scholarly journals Abundant Secretion of Bioactive Interleukin-1β by Human Macrophages Induced by Actinobacillus actinomycetemcomitans Leukotoxin

2005 ◽  
Vol 73 (1) ◽  
pp. 453-458 ◽  
Author(s):  
P. Kelk ◽  
R. Claesson ◽  
L. Hänström ◽  
U. H. Lerner ◽  
S. Kalfas ◽  
...  

ABSTRACT Actinobacillus actinomycetemcomitans produces a leukotoxin that selectively kills human leukocytes. Recently, we reported that macrophages are highly sensitive to leukotoxin and that their lysis involves activation of caspase 1. In this study, we show that leukotoxin also induces the production and release of proinflammatory cytokines from human macrophages. The macrophages were challenged with leukotoxin or lipopolysaccharide (LPS) from A. actinomycetemcomitans or LPS from Escherichia coli, and the production and secretion of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) were determined at the mRNA and protein levels by reverse transcription-PCR and enzyme-linked immunosorbent assay, respectively. Leukotoxin (1 to 30 ng/ml) induced abundant production and secretion of IL-1β, while the effects on IL-6 and TNF-α production were limited. Leukotoxin (1 ng/ml) caused a 10-times-higher release of IL-1β than did LPS (100 ng/ml). The secreted IL-1β was mainly the bioactive 17-kDa protein. At higher concentrations (>30 ng/ml), leukotoxin caused secretion of mainly inactive cytokine, the 31-kDa pro-IL-1β. The presence of specific antibodies to IL-1β or of a caspase 1 inhibitor blocked the secretion and production of the cytokine. Supernatants of leukotoxin-challenged macrophages stimulated bone resorption when tested in a mouse calvarial model. The activity could be blocked by an IL-1 receptor antagonist or specific antibodies to IL-1β. We concluded that A. actinomycetemcomitans leukotoxin can trigger abundant production and secretion of bioactive IL-1β by human macrophages, which is mediated by activation of caspase 1.

2006 ◽  
Vol 74 (3) ◽  
pp. 1916-1923 ◽  
Author(s):  
Chiang W. Lee ◽  
Soumaya Bennouna ◽  
Eric Y. Denkers

ABSTRACT Toxoplasma gondii-infected macrophages are blocked in production of the proinflammatory cytokines interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α) upon activation with lipopolysaccharide (LPS). Here, we used pathway-focused cDNA arrays to identify additional T. gondii-regulated transcriptional responses. Parasite infection decreased 57 (inclusive of IL-12 and TNF-α) and increased expression of 7 of 77 LPS-activated cytokine and cytokine-related genes. Interestingly, we found that the LPS-induced transcriptional response of the anti-inflammatory cytokine IL-10 was synergistically increased by T. gondii, results that we validated by conventional reverse transcription-PCR and enzyme-linked immunosorbent assay. Importantly, although the parasite exerted disparate effects in LPS-signaling leading to TNF-α versus IL-10 production, both responses required functional Toll-like receptor 4. We suggest that these effects represent parasite defense mechanisms to avoid or delay induction of antimicrobial activity and/or T-cell-mediated immunity during Toxoplasma infection.


Author(s):  
Ayşe Koçak ◽  
Aydan Köken Avşar ◽  
Duygu Harmancı ◽  
Gül Akdoğan ◽  
A. Merih Birlik

Objectives: This study aims to investigate the possible fibrotic role of meprin metalloproteases and possible fibrotic effects of activator protein-1 (AP-1) in scleroderma patients. Patients and methods: Between April 2018 and April 2019, a total of 85 scleroderma patients (9 males, 76 females; mean age: 54.9 years; range, 22 to 80 years) who met the 2013 American College of Rheumatology/European League Against Rheumatism criteria and 80 healthy control individuals (10 males, 70 females; mean age 42.9 years; range, 19 to 65 years) were included. Patients’ data and blood samples were collected. Messenger ribonucleic acid expressions of interleukin (IL)-6, AP-1 subunits, and tumor necrosis factor-alpha (TNF-α) were analyzed by quantitative real-time polymerase chain reaction. Serum meprin alpha and beta protein levels were analyzed using the enzyme-linked immunosorbent assay. Results: Meprin alpha and meprin beta protein levels increased in scleroderma patients. The AP-1 subunits (c-Fos, c-Jun), IL-6, and TNF-α increased in scleroderma patients, compared to controls. Conclusion: Our results provide evidence showing that increased meprins levels may be related to AP-1 levels and increased meprins levels may responsible for increased inflammatory TNF-α and IL-6 levels. All these data suggest meprins as promising therapeutic targets to restore the balance between inflammation and extracellular matrix deposition in scleroderma.


