scholarly journals Staphylococcus aureus α-Toxin Induces Inflammatory Cytokines via Lysosomal Acid Sphingomyelinase and Ceramides

2017 ◽  
Vol 43 (6) ◽  
pp. 2170-2184 ◽  
Author(s):  
Jie Ma ◽  
Erich Gulbins ◽  
Michael J. Edwards ◽  
Charles C. Caldwell ◽  
Martin Fraunholz ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Confocal Microscopy ◽  
Inflammatory Cytokines ◽  
Cathepsin B ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Clinical Problem ◽  
Acid Sphingomyelinase ◽  
Tnf Α ◽  
Factor Α

Background/Aims: Staphylococcus aureus (S. aureus) infections are a major clinical problem and range from mild skin and soft-tissue infections to severe and even lethal infections such as pneumonia, endocarditis, sepsis, osteomyelitis, and toxic shock syndrome. Toxins that are released from S. aureus mediate many of these effects. Here, we aimed to identify molecular mechanisms how α-toxin, a major S. aureus toxin, induces inflammation. Methods: Macrophages were isolated from the bone marrow of wildtype and acid sphingomyelinase-deficient mice, stimulated with S. aureus α-toxin and activation of the acid sphingomyelinase was quantified. The subcellular formation of ceramides was determined by confocal microscopy. Release of cathepsins from lysosomes, activation of inflammasome proteins and formation of Interleukin-1β (IL-1β) and Tumor Necrosis Factor-α (TNF-α) were analyzed by western blotting, confocal microscopy and ELISA. Results: We demonstrate that S. aureus α-toxin activates the acid sphingomyelinase in ex vivo macrophages and triggers a release of ceramides. Ceramides induced by S. aureus α-toxin localize to lysosomes and mediate a release of cathepsin B and D from lysosomes into the cytoplasm. Cytosolic cathepsin B forms a complex with Nlrc4. Treatment of macrophages with α-toxin induces the formation of IL-1β and TNF-α. These events are reduced or abrogated, respectively, in cells lacking the acid sphingomyelinase and upon treatment of macrophages with amitriptyline, a functional inhibitor of acid sphingomyelinase. Pharmacological inhibition of cathepsin B prevented activation of the inflammasome measured as release of IL-1β, while the formation of TNF-α was independent of cathepsin B. Conclusion: We demonstrate a novel mechanism how bacterial toxins activate the inflammasome and mediate the formation and release of cytokines: S. aureus α-toxin triggers an activation of the acid sphingomyelinase and a release of ceramides resulting in the release of lysosomal cathepsin B and formation of pro-inflammatory cytokines.

scholarly journals Expression and extracellular release of Trx80, the truncated form of thioredoxin, by TNF-α- and IL-1β-stimulated human synoviocytes from patients with rheumatoid arthritis

2007 ◽  
Vol 113 (3) ◽  
pp. 149-155 ◽  
Author(s):  
Hervé Lemarechal ◽  
Phillippe Anract ◽  
Jean-Louis Beaudeux ◽  
Dominique Bonnefont-Rousselot ◽  
Ohvanesse G. Ekindjian ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Inflammatory Cytokines ◽  
Protein Interactions ◽  
Ex Vivo ◽  
Truncated Form ◽  
Experimental Conditions ◽  
Extracellular Release ◽  
Tnf Α ◽  
Factor Α ◽  
Pro Inflammatory Cytokines

