Cytokines induce NF-κB in activated but not in quiescent rat hepatic stellate cells

1998 ◽  
Vol 275 (2) ◽  
pp. G269-G278 ◽  
Author(s):  
C. Hellerbrand ◽  
C. Jobin ◽  
L. L. Licato ◽  
R. B. Sartor ◽  
D. A. Brenner

The hepatic stellate cell (HSC), after a fibrogenic stimulus, is transformed from a quiescent to an activated phenotype, including the induction of responsiveness to a variety of agonists. We investigated the activation of nuclear factor-κB (NF-κB) and the expression of the NF-κB-responsive genes intercellular adhesion molecule 1 (ICAM-1) and macrophage inflammatory protein-2 (MIP-2) in freshly isolated and culture-activated HSC by tumor necrosis factor-α (TNF-α) or interleukin-1β. Inhibitor-κB was rapidly (<15 min) degraded, and NF-κB activity was induced in culture-activated but not in freshly isolated HSC after cytokine stimulation. After 30 min of stimulation, immunofluorescence revealed that the NF-κB p65 subunit was predominantly found in the nuclei of activated HSC compared with the cytoplasmic localization in unstimulated cells. No nuclear translocation appeared in freshly isolated HSC after stimulation, despite the presence of functional TNF-α receptors. NF-κB nuclear translocation appeared first partially after 4–5 days and completely after 9 days in culture. Consistent with this time course TNF-α induced the mRNA of the NF-κB-dependent genes ICAM-1 and MIP-2 in activated but not in quiescent HSC. Therefore, cytokines induce NF-κB activity and ICAM-1 and MIP-2 mRNAs in activated but not in quiescent HSC, through a postreceptor mechanism of regulation.

2020 ◽  
Vol 48 (9) ◽  
pp. 030006052094513
Author(s):  
Yefei Zhang ◽  
Huahua Liu ◽  
Weiliang Tang ◽  
Qiongya Qiu ◽  
Jiahao Peng

Objective To assess the effects of resveratrol (RSV) on expression of adhesion molecules in endothelial progenitor cells (EPCs) following tumor necrosis factor-α (TNF-α) stimulation. Methods EPCs were treated with RSV and stimulated with TNF-α. A mononuclear cell (MNC) adhesion assay was used to assess the effects of RSV on TNF-α-induced MNC adhesion. Vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin expression levels and nuclear factor κB (NF-κB) activation were assessed by immunoblotting. Results MNC adhesion to TNF-α-treated EPCs and VCAM-1/ICAM-1/E-selectin levels in EPCs were increased following TNF-α stimulation and decreased following RSV treatment. TNF-α enhanced NF-κB inhibitor α (IκB-α) phosphorylation in the cytosol as well as nuclear NF-κB p65 levels, both of which were decreased by RSV. Conclusions These findings provide new insights into RSV’s anti-inflammatory and anti-atherosclerotic effects. RSV’s mechanism of action might involve downregulation of VCAM-1, ICAM-1 and E-selectin by partial blockade of TNF-α-induced NF-κB activation and IκB-α phosphorylation in EPCs.


2001 ◽  
Vol 281 (6) ◽  
pp. H2549-H2558 ◽  
Author(s):  
Tareck O. Nossuli ◽  
Nikolaos G. Frangogiannis ◽  
Pascal Knuefermann ◽  
Venkatesh Lakshminarayanan ◽  
Oliver Dewald ◽  
...  

Early chemokine induction in the area at risk of an ischemic-reperfused (I/R) myocardium is first seen in the venular endothelium. Reperfusion is associated with several induction mechanisms including increased extracellular tumor necrosis factor (TNF)-α, reactive oxygen intermediate (ROI) species formation, and adhesion of leukocytes to the venular endothelium. To test the hypothesis that chemokine induction in cardiac venules can occur by ROIs in a TNF-α-independent manner, and in the absence of leukocyte accumulation, we utilized wild-type (WT) and TNF-α double-receptor knockout mice (DKO) in a closed-chest mouse model of myocardial ischemia (15 min) and reperfusion (3 h), in which there is no infarction. We demonstrate that a single brief period of I/R induces significant upregulation of the chemokines macrophage inflammatory protein (MIP) -1α, -1β, and -2 at both the mRNA and protein levels. This induction was independent of TNF-α, whereas levels of these chemokines were increased in both WT and DKO mice. Chemokine induction was seen predominantly in the endothelium of small veins and was accompanied by nuclear translocation of nuclear factor-κB and c-Jun (AP-1) in venular endothelium. Intravenous infusion of the oxygen radical scavenger N-2-mercaptopropionyl glycine (MPG) initiated 15 min before ischemia and maintained throughout reperfusion obviated chemokine induction, but MPG administration after reperfusion had begun had no effect. The results suggest that ROI generation in the reperfused myocardium rapidly induces C-C and C-X-C chemokines in the venular endothelium in the absence of infarction or irreversible cellular injury.


