scholarly journals E1A Sensitizes Cells to Tumor Necrosis Factor Alpha by Downregulating c-FLIPS

2003 ◽  
Vol 77 (4) ◽  
pp. 2651-2662 ◽  
Author(s):  
Denise Perez ◽  
Eileen White
Keyword(s):  
Gene Expression ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Caspase 8 ◽  
Necrosis Factor Alpha ◽  
Signaling Complex ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Tumor necrosis factor alpha (TNF-α) activates both apoptosis and NF-κB-dependent survival pathways, the former of which requires inhibition of gene expression to be manifested. c-FLIP is a TNF-α-induced gene that inhibits caspase-8 activation during TNF-α signaling. Adenovirus infection and E1A expression sensitize cells to TNF-α by allowing apoptosis in the absence of inhibitors of gene expression, suggesting that it may be disabling a survival signaling pathway. E1A promoted TNF-α-mediated activation of caspase-8, suggesting that sensitivity was occurring at the level of the death-inducing signaling complex. Furthermore, E1A expression downregulated c-FLIPS expression and prevented its induction by TNF-α. c-FLIPS and viral FLIP expression rescued E1A-mediated sensitization to TNF-α by restoring the resistance of caspase-8 to activation, thereby preventing cell death. E1A inhibited TNF-α-dependent induction of c-FLIPS mRNA and stimulated ubiquitination- and proteasome-dependent degradation of c-FLIPS protein. Since elevated c-FLIP levels confer resistance to apoptosis and promote tumorigenicity, interference with its induction by NF-κB and stimulation of its destruction in the proteasome may provide novel therapeutic approaches for facilitating the elimination of apoptosis-refractory tumor cells.

scholarly journals Regulation of Tumor Necrosis Factor Alpha Gene Expression by Mycobacteria Involves the Assembly of a Unique Enhanceosome Dependent on the Coactivator Proteins CBP/p300

2003 ◽  
Vol 23 (2) ◽  
pp. 526-533 ◽  
Author(s):  
Robert Barthel ◽  
Alla V. Tsytsykova ◽  
Amy K. Barczak ◽  
Eunice Y. Tsai ◽  
Christopher C. Dascher ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Regulatory Elements ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor ◽  
Stimulation Of

ABSTRACT Tumor necrosis factor alpha (TNF-α) plays an important role in host containment of infection by Mycobacterium tuberculosis, one of the leading causes of death by an infectious agent globally. Using the pathogenic M. tuberculosis strain H37Rv, we present evidence that upon stimulation of monocytic cells by M. tuberculosis a unique TNF-α enhanceosome is formed, and it is distinct from the TNF-α enhanceosome that forms in T cells stimulated by antigen engagement or virus infection. A distinct set of activators including ATF-2, c-jun, Ets, Sp1, Egr-1 and the coactivator proteins CBP/p300 are recruited to the TNF-α promoter after stimulation with M. tuberculosis. Furthermore, the formation of this enhanceosome is dependent on inducer-specific helical phasing relationships between transcription factor binding sites. We also show that the transcriptional activity of CBP/p300 is potentiated by mycobacterial stimulation of monocytes. The identification of TNF-α regulatory elements and coactivators involved in M. tuberculosis-stimulated gene expression thus provides potential selective molecular targets in the modulation of TNF-α gene expression in the setting of mycobacterial infection.

scholarly journals Tumor Necrosis Factor Alpha Induction of NF-κB Requires the Novel Coactivator SIMPL

2004 ◽  
Vol 24 (21) ◽  
pp. 9317-9326 ◽  
Author(s):  
Hyung-Joo Kwon ◽  
Erin Haag Breese ◽  
Eva Vig-Varga ◽  
Yong Luo ◽  
Younghee Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Type I ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT A myriad of stimuli including proinflammatory cytokines, viruses, and chemical and mechanical insults activate a kinase complex composed of IκB kinase β (IKK-β), IKK-α, and IKK-γ/N, leading to changes in NF-κB-dependent gene expression. However, it is not clear how the NF-κB response is tailored to specific cellular insults. Signaling molecule that interacts with mouse pelle-like kinase (SIMPL) is a signaling component required for tumor necrosis factor alpha (TNF-α)-dependent but not interleukin-1-dependent NF-κB activation. Herein we demonstrate that nuclear localization of SIMPL is required for type I TNF receptor-induced NF-κB activity. SIMPL interacts with nuclear p65 in a TNF-α-dependent manner to promote endogenous NF-κB-dependent gene expression. The interaction between SIMPL and p65 enhances p65 transactivation activity. These data support a model in which TNF-α activation of NF-κB dependent-gene expression requires nuclear relocalization of p65 as well as nuclear relocalization of SIMPL, generating a TNF-α-specific induction of gene expression.

