Iron activates NF-κB in Kupffer cells

2002 ◽  
Vol 283 (3) ◽  
pp. G719-G726 ◽  
Author(s):  
Hongyun She ◽  
Shigang Xiong ◽  
Min Lin ◽  
Ebrahim Zandi ◽  
Cecilia Giulivi ◽  
...  
Keyword(s):  
Liver Injury ◽  
Kupffer Cells ◽  
Promoter Activity ◽  
Redox Status ◽  
Dependent Manner ◽  
Activator Protein 1 ◽  
Paramagnetic Resonance ◽  
Tnf Α ◽  
Electron Paramagnetic ◽  
Necrosis Factor

10.1152/ajpgi.00108. 2002.— Iron exacerbates various types of liver injury in which nuclear factor (NF)-κB-driven genes are implicated. This study tested a hypothesis that iron directly elicits the signaling required for activation of NF-κB and stimulation of tumor necrosis factor (TNF)-α gene expression in Kupffer cells. Addition of Fe2+ but not Fe3+ (∼5–50 μM) to cultured rat Kupffer cells increased TNF-α release and TNF-α promoter activity in a NF-κB-dependent manner. Cu+ but not Cu2+ stimulated TNF-α protein release and promoter activity but with less potency. Fe2+ caused a disappearance of the cytosolic inhibitor κBα, a concomitant increase in nuclear p65 protein, and increased DNA binding of p50/p50 and p65/p50 without affecting activator protein-1 binding. Addition of Fe2+ to the cells resulted in an increase in electron paramagnetic resonance-detectable ·OH peaking at 15 min, preceding activation of NF-κB but coinciding with activation of inhibitor κB kinase (IKK) but not c-Jun NH2-terminal kinase. In conclusion, Fe2+ serves as a direct agonist to activate IKK, NF-κB, and TNF-α promoter activity and to induce the release of TNF-α protein by cultured Kupffer cells in a redox status-dependent manner. We propose that this finding offers a molecular basis for iron-mediated accentuation of TNF-α-dependent liver injury.

Lipopolysaccharide andd-galactosamine-induced hepatic injury is mediated by TNF-α and not by Fas ligand

2000 ◽  
Vol 278 (5) ◽  
pp. R1196-R1201 ◽  
Author(s):  
Michael D. Josephs ◽  
F. Rena Bahjat ◽  
Kunitaro Fukuzuka ◽  
Riadh Ksontini ◽  
Carmen C. Solorzano ◽  
...  
Keyword(s):  
Liver Injury ◽  
Hepatic Injury ◽  
Fas Ligand ◽  
Nuclear Dna ◽  
Spontaneous Mutation ◽  
Hepatic Expression ◽  
Soluble Fas ◽  
Tnf Α ◽  
Necrosis Factor

Tumor necrosis factor (TNF)-α and Fas ligand (FasL) are trimeric proteins that induce apoptosis through similar caspase-dependent pathways. Hepatocytes are particularly sensitive to inflammation-induced programmed cell death, although the contribution of TNF-α and/or FasL to this injury response is still unclear. Here, we report that d-galactosamine and lipopolysaccharide-induced liver injury in C57BL/6 mice is associated with increased hepatic expression of both TNF-α and FasL mRNA. Pretreatment of mice with a TNF-binding protein improved survival, reduced plasma aspartate aminotransferase concentrations, and attenuated the apoptotic liver injury, as determined histologically and by in situ 3′ OH end labeling of fragmented nuclear DNA. In contrast, pretreatment of mice with a murine-soluble Fas fusion protein (Fasfp) had only minimal effect on survival, and apoptotic liver injury was either unaffected or exacerbated depending on the dose of Fasfp employed. Similarly, mice with a spontaneous mutation in FasL (B6Smn.C3H- Faslgldderived from C57BL/6) were equally sensitive tod-galactosamine/lipopolysaccharide-induced shock. We conclude that the shock and apoptotic liver injury afterd-galactosamine/lipopolysaccharide treatment are due primarily to TNF-α release, whereas increased FasL expression appears to contribute little to the mortality and hepatic injury.

scholarly journals Blood redox state and survival in patients with rectal cancer

2015 ◽  
Vol 17 (4) ◽  
Author(s):  
A. P. Burlaka ◽  
V. V. Holotyuk ◽  
A. V. Vovk ◽  
S. M. Lukin ◽  
Ye. P. Sydoryk
Keyword(s):  
Rectal Cancer ◽  
Redox State ◽  
Venous Blood ◽  
Reference Sample ◽  
Redox Status ◽  
Paramagnetic Resonance ◽  
Blood Samples ◽  
Cell Functions ◽  
Electron Paramagnetic ◽  
Concentration Of Electrons

