scholarly journals Moesin Functions as a Lipopolysaccharide Receptor on Human Monocytes

1999 ◽  
Vol 67 (7) ◽  
pp. 3215-3220 ◽  
Author(s):  
Ziad N. Tohme ◽  
Salomon Amar ◽  
Thomas E. Van Dyke
Keyword(s):  
Interleukin 1 ◽  
Biologically Active ◽  
Sequence Motif ◽  
Human Monocytes ◽  
Tissue Destruction ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Tnf Α ◽  
Partial Blocking ◽  
Lps Binding

ABSTRACT Bacterial endotoxin (lipopolysaccharide [LPS]), a glycolipid found in the outer membranes of gram-negative bacteria, induces the secretion of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), and IL-6 by monocytes/macrophages. The secretion of these biologically active compounds leads to multiple pathological conditions, such as septic shock. There is substantial evidence that chronic exposure to LPS mediates, at least in part, the tissue destruction associated with gram-negative infection. CD14, a 55-kDa protein, has been identified as an LPS receptor. In conjunction with a serum protein, LPS binding protein (LBP), LPS-CD14 interactions mediate many LPS functions in the inflammatory response. However, CD14 lacks a cytoplasmic domain, or any known signal transduction sequence motif, suggesting the existence of another cell surface domain capable of transducing signals. In this paper, we report a second, CD14-independent LPS binding site, which, based on biological activity, appears to be a functional LPS receptor. Cross-linking experiments were performed to identify LPS binding sites. Two molecules were identified: a 55-kDa protein (CD14) and a second, 78-kDa band. Sequencing of the 78-kDa protein by mass spectroscopic analysis revealed 100% homology with moesin (membrane-organizing extension spike protein). Antibody to CD14 induced partial blocking of the LPS response. However, antimoesin monoclonal antibody completely blocked the LPS-induced TNF-α response in human monocytes, without blocking CD14 binding of LPS. Irrelevant isotype controls had no effect. Additional experiments were performed to evaluate the specificity of the antimoesin blocking. Separate experiments evaluated antimoesin effects on monocyte chemotaxis, IL-1 production in response to IL-1 stimulation, and TNF-α secretion in response toStaphylococcus aureus stimulation. Antimoesin blocked only LPS-mediated events. The data suggest that moesin functions as an independent LPS receptor on human monocytes. The role of moesin in transduction of CD14-mediated signals is discussed.

scholarly journals High-Affinity Interaction between Gram-Negative Flagellin and a Cell Surface Polypeptide Results in Human Monocyte Activation

2000 ◽  
Vol 68 (10) ◽  
pp. 5525-5529 ◽  
Author(s):  
Patrick F. McDermott ◽  
Federica Ciacci-Woolwine ◽  
James A. Snipes ◽  
Steven B. Mizel
Keyword(s):  
Cell Surface ◽  
Mutational Analysis ◽  
Hypervariable Region ◽  
Gram Negative Bacteria ◽  
Human Monocytes ◽  
Necrosis Factor Alpha ◽  
Potent Inducer ◽  
Gram Negative ◽  
High Affinity ◽  
Tnf Α

ABSTRACT Flagella from diverse gram-negative bacteria induce tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) synthesis by human monocytes (F. Ciacci-Woolwine, P. F. McDermott, and S. B. Mizel, Infect. Immun. 67:5176–5185, 1999). In this study, we establish that purified flagellin (FliC or FljB), the major filament protein from Salmonella enterica serovar Enteritidis,S. enterica serovar Typhimurium, and Pseudomonas aeruginosa, is an extremely potent inducer of TNF-α production by human monocytes and THP-1 myelomonocytic cells. Fifty percent of maximal TNF-α production (EC50) was obtained with 1.5 × 10−11 M flagellin (0.75 ng/ml). Mutagenesis studies revealed that the central hypervariable region of flagellin is essential for the TNF-α-inducing activity of the protein. Although less active than the wild-type protein, a Salmonellaflagellin mutant composed of only the central hypervariable region retained substantial TNF-α-inducing activity at nanomolar concentrations. In contrast, the conserved amino- and carboxy-terminal regions are inactive. Mutational analysis of the hypervariable region revealed that it contains two equally active TNF-α-inducing domains. The ability of THP-1 cells to respond to purified flagellins is dramatically reduced by mild trypsin treatment of the cells. Taken together, our results demonstrate that the cytokine-inducing activity of flagellins from gram-negative bacteria results from the interaction of these proteins with high-affinity cell surface polypeptide receptors on monocytes.