2021 ◽  
Vol 17 ◽  
Author(s):  
Lili Legiawati

: Diabetes mellitus is a metabolic disorder caused by an increase in insulin resistance, a decrease in insulin production, or both of them, resulting in a high level of blood glucose or hyperglycemia. An uncontrolled state of DM may cause complications, namely skin disorder. One or more skin disorders are found amongst 74% of T2DM patients, with the highest percentage is dry skin (47%), followed by infection (10%), diabetic hand (5%), hair loss and diabetic dermopathy (each 4%). In DM, the state of hyperglycemia and production of advanced glycaemic end-products (AGEs) profoundly impact skin changes. In the pathological pathway, AGEs induce oxidative stress and inflammation. Nonetheless, AGEs level is higher in T2DM patients compared to non-T2DM people. This is caused by hyperglycemia and oxidative stress. Binding between AGEs and receptor of AGEs (RAGE) promotes pathway of oxidative stress and inflammation cascade via mitogen-activated protein kinases (MAPK), nuclear factor-k-light-chain-enhancer of activated β cells (NF-kβ), interleukin- 6 (IL-6), tumor necrosis factor-α (TNF-α), expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 2 (VCAM-2) pathway which furtherly effectuates DM complication including skin disorders.


2000 ◽  
Vol 14 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Markus Bitzer ◽  
Gero von Gersdorff ◽  
Dan Liang ◽  
Alfredo Dominguez-Rosales ◽  
Amer A. Beg ◽  
...  

A number of pathogenic and proinflammatory stimuli, and the transforming growth factor-β (TGF-β) exert opposing activities in cellular and immune responses. Here we show that the RelA subunit of nuclear factor κB (NF-κB/RelA) is necessary for the inhibition of TGF-β-induced phosphorylation, nuclear translocation, and DNA binding of SMAD signaling complexes by tumor necrosis factor-α (TNF-α). The antagonism is mediated through up-regulation of Smad7 synthesis and induction of stable associations between ligand-activated TGF-β receptors and inhibitory Smad7. Down-regulation of endogenous Smad7 by expression of antisense mRNA releases TGF-β/SMAD-induced transcriptional responses from suppression by cytokine-activated NF-κB/RelA. Following stimulation with bacterial lipopolysaccharide (LPS), or the proinflammatory cytokines TNF-α and interleukin-1β (IL-1β, NF-κB/RelA induces Smad7 synthesis through activation of Smad7 gene transcription. These results suggest a mechanism of suppression of TGF-β/SMAD signaling by opposing stimuli mediated through the activation of inhibitory Smad7 by NF-κB/RelA.


2000 ◽  
Vol 279 (6) ◽  
pp. L1137-L1145 ◽  
Author(s):  
Edward Abraham ◽  
Aaron Carmody ◽  
Robert Shenkar ◽  
John Arcaroli

Acute lung injury is characterized by accumulation of neutrophils in the lungs, accompanied by the development of interstitial edema and an intense inflammatory response. To assess the role of neutrophils as early immune effectors in hemorrhage- or endotoxemia-induced lung injury, mice were made neutropenic with cyclophosphamide or anti-neutrophil antibodies. Endotoxemia- or hemorrhage-induced lung edema was significantly reduced in neutropenic animals. Activation of the transcriptional regulatory factor nuclear factor-κB after hemorrhage or endotoxemia was diminished in the lungs of neutropenic mice compared with nonneutropenic controls. Hemorrhage or endotoxemia was followed by increases in pulmonary mRNA and protein levels for interleukin-1β (IL-1β), macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-α (TNF-α). Endotoxin-induced increases in proinflammatory cytokine expression were greater than those found after hemorrhage. The amounts of mRNA or protein for IL-1β, MIP-2, and TNF-α were significantly lower after hemorrhage in the lungs of neutropenic versus nonneutropenic mice. Neutropenia was associated with significant reductions in IL-1β and MIP-2 but not in TNF-α expression in the lungs after endotoxemia. These experiments show that neutrophils play a centrol role in initiating acute inflammatory responses and causing injury in the lungs after hemorrhage or endotoxemia.