Thioredoxin (Trx) plays several important roles, through changes to sulfhydryl reactions and protein interactions, in controlling cellular signalling processes in RA (rheumatoid arthritis). Trx80, the 10 kDa C-terminal truncated form of Trx, is a potent mitogenic cytokine and is involved in the Th1 response. In the present study, we have investigated the ability of synoviocytes from five RA patients to induce Trx80 after ex vivo stimulation by the pro-inflammatory cytokines IL-1β (interleukin-1β) and TNF-α (tumour necrosis factor-α) or by H2O2. Synoviocytes from five OA (osteoarthritis) patients were used as controls. Immunoprecipitation assays using two different antibodies showed that RA, but not OA, cells expressed intact Trx80 protein in culture even when not stimulated. Treatment with pro-inflammatory cytokines alone or in combination enhanced this basal production and induced the extracellular release of Trx80 by all of the RA cells tested. Under our experimental conditions, the rate of Trx80 release from RA cells was approx. 30% of the total Trx produced. In contrast, Trx80 was not detected in response to H2O2 in RA or OA synoviocyte lysates and their respective culture supernatants, indicating that the oxidative process induced by H2O2 in synoviocytes was unable to modify Trx80 release. Moreover, Trx80 induced synoviocyte proliferation as evaluated by [3H]thymidine incorporation. These results highlight the effect of the inflammatory process on the release of both Trx and Trx80 from RA synoviocytes, and suggest that the cytokine-induced increase in Trx80 cell release may constitute a link between inflammation and the immune system in RA.

Molecular Mechanisms of Curcumin in Neuroinflammatory Disorders: A Mini Review of Current Evidences

2019 ◽  
Vol 19 (3) ◽  
pp. 247-258 ◽  
Author(s):  
Mahsa Hatami ◽  
Mina Abdolahi ◽  
Neda Soveyd ◽  
Mahmoud Djalali ◽  
Mansoureh Togha ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
English Language ◽  
Molecular Mechanisms ◽  
Randomized Clinical Trials ◽  
Mitochondrial Dynamics ◽  
Nuclear Factor Κb ◽  
General Term ◽  
Neuroinflammatory Disease ◽  
Tnf Α ◽  
Factor Α

Objective: Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer’s, Parkinson’s, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders. Methods: A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review. Results: The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes. Conclusion: It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.

Tumor necrosis factor-α-associated lysosomal permeabilization is cathepsin B dependent

2002 ◽  
Vol 283 (4) ◽  
pp. G947-G956 ◽  
Author(s):  
Nathan W. Werneburg ◽  
M. Eugenia Guicciardi ◽  
Steven F. Bronk ◽  
Gregory J. Gores
Keyword(s):  
Tumor Necrosis Factor ◽  
Cathepsin B ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Fluorescent Protein ◽  
Tnf Α ◽  
Calcein Release ◽  
Green Fluorescent ◽  
Factor Α ◽  
Necrosis Factor

Cathepsin B (Cat B) is released from lysososomes during tumor necrosis factor-α (TNF-α) cytotoxic signaling in hepatocytes and contributes to cell death. Sphingosine has recently been implicated in lysosomal permeabilization and is increased in the liver by TNF-α. Thus the aims of this study were to examine the mechanisms involved in TNF-α-associated lysosomal permeabilization, especially the role of sphingosine. Confocal microscopy demonstrated Cat B-green fluorescent protein and LysoTracker Red were both released from lysosomes after treatment of McNtcp.24 cells with TNF-α/actinomycin D, a finding compatible with lysosomal destabilization. In contrast, endosomes labeled with Texas Red dextran remained intact, suggesting lysosomes were specifically targeted for permeabilization. LysoTracker Red was released from lysosomes in hepatocytes treated with TNF-α or sphingosine in Cat B(+/+) but not Cat B(−/−) hepatocytes, as assessed by a fluorescence-based assay. With the use of a calcein release assay in isolated lysosomes, sphingosine permeabilized liver lysosomes isolated from Cat B(+/+) but not Cat B(−/−) liver. C6ceramide did not permeabilize lysosomes. In conclusion, these data implicate a sphingosine-Cat B interaction inducing lysosomal destabilization during TNF-α cytotoxic signaling.