2019 ◽  
Vol 17 ◽  
pp. 205873921984197
Author(s):  
Guihong Huang ◽  
Juan Li ◽  
Wanlian Li ◽  
Tianxu Liu ◽  
Guojun Jiang ◽  
...  

The fruit and root of Clausena lansium are remedy for bronchitis in oriental traditional medicine. Extracts from Clausena lansium are reported to have antioxidant, anti-inflammatory, and anticancer activities. This study is designed to investigate whether the ethanol extract of Clausena lansium (Lour.) Skeels could inhibit the lipopolysaccharides (LPS)-induced inflammatory in RAW 264.7 macrophages and the underlining mechanisms. Enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) are used to detect the secretion of tumor necrosis factor alpha (TNF-α) protein and expression of TNF-α mRNA, respectively. RT-PCR and Western blotting are used to determine the mRNA and protein levels of TLR4, MYD88, and TRAF6, respectively. The extract of Clausena lansium suppressed the expression and secretion of TNF-α, which is released by RAW 264.7 cells after LPS induction. Meanwhile, the expression of TLR4, MYD88, and TRAF6 are decreased by extracts from Clausena lansium. Meanwhile, NBP2-29328, an inhibitor of MYD88, synergistically enhances the inhibiting effect of extract from Clausena lansium. The results imply that ethanol extract from Clausena lansium attenuate macrophage-mediated inflammation and TLR4/MYD88/TRAF6 pathway is its potential target.


2002 ◽  
Vol 70 (7) ◽  
pp. 3736-3743 ◽  
Author(s):  
Claudia Brodskyn ◽  
Julie Patricio ◽  
Rubem Oliveira ◽  
Lucas Lobo ◽  
Andrea Arnholdt ◽  
...  

ABSTRACT To investigate the possible effects of glycoinositolphospholipid (GIPL) from Trypanosoma cruzi on human antigen presenting cells, we tested their effects on lipopolysaccharide (LPS)-stimulated human macrophages and dendritic cells (DC). Human macrophages or DC were incubated with GIPL (50 μg/ml) and LPS (500 pg/ml) and tumor necrosis factor alpha (TNF-α), interleukin 8 (IL-8), IL-10, and IL-12p40 levels in supernatants were analyzed by enzyme-linked immunosorbent assay. TNF-α, IL-10, and IL-12 secretion were significantly decreased by GIPL both in macrophages and DC. In contrast, GIPL did not alter IL-8 production. We also analyzed the expression of CD80, CD86, HLA-DR, CD40, and CD57 on the macrophage surface after stimulation with LPS in the presence or absence of T. cruzi GIPL. GIPL led to a down-regulation in the expression of all tested molecules. We additionally examined the influence of T. cruzi GIPL on the response of human DC to LPS. LPS-induced HLA-DR, CD83, and CD86 up-regulation was significantly inhibited by GIPL. A slight down-regulation in CD80 and CD40 expression on DC surfaces in the presence of GIPL was also noticed. Similarly, GIPL led to down-modulation of CD83, CD80, CD86, and HLA-DR surface expression and TNF-α and IL-10 production when DC were stimulated by CD40L. The ceramide portion of GIPL was responsible for most of the activity exhibited by the whole molecule. Considering the important role of the immune response in determining the fate of the host-parasite relationship, the immunoregulatory activities of T. cruzi GIPL are potentially important for parasite evasion and then pathogenesis of infection with protozoan parasites.


2007 ◽  
Vol 75 (4) ◽  
pp. 1870-1877 ◽  
Author(s):  
Kirti V. Sawant ◽  
David N. McMurray

ABSTRACT The early influx of neutrophils to the site of infection may be an important step in host resistance against Mycobacterium tuberculosis. In this study, we investigated the effect of M. tuberculosis infection on the ability of guinea pig neutrophils to produce interleukin-8 (IL-8; CXCL8) and tumor necrosis factor alpha (TNF-α) and to activate alveolar macrophages. Neutrophils and alveolar macrophages were isolated from naïve guinea pigs, cultured together or alone, and infected with virulent M. tuberculosis for 3, 12, and 24 h. IL-8 protein production in cocultures, as measured by using an enzyme-linked immunosorbent assay, was found to be additive at 24 h and significantly greater in M. tuberculosis-infected cocultures than in uninfected cocultures and in cultures of the infected neutrophils or macrophages alone. The IL-8 mRNA levels, determined by real-time reverse transcription-PCR, were elevated at 24 h in infected cocultures and infected cells cultured alone. In order to elucidate the contributions of neutrophils and their soluble mediators to the activation of alveolar macrophages, neutrophils and alveolar macrophages were cultured in a contact-independent manner by using a Transwell insert system. Neutrophils were infected with virulent M. tuberculosis in the upper wells, and alveolar macrophages were cultured in the lower wells. The release of hydrogen peroxide from alveolar macrophages exposed to soluble products from infected neutrophils was significantly increased compared to that from unexposed alveolar macrophages. Significant up-regulation of IL-1β and TNF-α mRNA levels in alveolar macrophages was observed at 24 and 30 h, respectively, compared to those in cells not exposed to soluble neutrophil products. Treatment with anti-guinea pig TNF-α polyclonal antibody completely abolished the response of alveolar macrophages to neutrophil products. This finding suggests that TNF-α produced by infected neutrophils may be involved in the activation of alveolar macrophages and hence may contribute to the containment of M. tuberculosis infection during the early period of infection.


