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 ability of neonatal and adult cardiomyocytes to activate the nuclear factor (NF)-kappaB pathway in response to lipopolysaccharide and interleukin-1beta challenge has been investigated and compared with that of peritoneal macrophages. The activation of the IkappaB kinase and the phosphorylation and degradation of IkappaBalpha and IkappaBbeta was much lower in adult cardiomyocytes than in the neonatal counterparts and macrophages. This restricted activation of the NF-kappaB pathway resulted in a significant reduction in the time of nuclear activation of NF-kappaB, as deduced by electrophoretic mobility shift assays and in the transcription of target genes, such as IkappaBalpha, cyclooxygenase-2 (COX-2) and nitric-oxide synthase-2 (NOS-2). Studies on chromatin immunoprecipitation showed binding of NF-kappaB proteins to the regulatory kappaB sites identified in the promoters of the IkappaBalpha, COX-2, and NOS-2 genes in macrophages and, to a lower extent, in neonatal cardiomyocytes. The binding to these kappaB sites in adult cardiomyocytes was observed only in the IkappaBalpha promoter and was minimal or absent in the COX-2 and NOS-2 promoters, respectively, suggesting a restricted activation of NF-kappaB-regulated genes in these cells. These data indicate that the function of the NF-kappaB pathway in adult cardiomyocytes is limited in time, which results in the expression of a reduced number of genes and provides a functional explanation for the absence of NOS-2 inducibility in these cells under proinflammatory conditions.
 ...
PMID:Selective impairment of nuclear factor-kappaB-dependent gene transcription in adult cardiomyocytes: relevance for the regulation of the inflammatory response in the heart. 1767 83

Severe acute respiratory syndrome coronavirus (SARS-CoV) infects many organs, such as lung, liver, and immune organs and causes life-threatening atypical pneumonia, SARS causes high morbidity and mortality rates. The molecular mechanism of SARS pathogenesis remains elusive. Inflammatory stimuli can activate IkappaB kinase (IKK) signalsome and subsequently the nuclear factor kappa B (NF-kappaB), which influences gene expression of cyclooxygenase-2 (Cox-2) along with other transcription factors. In this work, we found that the membrane (M) protein of SARS-CoV physically interacted with IKKbeta using a co-immunoprecipitation assay (IPA). Expression of M suppressed tumor necrosis factor alpha (TNF-alpha) induced NF-kappaB activation using a luciferase reporter assay. Further investigation showed M protein suppressed Cox-2 expression using a luciferase reporter gene assay, RT-PCR and Western blot analysis. The carboxyl terminal of M protein was sufficient for the M protein function. Together, these results indicate that SARS-CoV M suppresses NF-kappaB activity probably through a direct interaction with IKKbeta, resulting in lower Cox-2 expression. Suppression of NF-kappaB activity and Cox-2 expression may contribute to SARS pathogenesis.
 ...
PMID:The membrane protein of SARS-CoV suppresses NF-kappaB activation. 1770 88

Based on our previous observations that 1-O-acetylbritannilactone (R)-4((3aS,4S,7aR)-4-hydroxy-6-methyl-3-methylene-2-oxo-2,3,3a,4,7,7a-hexahydrobenzofuran-5-yl)pentyl acetate (ABL) suppresses prostaglandin E(2) and nitric oxide synthesis in macrophages, the present study was designed to explore the effect of ABL on neointimal hyperplasia after balloon injury and its mechanism of action. In male Sprague-Dawley rats, 26 mg/kg ABL or polyglycol (control) was administered daily from 3 days before injury to 2 weeks after conventional balloon injury. ABL administration led to a significant reduction in neointimal formation (neointima to media ratio, 1.94 +/- 0.43 versus 0.84 +/- 0.29, P < 0.01) and proliferative activity of vascular smooth muscle cells after balloon injury in rats. Western blot analysis revealed that this is correlated to the inhibition of nuclear factor (NF)-kappaB activation and to the reduced expression of cyclooxygenase-2. Investigation of potential signaling pathways demonstrated that ABL inhibited NF-kappaB activation via the blockade of the inhibitor of NF-kappaB kinase-beta activation and the suppression of the degradation of the inhibitors of NF-kappaB-alpha. These findings suggest that ABL is a potential inhibitor of neointimal formation because it blocks injury-induced NF-kappaB activation and may have beneficial effects in reducing the risk of restenosis after angioplasty.
 ...
PMID:Acetylbritannilactone Inhibits Neointimal Hyperplasia after Balloon Injury of Rat Artery by Suppressing Nuclear Factor-{kappa}B Activation. 1791 74

