMO

Reactive oxygen species are highly reactive molecules that as well as being ubiquitously expressed throughout the body, are also known to be involved in many diseases and disorders including bacterial infection. Current technology has limited success in the accurate detection and identification of specific reactive oxygen species. To combat this, we have developed an electrochemical biosensor that is constructed from single walled carbon nanotubes that have been immobilised on an indium tin oxide surface functionalised with osmium-based compound. This sensor was integrated within mouse macrophage cells (RAW 264.7) with multiple serotypes of bacteria used to initiate an immune response. Intracellular hydrogen peroxide was then measured in response to the interaction of the lipopolysaccharides, present on the outer wall of Gram-negative bacteria, with the Toll-like Receptor 4. Additional controls of n-acetylcysteine and sodium pyruvate were implemented to prove the specificity of the sensor towards hydrogen peroxide. The sensors were found to have a lower limit of detection of 368 nM hydrogen peroxide. An increase in intracellular hydrogen peroxide was detected within 3 seconds of interaction of the bacteria with the macrophage cells. This low limit of detection combined with the rapid response of the sensor resulted in the unprecedented detection of hydrogen peroxide on a temporal level not previously seen in response to a bacterial threat. From the three serotypes of Gram-negative bacteria that were tested, there were distinct differences in hydrogen peroxide production. This proves that the innate immune system has the ability to respond dynamically and rapidly, after infection prior to the activation of the adaptive immune system.


Assuntos
Técnicas Biossensoriais/métodos , Bactérias Gram-Negativas/imunologia , Peróxido de Hidrogênio/análise , Macrófagos/química , Macrófagos/imunologia , Animais , Técnicas Eletroquímicas/métodos , Infecções por Bactérias Gram-Negativas/imunologia , Peróxido de Hidrogênio/imunologia , Imunidade Inata , Limite de Detecção , Lipopolissacarídeos/imunologia , Macrófagos/microbiologia , Camundongos , Nanotubos de Carbono/química , Células RAW 264.7 , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/imunologia , Receptor 4 Toll-Like/imunologia
13.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31308080

RESUMO

Macrophages are critical mediators of innate immunity and must be overcome for bacterial pathogens to cause disease. The Gram-positive bacterium Staphylococcus aureus produces virulence factors that impede macrophages and other immune cells. We previously determined that production of the metabolic cofactor lipoic acid by the lipoic acid synthetase, LipA, blunts macrophage activation. A ΔlipA mutant was attenuated during infection and was more readily cleared from the host. We hypothesized that bacterial lipoic acid synthesis perturbs macrophage antimicrobial functions and therefore hinders the clearance of S. aureus Here, we found that enhanced innate immune cell activation after infection with a ΔlipA mutant was central to attenuation in vivo, whereas a growth defect imparted by the lipA mutation made a negligible contribution to overall clearance. Macrophages recruited to the site of infection with the ΔlipA mutant produced larger amounts of bactericidal reactive oxygen species (ROS) and reactive nitrogen species (RNS) than those recruited to the site of infection with the wild-type strain or the mutant strain complemented with lipA ROS derived from the NADPH phagocyte oxidase complex and RNS derived from the inducible nitric oxide synthetase, but not mitochondrial ROS, were critical for the restriction of bacterial growth under these conditions. Despite enhanced antimicrobial immunity upon primary infection with the ΔlipA mutant, we found that the host failed to mount an improved recall response to secondary infection. Our data suggest that lipoic acid synthesis in S. aureus promotes bacterial persistence during infection through limitation of ROS and RNS generation by macrophages. Broadly, this work furthers our understanding of the intersections between bacterial metabolism and immune responses to infection.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Macrófagos Peritoneais/metabolismo , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/genética , Ácido Tióctico/biossíntese , Animais , Proteínas de Bactérias/metabolismo , Feminino , Interações Hospedeiro-Patógeno/imunologia , Ativação de Macrófagos , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/microbiologia , Masculino , Camundongos , Viabilidade Microbiana , Mutação , NADPH Oxidases/genética , NADPH Oxidases/imunologia , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Espécies Reativas de Nitrogênio/antagonistas & inibidores , Espécies Reativas de Nitrogênio/imunologia , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/metabolismo , Ácido Tióctico/farmacologia
14.
J Agric Food Chem ; 67(32): 9070-9078, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31343168

