Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apoptosis induced by toxic bile acids is thought to contribute to liver injury during cholestasis. The transcription factor AP-1 is involved in the induction of apoptosis depending on stimulus and cell type. It is not known whether the major human toxic bile acid, glycochenodeoxycholic acid (GCDCA), modulates AP-1 in hepatocytes. Our data show that GCDCA (75 microM, 4 h) significantly upregulates cFos and JunB as demonstrated by microarray analysis and real-time PCR in HepG2-Ntcp hepatoma cells. GCDCA (75 microM, 4 h) also induced AP-1 activation as determined by EMSA that was most distinct after 30 min. In parallel, AP-1 transcriptional activity increased by 40% after exposure to GCDCA. Curcumin, an AP-1 inhibitor, dose-dependently reduced (1-25 microM) or completely abolished (50 microM) the apoptotic effect of GCDCA. Thus, GCDCA-induced upregulation of AP-1-dependent genes appears important for the cytotoxicity of this bile acid.
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PMID:The human transcription factor AP-1 is a mediator of bile acid-induced liver cell apoptosis. 1638 75

The activator protein-1 (AP-1) family of transcription factors, including the most common member c-Jun-c-Fos, participates in regulation of expression of numerous genes involved in proliferation, apoptosis, and tumorigenesis in response to a wide array of stimuli including pro-inflammatory cytokines, growth factors, stress, and tumor promoters. A number of plant polyphenols including curcumin, a yellow compound in the spice turmeric, have been shown to inhibit the activation of AP-1. Curcumin is a polyphenolic dienone that is potentially reactive as a Michael acceptor and also is a strong anti-oxidant. Multiple activities reported for curcumin, including inhibition of the stress-induced activation of AP-1, have been suggested to involve the anti-oxidant properties of curcumin. In the present study, a library of analogs of curcumin was screened for activity against the TPA-induced activation of AP-1 using the Panomics AP-1 Reporter 293 stable cell line which is designed for screening potential inhibitors. Numerous analogs were identified that were more active than curcumin, including analogs that were not anti-oxidants and analogs that were not Michael acceptors. Clearly, anti-oxidant activity or reactivity as a Michael acceptor is not an essential feature of active compounds. In addition, a number of analogs were identified that enhanced the TPA-induced activation of AP-1. The results from screening were confirmed using BV-2 microglial cells where curcumin and analogs were shown to inhibit LPS-induced COX-2 expression; analogs identified as more potent than curcumin in the screening assay were also more potent than curcumin in preventing COX-2 expression.
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PMID:TPA-induced up-regulation of activator protein-1 can be inhibited or enhanced by analogs of the natural product curcumin. 1693 60

Xanthorrhizol is an active component isolated from Curcuma xanthorrhiza Roxb. (Zingiberaceae) that is traditionally used in Indonesia for medicinal purposes. In the present study, we found that the topical application of xanthorrhizol before 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment significantly inhibits TPA-induced mouse ear edema and TPA-induced tumor promotion in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated ICR mouse skin. The topical application of xanthorrhizol following the induction of papillomas with TPA-induced hyperplasia and dysplasia also reduced tumor multiplicity and incidence in DMBA-initiated mouse skin. To further elucidate the molecular mechanisms underlying the antitumor-promoting activity of xanthorrhizol, its effect on the TPA-induced expression of ornithine decarboxylase (ODC), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) and the upstream signaling molecules controlling these proteins were explored in mouse skin. The pre-treatment with xanthorrhizol inhibited the expression of ODC, iNOS and COX-2 proteins and nuclear factor-kappaB (NF-kappaB) activation in both mouse skin with TPA-induced acute inflammation and DMBA-initiated mouse skin promoted by TPA for 19 weeks. When mouse skin was treated after TPA-induced production of papillomas, xanthorrhizol remarkably suppressed the expression of ODC, iNOS and COX-2 and inhibited the activation of NF-kappaB. Furthermore, western blot analysis showed that xanthorrhizol suppressed the activation of extracellular signal-regulated protein kinase, p38, c-Jun-N-terminal kinase and Akt in mice after topical application for 6 weeks following the induction of papillomas. Taken together, the present study demonstrates that xanthorrhizol not only delays or inhibits tumor formation, but also reverses the carcinogenic process at pre-malignant stages by reducing the protein levels of ODC, iNOS and COX-2 regulated by the NF-kappaB, mitogen-activated protein kinases and/or Akt.
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PMID:Xanthorrhizol inhibits 12-O-tetradecanoylphorbol-13-acetate-induced acute inflammation and two-stage mouse skin carcinogenesis by blocking the expression of ornithine decarboxylase, cyclooxygenase-2 and inducible nitric oxide synthase through mitogen-activated protein kinases and/or the nuclear factor-kappa B. 1723 20

