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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Alveolar macrophages regulate the inflammatory and immune responses within the lung through cytokine production. Nuclear factor kappa B (NF-kappaB), a transcription factor, controls the synthesis of cytokines such as interleukin 1beta, tumour necrosis factor alpha, and
interleukin 8
. In quiescent cells, NF-kappaB is located in the cytosol as a dimer of protein components (p50,
p65
) bound to an inhibitor (IkappaB). Upon activation, NF-kappaB translocates to the nucleus and binds to DNA. To determine the constitutive level of NF-kappaB activation in non-smoking normal volunteers, immunohistochemical analysis of alveolar macrophages from 29 subjects was performed with antibody directed against the
p65
component of NF-kappaB. These results were confirmed in four subjects by electrophoretic mobility shift assay (EMSA). A human monocytic cell line, THP-1 with and without endotoxin stimulation was used as positive and negative controls, respectively. The mean number of positive cells was 4.1%+/-0.8. EMSA performed on whole cell extracts from four normal volunteers demonstrated minimal constitutive binding compared to the positive control. Supershift assay revealed the presence of the
p65
dimer. By both immunohistochemistry and EMSA, alveolar macrophages from healthy non-smoking individuals demonstrate minimal NF-kappaB activation. Immunohistochemistry is a sensitive and quantifiable technique requiring only a minimal number of cells, and this technique may be useful in monitoring small changes in NF-kappaB activation in inflammatory diseases of the lung.
...
PMID:Constitutive NF-kappaB levels in human alveolar macrophages from normal volunteers. 987 23
Gold compounds have long been used in the treatment of rheumatoid arthritis (RA). However, their actions in RA have not been clarified. In this study, we examined the effect of one of the monovalent gold compounds, aurothioglucose (AuTG), on the IL-1-induced production of IL-6,
IL-8
and granulocyte macrophage colony stimulating factor (GM-CSF) from rheumatoid synovial fibroblasts (RSF) isolated from three RA patients. IL-6 and
IL-8
induction but not GM-CSF induction was inhibited in most of the RSF after pretreatment with AuTG. Since gene expression of these cytokines is known to be under the control of a common transcription factor, NF-kappaB, the effect of AuTG on the cellular localization of NF-kappaB (
p65
subunit) and on NF-kappaB-DNA binding was examined. Although AuTG treatment did not prevent NF-kappaB nuclear translocation, AuTG blocked the DNA-binding activity of NF-kappaB when examined in vitro. Morphologically, both metal-specific cell staining using p-dimethylaminobenzylidene rhodamine and transmission electron microscopic examinations demonstrated the accumulation of metal gold in the cytoplama and some organella (mitochondria and lysosomes) of the AuTG-treated RSF. These results indicate that one of the anti-rheumatic actions of AuTG might be through its inhibitory action on NF-kappaB.
...
PMID:Inhibition of IL-6 and IL-8 induction from cultured rheumatoid synovial fibroblasts by treatment with aurothioglucose. 1006 13
PG490 (triptolide) is a diterpene triepoxide with potent immunosuppressive and antiinflammatory properties. PG490 inhibits interleukin(IL)-2 expression by normal human peripheral blood lymphocytes stimulated with phorbol 12-myristate 13-acetate (PMA) and antibody to CD3 (IC50 of 10 ng/ml), and with PMA and ionomycin (Iono, IC50 of 40 ng/ml). In Jurkat T-cells, PG490 inhibits PMA/Iono-stimulated IL-2 transcription. PG490 inhibits the induction of DNA binding activity at the purine-box/antigen receptor response element (ARRE)/nuclear factor of activated T-cells (NF-AT) target sequence but not at the NF-kappaB site. PG490 can completely inhibit transcriptional activation at the purine-box/ARRE/NF-AT and NF-kappaB target DNA sequences triggered by all stimuli examined (PMA, PMA/Iono, tumor necrosis factor-alpha). PG490 also inhibits PMA-stimulated activation of a chimeric transcription factor in which the C-terminal TA1 transactivation domain of NF-kappaB
p65
is fused to the DNA binding domain of GAL4. In 16HBE human bronchial epithelial cells,
IL-8
expression is regulated predominantly by NF-kappaB, and PG490 but not cyclosporin A can completely inhibit expression of
IL-8
. The mechanism of PG490 inhibition of cytokine gene expression differs from cyclosporin A and involves nuclear inhibition of transcriptional activation of NF-kappaB and the purine-box regulator operating at the ARRE/NF-AT site at a step after specific DNA binding.