RESUMO

In this study, an immunologically active novel microparticulate mushroom ß-glucan (PRA-1p) was prepared using an alkali-soluble glucan PRA-1 by an emulsification and cross-linking method. PRA-1 was a hyperbranched (1→3),(1→6)-ß-d-glucan with a degree of branching of 0.89, isolated from the sclerotia of Polyporus rhinocerus. PRA-1 had a rod-like conformation, while PRA-1p exhibited a monodisperse and homogeneous spherical conformation with a diameter ranging from 0.3 to 2.0 µm in water. PRA-1p significantly induced nitric oxide and reactive oxygen species production as well as morphological changes of murine macrophages (RAW 264.7 cells) and upregulated their phagocytic activity. Furthermore, PRA-1p treatment markedly enhanced the secretion of cytokines, including cutaneous T cell-attracting chemokine 27, granulocyte-colony-stimulating factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 1α, macrophage inflammatory protein 2, regulated on activation, normal T cell expressed and secreted, soluble tumor necrosis factor receptor 1, and tissue inhibitors of metalloproteinases. Activation of RAW 264.7 cells triggered by PRA-1p was associated with activation of inducible nitric oxide synthase, nuclear factor κB, extracellular signal-regulated kinase, and protein kinase B. This work suggests that novel PRA-1p derived from the mushroom sclerotia of P. rhinocerus has potential application as an immunostimulatory agent.


Assuntos
Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polyporus/química , beta-Glucanas/química , beta-Glucanas/farmacologia , Animais , Quimiocina CCL27/genética , Quimiocina CCL27/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Fatores Imunológicos/isolamento & purificação , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , NF-kappa B/genética , NF-kappa B/imunologia , Óxido Nítrico/imunologia , Fagocitose/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Polyporus/imunologia , Células RAW 264.7 , Espécies Reativas de Oxigênio/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , beta-Glucanas/isolamento & purificação
15.
Artigo em Inglês | MEDLINE | ID: mdl-31300124

RESUMO

S. Choleraesuis (Choleraesuis) and S. Typhimurium (Typhimurium) cause salmonellosis in pigs and humans. The effects of vaccine strains pSV-less Typhimurium OU5048 and Choleraesuis OU7266 and SPI-2-mutant Choleraesuis SC2284 on the immune responses of pigs against Typhimurium, Choleraesuis, and S. Enteritidis (Enteritidis) with or without the virulence plasmid (pSV) were determined. After oral vaccination of three vaccine groups and challenge with Choleraesuis CN36, the level of Salmonella-specific IgG in sera and the bactericidal effects and superoxide generation of peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes (PMNs) against the above strains were determined using ELISA and NBT assay, respectively. Among three vaccine strains tested, OU7266 stimulated the highest Salmonella-specific IgG levels. Complement inactivation increased IgG concentration, while E. coli absorption reduced IgG levels. The pSV-containing strains were less resistant to serum killing than the pSV-less strains, and Enteritidis exhibited the lowest resistance to serum killing. Serovars tested, vaccine strains, and timeline periods postvaccination and challenge were important factors affecting superoxide production. The two Choleraesuis vaccine strains stimulated greater levels of superoxide from PMNs and PBMCs than the Typhimurium strains. The PMNs and PBMCs in challenged and vaccinated pigs reduced more superoxide than those in challenged hosts. In vaccinated hosts, pSV-less Salmonella strains triggered lower levels of PMN/PBMC-generated superoxide upon challenge than strains with pSV against Enteritidis and Choleraesuis. Overall, Choleraesuis OU7266 may be better than the other vaccine strains in generating the greatest IgG levels, serum bactericidal activity and superoxide levels. The pSV likely influences the immune responses.


Assuntos
Imunoglobulina G/sangue , Salmonelose Animal/prevenção & controle , Vacinas contra Salmonella/uso terapêutico , Doenças dos Suínos/prevenção & controle , Animais , Anticorpos Antibacterianos/sangue , Proteínas do Sistema Complemento/imunologia , Escherichia coli/imunologia , Escherichia coli/metabolismo , Feminino , Leucócitos Mononucleares/imunologia , Neutrófilos/imunologia , Espécies Reativas de Oxigênio/imunologia , Salmonella , Salmonelose Animal/imunologia , Vacinas contra Salmonella/imunologia , Salmonella typhimurium , Ensaios de Anticorpos Bactericidas Séricos , Suínos , Vacinação/veterinária , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/uso terapêutico
16.
Mol Immunol ; 112: 283-290, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31228660