Curcumin, a natural compound, is a well-known chemopreventive agent with potent anticarcinogenic activity in a wide variety of tumor cells. Curcumin inhibits cancer cell proliferation in part by suppressing cyclin D1 and inducing expression of the cyclin-dependent kinase inhibitor p21(Waf1/Cip1). Both p53-dependent and p53-independent mechanisms regulate p21(Waf1/Cip1) expression, but the mechanism by which curcumin regulates p21(Waf1/Cip1) expression remains unknown. Here, we report that transcription of the p21(Waf1/Cip1) gene is activated by early growth response-1 (Egr-1) independently of p53 in response to curcumin treatment in U-87MG human glioblastoma cells. Egr-1 is a transcription factor that helps regulate differentiation, growth, and apoptosis in many cell types. Egr-1 expression is induced by curcumin through extracellular signal-regulated kinase (ERK) and c-Jun NH(2)-terminal kinase (JNK), but not the p38, mitogen-activated protein kinase (MAPK) pathways, which mediate the transactivation of Elk-1. Transient expression of Egr-1 enhanced curcumin-induced p21(Waf1/Cip1) promoter activity, whereas suppression of Egr-1 expression by small interfering RNA abrogated the ability of curcumin to induce p21(Waf1/Cip1) promoter activity. In addition, stable knockdown of Egr-1 expression in U-87MG cells suppressed curcumin-induced p21 expression. Our results indicate that ERK and JNK MAPK/Elk-1/Egr-1 signal cascade is required for p53-independent transcriptional activation of p21(Waf1/Cip1) in response to curcumin in U-87MG human glioblastoma cells.
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PMID:p21 Waf1/Cip1 expression by curcumin in U-87MG human glioma cells: role of early growth response-1 expression. 1831

Curcumin can reduce inflammation and neurodegeneration, but its chemical instability and metabolism raise concerns, including whether the more stable metabolite tetrahydrocurcumin (TC) may mediate efficacy. We examined the antioxidant, anti-inflammatory, or anti-amyloidogenic effects of dietary curcumin and TC, either administered chronically to aged Tg2576 APPsw mice or acutely to lipopolysaccharide (LPS)-injected wild-type mice. Despite dramatically higher drug plasma levels after TC compared with curcumin gavage, resulting brain levels of parent compounds were similar, correlating with reduction in LPS-stimulated inducible nitric-oxide synthase, nitrotyrosine, F2 isoprostanes, and carbonyls. In both the acute (LPS) and chronic inflammation (Tg2576), TC and curcumin similarly reduced interleukin-1beta. Despite these similarities, only curcumin was effective in reducing amyloid plaque burden, insoluble beta-amyloid peptide (Abeta), and carbonyls. TC had no impact on plaques or insoluble Abeta, but both reduced Tris-buffered saline-soluble Abeta and phospho-c-Jun NH(2)-terminal kinase (JNK). Curcumin but not TC prevented Abeta aggregation. The TC metabolite was detected in brain and plasma from mice chronically fed the parent compound. These data indicate that the dienone bridge present in curcumin, but not in TC, is necessary to reduce plaque deposition and protein oxidation in an Alzheimer's model. Nevertheless, TC did reduce neuroinflammation and soluble Abeta, effects that may be attributable to limiting JNK-mediated transcription. Because of its favorable safety profile and the involvement of misfolded proteins, oxidative damage, and inflammation in multiple chronic degenerative diseases, these data relating curcumin dosing to the blood and tissue levels required for efficacy should help translation efforts from multiple successful preclinical models.
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PMID:Curcumin structure-function, bioavailability, and efficacy in models of neuroinflammation and Alzheimer's disease. 1841 33

