Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.10 (IKK)
4,900 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of p44/42 mitogen-activated protein kinase (MAPK), p38, and c-Jun NH(2)-terminal kinase (JNK) in tumor necrosis factor (TNF)-alpha-induced cyclooxygenase (COX)-2 expression was studied in NCI-H292 epithelial cells. TNF-alpha-mediated COX-2 expression and COX-2 promoter activity were inhibited by the MAPK kinase inhibitor PD98059 or the p38 inhibitor SB203580. Treatment of cells for 10 min with TNF-alpha resulted in activation of p44/42 MAPK, p38, and JNK. C2-ceramide (a cell-permeable ceramide analog), bacterial neutral sphingomyelinase (Smase; an enzyme that degrades sphingomyelin to ceramide), and N-oleoylethanolamine (a ceramidase inhibitor) all induced activation of MAPKs, COX-2 expression, nuclear factor (NF)-kappaB DNA-protein binding, and COX-2 promoter activity. The inactive analog, dihydro-C2-ceramide, had no effect. SMase- or C2-ceramide-induced COX-2 expression and COX-2 promoter activity were also inhibited by PD98059 or SB203580. Glutathione, a neutral SMase inhibitor, attenuated TNF-alpha- or SMase-induced activation of MAPKs, COX-2 expression, and COX-2 promoter activity. TNF-alpha- or C2-ceramide-induced COX-2 promoter activity was inhibited by the dominant negative mutant of extracellular signal-regulated kinase 2, p38, JNK, IkappaB kinase (IKK)1, or IKK2. IKK activity was stimulated by either TNF-alpha or C2-ceramide, and these effects were inhibited by PD98059 or SB203580. All these results suggest that, in NCI-H292 epithelial cells, activation of MAPKs by ceramide contributes to the TNF-alpha signaling that occurs downstream of neutral SMase activation and results in the stimulation of IKK1/2, and NF-kappaB in the COX-2 promoter, followed by initiation of COX-2 expression.
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PMID:Tumor necrosis factor-alpha-induced cyclooxygenase-2 expression via sequential activation of ceramide-dependent mitogen-activated protein kinases, and IkappaB kinase 1/2 in human alveolar epithelial cells. 1117 44

The prostaglandin H synthases (PGHS) catalyze the conversion of arachidonic acid to prostaglandin H(2), the committed step in prostanoid synthesis. Two forms of PGHS exist, PGHS-1 (COX-1) and PGHS-2 (COX-2). The gene encoding the latter form is known to be inducible by a number of stimuli including several inflammatory mediators. Recent evidence indicates that the inducible cyclooxygenase may have both pro- and anti-inflammatory properties through the generation of different prostaglandins. Previous reports indicate that the transcription factor NF-kappaB can function upstream of COX-2 to control transcription of this gene and that the cyclopentenone prostaglandins can inhibit NF-kappaB activation via the inhibition of the IkappaB kinase. Thus, it is suggested that cyclopentenones feed back to inhibit continued nuclear accumulation of NF-kappaB. In this report we demonstrate COX-2 expression inhibits nuclear translocation of NF-kappaB, and we confirm that the cyclopentenone prostaglandins inhibit NF-kappaB. In addition, we show that prostaglandin E(2) and its analogs promote the inherent transcriptional activity of the p65/RelA subunit of NF-kappaB in a manner independent of induced nuclear accumulation. Consistent with this evidence, prostaglandin E(2) strongly synergizes with the inflammatory cytokine tumor necrosis factor-alpha to promote NF-kappaB-dependent transcription and gene expression. The data provide a molecular rationale to explain both the pro- and anti-inflammatory nature of COX-2.
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PMID:Positive and negative regulation of NF-kappaB by COX-2: roles of different prostaglandins. 1150 75

In addition to antagonizing inflammation by inhibiting the activity of cyclooxygenases (COX), nonsteroidal anti-inflammatory drugs (NSAID) block T-cell activation. The immunosuppressant activity of NSAID correlates with their ability to block transcription factors required for the expression of inducible response genes triggered by T-cell antigen receptor (TCR) engagement. Whereas the inhibition of nuclear factor-kappaB by aspirin and sodium salicylate can be partly accounted for by their binding to IkappaB kinase-beta, the broad range of transcriptional targets of NSAID suggests that the products of COX activity might affect one or more among the early steps in the TCR-signaling cascade. Here we show that the inhibition of NF-AT activation by NSAID correlates with a selective inhibition of p38 MAP kinase induction. The suppression of TCR-dependent p38 activation by NSAID can be fully overcome by prostaglandin E(2), underlining the requirement for COX activity in p38 activation. Furthermore, the inhibition of COX-1 results in defective induction of the COX-2 gene, which behaves as an early TCR responsive gene. The data identify COX-1 and COX-2 as integral and sequential components of TCR signaling to p38 and contribute to elucidate the molecular basis of immunosuppression by NSAID.
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PMID:Nonsteroidal anti-inflammatory drugs suppress T-cell activation by inhibiting p38 MAPK induction. 1170 Mar 29