...
PMID:Immunosuppressant PG490 (triptolide) inhibits T-cell interleukin-2 expression at the level of purine-box/nuclear factor of activated T-cells and NF-kappaB transcriptional activation. 1022 9
We demonstrated recently that constitutive expression of proinflammatory cytokines interleukin (IL)-1alpha, IL-6,
IL-8
, and granulocyte-macrophage colony-stimulating factor in head and neck squamous cell carcinoma is correlated with activation of transcription factor nuclear factor (NF)-kappaB/Rel A (p50/
p65
), which binds the promoter region within each of the genes encoding this repertoire of cytokines. NF-kappaB can be activated after signal-dependent phosphorylation and degradation of inhibitor-kappaBalpha and has been reported to promote cell survival and growth. In the present study, we expressed a phosphorylation site mutant of inhibitor-kappaBalpha (IkappaBalphaM) in head and neck squamous cell carcinoma lines UM-SCC-9, -11B, and -38 to determine the effect of inhibition of NF-kappaB on cytokine expression, cell survival in vitro, and growth in vivo. After transfection with IKBalphaM, only a few UM-SCC-9 clones were obtained that stably expressed the mutant IkappaB, suggesting that expression of a mutant IkappaBalpha may affect survival of the transfected UM-SCC cell lines. After cotransfection of IkappaBalphaM with a Lac-Z reporter, we found that the number of surviving beta-galactosidase-positive cells in the three cell lines was reduced by 70-90% when compared with controls transfected with vector lacking the insert. In UM-SCC-9 cells that stably expressed IkappaBalphaM, inhibition of constitutive and tumor necrosis factor-a induced NF-kappaB activation, and production of all four cytokines was observed. Although UM-SCC-9 IkappaBalphaM-transfected cells proliferated at the same rate as vector-transfected cells in vitro, a significant reduction in growth of tumor xenografts was observed in SCID mice in vivo. The decreased growth of UM-SCC-9 IkappaBalphaM-transfected tumor cells accompanied decreased immunohistochemical detection of the activated form of NF-kappaB in situ. These results provide evidence that NF-KB and IkappaBalpha play an important role in survival, constitutive and inducible expression of proinflammatory cytokines, and growth of squamous cell carcinoma. NF-kappaB could serve as a potential target for therapeutic intervention against cytokine and other immediate-early gene responses that contribute to the survival, growth, and pathogenesis of these cancers.
...
PMID:Expression of a dominant-negative mutant inhibitor-kappaBalpha of nuclear factor-kappaB in human head and neck squamous cell carcinoma inhibits survival, proinflammatory cytokine expression, and tumor growth in vivo. 1041 12
Glucocorticoids are potent antiinflammatory drugs. They inhibit the expression of proinflammatory cytokines and adhesion molecules. It has recently been proposed that the underlying basis to such inhibition is the induction of the protein I kappa B, which inhibits the transcription factor NF-kappa B. The latter is a key activator of the genes encoding cytokines and adhesion molecules. The present study shows that the synthetic glucocorticoid, dexamethasone, inhibits the induction of the proinflammatory cytokine
IL-8
and the adhesion molecules VCAM-1 and ICAM-1 in human 1321N1 astrocytoma and SK.N.SH neuroblastoma cells. However, dexamethasone failed to induce I kappa B or inhibit activation of NF-kappa B by IL-1 in the two cell types. EMSA confirmed the identity of the activated NF-kappa B by demonstrating that an oligonucleotide, containing the wild-type NF-kappa B-binding motif, inhibited formation of the NF-kappa B-DNA complexes whereas a mutated form of the NF-kappa B-binding motif was ineffective. In addition, supershift analysis showed that the protein subunits p50 and
p65
were prevalent components in the activated NF-kappa B complexes. The lack of effect of dexamethasone on the capacity of IL-1 to activate NF-kappa B correlated with its inability to induce I kappa B and the ability of IL-1 to cause degradation of I kappa B, even in the presence of dexamethasone. The results presented in this paper strongly suggest that glucocorticoids may exert antiinflammatory effects in cells of neural origin by a mechanism(s) independent of NF-kappa B.
...