Curcumin (diferuloylmethane) is an active component of the spice turmeric and has a diversity of antitumor activities. In this study, we found that curcumin can inhibit cancer cell invasion and metastasis through activation of the tumor suppressor DnaJ-like heat shock protein 40 (HLJ1). Human lung adenocarcinoma cells (CL1-5) treated with curcumin (1-20 mumol/L) showed a concentration-dependent reduction in cell migration, invasion, and metastatic ability, and this was associated with increased HLJ1 expression. Knockdown of HLJ1 expression by siRNA was able to reverse the curcumin-induced anti-invasive and antimetastasis effects in vitro and in vivo. The HLJ1 promoter and enhancer in a luciferase reporter assay revealed that curcumin transcriptionally up-regulates HLJ1 expression through an activator protein (AP-1) site within the HLJ1 enhancer. JunD, one of the AP-1 components, was significantly up-regulated by curcumin (1-20 mumol/L) in a concentration- and time-dependent manner. Knockdown of JunD expression could partially reduce the curcumin-induced HLJ1 activation and diminish the anti-invasive effect of curcumin, indicating that JunD would seem to be involved in curcumin-induced HLJ1 expression. Curcumin was able to induce c-Jun NH(2)-kinase (JNK) phosphorylation, whereas the JNK inhibitor (SP-600125) could attenuate curcumin-induced JunD and HLJ1 expression. Activation of HLJ1 by curcumin further leads to up-regulation of E-cadherin and a suppression of cancer cell invasion. Our results show that curcumin induces HLJ1, through activation of the JNK/JunD pathway, and inhibits lung cancer cell invasion and metastasis by modulating E-cadherin expression. This is a novel mechanism and supports the application of curcumin in anti-cancer metastasis therapy.
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PMID:Curcumin inhibits lung cancer cell invasion and metastasis through the tumor suppressor HLJ1. 1879 31

Endothelial activation and surface expression of cell adhesion molecules (CAMs) is critical for binding and recruitment of circulating leukocytes in tissues during the inflammatory response. Endothelial CAM expression plays a critical role in the intestinal microvasculature in inflammatory bowel disease (IBD), as blockade of leukocyte alpha4-integrin binding by gut endothelial CAM ligands has therapeutic benefit in IBD. Mechanisms underlying expression of vascular cell adhesion molecule (VCAM)-1, a ligand for alpha4-integrin in primary cultures of human intestinal microvascular endothelial cells (HIMEC) has not been defined. We investigated the effect of curcumin, phosphatidylinositol 3-kinase (PI 3-kinase)/protein kinase B (Akt), and mitogen-activated protein kinase (MAPK) inhibitors on VCAM-1 expression and function in HIMEC. CAM expression was assessed and HIMEC-leukocyte adhesion was visualized under static and flow conditions. Western blotting and in vitro kinase assays were used to assess Akt and MAPK activation. Nuclear factor-kappaB (NF-kappaB) activation and nuclear translocation of its p65 subunit were determined. Tumor necrosis factor (TNF)-alpha/lipopolysaccharide (LPS)-induced VCAM-1 expression in HIMEC was suppressed by Akt small-interfering RNA, curcumin, and inhibitors of NF-kappaB (SN-50), p38 MAPK (SB-203580) and PI 3-kinase/Akt (LY-294002). VCAM-1 induction was partially suppressed by p44/42 MAPK (PD-098059) but unaffected by c-Jun NH2-terminal kinase (SP-600125) inhibition. Curcumin inhibited Akt/MAPK/NF-kappaB activity and prevented nuclear translocation of the p65 NF-kappaB subunit following TNF-alpha/LPS. At physiological shear stress, curcumin attenuated leukocyte adhesion to TNF-alpha/LPS-activated HIMEC monolayers. In conclusion, curcumin inhibited the expression of VCAM-1 in HIMECs through blockade of Akt, p38 MAPK, and NF-kappaB. Curcumin may represent a novel therapeutic agent targeting endothelial activation in IBD.
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PMID:Vascular cell adhesion molecule-1 expression in human intestinal microvascular endothelial cells is regulated by PI 3-kinase/Akt/MAPK/NF-kappaB: inhibitory role of curcumin. 1952 Jul 42