Epinephrine inhibits endotoxin-induced IL-1β production: roles of tumor necrosis factor-α and IL-10

1997 ◽  
Vol 273 (6) ◽  
pp. R1885-R1890 ◽  
Author(s):  
Tom Van Der Poll ◽  
Stephen F. Lowry
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Ex Vivo ◽  
Systemic Infection ◽  
Tnf Α ◽  
Cytokine Tumor Necrosis Factor ◽  
Dose Dependent Decrease ◽  
Factor Α ◽  
Necrosis Factor

Epinephrine has been found to inhibit the production of the proinflammatory cytokine tumor necrosis factor (TNF)-α and to enhance the production of anti-inflammatory cytokine interleukin (IL)-10. To determine the effect of epinephrine on IL-1β production, the following experiments were performed: 1) blood obtained from subjects at 4–21 h after the start of a continuous infusion of epinephrine (30 ng ⋅ kg−1⋅ min−1) produced less IL-1β after ex vivo stimulation with lipopolysaccharide (LPS), compared with blood drawn from subjects infused with saline; 2) in whole blood in vitro, epinephrine caused a dose-dependent decrease in LPS-induced IL-1β production, which was likely mediated via adrenergic receptors; and 3) inhibition of TNF and enhancement of IL-10 both contributed to epinephrine-induced inhibition of IL-1β production. Epinephrine, either endogenously produced or administered as a component of sepsis treatment, may attenuate excessive activity of proinflammatory cytokines early in the course of systemic infection.

scholarly journals Chlorogenic Acid and Geniposide Combination Prevents NASH in Rats Fed High-fat diet via Microbiota and TLR4-LPS Pathway

2021 ◽  
Author(s):  
Zhijia Zhou ◽  
Lingxia Xu ◽  
Shaoliang Zhang ◽  
Shilin Xu ◽  
Yanmiao Yang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Chlorogenic Acid ◽  
Inflammatory Cytokines ◽  
High Fat Diet ◽  
Oral Treatment ◽  
Variable Region ◽  
High Fat ◽  
Tnf Α ◽  
Abundance And Diversity ◽  
Factor Α

Abstract Objective: Chlorogenic acid and geniposide (CG) are derived from traditional Chinese medicine, Yinchenhao Recipe (QCHR), and can improve the clinical efficacy of NASH patients. This study investigated the effects of CG on NASH and expounded its Potential mechanism of action through the LPS-TLR4 pathway and microbiota. Methods: Rats were randomized into Control (C), Model (M), Chlorogenic Acid and Geniposide (CG), Pioglitazone (PH) and Bifico (B) groups. After an 8-week high-fat diet (HFD), CG, PH and B oral treatment were initiated and carried out for a further 8 weeks. The stool samples were used in a16S rDNA V4 highly variable region measurement method in order to regulate the role of CG in gut microbiota. The concentrations of triglyceride (TG), cholesterol (CHO), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) in LPS were detected by the corresponding methods. Results: Observations were made that CG significantly improved the pathology of the liver and terminal ileum tissue. The accumulation of TG and the content of inflammatory cytokines in the liver were significantly decreased and the abundance of Proteobacteria was significantly down-regulated. The expression of TLR4, AP-1, MyD88, and phosphorylated NF-κB p65 were significantly decreased. All the findings above indicated that CG was highly effective in improving the composition of gut microbiota, decreasing the production of endogenous LPS, and reducing the secretion of inflammatory cytokines through the gut-liver axis.Conclusion: CG can regulate the abundance and diversity of the intestinal microbial community and improve liver inflammation and steatosis in NASH rats by reducing LPS-TLR4-mediated inflammation.

scholarly journals Effect of the proinflammatory cytokine TNF-α on intestinal riboflavin uptake: inhibition mediated via transcriptional mechanism(s)

2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Significant Inhibition ◽  
Mrna Levels ◽  
In Vivo Models ◽  
Uptake Inhibition ◽  
Tnf Α ◽  
Vitro Model ◽  
Factor Α

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.