PMID:Antiinflammatory effects of glucocorticoids in brain cells, independent of NF-kappa B. 1043 51
The present study aims at investigating the effects of mannitol and dimethylthiourea, known hydroxyl radical scavengers, on lipid peroxidation as an indicative of oxidative damage, NF-kappa B activation and
IL-8
production by Helicobacter pylori in gastric epithelial cells. A human gastric epithelial cell line, AGS, treated with or without mannitol and dimethylthiourea, was incubated in the absence or the presence of H. pylori. As a result, H. pylori significantly stimulated the productions of lipid peroxide and
IL-8
. Treatment with H. pylori resulted in the activation of two species of NF-kappa B dimers (a p50/
p65
heterodimer and a p50 homodimer). Mannitol and dimethylthiourea significantly inhibited lipid peroxide production, NF-kappa B complex formation and
IL-8
production by H. pylori. In conclusion, mannitol and dimethylthiourea may attenuate H. pylori-induced gastric inflammation by inhibiting lipid peroxidation and NF-kappa B activation and thereby decreasing
IL-8
production.
...
PMID:Effects of mannitol and dimethylthiourea on helicobacter pylori-induced IL-8 production in gastric epithelial cells. 1047 80
Pulmonary epithelial cells, covering a 70-m2 surface area, have not previously been considered an important source of chemokines in pulmonary tuberculosis. We analyzed
IL-8
secretion from A549 cells and primary normal human bronchial epithelial cells (NHBE) infected by Mycobacterium tuberculosis. Direct infection of A549 cells by M. tuberculosis caused
IL-8
secretion of 7720 +/- 1610 pg/106 cells, but no
IL-8
secretion from NHBE after 24 h. In contrast, conditioned media from M. tuberculosis-infected human monocytes (CoMTB) induced a much greater
IL-8
secretion of 92,635 +/- 13,180 pg/106 A549 cells and 13,416 +/- 3,529 pg/106 NHBE after 24 h. CoMTB induced rapid
IL-8
mRNA accumulation, which was stable over 24 h, compared with TNF-alpha-induced transcripts. CoMTB stimulated nuclear binding of
p65
, p50, and c-Rel subunits of NF-kappa B to
IL-8
promoter sequences. Transient transfections with
IL-8
promoter reporter constructs showed NF-kappa B binding-site mutations abolished
IL-8
promoter activity while NF-IL-6 binding-site mutations decreased promoter activity to 50.2 +/- 6.3% of wild-type activity. IL-1R antagonist but not neutralizing anti-TNF-alpha inhibited epithelial cell
IL-8
secretion, mRNA accumulation, and NF-kappa B binding. Recombinant IL-1 beta (2 ng/ml) induced similar levels of
IL-8
secretion to CoMTB in both A549 cells and NHBE. Pulmonary epithelial cells are a major source of
IL-8
in the initial host response to pulmonary tuberculosis. Such
IL-8
secretion is NF-kappa B dependent, NF-IL-6 requiring, and activated by an IL-1-mediated pathway as a consequence of phagocytosis of M. tuberculosis by monocytes.
...
PMID:Pulmonary epithelial cells are a source of IL-8 in the response to Mycobacterium tuberculosis: essential role of IL-1 from infected monocytes in a NF-kappa B-dependent network. 1049 Sep 95
We previously reported that human head and neck squamous cell carcinomas (HNSCCs) express the pro-inflammatory and pro-angiogenic cytokines interleukin (IL)-1alpha, IL-6,
IL-8
, and granulocyte-macrophage colony-stimulating factor in vitro and in vivo. The promoter region of the genes encoding these cytokines include binding sites for the transcription factors nuclear factor (NF) kappaB/Rel A, activator protein-1 (AP-1), and CCAAT enhancer-binding protein beta (C/EBPbeta, or NF-IL6), which have been reported to contribute to activation of these cytokine genes. In the study presented here, we examined the activation, composition, and function of these transcription factors in HNSCC cell lines that express pro-inflammatory cytokines, by using electrophoretic mobility shift and reporter-gene assays. Constitutive activation of NF-kappaB, AP-1, and NF-IL6 DNA-binding proteins was detected. Supershift analysis with antibodies specific for NF-kappaB, AP-1, and NF-IL6 binding proteins showed that the NF-kappaB-binding protein included
p65
/Rel A and p50; AP-1 activity included c-jun, junB, junD, and Fra-1; and NF-IL6 included C/EBPbeta. Mutational analysis of the NF-kappaB, AP-1, and NF-IL6 sites in the
IL-8
promoter region showed that NF-kappaB and AP-1 sites contributed to constitutive
IL-8
reporter activity in HNSCC. HNSCC lines that exhibited increased
IL-8
secretion relative to simian virus 40-immortalized and primary keratinocyte cell lines also demonstrated a concordant increase in NF-kappaB reporter activity relative to nonmalignant keratinocytes. We concluded that the early transcription factors NF-kappaB, AP-1, and NF-IL6 are constitutively activated in human HNSCC cell lines and that NF-kappaB and AP-1 promote expression of the pro-inflammatory and pro-angiogenic cytokine
IL-8
in HNSCC. The demonstration of the activation of these transcription factors will be helpful in defining the identity and role of these and other early gene products that contribute to pathogenesis of the malignant phenotype in HNSCC and in defining potential targets for pharmacologic and molecular therapy of HNSCC. Mol. Carcinog. 26:119-129, 1999. Published 1999 Wiley-Liss, Inc.