We investigated whether oral administration of curcumin suppressed type II collagen-induced arthritis (CIA) in mice and its effect and mechanism on matrix metalloproteinase (MMP)-1 and MMP-3 production in CIA mice, RA fibroblast-like synoviocytes (FLS), and chondrocytes. CIA in mice was suppressed by oral administration of curcumin in a dose-dependent manner. Macroscopic observations were confirmed by histological examinations. Histological changes including infiltration of immune cells, synovial hyperplasia, cartilage destruction, and bone erosion in the hind paw sections were extensively suppressed by curcumin. The histological scores were consistent with clinical arthritis indexes. Production of MMP-1 and MMP-3 were inhibited by curcumin in CIA hind paw sections and tumor necrosis factor (TNF)-alpha-stimulated FLS and chondrocytes in a dose-dependent manner. As for the mechanism, curcumin inhibited activating phosphorylation of protein kinase Cdelta (PKCdelta) in CIA, FLS, and chondrocytes. Curcumin also suppressed the JNK and c-Jun activation in those cells. This study suggests that the suppression of MMP-1 and MMP-3 production by curcumin in CIA is mediated through the inhibition of PKCdelta and the JNK/c-Jun signaling pathway.
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PMID:Oral administration of curcumin suppresses production of matrix metalloproteinase (MMP)-1 and MMP-3 to ameliorate collagen-induced arthritis: inhibition of the PKCdelta/JNK/c-Jun pathway. 1976 44

Recent studies have shown that the c-Jun N-terminal kinase (JNK) signaling pathway is involved in dopaminergic neuronal degeneration, and direct blockade of JNK by specific inhibitors may prevent or effectively slow the progression of Parkinson disease (PD). Previous studies have revealed that the natural phenolic compound curcumin can reduce inflammation and oxidation, which makes it a potential therapeutic agent for neurodegenerative diseases. In this study, we investigated whether curcumin protects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP) or 1-methyl-4-phenylpyridnium ion- (MPP(+)) induced dopaminergic neurotoxicity in C57BL/6N mice or SH-SY5Y cells by inhibiting JNK pathways both in vivo and in vitro. Curcumin treatment significantly improved behavioral deficits, and enhanced the survival of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) in the MPTP-induced PD model mice. Most importantly, curcumin treatment significantly inhibited MPTP/MPP(+)-induced phosphorylation of JNK1/2 and c-Jun, and cleaved caspase-3. Our study suggests that the neuroprotective effect of curcumin is not related simply to its antiinflammatory and antioxidant properties, but involves other mechanisms, particularly by targeting the JNK pathways.
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PMID:Curcumin prevents dopaminergic neuronal death through inhibition of the c-Jun N-terminal kinase pathway. 2023 Feb 79

Curcumin, a natural compound isolated from turmeric, may inhibit cell proliferation in various tumor cells through a mechanism that is not fully understood. The enhancer of zeste homolog 2 (EZH2) gene is overexpressed in human breast cancers with poor prognosis. In this study, we observed a dose- and time-dependent down-regulation of expression of EZH2 by curcumin that correlates with decreased proliferation in the MDA-MB-435 breast cancer cell line. The curcumin treatment resulted in an accumulation of cells in the G(1) phase of the cell cycle. Further investigation revealed that curcumin-induced down-regulation of EZH2 through stimulation of three major members of the mitogen-activated protein kinase (MAPK) pathway: c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 kinase. These data suggest that an underlying mechanism of the MAPK pathway mediates the down-regulation of EZH2, thus contributing to the anti-proliferative effects of curcumin against breast cancer.
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PMID:Curcumin induces down-regulation of EZH2 expression through the MAPK pathway in MDA-MB-435 human breast cancer cells. 2038 24


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