Activated protein C inhibits lipopolysaccharide-induced nuclear translocation of nuclear factor κB (NF-κB) and tumour necrosis factor α (TNF-α) production in the THP-1 monocytic cell line

2000 ◽  
Vol 110 (1) ◽  
pp. 130-134 ◽  
Author(s):  
B. White ◽  
M. Schmidt ◽  
C. Murphy ◽  
W. Livingstone ◽  
D. O'Toole ◽  
...  
2002 ◽  
Vol 88 (08) ◽  
pp. 267-273 ◽  
Author(s):  
Mehtap Yuksel ◽  
Mitsuhiro Uchiba ◽  
Seikoh Horiuchi ◽  
Hiroaki Okabe ◽  
Kenji Okajima

SummaryActivated protein C (APC), an important natural anticoagulant, inhibits tumor necrosis factor-α (TNF-α) production and attenuates various deleterious events induced by lipopolysaccharide (LPS), contributing thereby to a significant reduction of mortality in patients with severe sepsis. In this study, we investigated the mechanism(s) by which APC inhibits TNF-α production by LPS-stimulated human monocytes in vitro. Although APC inhibited LPS-induced TNF-α production in a concentration-dependent fashion, diisopropyl fluorophosphate-treated APC, an active-site-blocked APC, had no effect. APC inhibited both the binding of nuclear factor-κB (NF-κB) to target sites and the degradation of IκBα. APC also inhibited both the binding of activator protein-1 (AP-1) to target sites and the activation of mitogen-activated protein kinase pathways. These observations strongly suggest that APC inhibited LPS-induced TNF-α production by inhibiting the activation of both NF-κB and AP-1 and that the inhibitory activity of APC might depend on its serine protease activity. These results would at least partly explain the mechanism(s) by which APC reduces the tissue injury seen in animal models of sepsis and in patients with sepsis.


Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4123-4129 ◽  
Author(s):  
Hirotaka Kuwata ◽  
Yasuyuki Watanabe ◽  
Hiroyuki Miyoshi ◽  
Masahiro Yamamoto ◽  
Tsuneyasu Kaisho ◽  
...  

Abstract Interleukin-10 (IL-10) plays an important role in prevention of chronic inflammation in vivo. However, the molecular mechanism by which IL-10 exerts its anti-inflammatory response is poorly understood. Here, we performed a microarray analysis and identified Bcl-3 as an IL-10-inducible gene in macrophages. Lentiviral vector-mediated expression of Bcl-3 inhibited lipopolysaccharide (LPS)-induced production of tumor necrosis factor α (TNF-α), but not IL-6, in macrophages. In Bcl-3-transduced and IL-10-pretreated macrophages, LPS-induced nuclear translocation of nuclear factor κB (NF-κB) p65 was not impaired. However, DNA binding by NF-κB p50/p65 was profoundly inhibited. Nuclear localization of Bcl-3 was associated with inhibition of LPS-induced TNF-α production. Overexpression of Bcl-3 suppressed activation of the TNF-α promoter, but not the IL-6 promoter. Bcl-3 interacted with NF-κB p50 and was recruited to the TNF-α promoter, but not the IL-6 promoter, indicating that Bcl-3 facilitates p50-mediated inhibition of TNF-α expression. Furthermore, Bcl-3-deficient macrophages showed defective IL-10-mediated suppression of LPS induction of TNF-α, but not IL-6. These findings suggest that IL-10-induced Bcl-3 is required for suppression of TNF-α production in macrophages. (Blood. 2003; 102:4123-4129)


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.


1999 ◽  
Vol 67 (11) ◽  
pp. 5573-5578 ◽  
Author(s):  
Shogo Takashiba ◽  
Thomas E. Van Dyke ◽  
Salomon Amar ◽  
Yoji Murayama ◽  
Aubrey W. Soskolne ◽  
...  

ABSTRACT During infection, circulating blood monocytes migrate from the vasculature to the extravascular compartments where they mature into tissue macrophages. The maturation process prepares the cell to actively participate in the inflammatory and the immune responses, and many transcription factors have been found to be involved. Here we report on a novel role for nuclear factor κB (NF-κB) in this process. Its accumulation in the cytoplasm of differentiated macrophages is responsible for the enhanced ability of the cell to respond to lipopolysaccharide (LPS) stimulation, as determined by tumor necrosis factor alpha (TNF-α) secretion. Differentiation of the human monocytic cell line THP-1 into macrophage-like cells was induced by exposure of the cells to phorbol myristate acetate. DNA-bindable NF-κB was not detected in the cytoplasm of undifferentiated THP-1 cells but accumulated in the cytoplasm of the cells following differentiation. No TNF-α was detected in the media of resting differentiated and nondifferentiated THP-1 cells. Stimulation with LPS of differentiated cells induced the production of higher levels of TNF-α than stimulation of nondifferentiated cells. This hyperresponsiveness to LPS was found in the mRNA and secreted TNF-α levels. Furthermore, stimulation with LPS induced the translocation of NF-κB from the cytoplasm into the nucleus. This translocation process was more rapid in the differentiated cells than in the nondifferentiated cells, and the resultant accumulated levels of NF-κB in the nucleus were higher. The DNA-bindable NF-κB was identified as a heterodimer of p65 and p50. The results suggest that NF-κB accumulation in the cytoplasm during maturation of monocytes to macrophages primes the cells for enhanced responsiveness to LPS and results in the rapid secretion of inflammatory mediators, such as TNF-α, by mature macrophages following LPS challenge.