Seliciclib (CYC202, R-Roscovitine) is a 2, 6, 9-substituted purine analog that is currently in phase II clinical trials as an anticancer agent. We show in this study that R-Roscovitine can downregulate nuclear factor-kappa B (NF-kappaB) activation in response to tumor necrosis factor (TNF)alpha and interleukin 1. Activation of p53-dependent transcription is not compromised when R-Roscovitine is combined with TNFalpha. We characterize the molecular mechanism governing NF-kappaB repression and show that R-Roscovitine inhibits the IkappaB kinase (IKK) kinase activity, which leads to defective IkappaBalpha phosphorylation, degradation and hence nuclear function of NF-kappaB. We further show that the downregulation of the NF-kappaB pathway is also at the level of p65 modification and that the phosphorylation of p65 at Ser 536 is repressed by R-Roscovitine. Consistent with repression of canonical IKK signaling pathway, the induction of NF-kappaB target genes monocyte chemoattractant protein, intercellular adhesion molecule-1, cyclooxygenase-2 and IL-8 is also inhibited by R-Roscovitine. We further show that treatment of cells with TNFalpha and R-Roscovitine causes potentiation of cell death. Based on these results, we suggest the potential use of R-Roscovitine as a bitargeted anticancer drug that functions by simultaneously causing p53 activation and NF-kappaB suppression. This study also provides mechanistic insight into the molecular mechanism of action of R-Roscovitine, thereby possibly explaining its anti-inflammatory properties.
 ...
PMID:R-Roscovitine simultaneously targets both the p53 and NF-kappaB pathways and causes potentiation of apoptosis: implications in cancer therapy. 1797 52

Luteolin, a plant flavonoid, has potent anti-inflammatory properties both in vitro and in vivo. However, the molecular mechanism of luteolin-mediated immune modulation has not been fully understood. In this study, we examined the effects of luteolin on the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)), as well as the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) in mouse alveolar macrophage MH-S and peripheral macrophage RAW 264.7 cells. Luteolin dose-dependently inhibited the expression and production of these inflammatory genes and mediators in macrophages stimulated with lipopolysaccharide (LPS). Semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay further confirmed the suppression of LPS-induced TNF- alpha, IL-6, iNOS and COX-2 gene expression by luteolin at a transcriptional level. Luteolin also reduced the DNA binding activity of nuclear factor-kappa B (NF-kappaB) in LPS-activated macrophages. Moreover, luteolin blocked the degradation of IkappaB-alpha and nuclear translocation of NF-kappaB p65 subunit. In addition, luteolin significantly inhibited the LPS-induced DNA binding activity of activating protein-1 (AP-1). We also found that luteolin attenuated the LPS-mediated protein kinase B (Akt) and IKK phosphorylation, as well as reactive oxygen species (ROS) production. In sum, these data suggest that, by blocking NF-kappaB and AP-1 activation, luteolin acts to suppress the LPS-elicited inflammatory events in mouse alveolar macrophages, and this effect was mediated, at least in part, by inhibiting the generation of reactive oxygen species. Our observations suggest a possible therapeutic application of this agent for treating inflammatory disorders in lung.
 ...
PMID:Luteolin suppresses inflammation-associated gene expression by blocking NF-kappaB and AP-1 activation pathway in mouse alveolar macrophages. 1797 62