2017 ◽  
Vol 68 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Mahmoud M. Said ◽  
Marwa M. Abd Rabo

AbstractAluminium (Al) is a neurotoxic metal that contributes to the progression of several neurodegenerative diseases. The aim of the present study was to evaluate the protective effect of dietary eugenol supplementation against aluminium (Al)- induced cerebral damage in rats. Male Wistar rats were divided into four groups: normal controls, rats fed a diet containing 6,000 μg g-1eugenol, rats intoxicated daily with aluminium chloride (84 mg kg-1body weight) p. o. and fed either a basal diet or a eugenol-containing diet. Daily oral administration of Al for four consecutive weeks to rats significantly reduced brain total antioxidant status (TAS) (11.42±0.31 μmol g-1tissue, p<0.001) with a subsequent significant enhancement of lipid peroxidation (MDA) (32.55±1.68 nmol g-1tissue, p<0.002). In addition, Al enhanced brain acetylcholinesterase activity (AChE) (46.22±4.90 U mg-1protein, p<0.001), tumour necrosis factor alpha (TNF-α) (118.72±11.32 pg mg-1protein, p<0.001), and caspase 3 (Casp-3) (8.77±1.26 ng mg-1protein, p<0.001) levels, and in contrast significantly suppressed brain-derived neurotrophic factor (BDNF) (82.74±14.53 pg mg-1protein, p<0.002) and serotonin (5-HT) (1.54±0.12 ng mg-1tissue, p<0.01) levels. Furthermore, decreased glial fibrillary acidic protein (GFAP) immunostaining was noticed in the striatum of Al-intoxicated rats, compared with untreated controls. On the other hand, co-administration of dietary eugenol with Al intoxication restored brain BDNF (108.76±2.64 pg mg-1protein) and 5-HT (2.13±0.27 ng mg-1tissue) to normal levels, enhanced brain TAS (13.43±0.24 μmol g-1tissue, p<0.05), with a concomitant significant reduction in TNF-α (69.98±4.74 pg mg-1protein) and Casp-3 (3.80±0.37 ng mg-1protein) levels (p<0.001), as well as AChE activity (24.50±3.25 U mg-1protein, p<0.001), and increased striatal GFAP immunoreactivity, compared with Al-treated rats. Histological findings of brain tissues verified biochemical data. In conclusion, eugenol holds potential as a neuroprotective agent through its hydrophobic, antioxidant, and anti-apoptotic properties, as well as its neurotrophic ability against Al-induced brain toxicity in rats.


2001 ◽  
Vol 69 (8) ◽  
pp. 4823-4830 ◽  
Author(s):  
Véronique Jubier-Maurin ◽  
Rose-Anne Boigegrain ◽  
Axel Cloeckaert ◽  
Antoine Gross ◽  
Maria-Teresa Alvarez-Martinez ◽  
...  

ABSTRACT Brucella spp. can establish themselves and cause disease in humans and animals. The mechanisms by whichBrucella spp. evade the antibacterial defenses of their host, however, remain largely unknown. We have previously reported that live brucellae failed to induce tumor necrosis factor alpha (TNF-α) production upon human macrophage infection. This inhibition is associated with a nonidentified protein that is released into culture medium. Outer membrane proteins (OMPs) of gram-negative bacteria have been shown to modulate macrophage functions, including cytokine production. Thus, we have analyzed the effects of two major OMPs (Omp25 and Omp31) of Brucella suis 1330 (wild-type [WT] B. suis) on TNF-α production. For this purpose, omp25and omp31 null mutants of B. suis(Δomp25 B. suis and Δomp31 B. suis, respectively) were constructed and analyzed for the ability to activate human macrophages to secrete TNF-α. We showed that, in contrast to WTB. suis or Δomp31 B. suis, Δomp25 B. suis induced TNF-α production when phagocytosed by human macrophages. The complementation of Δomp25 B. suis with WT omp25 (Δomp25-omp25 B. suis mutant) significantly reversed this effect: Δomp25-omp25 B. suis-infected macrophages secreted significantly less TNF-α than did macrophages infected with the Δomp25 B. suismutant. Furthermore, pretreatment of WT B. suis with an anti-Omp25 monoclonal antibody directed against an epitope exposed at the surface of the bacteria resulted in substancial TNF-α production during macrophage infection. These observations demonstrated that Omp25 of B. suis is involved in the negative regulation of TNF-α production upon infection of human macrophages.