Hemoglobin and LPS Act in Synergy to Amplify the Inflammatory Response

2007 ◽  
Vol 86 (9) ◽  
pp. 878-882 ◽  
Author(s):  
C. Bodet ◽  
F. Chandad ◽  
D. Grenier
Keyword(s):  
Gingival Crevicular Fluid ◽  
Inflammatory Responses ◽  
Interleukin 1 ◽  
Fusobacterium Nucleatum ◽  
Necrosis Factor Alpha ◽  
Vascular Disruption ◽  
Tnf Α ◽  
Factor Alpha ◽  
Crevicular Fluid ◽  
Lps Binding

Vascular disruption and bleeding during periodontitis likely increase the levels of hemoglobin in gingival crevicular fluid. The aim of this study was to investigate the effect of hemoglobin on the inflammatory responses of human macrophages stimulated with lipopolysaccharides (LPS) isolated from periodontopathogens. The production of interleukin-1 beta (IL-1β), IL-6, IL-8, and tumor necrosis factor alpha (TNF-α) by macrophages following challenges with Porphyromonas gingivalis and Fusobacterium nucleatum LPS in the presence or absence of human hemoglobin was analyzed by ELISA. The effect of hemoglobin on LPS-binding to macrophages was evaluated with 3H-LPS. Hemoglobin and LPS from periodontopathogens acted in synergy to stimulate the production of high levels of IL-1β, IL-6, IL-8, and TNF-α by macrophages. Hemoglobin also enhanced LPS-binding to macrophages. This study suggests that hemoglobin contributes to increases in the levels of pro-inflammatory mediators in periodontal sites by acting in synergy with LPS from periodontopathogens, thus favoring the progression of periodontitis.

scholarly journals Activation of Interleukin-1 Receptor-Associated Kinase by Gram-Negative Flagellin

2001 ◽  
Vol 69 (7) ◽  
pp. 4424-4429 ◽  
Author(s):  
Marlena A. Moors ◽  
Liwu Li ◽  
Steven B. Mizel
Keyword(s):  
Cell Line ◽  
Salmonella Enteritidis ◽  
Mutant Cell ◽  
Interleukin 1 ◽  
Central Component ◽  
No Production ◽  
Gram Negative Bacteria ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Tnf Α

ABSTRACT Flagellin from various species of gram-negative bacteria activates monocytes to produce proinflammatory cytokines. We have analyzed the pathway by which Salmonella enteritidis flagellin (FliC) activates murine and human monocyte/macrophage-like cell lines. Since lipopolysaccharide (LPS), the principal immune stimulatory component of gram-negative bacteria, is known to signal through Toll-like receptor 4 (TLR4), we tested the possibility that FliC also signals via TLR4. When murine HeNC2 cells were stimulated with LPS in the presence of a neutralizing anti-TLR4 monoclonal antibody, tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) production were markedly reduced. In contrast, FliC-mediated TNF-α and NO production were minimally affected by the anti-TLR4 antibody. Furthermore, FliC, unlike LPS, stimulated TNF-α production in the TLR4 mutant cell line, GG2EE, indicating that TLR4 is not essential for FliC-mediated signaling. To test the possibility that FliC signals via another TLR, we measured FliC-mediated activation of interleukin-1 (IL-1) receptor-associated kinase (IRAK), a central component in IL-1R/TLR signaling. FliC induced IRAK activation in HeNC2 and GG2EE cells as well as in the human promonocytic cell line THP-1. IRAK activation was rapid in HeNC2 cells, with maximal activity observed after 5 min of treatment with FliC. In addition, FliC-mediated IRAK activation exhibited the same concentration dependence as was demonstrated for the induction of TNF-α. These results represent the first demonstration of IRAK activation by a purified bacterial protein and strongly suggest that a TLR distinct from TLR4 is involved in the macrophage inflammatory response to FliC.