2001 ◽  
Vol 354 (3) ◽  
pp. 573-579 ◽  
Author(s):  
Toyone KIKUMORI ◽  
Fukushi KAMBE ◽  
Takashi NAGAYA ◽  
Hiroomi FUNAHASHI ◽  
Hisao SEO

We have recently demonstrated that nuclear factor κB (NF-κB) mediates the tumour necrosis factor α (TNF-α)-dependent expression of the gene encoding interleukin 6 (IL-6) in rat thyroid FRTL-5 cells cultured in the presence of thyrotropin (TSH). In the present study we investigated how TSH is involved in the activation of NF-κB by TNF-α in the cells. Electrophoretic mobility-shift assay revealed that, in the absence of TSH, TNF-α activated a single protein–DNA complex containing the p50 subunit but not other NF-κB subunits such as p65. In contrast, two distinct protein–DNA complexes were activated in the presence of TSH: the faster-migrating complex contained only p50 subunit; the slower-migrating complex consisted of p65–p50heterodimer. This TSH effect was mimicked by forskolin and thyroid-stimulating antibodies obtained from patients with Graves's disease, suggesting that an increase in intracellular cAMP is responsible for the induction of different NF-κBs by TNF-α. A transient transfection study with a luciferase reporter gene driven by multimerized NF-κB sites demonstrated that TNF-α increased the luciferase activities only in the presence of TSH, and that this increase was inhibited by the co-transfection of mutant p65, which prevented the function of wild-type p65 in a dominant-negative manner. Accordingly, TNF-α activated the expression of the IL-6 gene in the presence of TSH but not in its absence. Although the expression of the p105 gene, another known target for NF-κB, was increased by TNF-α in the absence of TSH, the presence of TSH further increased the mRNA level. Taken together, these observations indicate that the presence of TSH is crucial for the NF-κB-mediated actions of TNF-α on thyroid follicular cells.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 378
Author(s):  
Apparao Peddapalli ◽  
Manish Gehani ◽  
Arunasree M. Kalle ◽  
Siva R. Peddapalli ◽  
Angela E. Peter ◽  
...  

The immunological findings from autopsies, biopsies, and various studies in COVID-19 patients show that the major cause of morbidity and mortality in COVID-19 is excess immune response resulting in hyper-inflammation. With the objective to review various mechanisms of excess immune response in adult COVID-19 patients, Pubmed was searched for free full articles not related to therapeutics or co-morbid sub-groups, published in English until 27 October 2020, irrespective of type of article, country, or region. Joanna Briggs Institute’s design-specific checklists were used to assess the risk of bias. Out of 122 records screened for eligibility, 42 articles were included in the final review. The review found that eventually, most mechanisms result in cytokine excess and up-regulation of Nuclear Factor-κB (NF-κB) signaling as a common pathway of excess immune response. Molecules blocking NF-κB or targeting downstream effectors like Tumour Necrosis Factor α (TNFα) are either undergoing clinical trials or lack specificity and cause unwanted side effects. Neutralization of upstream histamine by histamine-conjugated normal human immunoglobulin has been demonstrated to inhibit the nuclear translocation of NF-κB, thereby preventing the release of pro-inflammatory cytokines Interleukin (IL) 1β, TNF-α, and IL-6 and IL-10 in a safer manner. The authors recommend repositioning it in COVID-19.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1571
Author(s):  
Ji Yeong Yang ◽  
So-Yeun Woo ◽  
Mi Ja Lee ◽  
Hyun Young Kim ◽  
Jin Hwan Lee ◽  
...  

Extracts from barley seedlings (BS) have known antioxidant and anti-inflammatory activities. The flavonoid lutonarin (LN) is a component of BS extract and has several known bioactivities. Here, we evaluated LN anti-inflammatory efficacy against lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Lutonarin was isolated from BS by methanol extraction and characterized by ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Lutonarin did not reduce the viability or enhance the apoptosis rate of RAW 264.7 macrophages at concentrations up to 150 µM. Concentrations within 20–60 µM dose-dependently suppressed the LPS-induced expression, phosphorylation, and nuclear translocation of the inflammatory transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Furthermore, LN suppressed the LPS-induced upregulation of proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α and of the inflammatory enzyme cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Lutonarin may be a safe and effective therapeutic agent for alleviation of pathological inflammation.


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