<p>The cells of an organism have a definite concentration of electrons that characterizes their stable redox status. Electrons are transported to the oxygen and create the potential energy to realize the cell functions such as growth<br />and apoptosis. Imbalance in the redox state of cells initiates the development and progression of the most socially significant pathologies. The aim of the research was to study the blood redox state in patients with rectal cancer (RC ) (the levels of ceruloplasmin (CP), transferrin (TF) and “free iron” (“FI”), superoxyd-, NO-generating activity of neutrophils and platelets) and its impact on оverall survival (ОS ). Venous blood samples of 60 patients with RC (T2-4N0-2M0G2) and 20 donors were studied. The defining levels of CP, TF, “FI” in blood was performed by electron paramagnetic resonance (EPR) at the temperature of liquid nitrogen (T=77 K ). The blood redox state in patients with RC are formed by: 2 times reduced CP activity in comparison with the<br />reference sample; 3 times reduced TF content and 10 times increased “FI” levels; slightly increased superoxide generating activity of neutrophils and 8–14 times increased superoxide generating activity of platelets; 3.7 and 4.3 times reduced NO generation rate of neutrophils and platelets, respectively. It was found that the survival in patients with RC was significantly influenced by the level of CP activity (p&lt;0.044), levels of “FI” (p&lt;0.026), superoxide generating activity of NADP·H-oxidase of neutrophils (p&lt;0.043). It was found that the adenocarcinoma progression in patients with RC (T2-4N0-2M0G2) was ccompanied bychange in the blood redox state by reducing CP activity and level of TF that led to the emergence of “FI” and the increase of its level. Besides, the changes of superoxyde- and NO-generating activity NADP∙H-oxidase and iNOS of neutrophils and platelets significantly influenced the imbalance of the blood redox state in the patients. The state of redox forming blood components in patients correlated with the оverall 5-year survival. It was found that the CP</p><p>activity, the “FI” level and the superoxide-generating activity of NADP·H-xidase of neutrophils and platelets hadsignificant effect on ОS .</p>

Effects of tributyltin on placental cytokine production

2018 ◽  
Vol 46 (8) ◽  
pp. 867-875 ◽  
Author(s):  
Yuko Arita ◽  
Michael Kirk ◽  
Neha Gupta ◽  
Ramkumar Menon ◽  
Darios Getahun ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Cytokine Production ◽  
Heme Oxygenase 1 ◽  
Dependent Manner ◽  
Neurodevelopmental Outcomes ◽  
Placental Function ◽  
Tnf Α ◽  
Explant Cultures ◽  
High Doses ◽  
Necrosis Factor

Abstract Objective Tributyltin (TBT) is a persistent pollutant but its effects on placental function are poorly understood as are its possible interactions with infection. We hypothesized that TBT alters the production of sex hormones and biomarkers for inflammation and neurodevelopment in an infection-dependent manner. Methods Placental explant cultures were treated with 0–5000 nM TBT in the presence and absence of Escherichia coli. A conditioned medium was harvested and concentrations of steroids (progesterone, P4; testosterone, T and estradiol, E2) as well as biomarkers of inflammation [interleukin (IL)-1β (IL-1β), tumor necrosis factor (TNF-α), IL-10, IL-6, soluble glycoprotein 130 (sgp-130) and heme oxygenase-1 (HO-1)], oxidative stress [8-iso-prostaglandin (8-IsoP)] and neurodevelopment [brain-derived neurotrophic factor (BDNF)] were quantified. Results TBT increased P4 slightly but had little or no effect on T or E2 production. IL-1β, IL-6, sgp-130, IL-10 and 8-IsoP production was enhanced by TBT. P4 and IL-6 production was also enhanced by TBT for bacteria-stimulated cultures but TBT significantly inhibited bacteria-induced IL-1β and sgp-130 production. High doses of TBT also inhibited BDNF production. Conclusions TBT increases P4 but has minimal effect on downstream steroids. It enhances the production of inflammatory biomarkers such as IL-1β, TNF-α, IL-10 and IL-6. Inhibition of sgp-130 by TBT suggests that TBT may increase bioactive IL-6 production which has been associated with adverse neurodevelopmental outcomes. Reduced expression of BDNF also supports this possibility.

scholarly journals Prostaglandin E2 and Tumor Necrosis Factor α Cooperate to Activate Human Dendritic Cells: Synergistic Activation of Interleukin 12 Production

1997 ◽  
Vol 186 (9) ◽  
pp. 1603-1608 ◽  
Author(s):  
Claudia Rieser ◽  
Günther Böck ◽  
Helmut Klocker ◽  
Georg Bartsch ◽  
Martin Thurnher
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Tumor Necrosis Factor ◽  
Prostaglandin E2 ◽  
Tumor Necrosis ◽  
Interleukin 12 ◽  
Dependent Manner ◽  
Tnf Α ◽  
Human Dendritic Cells ◽  
Necrosis Factor

