Effect of tumor necrosis factor-α and interleukin-1α on heme oxygenase-1 expression in human endothelial cells

1998 ◽  
Vol 274 (3) ◽  
pp. H883-H891 ◽  
Author(s):  
Christi M. Terry ◽  
Jennifer A. Clikeman ◽  
John R. Hoidal ◽  
Karleen S. Callahan

Heme iron exacerbates oxidant damage by catalyzing the production of free radicals. Heme oxygenase is the rate-limiting enzyme involved in heme catabolism. An inducible form of heme oxygenase, heme oxygenase-1 (HO-1), is upregulated in oxidant and inflammatory settings, and recent work suggests that HO-1 induction may serve a protective function against oxidant injury. The ability of the endogenous inflammatory mediators, interleukin (IL)-1α, tumor necrosis factor-α (TNF-α), and IL-6, to enhance HO-1 expression in cultured human endothelial cells was examined in this study. HO-1 mRNA and protein expression were upregulated by IL-1α and TNF-α exposure but not by IL-6. Induction of HO-1 mRNA by IL-1α and TNF-α occurred in a concentration- and time-dependent fashion, with maximal expression occurring by 4 h for both cytokines. Induction depended on protein synthesis and occurred at the transcriptional level. Inhibition of the AP-1 transcription factor with curcumin decreased the cytokine induction of HO-1 mRNA, suggesting the involvement of this transcription factor in cytokine signaling of HO-1. The results of this study indicate that the endogenous inflammatory cytokines IL-1α and TNF-α induce HO-1 in endothelial cells, providing further evidence that HO-1 may be an important cellular response to inflammatory stress.

2010 ◽  
Vol 58 (14) ◽  
pp. 8430-8436 ◽  
Author(s):  
Domenico Trombetta ◽  
Francesco Cimino ◽  
Mariateresa Cristani ◽  
Giuseppina Mandalari ◽  
Antonella Saija ◽  
...  

1998 ◽  
Vol 187 (7) ◽  
pp. 1069-1079 ◽  
Author(s):  
Klaus Ruckdeschel ◽  
Suzanne Harb ◽  
Andreas Roggenkamp ◽  
Mathias Hornef ◽  
Robert Zumbihl ◽  
...  

In this study, we investigated the activity of transcription factor NF-κB in macrophages infected with Yersinia enterocolitica. Although triggering initially a weak NF-κB signal, Y. enterocolitica inhibited NF-κB activation in murine J774A.1 and peritoneal macrophages within 60 to 90 min. Simultaneously, Y. enterocolitica prevented prolonged degradation of the inhibitory proteins IκB-α and IκB-β observed by treatment with lipopolysaccharide (LPS) or nonvirulent, plasmid-cured yersiniae. Analysis of different Y. enterocolitica mutants revealed a striking correlation between the abilities of these strains to inhibit NF-κB and to suppress the tumor necrosis factor α (TNF-α) production as well as to trigger macrophage apoptosis. When NF-κB activation was prevented by the proteasome inhibitor MG-132, nonvirulent yersiniae as well as LPS became able to trigger J774A.1 cell apoptosis and inhibition of the TNF-α secretion. Y. enterocolitica also impaired the activity of NF-κB in epithelial HeLa cells. Although neither Y. enterocolitica nor TNF-α could induce HeLa cell apoptosis alone, TNF-α provoked apoptosis when activation of NF-κB was inhibited by Yersinia infection or by the proteasome inhibitor MG-132. Together, these data demonstrate that Y. enterocolitica suppresses cellular activation of NF-κB, which inhibits TNF-α release and triggers apoptosis in macrophages. Our results also suggest that Yersinia infection confers susceptibility to programmed cell death to other cell types, provided that the appropriate death signal is delivered.


2005 ◽  
Vol 60 (5-6) ◽  
pp. 478-484 ◽  
Author(s):  
Jan Rether ◽  
Gerhard Erkel ◽  
Olov Sterner ◽  
Timm Anke

In a search for inhibitors of the inducible tumor necrosis factor-α (TNF-α) promoter activity and synthesis, a new chlorinated cyclopentenone was isolated from fermentations of the ascomycete Mollisia melaleuca. The structure was determined by a combination of spectroscopic techniques. The compound blocked the inducible human TNF-α promoter activity and synthesis with IC50-values of 2.5-5 μg/ml (8.1-16.1 μм). Studies on the mode of action of the compound revealed that the inhibition of TNF-α promoter activity is caused by an inhibition of the phosphorylation of the IϰB protein which prevents the activation of the transcription factor NF-ϰB. No cytotoxic, antibacterial and antifungal activities could be observed up to 100 μg/ml (323 μм) of the compound.


Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 558-566 ◽  
Author(s):  
Ramesh Sakiri ◽  
Belakere Ramegowda ◽  
Vernon L. Tesh

Shiga toxins (Stxs) produced by Shigella dysenteriae 1 andEscherichia coli have been implicated in the pathogenesis of bloody diarrhea, acute renal failure, and neurologic abnormalities. The pathologic hallmark of Stx-mediated tissue damage is the development of vascular lesions in which endothelial cells are swollen and detached from underlying basement membranes. However, in vitro studies using human vascular endothelial cells demonstrated minimal Stx-induced cytopathic effects, unless the target cells were also incubated with the proinflammatory cytokines tumor necrosis factor-α (TNF-α) or interleukin-1β (IL-1β). These cytokines have been shown to upregulate the expression of the Stx-binding membrane glycolipid globotriaosylceramide (Gb3). We show here that purified Stx1 induces TNF secretion by a human monocytic cell line, THP-1, in a dose- and time-dependent manner. Treatment of cells with both lipopolysaccharides (LPS) and Stx1 results in augmented TNF production. Treatment with the nontoxic Gb3-binding subunit of Stx1 or with an anti-Gb3 monoclonal antibody did not trigger TNF production. Northern blot analyses show that Stx1 causes increased TNF-α production through transcriptional activation. Increased levels of TNF-α mRNA are preceded by the nuclear translocation of the transcriptional activators NF-κB and AP-1 and the loss of cytoplasmic IκB-α. These data are the first to show that, in addition to direct cytotoxicity, Stxs possess cellular signaling capabilities sufficient to induce the synthesis of cytokines that may be necessary for target cell sensitization and the development of vascular lesions.


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