A series of 11 labdane-type diterpenoids (1-11) with various patterns of substitution were tested for potential anti-inflammatory activity. Of these compounds, 4 and 11 were selected to evaluate their influence on targets relevant to the regulation of the inflammatory response. These diterpenoids reduced the production of nitric oxide (NO), prostaglandin E2, and tumor necrosis factor-alpha in LPS-activated RAW 264.7 macrophages, with IC50 in the range 1-10 microM. Inhibition of these inflammatory mediators was related to inhibition of the expression of nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2) at the transcriptional level, as determined by western-blot and RT-PCR. Examination of the effects of these diterpenoids on nuclear factor kappaB signaling showed that both compounds inhibit the phosphorylation of IkappaBalpha and IkappaBbeta, preventing their degradation and the nuclear translocation of the NF-kappaB p65 subunit. Inhibition of IKK activity was also observed. These derivatives displayed significant anti-inflammatory activity in vivo, suppressing mouse ear edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and inhibiting myeloperoxidase activity, an index of neutrophil infiltration. The anti-inflammatory effects of these labdane diterpenoids, together with their low cell toxicity, suggest potential therapeutic applications in the regulation of the inflammatory response.
 ...
PMID:Suppression of inflammatory responses by labdane-type diterpenoids. 1819 Sep 42

Cyclooxygenase-2 (COX-2) is reported to be one of the early-response gene products induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). However, the relevance of COX-2 in TPA-induced cell transformation and the underlying mechanisms remains to be explored. Initially, we verified COX-2 induction after TPA treatment in mouse embryonic fibroblasts (MEF) and mouse epidermal cells Cl 41. More importantly, introduction of COX-2 small interfering RNA in MEFs or Cl 41 cells suppressed the cell transformation caused by TPA treatment. This inhibition could be reversed by overexpression of human full-length COX-2, indicating that COX-2 is at least one of the critical molecules involved in TPA-induced cell transformation. We further showed that TPA-promoted cell cycle progression was partially suppressed by COX-2 small interfering RNA, indicating that COX-2 also participated in TPA-associated cell cycle progression. Investigation of the upstream signaling pathways revealed that c-Jun-NH(2)-kinase 1 (JNK1), but not JNK2, played important roles in COX-2 induction, because knockout of JNK1 gene rather than JNK2 gene markedly impaired COX-2 induction. Furthermore, inhibition of c-Jun/activator protein 1 pathway or JNKs/c-Jun pathway by overexpression of dominant negative mutants of c-Jun, or MKK4 and MKK7 together, resulted in impairment of COX-2 induction, suggesting that JNK1/c-Jun/activator protein 1 pathway is involved in TPA-associated COX-2 induction. In contrast, IKK/p65 nuclear factor-kappaB pathway was not implicated because knockout of IKKalpha, IKKbeta, or p65 gene did not affect COX-2 induction although nuclear factor-kappaB was activated by TPA. In addition, the TPA-promoted cell cycle progression was found impaired in JNK1-deficient, but not in JNK2-deficient, MEFs. Our results show that JNK1-associated COX-2 induction is implicated in TPA-associated cell transformation and cell cycle progression.
 ...
PMID:A JNK1/AP-1-dependent, COX-2 induction is implicated in 12-O-tetradecanoylphorbol-13-acetate-induced cell transformation through regulating cell cycle progression. 1823 71

It has been shown that ultrasound (US) stimulation accelerates fracture healing in the animal models and in clinical studies. Cyclooxygenase-2 (COX-2) is a crucial mediator in mechanically induced bone formation. AMP-activated protein kinase (AMPK) has reported to sense and regulate the cellular energy status in various cell types. Here we found that US-mediated COX-2 expression was attenuated by LKB1 and AMPKalpha1 small interference RNA (siRNA) in human osteoblasts. Pretreatment of osteoblasts with AMPK inhibitor (araA and compound C), p38 inhibitor (SB203580), NF-kappaB inhibitor (PDTC), IkappaB protease inhibitor (TPCK) and NF-kappaB inhibitor peptide also inhibited the potentiating action of US. US increased the kinase activity and phosphorylation of LKB1, AMPK and p38. Stimulation of osteoblasts with US activated IkappaB kinase alpha/beta (IKKalpha/beta), IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation at Ser(276), p65 and p50 translocation from the cytosol to the nucleus, and kappaB-luciferase activity. US-mediated an increase of IKKalpha/beta activity, kappaB-luciferase activity and p65 and p50 binding to the NF-kappaB element was inhibited by araA, SB203580 and LKB1 siRNA. Our results suggest that US increased COX-2 expression in osteoblasts via the LKB1/AMPKalpha1/p38/IKKalphabeta and NF-kappaB signaling pathway.
 ...
PMID:AMP-activated protein kinase is involved in COX-2 expression in response to ultrasound in cultured osteoblasts. 1827 12