Acute Immunomodulatory Effects of Fentanyl and its Three New Analogues in Swiss Albino Mice

2017 ◽  
Vol 3 (1) ◽  
pp. 24 ◽  
Author(s):  
Shiv Kumar Yadav ◽  
Rahul Bhattacharya
Keyword(s):  
Pain Management ◽  
Opioid Receptor ◽  
Inflammatory Cytokines ◽  
Opioid Analgesic ◽  
Interleukin 10 ◽  
Acute Effect ◽  
Post Exposure ◽  
Tnf Α ◽  
Pre Treatment ◽  
Factor Α

Fentanyl is a potent synthetic opioid analgesic. However, due to its several limitations, new analogues are being synthesised for better pain management. We have earlier reported the synthesis and bio-efficacy of fentanyl and its eight new analogues (1-8) in mice. Among eight analogues tested, N-(1-(2-phenoxyethyl)-4-piperidinyl)propionanilide (2), N-isopropyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (5), and N-t-butyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (6) were found to be more effective and less toxic compared to fentanyl. Therapeutic efficacy of fentanyl and its analogues are known to be compromised due to many adverse effects, including alterations in the immune system. Therefore, the present study was undertaken to assess the acute effect of fentanyl and its three analogues (2, 5, and 6) on plasma levels of different pro-inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and anti-inflammatory cytokines such as interleukin-10 (IL-10) at different time points. Mice were intraperitoneally treated with 0.50 LD50 of the compounds and cytokines were measured 1 h, 2 h, 4 h, and 24 h post-exposure. Compared to control, none of the treatments produced any change in TNF-α and IL-1β levels. However, IL-6 levels were significantly elevated between 1 h to 2 h post-exposure in fentanyl and analogue 2 treated groups. Further, IL-10 levels were found to be significantly increased in fentanyl, analogue 2, and 6 treated groups at 1 h and 2 h post-exposure. Pre-treatment of naltrexone (opioid receptor antagonist) blocked the effects of fentanyl, confirming that its effects were opioid receptor- dependent. However, effect of naltrexone on analogue 2 and 6 was not conclusively evidenced, indicating that immunomodulatory changes caused by the analogues could have some additional implications as well. The present study reveals undesirable effects of fentanyl and its new analogues on cytokines homeostasis, thereby limiting their use in pain management.

scholarly journals Immunomodulatory Responses Of Toll Like Receptors Against 2019nCoV

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Amany Sayed Maghraby
Keyword(s):  
Inflammatory Cytokines ◽  
English Language ◽  
Toll Like Receptors ◽  
Complex Molecules ◽  
Ribonucleic Acids ◽  
Histocompatibility Complex ◽  
Tnf Α ◽  
Factor Α ◽  
Molecular Signals ◽  
Pro Inflammatory Cytokines

The present review discusses the immune signals via toll like receptors (TLRs) against 2019nCoV. We researched using different database, up to June 18th, 2020. All the included articles were published in English language. The outcome of this review, that some TLRs agonists or antagonists are progressed as drugs to combat and down regulating TLRs immune signals respectively. TLRs 3 and 4 recognized 2019nCoV spike protein through immune and molecular signals that leading to immune stimulation of pro-inflammatory cytokines and even the immune fever. While the TLRs7 and 8 recognized single-stranded ribonucleic acids (ssRNAs) leading to elevation of the tumour necrosis factor α (TNF-α), interleukin (IL)-6 and -12 levels. TLRs agonists or antagonists utilized as immunotherapeutic targets against 2019nCoV via TLRs signals. Chloroquine and hydroxychloroquine; the approval compounds for 2019nCoV therapy can be inhibiting the class II major histocompatibility complex molecules expression and antigen presentation and even immune suppressions of the pro-inflammatory cytokines profile.

Abstract 14810: Sam68 Promotes Nf-kb Signaling and Inflammation and Impedes the Recovery of Arterial Injury

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shuling Han ◽  
Junlan Zhou ◽  
Gangjian Qin
Keyword(s):  
Inflammatory Cytokines ◽  
Molecular Mechanisms ◽  
Mononuclear Cells ◽  
Vascular Inflammation ◽  
Critical Role ◽  
Inflammatory Cells ◽  
Peritoneal Macrophages ◽  
Post Injury ◽  
Raw264.7 Macrophages ◽  
Tnf Α