RESUMO

Dehydroepiandrosterone (DHEA) has anti-inflammatory, anti-oxidant and immune-regulating properties, while the mechanism of DHEA actions remains unclear. The present study aims to investigate the effect and possible mechanism of DHEA on immune function of mice in vivo and in vitro. In vivo, a lipopolysaccharide (LPS)-induced experimental inflammation model was constructed to analyze the regulation of DHEA on anti-oxidative and immune function in ICR mice; In vitro, the effects of DHEA on the biological functions of lymphocytes and macrophages were studied. The results showed that DHEA increased the activity of total antioxidant capacity and superoxide dismutase, while it decreased the level of reactive oxygen species in LPS-induced mice. Meanwhile, DHEA increased the proportion of T lymphocytes and decreased that of B lymphocytes in primary cultured spleen lymphocytes, and markedly enhanced the Th1/Th2 ratio in spleen T lymphocytes. Furthermore, DHEA significantly increased the Th1 type cytokine (IL-2 and IFN-α) and decreased the Th2 type cytokine (IL-4 and IL-10) levels in LPS-induced mice or in primary cultured spleen T lymphocytes. In addition, DHEA improved the phagocytic ability, enhanced the NO production and increased the iNOS activity in peritoneal macrophages. Our data indicates that DHEA increases the macrophages function via improving NO content and up-regulating TNF-α expression levels; and it evoked a Th1 immuno-response and repressed a Th2 immuno-response through promoting a shift in Th1/Th2 balance toward Th1-dominant immunity in vivo and in vitro. These results provide substantial evidence on the mechanism of DHEA-mediated immune function and the efficient protection against infectious and inflammatory response in animals and humans.


Assuntos
Desidroepiandrosterona/imunologia , Animais , Antioxidantes/metabolismo , Citocinas/imunologia , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Óxido Nítrico Sintase Tipo II/imunologia , Óxidos de Nitrogênio/imunologia , Espécies Reativas de Oxigênio/imunologia , Baço/imunologia , Superóxido Dismutase/imunologia , Células Th1/imunologia , Equilíbrio Th1-Th2/efeitos dos fármacos , Células Th2/imunologia , Regulação para Cima/imunologia
17.
Redox Biol ; 26: 101239, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31212216

RESUMO

Macrophages are highly plastic cells of the innate immune system. Macrophages play central roles in immunity against microbes and contribute to a wide array of pathologies. The processes of macrophage activation and their functions have attracted considerable attention from life scientists. Although macrophages are highly resistant to many toxic stimuli, including oxidative stress, macrophage death has been reported in certain diseases, such as viral infections, tuberculosis, atherosclerotic plaque development, inflammation, and sepsis. While most studies on macrophage death focused on apoptosis, a significant body of data indicates that programmed necrotic cell death forms may be equally important modes of macrophage death. Three such regulated necrotic cell death modalities in macrophages contribute to different pathologies, including necroptosis, pyroptosis, and parthanatos. Various reactive oxygen and nitrogen species, such as superoxide, hydrogen peroxide, and peroxynitrite have been shown to act as triggers, mediators, or modulators in regulated necrotic cell death pathways. Here we discuss recent advances in necroptosis, pyroptosis, and parthanatos, with a strong focus on the role of redox homeostasis in the regulation of these events.


Assuntos
Ativação de Macrófagos , Macrófagos/imunologia , /imunologia , Piroptose/imunologia , Animais , Humanos , Inflamação , Macrófagos/patologia , Oxirredução , Placa Aterosclerótica/imunologia , Placa Aterosclerótica/patologia , Espécies Reativas de Nitrogênio/imunologia , Espécies Reativas de Oxigênio/imunologia , Sepse/imunologia , Sepse/microbiologia , Sepse/patologia , Tuberculose/imunologia , Tuberculose/microbiologia , Tuberculose/patologia , Viroses/imunologia , Viroses/patologia , Viroses/virologia
18.
Fish Shellfish Immunol ; 92: 331-340, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31176765

RESUMO

Red blood cells (RBCs) are widely accepted as their primary function in respiration. Recent studies in mammals have revealed a vital role in immune responses of RBCs; however, little is known about immune function of teleost erythrocytes. Here we demonstrated that RBCs from grass carp (Ctenopharyngodon idella) were capable of binding and aggregating the bacteria with apparent morphological alterations. The phagocytosis by teleost RBCs (erythrophagocytosis) was visualized by confocal, scanning and transmission electron microscopy. Hb-FeII of hemoglobin (Hb) could quickly be auto-oxidated to Hb-FeIII (methemoglobin/metHb) in the presence of oxygen (O2), and release superoxide radical (O2-.) which could be spontaneously dismutated into H2O2 that could further oxidize Hb-FeIII to transient HbFeIV-OH (ferryl-Hb). Furthermore, bacterial extracellular proteases and pathogen-associated molecular patterns (PAMPs) binding to Hb could synergistically activate pseudoperoxidase, subsequently facilitated the generation of reactive oxygen species (ROS) which were toxic to the bacteria. Our results indicated that erythrocyte pertains anti-bacterial activity using unique ROS generation pathway via oxidation of hemoglobin and associated with its phagocytosis.