scholarly journals Stat1 as a Component of Tumor Necrosis Factor Alpha Receptor 1-TRADD Signaling Complex To Inhibit NF-κB Activation

2000 ◽  
Vol 20 (13) ◽  
pp. 4505-4512 ◽  
Author(s):  
Yingjian Wang ◽  
Tong R. Wu ◽  
Shiying Cai ◽  
Thomas Welte ◽  
Y. Eugene Chin
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Death Domain ◽  
Necrosis Factor Alpha ◽  
Signaling Complex ◽  
Tnf Α ◽  
Factor Alpha ◽  
Domain Protein ◽  
Necrosis Factor

ABSTRACT Activated tumor necrosis factor alpha (TNF-α) receptor 1 (TNFR1) recruits TNFR1-associated death domain protein (TRADD), which in turn triggers two opposite signaling pathways leading to caspase activation for apoptosis induction and NF-κB activation for antiapoptosis gene upregulation. Here we show that Stat1 is involved in the TNFR1-TRADD signaling complex, as determined by employing a novel antibody array screening method. In HeLa cells, Stat1 was associated with TNFR1 and this association was increased with TNF-α treatment. TNFR1 signaling factors TRADD and Fas-associated death domain protein (FADD) were also found to interact with Stat1 in a TNF-α-dependent process. Our in vitro recombinant protein-protein interaction studies demonstrated that Stat1 could directly interact with TNFR1 and TRADD but not with FADD. Interaction between Stat1 and receptor-interacting protein (RIP) or TNFR-associated factor 2 (TRAF2) was not detected. Examination of Stat1-deficient cells showed an apparent increase in TNF-α-induced TRADD-RIP and TRADD-TRAF2 complex formation, while interaction between TRADD and FADD was unaffected. As a consequence, TNF-α-mediated I-κB degradation and NF-κB activation were markedly enhanced in Stat1-deficient cells, whereas overexpression of Stat1 in 293T cells blocked NF-κB activation by TNF-α. Thus, Stat1 acts as a TNFR1-signaling molecule to suppress NF-κB activation.

scholarly journals Association of tumor necrosis factor-alpha -308 G/A and -238 G/A polymorphism with diabetic retinopathy: a systematic review and updated meta-analysis.

2020 ◽  
Author(s):  
Wenna Gao ◽  
Ruilin Zhu ◽  
liu yang
Keyword(s):  
Diabetic Retinopathy ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Meta Analysis ◽  
Entire Group ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

Background: Mounting evidence has suggested tumor necrosis factor-alpha (TNF-α) can promote the development of diabetic retinopathy (DR), and TNF-α gene variants may influence DR risk. However, the results are quite different. Objectives: To comprehensively address this issue, we performed the meta-analysis to evaluate the association of TNF-α-308 G/A and -238 G/A polymorphism with DR. Method: Data were retrieved in a systematic manner and analyzed using STATA Statistical Software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Allelic and genotypic comparisons between cases and controls were evaluated. Results: For the TNF-α-308 G/A polymorphism, overall analysis suggested a marginal association with DR [the OR(95%CI) of (GA versus GG), (GA + AA) versus GG, and (A versus G) are 1.21(1.04, 1.41), 1.20(1.03, 1.39), and 1.14(1.01, 1.30), respectively]. And the subgroup analysis indicated an enhanced association among the European population. For the TNF-α-238 G/A polymorphism, there was mild correlation in the entire group [the OR(95%CI) of (GA versus GG) is 1.55(1.14,2.11) ], which was strengthened among the Asian population. Conclusion: The meta-analysis suggested that -308 A and -238 A allele in TNF-α gene potentially increased DR risk and showed a discrepancy in different ethnicities.