Interleukin (IL)-12 is a proinflammatory cytokine that contributes to innate resistance and to the development of antigen-specific T cell responses. Among other effects, prostaglandin E2 (PGE2) inhibits the production of IL-12 by macrophages activated with lipopolysaccharide (LPS). Here we investigated the effects of PGE2 on human dendritic cells (DCs) which develop in the presence of GM-CSF and IL-4. We demonstrate that in the absence of LPS, PGE2 dose dependently stimulated the production of IL-12 by DCs. Although PGE2 alone stimulated the production of low amounts of IL-12 only, it synergized with tumor necrosis factor (TNF)-α to induce high levels of IL-12 production by DCs. Addition of TNF-α in the absence of PGE2 had no effect on IL-12 production. Conversely, in the presence of LPS, PGE2 inhibited IL-12 production by DCs in a dose-dependent manner. The combination of PGE2 and TNF-α efficiently silenced mannose receptor–mediated endocytosis in DCs and readily induced neo-expression of the CD83 antigen. In addition, the expression of various surface antigens such as major histocompatibility complex class I and II, adhesion, as well as costimulatory molecules was upregulated by this treatment. The effects of PGE2 on IL-12 synthesis and CD83 expression could be mimicked by dibutyryl-cAMP and forskolin, indicating that they were due to the intracellular elevation of cAMP levels. DC treated with PGE2 and TNF-α were most potent in stimulating allogeneic T cell proliferation. Our data demonstrate that PGE2 contributes to the maturation of human DCs and that PGE2 can be a potent enhancer of IL-12 production by human DCs.

scholarly journals Therapeutic effect and mechanism of action of quercetin in a rat model of osteoarthritis

2019 ◽  
Vol 48 (3) ◽  
pp. 030006051987346 ◽  
Author(s):  
Jun Zhang ◽  
Jing Yin ◽  
Daohong Zhao ◽  
Chaoran Wang ◽  
Yuhao Zhang ◽  
...  
Keyword(s):  
Therapeutic Effect ◽  
Mechanism Of Action ◽  
Rat Model ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Toll Like Receptor ◽  
Tnf Α ◽  
Dose Dependent ◽  
Light Chain Enhancer ◽  
Necrosis Factor

Objective To study the therapeutic effect and mechanism of action of quercetin in a rat model of osteoarthritis (OA). Methods The OA rat model was established by intra-articular injection of papain. Changes in knee diameter, toe volume and histopathology were measured. Levels of interleukin (IL)-β and tumor necrosis factor (TNF)-α were assessed by ELISA. Relative expression of Toll-like receptor (TLR)-4 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was evaluated by western blotting. Results Compared with rats treated with papain alone, changes in knee diameter, toe volume and Makin' s score were less apparent in OA rats treated with quercetin. Levels of serum IL-1β and TNF-α were also reduced in quercetin-treated OA rats. Expression of TLR-4 and NF-κB was significantly suppressed in a dose-dependent manner in quercetin-treated OA rats. Conclusion Quercetin exhibited a therapeutic effect in OA rats, which may be related to inhibition of IL-1β and TNF-α production via the TLR-4/NF-κB pathway.

scholarly journals Intracellular Free Iron and Its Potential Role in Ultrahigh-Pressure-Induced Inactivation of Escherichia coli

2012 ◽  
Vol 79 (2) ◽  
pp. 722-724 ◽  
Author(s):  
Yuan Yan ◽  
Joy G. Waite-Cusic ◽  
Periannan Kuppusamy ◽  
Ahmed E. Yousef
Keyword(s):  
Escherichia Coli ◽  
Iron Chelator ◽  
Ultrahigh Pressure ◽  
Dependent Manner ◽  
Paramagnetic Resonance ◽  
Free Iron ◽  
Content Type ◽  
E Coli ◽  
Electron Paramagnetic ◽  
Dose Dependent

ABSTRACTIntracellular free iron ofEscherichia coliwas determined by whole-cell electron paramagnetic resonance spectrometry. Ultrahigh pressure (UHP) increased both intracellular free iron and cell lethality in a pressure-dose-dependent manner. The iron chelator 2,2′-dipyridyl protected cells against UHP treatments. A mutation that produced iron overload conditions sensitizedE. colito UHP treatment.