...
PMID:Constitutive activation of transcription factors NF-(kappa)B, AP-1, and NF-IL6 in human head and neck squamous cell carcinoma cell lines that express pro-inflammatory and pro-angiogenic cytokines. 1050 55
Expression of the pleiotropic cytokine interleukin (IL)-6 can be stimulated by the proinflammatory cytokine tumor necrosis factor (TNF) and the microbial alkaloid staurosporine (STS). In this report, the transcriptional mechanisms were thoroughly investigated. Whereas transcription factors binding to the activator protein-1-, cAMP-responsive element-, and CAAT enhancer-binding protein-responsive sequences are necessary for gene activation by STS, nuclear factor (NF)-kappaB alone is responsible and sufficient for inducibility by TNF, which reveals distinct signaling pathways for both compounds. At the cofactor level, cAMP-responsive element-binding protein-binding protein (CBP) or p300 potentiate basal and induced IL-6 promoter activation via multiple protein-protein interactions with all transcription factors bound to the promoter DNA. However, the strongest promoter activation relies on the
p65
NF-kappaB subunit, which specifically engages CBP/p300 for maximal transcriptional stimulation by its histone acetyltransferase activity. Moreover, treatment of chromatin-integrated promoter constructions with the histone deacetylase inhibitor trichostatin A exclusively potentiates TNF-dependent (i.e. NF-kappaB-mediated) gene activation, while basal or STS-stimulated IL-6 promoter activity remains completely unchanged. Similar observations were recorded with other natural NF-kappaB-driven promoters, namely
IL-8
and endothelial leukocyte adhesion molecule (ELAM). We conclude that, within an "enhanceosome-like" structure, NF-kappaB is the central mediator of TNF-induced IL-6 gene expression, involving CBP/p300 and requiring histone acetyltransferase activity.
...
PMID:The nuclear factor-kappaB engages CBP/p300 and histone acetyltransferase activity for transcriptional activation of the interleukin-6 gene promoter. 1054 43
Clostridium difficile causes an intense inflammatory colitis through the actions of two large exotoxins, toxin A and toxin B.
IL-8
is believed to play an important role in the pathophysiology of C. difficile-mediated colitis, although the mechanism whereby the toxins up-regulate the release of
IL-8
from target cells is not well understood. In this study, we investigated the mechanisms through which toxin A induces
IL-8
secretion in human monocytes. We found that cellular uptake of toxin A is required for the up-regulation of
IL-8
, an effect that is not duplicated by a recombinant toxin fragment comprising the cell-binding domain alone. Toxin A induced
IL-8
expression at the level of gene transcription and this effect occurred through a mechanism requiring intracellular calcium and calmodulin activation. Additionally, the effects of toxin A were inhibited by the protein tyrosine kinase inhibitor genistein, but were unaffected by inhibitors of protein kinase C and phosphatidylinositol-3 kinase. We determined that toxin A activates nuclear translocation of the transcription factors NF-kappa B and AP-1, but not NF-IL-6. NF-kappa B inhibitors blocked the ability of toxin A to induce
IL-8
secretion, and supershift analysis indicated that the major isoform of NF-kappa B activated by the toxin is a p50-
p65
heterodimer. This study is the first to identify intracellular signaling pathways and transcription factors involved in the C. difficile toxin-mediated up-regulation of
IL-8
synthesis and release by target cells. This information should increase our understanding of the pathogenesis of C. difficile colitis and the nature of
IL-8
gene regulation as well.
...
PMID:Roles of intracellular calcium and NF-kappa B in the Clostridium difficile toxin A-induced up-regulation and secretion of IL-8 from human monocytes. 1055 38
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