Because the transcription factor, nuclear factor (NF)-kappaB, plays a key role in cellular inflammatory and immune responses, components of the NF-kappaB-activating signaling pathways are frequently used as targets for anti-inflammatory agents. This study shows that 2-(3',4'-dihydroxyphenyl)-5-hydroxybenzo[b]furan (GF-015) and 2,3-di(3',4'-dihydroxy-transstyryl) pyridine (GF-90), two conjugated polyhydroxybenzene derivatives, inhibited a common step in NF-kappaB activation in human NCI-H292 epithelial cells by preventing tumor necrosis factor (TNF)-alpha- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced IkappaB kinase (IKK) complex activation. Both agents inhibited the TNF-alpha- or TPA-induced expression of cyclooxygenase (COX)-2 mRNA and protein, COX-2 promoter activity, and prostaglandin E2 (PGE2) production. Overexpression of wild-type NF-kappaB-inducing kinase, IKKalpha, and IKKbeta led, respectively, to 3.5-, 2.6-, and 2.6-fold increases in COX-2 promoter activity, and these effects were inhibited by both compounds. GF-015 and GF-90 also prevented the TNF-alpha- and TPA-induced activation of IKK and NF-kappaB-specific DNA-protein binding activity. These results suggest that the inhibitory effect of GF-015 and GF-90 on TNF-alpha-induced COX-2 protein expression was caused by suppression of IKK activity and NF-kappaB activation in the COX-2 promoter, resulting in attenuation of COX-2 gene expression and PGE2 production.
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PMID:Conjugated polyhydroxybenzene derivatives block tumor necrosis factor-alpha-mediated nuclear factor-kappaB activation and cyclooxygenase-2 gene transcription by targeting IkappaB kinase activity. 1172 53

1. Although capsaicin analogs might be a potential strategy to manipulate inflammation, the mechanism is still unclear. In this study, the effects and action mechanisms of vanilloid analogs on iNOS and COX-2 expression were investigated in RAW264.7 macrophages. 2. Capsaicin and resiniferatoxin (RTX) can inhibit LPS- and IFN-gamma-mediated NO production, and iNOS protein and mRNA expression with similar IC50 values of around 10 microm. 3. Capsaicin also transcriptionally inhibited LPS- and PMA-induced COX-2 expression and PGE2 production. However, this effect exhibited a higher potency (IC50: 0.2 microm), and RTX failed to elicit such responses at 10 microm. 4. Interestingly, we found that capsazepine, a competitive TRPV1 antagonist, did not prevent the inhibition elicited by capsaicin or RTX. Nevertheless, it mimicked vanilloids in inhibiting iNOS/NO and COX-2/PGE2 induction with an IC50 value of 3 microm. RT-PCR and immunoblotting analysis excluded the expression of TRPV1 in RAW264.7 macrophages. 5. The DNA binding assay demonstrated the abilities of vanilloids to inhibit LPS-elicited NF-kappaB and AP-1 activation and IFN-gamma-elicited STAT1 activation. The reporter assay of AP-1 activity also supported this action. 6. The kinase assay indicated that ERK, JNK, and IKK activation by LPS were inhibited by vanilloids. 7. In conclusion, vanilloids can modulate the expression of inflammatory iNOS and COX-2 genes in macrophages through interference with upstream signalling events of LPS and IFN-gamma. These findings provide new insights into the potential benefits of the active ingredient in hot chilli peppers in inflammatory conditions.
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PMID:Signal transduction for inhibition of inducible nitric oxide synthase and cyclooxygenase-2 induction by capsaicin and related analogs in macrophages. 1453 Feb 14

Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been shown to inhibit the effects of proinflammatory cytokines such as interleukin-1beta (IL-1beta). This cytokine plays a key role in articular pathophysiologies by inducing the production of inflammatory mediators such as nitric oxide (NO) and prostaglandin E(2) (PGE(2)). We previously demonstrated that 15d-PGJ(2) was more potent than troglitazone to counteract IL-1beta effects on chondrocytes. Here, we studied the action of 15d-PGJ(2) on intracellular targets in nuclear factor-kappaB (NF-kappaB) signalling pathway in IL-1beta treated rat chondrocytes. We found that 15d-PGJ(2) decreased inhibitor kappaBalpha (IkappaBalpha) degradation but not its phosphorylation by specifically inhibiting IkappaB kinase beta (IKKbeta), but not IKKalpha, enzymatic activity. We further evaluated the involvement of PPARgamma in the anti-inflammatory action of its ligands. In chondrocytes overexpressing functional PPARgamma protein, 15d-PGJ(2) pre-treatment inhibited inducible NO synthase and COX-2 mRNA expression, nitrite and PGE(2) production, p65 translocation and NF-kappaB activation. Troglitazone or rosiglitazone pre-treatment had no effect. 15d-PGJ(2) exhibited the same effect in chondrocytes overexpressing mutated PPARgamma protein. These results suggest that 15d-PGJ(2) exerts its anti-inflammatory effect in rat chondrocytes by a PPARgamma-independent mechanism, which can be conferred to a partial inhibition of IkappaBalpha degradation.
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PMID:15-Deoxy-delta(12,14)-prostaglandin J(2) inhibits IL-1beta-induced IKK enzymatic activity and IkappaBalpha degradation in rat chondrocytes through a PPARgamma-independent pathway. 1530 20

Guggulsterone, derived from Commiphora mukul and used to treat obesity, diabetes, hyperlipidemia, atherosclerosis, and osteoarthritis, has been recently shown to antagonize the farnesoid X receptor and decrease the expression of bile acid-activated genes. Because activation of NF-kappaB has been closely linked with inflammatory diseases affected by guggulsterone, we postulated that it must modulate NF-kappaB activation. In the present study, we tested this hypothesis by investigating the effect of this steroid on the activation of NF-kappaB induced by inflammatory agents and carcinogens. Guggulsterone suppressed DNA binding of NF-kappaB induced by tumor necrosis factor (TNF), phorbol ester, okadaic acid, cigarette smoke condensate, hydrogen peroxide, and interleukin-1. NF-kappaB activation was not cell type-specific, because both epithelial and leukemia cells were inhibited. Guggulsterone also suppressed constitutive NF-kappaB activation expressed in most tumor cells. Through inhibition of IkappaB kinase activation, this steroid blocked IkappaBalpha phosphorylation and degradation, thus suppressing p65 phosphorylation and nuclear translocation. NF-kappaB-dependent reporter gene transcription induced by TNF, TNFR1, TRADD, TRAF2, NIK, and IKK was also blocked by guggulsterone but without affecting p65-mediated gene transcription. In addition, guggulsterone decreased the expression of gene products involved in anti-apoptosis (IAP1, xIAP, Bfl-1/A1, Bcl-2, cFLIP, and survivin), proliferation (cyclin D1 and c-Myc), and metastasis (MMP-9, COX-2, and VEGF); this correlated with enhancement of apoptosis induced by TNF and chemotherapeutic agents. Overall, our results indicate that guggulsterone suppresses NF-kappaB and NF-kappaB-regulated gene products, which may explain its anti-inflammatory activities.
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PMID:Guggulsterone inhibits NF-kappaB and IkappaBalpha kinase activation, suppresses expression of anti-apoptotic gene products, and enhances apoptosis. 1532 87

Evodiamine, an alkaloidal component extracted from the fruit of Evodiae fructus (Evodia rutaecarpa Benth., Rutaceae), exhibits antiproliferative, antimetastatic, and apoptotic activities through a poorly defined mechanism. Because several genes that regulate cellular proliferation, carcinogenesis, metastasis, and survival are regulated by nuclear factor-kappaB (NF-kappaB), we postulated that evodiamine mediates its activity by modulating NF-kappaB activation. In the present study, we investigated the effect of evodiamine on NF-kappaB and NF-kappaB-regulated gene expression activated by various carcinogens. We demonstrate that evodiamine was a highly potent inhibitor of NF-kappaB activation, and it abrogated both inducible and constitutive NF-kappaB activation. The inhibition corresponded with the sequential suppression of IkappaBalpha kinase activity, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation, p65 nuclear translocation, and p65 acetylation. Evodiamine also inhibited tumor necrosis factor (TNF)-induced Akt activation and its association with IKK. Suppression of Akt activation was specific, because it had no effect on JNK or p38 MAPK activation. Evodiamine also inhibited the NF-kappaB-dependent reporter gene expression activated by TNF, TNFR1, TRADD, TRAF2, NIK, and IKK but not that activated by the p65 subunit of NF-kappaB. NF-kappaB-regulated gene products such as Cyclin D1, c-Myc, COX-2, MMP-9, ICAM-1, MDR1, Survivin, XIAP, IAP1, IAP2, FLIP, Bcl-2, Bcl-xL, and Bfl-1/A1 were all down-regulated by evodiamine. This down-regulation potentiated the apoptosis induced by cytokines and chemotherapeutic agents and suppressed TNF-induced invasive activity. Overall, our results indicated that evodiamine inhibits both constitutive and induced NF-kappaB activation and NF-kappaB-regulated gene expression and that this inhibition may provide a molecular basis for the ability of evodiamine to suppress proliferation, induce apoptosis, and inhibit metastasis.
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PMID:Evodiamine abolishes constitutive and inducible NF-kappaB activation by inhibiting IkappaBalpha kinase activation, thereby suppressing NF-kappaB-regulated antiapoptotic and metastatic gene expression, up-regulating apoptosis, and inhibiting invasion. 1571 Jun 1