In this study, the anti-inflammatory effects of flavonoids isolated from the roots of Glycyrrhiza uralensis (Leguminosae), namely, isoliquiritin (the glycoside of isoliquirigenin) and isoliquiritigenin (the aglycone of isoliquiritin) were evaluated on lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Isoliquiritigenin (ILG) more potently inhibited LPS-induced nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production than isoliquiritin (ILT). Consistent with these findings, ILG reduced the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. In addition, the release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and the mRNA expression levels of these cytokines were reduced by ILG in a dose-dependent manner. Moreover, ILG attenuated the LPS-induced DNA binding activity and the transcription activity of nuclear factor-kappa B (NF-kappaB), and this was associated with a decrease in inhibitory kappa B-alpha (IkappaB-alpha) phosphorylation and in the subsequent blocking of p65 and p50 protein translocations to the nucleus. Furthermore, ILG suppressed the phosphorylations of IkappaB kinase (IKK), ERK1/2, and p38, whereas the phosphorylation of JNK1/2 was unaffected. These results suggest that the anti-inflammatory properties of ILG are caused by iNOS, COX-2, TNF-alpha, and IL-6 down-regulation due to NF-kappaB inhibition via the suppression of IKK, ERK1/2 and p38 phosphorylation in RAW 264.7 cells.
 ...
PMID:Isoliquiritigenin isolated from the roots of Glycyrrhiza uralensis inhibits LPS-induced iNOS and COX-2 expression via the attenuation of NF-kappaB in RAW 264.7 macrophages. 1829

The conversion of transforming growth factor beta (TGF-beta) from a tumor suppressor to a tumor promoter occurs frequently during mammary tumorigenesis, yet the molecular mechanisms underlying this phenomenon remain undefined. We show herein that TGF-beta repressed nuclear factor-kappaB (NF-kappaB) activity in normal NMuMG cells, but activated this transcription factor in their malignant counterparts, 4T1 cells, by inducing assembly of TGF-beta-activated kinase 1 (TAK1)-binding protein 1 (TAB1):I kappaB kinase beta (IKK beta) complexes, which led to the stimulation of a TAK1:IKK beta:p65 pathway. TAB1:IKK beta complexes could only be detected in NMuMG cells following their induction of epithelial-mesenchymal transition (EMT), which, on TGF-beta treatment, activated NF-kappaB. Expression of a truncated TAB1 mutant [i.e., TAB1(411)] reduced basal and TGF-beta-mediated NF-kappaB activation in NMuMG cells driven to undergo EMT by TGF-beta and in 4T1 cells stimulated by TGF-beta. TAB1(411) expression also inhibited TGF-beta-stimulated tumor necrosis factor-alpha and cyclooxygenase-2 expression in 4T1 cells. Additionally, the ability of human MCF10A-CA1a breast cancer cells to undergo invasion in response to TGF-beta absolutely required the activities of TAK1 and NF-kappaB. Moreover, small interfering RNA-mediated TAK1 deficiency restored the cytostatic activity of TGF-beta in MCF10A-CA1a cells. Finally, expression of truncated TAB1(411) dramatically reduced the growth of 4T1 breast cancers in syngeneic BALB/c, as well as in nude mice, suggesting a potentially important role of NF-kappaB in regulating innate immunity by TGF-beta. Collectively, our findings have defined a novel TAB1:TAK1:IKK beta:NF-kappaB signaling axis that forms aberrantly in breast cancer cells and, consequently, enables oncogenic signaling by TGF-beta.
 ...
PMID:Altered TAB1:I kappaB kinase interaction promotes transforming growth factor beta-mediated nuclear factor-kappaB activation during breast cancer progression. 1831 10


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>