scholarly journals Analysis of Subcellular RNA Fractions Revealed a Transcription-Independent Effect of Tumor Necrosis Factor Alpha on Splicing, Mediated by Spt5

2016 ◽  
Vol 36 (9) ◽  
pp. 1342-1353 ◽  
Author(s):  
Gil Diamant ◽  
Tal Eisenbaum ◽  
Dena Leshkowitz ◽  
Rivka Dikstein
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Independent Effect ◽  
Necrosis Factor Alpha ◽  
Pol Ii ◽  
Tnf Α ◽  
Factor Alpha ◽  
Induced Genes ◽  
Necrosis Factor

The proinflammatory cytokine tumor necrosis factor alpha (TNF-α) modulates the expression of many genes, primarily through activation of NF-κB. Here, we examined the global effects of the elongation factor Spt5 on nascent and mature mRNAs of TNF-α-induced cells using chromatin and cytosolic subcellular fractions. We identified several classes of TNF-α-induced genes controlled at the level of transcription, splicing, and chromatin retention. Spt5 was found to facilitate splicing and chromatin release in genes displaying high induction rates. Further analysis revealed striking effects of TNF-α on the splicing of 25% of expressed genes; the vast majority were not transcriptionally induced. Splicing enhancement of noninduced genes by TNF-α was transient and independent of NF-κB. Investigating the underlying basis, we found that Spt5 is required for the splicing facilitation of the noninduced genes. In line with this, Spt5 interacts with Sm core protein splicing factors. Furthermore, following TNF-α treatment, levels of RNA polymerase II (Pol II) but not Spt5 are reduced from the splicing-induced genes, suggesting that these genes become enriched with a Pol II-Spt5 form. Our findings revealed the Pol II-Spt5 complex as a highly competent coordinator of cotranscriptional splicing.

scholarly journals HSP70 Induction by ING Proteins Sensitizes Cells to Tumor Necrosis Factor Alpha Receptor-Mediated Apoptosis

2006 ◽  
Vol 26 (24) ◽  
pp. 9244-9255 ◽  
Author(s):  
Xiaolan Feng ◽  
Shirin Bonni ◽  
Karl Riabowol
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Kinase Inhibitor ◽  
Heat Shock Gene ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Primary Fibroblasts ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT ING proteins affect apoptosis, growth, and DNA repair by transducing stress signals such as DNA damage, binding histones, and subsequently regulating chromatin structure and p53 activity. p53 target genes, including the p21 cyclin-dependent kinase inhibitor and Bax, an inducer of apoptosis, are regulated by ING proteins. To identify additional targets downstream of p33ING1 and p32ING2, cDNA microarrays were performed on phenotypically normal human primary fibroblasts. The 0.36% of genes affected by ING proteins in primary fibroblasts were distinct from targets seen in established cells and included the HSP70 heat shock gene, whose promoter was specifically induced >10-fold. ING1-induced expression of HSP70 shifted cells from survival to a death pathway in response to tumor necrosis factor alpha (TNF-α), and p33ING1b protein showed synergy with TNF-α in inducing apoptosis, which correlated with reduced NF-κB-dependent transcription. These findings are consistent with previous reports that HSP70 promotes TNF-α-mediated apoptosis by binding I-κΒ kinase gamma and impairing NF-κB survival signaling. Induction of HSP70 required the amino terminus of ING1b but not the plant homeodomain region that was recently identified as a histone binding domain. Regulation of HSP70 gene expression by the ING tumor suppressors provides a novel link between the INGs and the stress-regulated NF-κB survival pathway important in hypoxia and angiogenesis.

scholarly journals Comparative Analysis of Lipopolysaccharide-Induced Tumor Necrosis Factor Alpha Activity in Serum and Lethality in Mice and Rabbits Pretreated with the Staphylococcal Superantigen Toxic Shock Syndrome Toxin 1

2001 ◽  
Vol 69 (11) ◽  
pp. 7169-7172 ◽  
Author(s):  
Martin M. Dinges ◽  
Patrick M. Schlievert
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Host Susceptibility ◽  
Necrosis Factor Alpha ◽  
Lethal Effects ◽  
Tnf Α ◽  
Factor Alpha ◽  
Toxic Shock Syndrome Toxin ◽  
Necrosis Factor