1 Uniaxial cyclic stretch leads to an upregulation of cyclooxygenase (COX)-2 through increases in the intracellular Ca(2+) concentration via the stretch-activated (SA) channel and following nuclear factor kappa B (NF-kappaB) activation in human fibroblasts. However, the signaling mechanism as to how the elevated Ca(2+) activates NF-kappaB is unknown. In this study, we examined the involvement of reactive oxygen species (ROS) as an intermediate signal, which links the elevated Ca(2+) with NF-kappaB activation. 2 4-Hydroxy-2-nonenal (HNE) was produced and modified IkappaB peaking at 2 min. The phosphorylation of IkappaB peaked at 8 min. HNE modification and IkappaB phosphorylation, NF-kappaB translocation to the nucleus, and following COX-2 production were inhibited by extracellular Ca(2+) removal or Gd(3+) application, as well as by the antioxidants. The stretch-induced Ca(2+) increase was inhibited by extracellular Ca(2+) removal, or Gd(3+) application. 3 IkappaB kinase (IKK) activity peaked at 4 min, which was inhibited by extracellular Ca(2+) removal, Gd(3+) or the antioxidants. IKK was also HNE-modified and, similarly to IkappaB, peaked at 2 min. IKK under static conditions was activated by exogenously applied HNE at a relatively low dose (1 microM), while it was inhibited at higher concentrations, suggesting that HNE could be one of the candidate signals in the stretch-induced NF-kappaB activation. 4 The present study suggests that the NF-kappaB activation by cyclic stretch is mediated by the following signal cascade: SA channel activation --> intracellular Ca(2+) increase --> production of ROS --> activation of IKK --> phosphorylation of IkappaB --> NF-kappaB translocation to the nucleus.
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PMID:Involvement of reactive oxygen species in cyclic stretch-induced NF-kappaB activation in human fibroblast cells. 1577 40

Zerumbone found in subtropical ginger Zingiber zerumbet Smith exhibits antiproliferative and antiinflammatory activities but underlying molecular mechanisms are poorly understood. As several genes that regulate proliferation and apoptosis are regulated by nuclear factor (NF)-kappaB, we hypothesized that zerumbone mediates its activity through the modulation of NF-kappaB activation. We found that zerumbone suppressed NF-kappaB activation induced by tumor necrosis factor (TNF), okadaic acid, cigarette smoke condensate, phorbol myristate acetate, and H2O2 and that the suppression was not cell type specific. Interestingly, alpha-humulene, a structural analogue of zerumbone lacking the carbonyl group, was completely inactive. Besides being inducible, constitutively active NF-kappaB was also inhibited. NF-kappaB inhibition by zerumbone correlated with sequential suppression of the IkappaBalpha kinase activity, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation, p65 nuclear translocation, and p65 acylation. Zerumbone also inhibited the NF-kappaB-dependent reporter gene expression activated by TNF, TNFR1, TRADD, TRAF2, NIK, and IKK but not that activated by the p65 subunit of NF-kappaB. NF-kappaB-regulated gene products, such as cyclin D1, COX-2, MMP-9, ICAM-1, c-Myc, survivin, IAP1, IAP2, XIAP, Bcl-2, Bcl-xL, Bfl-1/A1, TRAF1 and FLIP, were all downregulated by zerumbone. This downregulation led to the potentiation of apoptosis induced by cytokines and chemotherapeutic agents. Zerumbone's inhibition of expression of these NF-kappaB-regulated genes also correlated with the suppression of TNF-induced invasion activity. Overall, our results indicated that zerumbone inhibits the activation of NF-kappaB and NF-kappaB-regulated gene expression induced by carcinogens and that this inhibition may provide a molecular basis for the prevention and treatment of cancer by zerumbone.
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PMID:Zerumbone abolishes NF-kappaB and IkappaBalpha kinase activation leading to suppression of antiapoptotic and metastatic gene expression, upregulation of apoptosis, and downregulation of invasion. 1600 45


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