Background: The role of Src-associated in mitosis 68 kDa (Sam68) protein in cardiovascular biology has not been studied. A recent report suggests that Sam68 suppresses TNF-α-mediated NF-kB activation. Since NF-kB plays a critical role in vascular inflammation and injury via generation of inflammatory cytokines and recruitment of inflammatory cells, we sought to dissect the molecular mechanism by which Sam68 regulates NF-kB signaling and its functional significance during vascular injury. Methods & Results: The endothelial denudation injury was induced in the carotid arteries of Sam68-null (Sam68 -/- ) and WT mice. Sam68 -/- mice displayed an accelerated re-endothelialization ( P <0.05 at day 5 post-injury) and attenuated neointima formation (by 2.2 folds, P <0.05, at day 14), which was associated with a reduced number of macrophages and lowered expression of pro-inflammatory cytokines (i.e., TNF-alpha, MCP-1 and IL-6) in the injured vessels. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, MCP-1, and IL-6 and in the level of nuclear phospho-p65, which indicates attenuated NF-kB activation. These results were confirmed in peritoneal macrophages and macrophages differentiated from bone-marrow mononuclear cells of Sam68 -/- and WT mice. To identify molecular mechanisms, Raw264.7 cells were treated with TNF-α and Vehicle, followed by Sam68 co-immunoprecipitation and mass-spectrometric identification of the Sam68-interacting proteins. We found that TNF-α treatment results in altered interactions of Sam68 with 22 cytosolic, cytoskeletal, and nuclear proteins. Further experiments are under way to validate their involvement in the NF-kB signaling. Conclusions: Our results for the first time suggest that Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery, and this effect may be partially attributable to the exaggerated NF-kB activity.

Abstract 124: Sam68 Impedes the Recovery of Arterial Injury by Augmenting Inflammatory Response

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Shuling Han ◽  
Junlan Zhou ◽  
Baron T Arnone ◽  
Dauren Biyashev ◽  
Chan Boriboun ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Cytokines ◽  
Molecular Mechanisms ◽  
Mononuclear Cells ◽  
Vascular Inflammation ◽  
Critical Role ◽  
Inflammatory Cells ◽  
Peritoneal Macrophages ◽  
Raw264.7 Macrophages ◽  
Tnf Α

Background: The role of Src-associated in mitosis 68 kDa (Sam68) in cardiovascular biology has not been studied. A recent report suggests that Sam68 suppresses TNF-α-induced NF-κB activation. Since NF-κB plays a critical role in vascular inflammation and injury via generation of inflammatory cytokines and recruitment of inflammatory cells, we sought to dissect the mechanism by which Sam68 regulates NF-κB signaling and its functional significance during vascular injury. Methods & Results: The endothelial denudation injury was induced in the carotid arteries of Sam68-/- and WT mice. Sam68-/- mice displayed an accelerated re-endothelialization and attenuated neointima hyperplasia, which was associated with a reduced number of macrophages and lowered expression of pro-inflammatory cytokines (i.e., TNF-α, IL-1β and IL-6) in the injured vessels. Importantly, the ameliorated vascular remodeling was recapitulated in WT mice after transplantation of bone marrow (BM) from Sam68-/- mice, suggesting beneficial role was attributed largely to BM-derived inflammatory cells. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, IL-1β, and IL-6 and in the level of nuclear phospho-p65, indicating an attenuated NF-κB activation. These results were confirmed in peritoneal macrophages and macrophages differentiated from BM mononuclear cells of Sam68-/- and WT mice. To identify molecular mechanisms, Raw264.7 cells were treated with TNF-α and Vehicle, followed by Sam68 co-immunoprecipitation and mass-spec identification of Sam68-interacting proteins. Specifically, TNF-α treatment results in altered interactions of Sam68 with Filamin A (FLNA), a cytoskeleton protein known to be involved in NF-κB activation. Loss- and gain-of-function of Sam68 and FLNA suggest their mutual dependence in NF-κB activation and pro-inflammatory cytokine expression, and Sam68 is required for TRAF2-FLNA interaction. Conclusions: Our results for the first time suggest that Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery, and this effect is attributed, in part, to the exaggerated NF-κB activity via Sam68-FLNA interaction and consequent TRAF2 stabilization.

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