Role of inflammation in the development of colorectal cancer

2020 ◽  
Vol 20 ◽  
Author(s):  
Sridhar Muthusami ◽  
R. Ileng Kumaran ◽  
Kokelavani Nampalli Babu ◽  
Sneha Krishnamoorthy ◽  
Akash Guruswamy ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Chronic Inflammation ◽  
Interleukin 1 ◽  
Cell Types ◽  
Model Systems ◽  
Cytokine Gene Expression ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Proinflammatory Molecules

: Chronic inflammation can lead to the development of many diseases including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohn's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation together with genetic and epigenetic changes has been shown to lead to the development and progression of CRC. Various cell types present in the colon such as enterocytes, Paneth cells, goblet cells and macrophages express receptors for inflammatory cytokines and respond to tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6 and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key proinflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of proinflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy), to alleviate the symptoms or treat inflammationassociated CRC by using monoclonal antibodies or aptamers to block proinflammatory molecules, inhibitors of tyrosine kinases in inflammatory signaling cascade, competitive inhibitors of proinflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/proinflammatory cytokine gene expression.

scholarly journals Inhibition of Leukocyte Entry into the Brain by the Selectin Blocker Fucoidin Decreases Interleukin-1 (IL-1) Levels but Increases IL-8 Levels in Cerebrospinal Fluid during Experimental Pneumococcal Meningitis in Rabbits

2000 ◽  
Vol 68 (6) ◽  
pp. 3153-3157 ◽  
Author(s):  
Christian Østergaard ◽  
Runa Vavia Yieng-Kow ◽  
Thomas Benfield ◽  
Niels Frimodt-Møller ◽  
Frank Espersen ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Pneumococcal Meningitis ◽  
Interleukin 1 ◽  
Treated Group ◽  
Control Group ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Significant Difference ◽  
The Brain ◽  
Experimental Pneumococcal Meningitis

ABSTRACT The polysaccharide fucoidin is a selectin blocker that inhibits leukocyte recruitment into the cerebrospinal fluid (CSF) during experimental pneumococcal meningitis. In the present study, the effect of fucoidin treatment on the release of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), and IL-8 into the CSF was investigated. Rabbits (n = 7) were treated intravenously with 10 mg of fucoidin/kg of body weight every second hour starting 4 h after intracisternal inoculation of ∼106 CFU of Streptococcus pneumoniae type 3 (untreated control group, n = 7). CSF samples were obtained every second hour during a 16-h study period. Treatment with fucoidin caused a consistent and significant decrease in CSF IL-1 levels (in picograms per milliliter) between 12 and 16 h (0 versus 170, 0 versus 526, and 60 versus 1,467, respectively;P < 0.02). A less consistent decrease in CSF TNF-α levels was observed in the fucoidin-treated group, but with no significant difference between the two groups (P > 0.05). In contrast, there was no attenuation in CSF IL-8 levels. Indeed, there was a significant increase in CSF IL-8 levels (in picograms per milliliter) in the fucoidin-treated group at 10 and 12 h (921 versus 574 and 1,397 versus 569, respectively;P < 0.09). In conclusion, our results suggest that blood-derived leukocytes mainly are responsible for the release of IL-1 and to some degree TNF-α into the CSF during pneumococcal meningitis, whereas IL-8 may be produced by local cells within the brain.

scholarly journals Interaction of Antimicrobial Peptide Temporin L with Lipopolysaccharide In Vitro and in Experimental Rat Models of Septic Shock Caused by Gram-Negative Bacteria

2006 ◽  
Vol 50 (7) ◽  
pp. 2478-2486 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Roberto Ghiselli ◽  
Federico Mocchegiani ◽  
Fiorenza Orlando ◽  
...  
Keyword(s):  
Septic Shock ◽  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Amphibian Skin ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Rat Models ◽  
E Coli ◽  
Tnf Α

ABSTRACT Sepsis remains a major cause of morbidity and mortality in hospitalized patients, despite intense efforts to improve survival. The primary lead for septic shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the quest for compounds with antiendotoxin properties is actively pursued. We investigated the efficacy of the amphibian skin antimicrobial peptide temporin L in binding Escherichia coli LPS in vitro and counteracting its effects in vivo. Temporin L strongly bound to purified E. coli LPS and lipid A in vitro, as proven by fluorescent displacement assay, and readily penetrated into E. coli LPS monolayers. Furthermore, the killing activity of temporin L against E. coli was progressively inhibited by increasing concentrations of LPS added to the medium, further confirming the peptide's affinity for endotoxin. Antimicrobial assays showed that temporin L interacted synergistically with the clinically used β-lactam antibiotics piperacillin and imipenem. Therefore, we characterized the activity of temporin L when combined with imipenem and piperacillin in the prevention of lethality in two rat models of septic shock, measuring bacterial growth in blood and intra-abdominal fluid, endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, and lethality. With respect to controls and single-drug treatments, the simultaneous administration of temporin L and β-lactams produced the highest antimicrobial activities and the strongest reduction in plasma endotoxin and TNF-α levels, resulting in the highest survival rates.