Assuntos
Antibacterianos/imunologia , Carpas/imunologia , Eritrócitos/imunologia , Fagocitose/imunologia , Espécies Reativas de Oxigênio/imunologia , Aeromonas hydrophila/efeitos dos fármacos , Animais , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
19.
Mol Med Rep ; 20(1): 802-812, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31180517

RESUMO

Microglia are the major immune cells in the central nervous system. Microglial activation can be beneficial or detrimental depending on the stimuli and the physiopathological environment. Microglial activation is involved in a variety of neurodegenerative disorders. Different anesthetic agents have exhibited diverse effects on microglial activation and the engulfment process. The anthocyanin callistephin has been demonstrated to have antioxidant and anti­inflammatory properties, and these were assessed in the present study, with a focus on its effect on microglial activation. Mouse microglial cells C8­4B were treated with 100 ng/µl lipopolysaccharide (LPS) and 1 ng/µl interferon­Î³. Cells were subsequently treated with 2% isoflurane, 100 µM callistephin or both. LPS promoted apoptosis in C8­B4 cells, and this was reduced following treatment with isoflurane and callistephin. LPS­treated C8­B4 cells also exhibited enhanced production of reactive oxygen species and nitric oxide, excessive engulfment and increased caspase 3/7 activity. These detrimental alterations were suppressed following co­treatment with isoflurane and callistephin. LPS­induced apoptosis was facilitated via the expression of B­cell lymphoma­2 like 1 and poly (ADP­ribose) polymerase, which were subsequently restored following treatment with isoflurane and callistephin. Callistephin was demonstrated to be involved in the modulation of inducible nitric oxide synthase, cytochrome c oxidase subunit 2, tumor necrosis factor­α and nuclear factor­κ B. Callistephin enhanced the protective effects of isoflurane by modulating engulfment and apoptosis in C8­B4 cells. The potential underlying mechanism was identified to be the suppression of p38 phosphorylation. The present study thus suggested that the negative effects on microglial activity induced by LPS were ameliorated following treatment with callistephin, which also enhanced the effects of isoflurane. Callistephin may therefore constitute a candidate drug agent that may target inflammatory and growth regulatory signaling pathways, thus ameliorating certain aspects of neurodegenerative diseases.


Assuntos
Antocianinas/farmacologia , Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Inflamação/tratamento farmacológico , Isoflurano/farmacologia , Microglia/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Linhagem Celular , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Camundongos , Microglia/imunologia , Óxido Nítrico/imunologia , Fagocitose/efeitos dos fármacos , Espécies Reativas de Oxigênio/imunologia
20.
Free Radic Res ; 53(7): 780-790, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31185753

RESUMO

Oxidative stress is a key mechanism underlying ozone-induced lung injury. Mitochondria can release mitochondrial reactive oxidative species (mtROS), which may lead to the activation of NLRP3 inflammasome. The goal of this study was to examine the roles of mtROS and NLRP3 inflammasome in acute ozone-induced airway inflammation and bronchial hyperresponsiveness (BHR). C57/BL6 mice (n = 8/group) were intraperitoneally treated with vehicle (phosphate buffered saline, PBS) or mitoTEMPO (mtROS inhibitor, 20 mg/kg), or orally treated with VX-765 (caspse-1 inhibitor, 100 mg/kg) 1 h before the ozone exposure (2.5 ppm, 3 h). Compared to the PBS-treated ozone-exposed mice, mitoTEMPO reduced the level of total malondialdehyde in bronchoalveolar lavage (BAL) fluid and increased the expression of mitochondrial complexes II and IV in the lung 24 h after single ozone exposure. VX-765 inhibited ozone-induced BHR, BAL total cells including neutrophils and eosinophils, and BAL inflammatory cytokines including IL-1α, IL-1ß, KC, and IL-6. Both mitoTEMPO and VX-765 reduced ozone-induced mtROS and inhibited capase-1 activity in lung tissue whilst VX-765 further inhibited DRP1 and MFF expression, increased MFN2 expression, and down-regulated caspase-1 expression in the lung tissue. These results indicate that acute ozone exposure induces mitochondrial dysfunction and NLRP3 inflammasome activation, while the latter has a critical role in the pathogenesis of ozone-induced airway inflammation and BHR.


Assuntos
Hiper-Reatividade Brônquica/metabolismo , Inflamassomos/metabolismo , Inflamação/metabolismo , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Hiper-Reatividade Brônquica/imunologia , Modelos Animais de Doenças , Inflamassomos/imunologia , Inflamação/imunologia , Masculino , Camundongos , Mitocôndrias/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Espécies Reativas de Oxigênio/imunologia
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