ABSTRACT Host susceptibility to lipopolysaccharide (LPS) is correlated with the levels of circulating tumor necrosis factor alpha (TNF-α) that develop in response to circulating LPS. Mice are resistant, relative to rabbits, to the lethal effects of LPS. This study indicates that mice and rabbits are equally sensitive to the lethal effects of circulating TNF-α but that mice are more resistant than rabbits to the induction of circulating TNF-α by LPS.

scholarly journals Major Outer Membrane Protein Omp25 of Brucella suis Is Involved in Inhibition of Tumor Necrosis Factor Alpha Production during Infection of Human Macrophages

2001 ◽  
Vol 69 (8) ◽  
pp. 4823-4830 ◽  
Author(s):  
Véronique Jubier-Maurin ◽  
Rose-Anne Boigegrain ◽  
Axel Cloeckaert ◽  
Antoine Gross ◽  
Maria-Teresa Alvarez-Martinez ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Macrophage Infection ◽  
Necrosis Factor Alpha ◽  
Human Macrophages ◽  
Tnf Α ◽  
Brucella Suis ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Brucella spp. can establish themselves and cause disease in humans and animals. The mechanisms by whichBrucella spp. evade the antibacterial defenses of their host, however, remain largely unknown. We have previously reported that live brucellae failed to induce tumor necrosis factor alpha (TNF-α) production upon human macrophage infection. This inhibition is associated with a nonidentified protein that is released into culture medium. Outer membrane proteins (OMPs) of gram-negative bacteria have been shown to modulate macrophage functions, including cytokine production. Thus, we have analyzed the effects of two major OMPs (Omp25 and Omp31) of Brucella suis 1330 (wild-type [WT] B. suis) on TNF-α production. For this purpose, omp25and omp31 null mutants of B. suis(Δomp25 B. suis and Δomp31 B. suis, respectively) were constructed and analyzed for the ability to activate human macrophages to secrete TNF-α. We showed that, in contrast to WTB. suis or Δomp31 B. suis, Δomp25 B. suis induced TNF-α production when phagocytosed by human macrophages. The complementation of Δomp25 B. suis with WT omp25 (Δomp25-omp25 B. suis mutant) significantly reversed this effect: Δomp25-omp25 B. suis-infected macrophages secreted significantly less TNF-α than did macrophages infected with the Δomp25 B. suismutant. Furthermore, pretreatment of WT B. suis with an anti-Omp25 monoclonal antibody directed against an epitope exposed at the surface of the bacteria resulted in substancial TNF-α production during macrophage infection. These observations demonstrated that Omp25 of B. suis is involved in the negative regulation of TNF-α production upon infection of human macrophages.

scholarly journals Gamma Interferon and Lipopolysaccharide Interact at the Level of Transcription To Induce Tumor Necrosis Factor Alpha Expression

2001 ◽  
Vol 69 (5) ◽  
pp. 2847-2852 ◽  
Author(s):  
Julia Y. Lee ◽  
Kathleen E. Sullivan
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Gamma Interferon ◽  
Necrosis Factor Alpha ◽  
Rnase Protection ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Lipopolysaccharide (LPS) is a very potent inducer of tumor necrosis factor alpha (TNF-α) expression from monocytes and macrophages. Another inflammatory cytokine, gamma interferon (IFN-γ), can potentiate the effects of LPS, but the mechanism is not thoroughly understood. Previous reports emphasized the ability of IFN-γ to upregulate CD14 expression (the receptor for LPS), and nearly all studies have utilized sequential stimulation with IFN-γ followed by LPS to exploit this phenomenon. This study demonstrates that IFN-γ can upregulate the effect of LPS at the level of transcription. Human monoblastic Mono-Mac-6 cells produced up to threefold-greater levels of TNF-α when simultaneously stimulated with LPS and IFN-γ compared to treatment with LPS alone. RNase protection studies showed a similar increase in RNA beginning as early as within 30 min. The synthesis of TNF-α mRNA in IFN-γ- and LPS-treated Mono-Mac-6 cells was also temporally prolonged even though the message turnover rate was identical to that seen in LPS stimulated cells. The modulatory effect of IFN-γ may be mediated by Jak2.

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