Oxydative stress markers and cytokine levels in rosuvastatin-medicated hypercholesterolemia patients

2018 ◽  
Vol 44 (4) ◽  
pp. 530-538
Author(s):  
Aysun Çetin ◽  
İhsan Çetin ◽  
Semih Yılmaz ◽  
Ahmet Şen ◽  
Göktuğ Savaş ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Interleukin 1 ◽  
Paraoxonase 1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Phenotypic Effect ◽  
Necrosis Factor Alpha ◽  
Stress Markers ◽  
Tnf Α ◽  
Before And After

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.

scholarly journals Nutritional Value and Anti-inflammation Activity of Misutkaru with Added Gryllus bimaculatus Powder

2021 ◽  
Vol 19 (3) ◽  
pp. 467-476
Author(s):  
Jung-Soon Han
Keyword(s):  
Amino Acid ◽  
Inflammatory Cytokines ◽  
Nutritional Value ◽  
Interleukin 1 ◽  
Raw 264.7 Cells ◽  
Raw 264.7 ◽  
Gryllus Bimaculatus ◽  
Necrosis Factor Alpha ◽  
Automatic Amino Acid Analyzer ◽  
Tnf Α

Purpose: This study investigated the nutritional value of Misutkaru with added Gryllus bimaculatus powder (GBM) and its applicability as a healthy functional food.Methods: Chemical analysis of the moisture, crude fat, protein, and mineral contents was performed in accordance with the Association of Official Analytical Chemists (AOAC) guidelines. The amino acid and fatty acid compositions were analyzed using an automatic amino acid analyzer and gas chromatography, respectively. The levels of inflammatory cytokines tumor necrosis factor‑alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL‑6) induced by lipopolysaccharides in RAW 264.7 cells were measured.Results: The general composition per 100 g of GBM was 41.87 g protein, 19.75 g fat, and 28.52 g carbohydrates. The mineral content per 100 g of GBM was 889.66 mg calcium, 1189.73 mg potassium, 220.36 mg magnesium, 207.51 mg sodium, 694.81 mg phosphorus, and 15.50 mg zinc. In particular, valine (21.361 mg/kg), leucine (29.180 mg/kg), and isoleucine (15.562 mg/kg) were abundant in GBM. GBM also effectively downregulated the production of the inflammatory cytokines TNF-α, IL-1β, and IL-6 in RAW 264.7 macrophages.Conclusion: Misutkaru with added Gryllus bimaculatus powder may have potential for application in the development of food materials or foods to prevent muscle loss in elderly individuals and sarcopenia patients, build muscle, and prevent increase in blood lipid concentrations in middle aged people. In particular, as Gryllus bimaculatus is low in fat and carbohydrates, it can be used as a diet material.

Oxymatrine inhibits lipopolysaccharide-induced inflammation by down-regulating Toll-like receptor 4/nuclear factor-kappa B in macrophages

2015 ◽  
Vol 93 (4) ◽  
pp. 253-260 ◽  
Author(s):  
Yu Zhang ◽  
Ruhong Yan ◽  
Yae Hu
Keyword(s):  
Nitric Oxide ◽  
Interleukin 1 ◽  
Chinese Herb ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Anti Inflammatory

Oxymatrine (OMT) is the quinolizidine alkaloid extracted from the Chinese herb Sophora flavescens Ait. that has many pharmacological effects and is used for the treatment of some inflammatory diseases. In this study, RAW264.7 cells and THP-1 differentiated macrophages were pretreated with various concentrations of OMT at 2 h prior to treatment with lipopolysaccharide (LPS) (1.0 μg/mL) for different durations. We detected the anti-inflammatory effect of OMT in LPS-stimulated macrophages and investigated the molecular mechanism. We showed that OMT pretreatment significantly inhibited the LPS-induced secretion of nitric oxide (NO), interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) in supernatant, attenuated the mRNA levels of inducible nitric oxide synthase (iNOS), IL-1β, TNF-α, and Toll-like receptor 4 (TLR4), increased TLR4 and phosphorylation of inhibitor of kappa B-alpha (p-IBα) in cytosol, and decreased the nuclear level of nuclear factor-κB (NF-κB) p65 in macrophages. In conclusion, OMT exerts anti-inflammatory properties in LPS-stimulated macrophages by down-regulating the TLR4/NF-κB pathway.

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