1999 ◽  
Vol 277 (3) ◽  
pp. C403-C411 ◽  
Author(s):  
Hirotsugu Kobuchi ◽  
Sashwati Roy ◽  
Chandan K. Sen ◽  
Hao G. Nguyen ◽  
Lester Packer

The cell adhesion molecule intercellular adhesion molecule-1 (ICAM-1) plays a pivotal role in inflammatory responses. Quercetin (3,3′,4′,5,7-pentahydroxyflavone), a naturally occurring dietary flavonol, has potent anti-inflammatory properties. The effect of quercetin on ICAM-1 expression induced by agonists phorbol 12-myristate 13-acetate (PMA) and tumor necrosis factor-α (TNF-α) in human endothelial cell line ECV304 (ECV) was investigated. Quercetin treatment downregulated both PMA- and TNF-α-induced surface expression, as well as the ICAM-1 mRNA levels, in ECV cells in a dose-dependent (10–50 μM) manner. Quercetin had no effect on PMA- or TNF-α-induced nuclear factor-κB (NF-κB) activation. However, under similar conditions a remarkable dose-dependent downregulation of activator protein-1 (AP-1) activation was observed. This decrease in AP-1 activation was observed to be associated with the inhibitory effects of quercetin on the c-Jun NH2-terminal kinase (JNK) pathway. These results suggest that quercetin downregulates both PMA- and TNF-α-induced ICAM-1 expression via inhibiting both AP-1 activation and the JNK pathway.


2008 ◽  
Vol 294 (4) ◽  
pp. C985-C993 ◽  
Author(s):  
Emmanuel Lorne ◽  
Jaroslaw W. Zmijewski ◽  
Xia Zhao ◽  
Gang Liu ◽  
Yuko Tsuruta ◽  
...  

Reactive oxygen species (ROS) contribute to neutrophil activation and the development of acute inflammatory processes in which neutrophils play a central role. However, there is only limited information concerning the mechanisms through which extracellular ROS, and particularly cell membrane-impermeable species, such as superoxide, enhance the proinflammatory properties of neutrophils. To address this issue, neutrophils were exposed to superoxide generating combinations of xanthine oxidase and hypoxanthine or lumazine. Extracellular superoxide generation induced nuclear translocation of nuclear factor-κB (NF-κB) and increased neutrophil production of the NF-κB-dependent cytokines tumor necrosis factor-α (TNF-α) and macrophage inhibitory protein-2 (MIP-2). In contrast, there were no changes in TNF-α or MIP-2 expression when neutrophils lacking Toll-like receptor-4 (TLR4) were exposed to extracellular superoxide. Immunoprecipitation, confocal microscopy, and fluorescence resonance energy transfer (FRET) studies demonstrated association between TLR4 and xanthine oxidase. Exposure of neutrophils to heparin attenuated binding of xanthine oxidase to the cell surface as well as interactions with TLR4. Heparin also decreased xanthine oxidase-induced nuclear translocation of NF-κB as well as production of proinflammatory cytokines. These results demonstrate that extracellular superoxide has proinflammatory effects on neutrophils, predominantly acting through an TLR4-dependent mechanism that enhances nuclear translocation of NF-κB and increases expression of NF-κB-dependent cytokines.


2007 ◽  
Vol 81 (23) ◽  
pp. 13092-13104 ◽  
Author(s):  
Nadia El Mjiyad ◽  
Sébastien Bontems ◽  
Geoffrey Gloire ◽  
Julie Horion ◽  
Patricia Vandevenne ◽  
...  

ABSTRACT Intercellular adhesion molecule 1 (ICAM-1) expression is down-regulated in the center of cutaneous varicella lesions despite the expression of proinflammatory cytokines such as gamma interferon and tumor necrosis factor alpha (TNF-α). To study the molecular basis of this down-regulation, the ICAM-1 induction of TNF-α was analyzed in varicella-zoster virus (VZV)-infected melanoma cells (MeWo), leading to the following observations: (i) VZV inhibits the stimulation of icam-1 mRNA synthesis; (ii) despite VZV-induced nuclear translocation of p65, p52, and c-Rel, p50 does not translocate in response to TNF-α; (iii) the nuclear p65 present in VZV-infected cells is no longer associated with p50 and is unable to bind the proximal NF-κB site of the icam-1 promoter, despite an increased acetylation and accessibility of the promoter in response to TNF-α; and (iv) VZV induces the nuclear accumulation of the NF-κB inhibitor p100. VZV also inhibits icam-1 stimulation of TNF-α by strongly reducing NF-κB nuclear translocation in MRC5 fibroblasts. Taken together, these data show that VZV interferes with several aspects of the immune response by inhibiting NF-κB binding and the expression of target genes. Targeting NF-κB activation, which plays a central role in innate and adaptive immune responses, leads to obvious advantages for the virus, particularly in melanocytes, which are a site of viral replication in the skin.


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