2018 ◽  
Vol 44 (4) ◽  
pp. 530-538
Author(s):  
Aysun Çetin ◽  
İhsan Çetin ◽  
Semih Yılmaz ◽  
Ahmet Şen ◽  
Göktuğ Savaş ◽  
...  

Abstract Background Limited research is available concerning the relationship between oxidative stress and inflammation parameters, and simultaneously the effects of rosuvastatin on these markers in patients with hypercholesterolemia. We aimed to investigate the connection between cytokines and oxidative stress markers in patients with hypercholesterolemia before and after rosuvastatin treatment. Methods The study consisted of 30 hypercholesterolemic patients diagnosed with routine laboratory tests and 30 healthy participants. The lipid parameters, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), paraoxonase-1 (PON1) and malondialdehyde (MDA) levels in controls and patients with hypercholesterolemia before and after 12-week treatment with rosuvastatin (10 mg/kg/day), were analyzed by means of enzyme-linked immunosorbent assay. Results It was found that a 12-week cure with rosuvastatin resulted in substantial reductions in IL-1β, IL-6 and TNF-α and MDA levels as in rising activities of PON1 in patients with hypercholesterolemia. Before treatment, the PON1 levels were significantly negatively correlated with TNF-α and IL-6 in control group, while it was positively correlated with TNF-α in patients. Conclusion Our outcomes provide evidence of protected effect of rosuvastatin for inflammation and oxidative damage. It will be of great interest to determine whether the correlation between PON1 and cytokines has any phenotypic effect on PON1.


Medicines ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 106 ◽  
Author(s):  
Yuanjun Deng ◽  
Kairui Tang ◽  
Runsen Chen ◽  
Yajie Liu ◽  
Huan Nie ◽  
...  

Background: In traditional Chinese medicine, the Shugan-Jianpi recipe is often used in the treatment of nonalcoholic fatty liver disease (NAFLD). This study aimed to explore the mechanism of the Shugan-Jianpi recipe in relation to rats with NAFLD induced by a high-fat diet. Methods: Rats were randomly divided into eight groups: normal group (NG), model group (MG), low-dose Chaihu–Shugan–San group (L-CG), high-dose Chaihu–Shugan–San group (H-CG), low-dose Shenling–Baizhu–San group (L-SG), high-dose Shenling–Baizhu–San group (H-SG), low dose of integrated-recipes group (L-IG), and high dose of integrated-recipes group (H-IG). After 26 weeks, a lipid profile, aspartate, and alanine aminotransferases in serum were detected. The serum levels of inflammatory factors including interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) were analyzed using the enzyme linked immunosorbent assay (ELISA) method. Hepatic pathological changes were observed with hematoxylin-eosin (HE) and oil red O staining. The expression of the p38 mitogen-activated protein kinases (MAPK)/nuclear factor-κB (NF-κB) pathway was detected by quantitative real-time PCR and Western blotting. Results: A pathological section revealed that NAFLD rats have been successfully reproduced. Compared with the model group, each treatment group had different degrees of improvement. The Shugan-Jianpi recipe can inhibit the serum levels of IL-1β, IL-6, and TNF-α in NAFLD rats. The expression of mRNA and a protein related to the p38 MAPK/NF-κB signaling pathway were markedly decreased as a result of the Shugan-Jianpi recipe. Conclusions: The Shugan-Jianpi recipe could attenuate NAFLD progression, and its mechanism may be related to the suppression of the p38 MAPK/NF-κB signaling pathway in hepatocytes.


2020 ◽  
Author(s):  
Lida Zare ◽  
Akram Eidi ◽  
Mohammad Safarian ◽  
Mohammad Kazemi Arababadi

Abstract Background Angiography is a safe cardiovascular technique for the diagnosis and treatment of the cardiovascular disorders. The potential effects of angiography on the cytokines are yet to be clarified completely. Interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) are the important pro-inflammatory cytokines that participate in the pathogenesis of artery stenosis. The aim of his project was to study the angiography effects on the serum levels of IL-8 and TNF-α. Methods Fifty-five participants in three groups, without, with one and with more than one artery stenosis, were explored in this project. Serum levels of IL-8 and TNF-α were measured in the participants before and after angiography using enzyme linked immunosorbent assay (ELISA) technique. Results Serum levels of IL-8, but not TNF-α, were significantly decreased following angiography. X-ray doses had moderate positive correlation with serum levels of TNF-α in the patients with more than one artery stenosis. Serum levels of IL-8 and TNF-α were not different among male and female participants in all groups. Discussion Angiography may be a protective factor for inflammation in IL-8 dependent manner. Using angiography in the patients with more than one artery stenosis needs to be executed cautiously.


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