Epigallocatechin Gallate Modulates Cytokine Production by Bone Marrow-Derived Dendritic Cells Stimulated with Lipopolysaccharide or Muramyldipeptide, or Infected with Legionella pneumophila

2005 ◽  
Vol 230 (9) ◽  
pp. 645-651 ◽  
Author(s):  
James Rogers ◽  
Izabella Perkins ◽  
Alberto van Olphen ◽  
Nicholas Burdash ◽  
Thomas W. Klein ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Tumor Necrosis ◽  
Epigallocatechin Gallate ◽  
Dependent Manner ◽  
Enhanced Production ◽  
Tnf Α ◽  
Factor Α ◽  
Dose Dependent ◽  
Antimicrobial Immunity ◽  
Necrosis Factor

The primary polyphenol in green tea extract is the catechin epigallocatechin gallate (EGCG). Various studies have shown significant suppressive effects of catechin on mammalian cells, either tumor or normal cells, including lymphoid cells. Previous studies from this laboratory reported that EGCG has marked suppressive activity on murine macrophages infected with the intracellular bacterium Legionella pneumophila (Lp), an effect mediated by enhanced production of both tumor necrosis factor-α (TNF-α) and γ-interferon (IFN-γ). In the present study, primary murine bone marrow (BM)-derived dendritic cells (DCs), a phagocytic monocytic cell essential for innate immunity to intracellular microorganisms, such as Lp, were stimulated in vitro with the microbial stimulant lipopolysaccharide (LPS) from gram-negative bacteria, the cell wall component from gram-positive bacteria muramyldipeptide (MDP) or infected with Lp. Production of the T helper cell (Th1)-activating cytokine, interleukin-12 (IL-12) and the proinflammatory cytokine, tumor necrosis factor-α (TNF-α), produced mainly by phagocytic cells and important for antimicrobial immunity, was determined in cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). Treatment of the cells with EGCG inhibited, in a dose-dependent manner, production of IL-12. In contrast, enhanced production of TNF-α occurred in a dose-dependent manner in the DC cultures stimulated with either soluble bacterial product or infected with Lp. Thus, the results of this study show that the EGCG catechin has a marked effect in modulating production of these immunoregulatory cytokines in stimulated DCs, which are important for antimicrobial immunity, especially innate immunity. Further studies are necessary to characterize the physiologic function of the effect of EGCG on TNF-α and IL-12 during Lp infection, and the mechanisms involved.

Differential protective effects of Bcl-xL and Bcl-2 on apoptotic liver injury in transgenic mice

1999 ◽  
Vol 277 (3) ◽  
pp. G702-G708 ◽  
Author(s):  
Alix de la Coste ◽  
Monique Fabre ◽  
Nathalie McDonell ◽  
Arlette Porteu ◽  
Helène Gilgenkrantz ◽  
...  
Keyword(s):  
Liver Injury ◽  
Transgenic Mice ◽  
Fas Ligand ◽  
Dependent Manner ◽  
Protective Effects ◽  
Tnf Α ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Factor Α

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.

scholarly journals Bikunin Inhibits Lipopolysaccharide-Induced Tumor Necrosis Factor Alpha Induction in Macrophages

2004 ◽  
Vol 11 (6) ◽  
pp. 1140-1147 ◽  
Author(s):  
Hidenori Matsuzaki ◽  
Hiroshi Kobayashi ◽  
Tatsuo Yagyu ◽  
Kiyoshi Wakahara ◽  
Toshiharu Kondo ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Dose Dependent ◽  
Necrosis Factor

ABSTRACT Bikunin, a Kunitz-type protease inhibitor, exhibits anti-inflammatory activity in protection against cancer and inflammation. To investigate the molecular mechanism of this inhibition, we analyzed the effect of bikunin on tumor necrosis factor alpha (TNF-α) production in human peripheral mononuclear cells stimulated by lipopolysaccharide (LPS), an inflammatory inducer. Here, we show the following results. (i) LPS induced TNF-α expression in time- and dose-dependent manners through phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase pathways. (ii) Bikunin inhibits LPS-induced up-regulation of TNF-α protein expression in a dose-dependent manner, reaching 60% inhibition at the highest doses of bikunin tested (5.0 μM). (iii) Inhibition by bikunin of TNF-α induction correlates with the suppressive capacity of ERK1/2, JNK, and p38 signaling pathways, implicating repressions of at least three different signals in the inhibition. (iv) Bikunin blocks the induction of TNF-α target molecules interleukin-1β (IL-1β) and IL-6 proteins. (v) Bikunin is functional in vivo, and this glycoprotein blocks systemic TNF-α release in mice challenged with LPS. (vi) Finally, bikunin can prevent LPS-induced lethality. In conclusion, bikunin significantly inhibits LPS-induced TNF-α production, suggesting a mechanism of anti-inflammation by bikunin through control of cytokine induction during inflammation. Bikunin might be a candidate for the treatment of inflammation, including septic shock.

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