Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51812 (mitogen-activated protein)
 10,636 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the bucillamine (Buc) mechanism inhibiting interleukin (IL)-1beta-induced vascular endothelial growth factor (VEGF) production from human fibroblast-like synoviocytes (HFLS) which derived from the inflamed synovium of an RA patient using SA981, its active metabolite. HFLS did not produce IL-1beta, spontaneously. While SA981 partially inhibited IL-1beta-induced VEGF production at concentrations of 10 to 100 microM (10.1% and 14.2% inhibition of total VEGF production under IL-1beta coexistence condition, respectively), it failed to inhibit IL-1beta-induced IL-6 production at the same concentrations. IL-1beta induced phosphorylation of the mitogen-activated protein (MAP) kinases, IkappaBalpha, c-Jun and Akt. SA981 at a concentration of 100 microM partially inhibited IL-1beta-induced phosphorylation of p38MAPK and Akt (12.0% and 36.1% inhibition of each total amount of phosphoprotein under IL-1beta coexistence condition, respectively). The VEGF promoter includes four transcription factors: AP1, hypoxia-inducible factor (HIF), Sp1 and AP2 binding elements. HIF-1beta, Sp1 and AP1 increased under IL-1beta coexistence conditions. At a concentration of 100 microM, SA981 attenuated increases in HIF-1beta and Sp1 (10.1% and 19.8% inhibition of each total amount of transcription factor under IL-1beta coexistence condition, respectively), but not AP1. These results suggest that SA981 partially inhibits VEGF production via modifications on IL-1beta signaling. Attenuation of the expression of HIF-1beta and Sp1 (but not AP1) may be a key with respect to SA981's selective inhibition of VEGF production.
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PMID:Bucillamine mechanism inhibiting IL-1beta-induced VEGF production from fibroblast-like synoviocytes. 1792 May 34

We have reported that prostaglandin F2alpha (PGF2alpha) stimulates the synthesis of vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells. In addition, we recently showed that phosphatidylinositol 3 (PI3)-kinase activated by platelet-derived growth factor-BB (PDGF-BB) negatively regulates the interleukin-6 synthesis in these cells. In the present study, we investigated the effect of PDGF-BB on the PGF2alpha-induced VEGF synthesis in MC3T3-E1 cells. PDGF-BB, which alone did not affect the levels of VEGF, significantly enhanced the PGF2alpha-stimulated VEGF synthesis. The amplifying effect of PDGF-BB was dose dependent in the range between 10 and 70 ng/ml. LY294002 or wortmannin, specific inhibitors of PI3-kinase, which by itself failed to affect the PGF2alpha-stimulated VEGF synthesis, significantly suppressed the amplification by PDGF-BB. PD98059, a specific inhibitor of MEK1/2, suppressed the amplification by PDGF-BB of the PGF2alpha-stimulated VEGF synthesis similar to the levels of PGF2alpha with PD98059. PDGF-BB itself induced the phosphorylation of p44/p42 MAP kinase in these cells, and the effects of PDGF-BB and PGF2alpha on the phosphorylation of p44/p42 MAP kinase were additive. Moreover, LY294002 had little effect on the phosphorylation of p44/p42 MAP kinase induced by PGF2alpha with PDGF-BB. These results strongly suggest that PGF2alpha-stimulated VEGF synthesis is amplified by PI3-kinase-mediating PDGF-BB signaling in osteoblasts, and that the effect is exerted at a point downstream from p44/p42 MAP kinase.
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PMID:Platelet-derived growth factor-BB amplifies PGF2alpha-stimulated VEGF synthesis in osteoblasts: function of phosphatidylinositol 3-kinase. 1798 May 68

Endometriosis, a chronic gynecologic disease frequently resulting in chronic pelvic pain, severe dysmenorrhoea, and subfertility, is defined as the presence of endometrial tissue at extrauterine locations, most commonly on the peritoneum and ovaries. Conclusive diagnosis requires laparoscopic surgery followed by histological confirmation. The treatment options -at present- are limited to hormonal therapies and/or surgical ablation of the lesions, and are characterized by high recurrence rates, significant side-effects and limited duration of administration. The pathogenesis of endometriosis is still unclear and numerous immunological and inflammatory factors have been suggested to be involved in the development of the disease, including interleukin (IL)-1, IL-2, IL-6, IL-8, IL-12, tumour necrosis factor -alpha (TNF-alpha), regulated on activation, normal T-Cell expressed and secreted (RANTES) and its receptor cognate chemokine receptor 1 (CCR1), peroxisome proliferator activated receptors (PPARs), matrix metalloproteinases (MMPs) and cyclooxygenase (COX). Another crucial mechanism in endometriosis is the vascularisation of the endometriotic lesions, with a key role for vascular endothelial growth factor (VEGF). Recently, protease activated receptors (PARs), mitogen-activated protein kinases (MAPKs) and tyrosine kinases have also been associated with the pathophysiology of endometriosis. The aim of this article is to discuss molecules that have recently been found to have connections with the pathogenesis of endometriosis, as potential targets to develop new methods for noninvasive diagnosis and for novel medical management of this disease. This review also critically addresses how these molecules can be tested in basic, preclinical and clinical research, the status of this research and the importance of potential side effects.
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PMID:Non-steroidal targets in the diagnosis and treatment of endometriosis. 1839 58

Malignant gliomas have retained their dismal prognosis despite aggressive multimodal conventional therapeutic approaches, illustrating the need for novel therapeutic strategies. Recent advances in the cellular and molecular biology of gliomas have enhanced our understanding of the role of receptor tyrosine kinases (RTK) and RTK-mediated signal transduction pathways in tumor initiation, maintenance, angiogenesis, and vascular proliferation. Special attention has been focused on targets such as epidermal growth factor receptors (EGFR), platelet-derived growth factor receptors (PDGFR), vascular endothelial growth factor receptors (VEGFR), and on pathways such as the Ras/Raf/mitogen-activated protein (MAP)-kinase and phosphatidylinositol-3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathways. Novel targeted drugs known as small molecule inhibitors have been shown to modify the activity of these receptors and signaling pathways. Thus far, however, small molecule RTK inhibitor development has concentrated on a few RTK only, and drug activity has been comprehensively evaluated only in a limited number of different malignancies. One of the limiting factors for novel drug design and development is the incomplete knowledge of RTK functions in malignant glioma. This review summarizes current basic and clinical knowledge on the role of RTK in malignant glioma and on their importance as targets for new forms of therapy.
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PMID:Receptor tyrosine kinases as therapeutic targets in malignant glioma. 1847 93

Fibroblast growth factor (FGF2), but not vascular endothelial growth factor (VEGF), upregulates endothelial nitric oxide synthase (eNOS) protein expression, at least partially, via activation of extracellular signal-regulated kinase 2/1 (ERK2/1) in ovine fetoplacental artery endothelial (oFPAE) cells. Herein we further investigated the temporal effects of FGF2 and VEGF on other signalling pathways including members (Jun N-terminal kinase JNK1/2 and p38MAPK) of mitogen-activated protein kinases (MAPK), phosphatidylinositol-3 kinase/v-akt murine thymoma viral oncogene homologue 1 (PI3K/AKT1), and the tyrosine kinase c-SRC, and examined if either one or more of these pathways play a role in the differential regulation of eNOS by FGF2 and VEGF. We first confirmed that in oFPAE cells, FGF2, but not VEGF, increased eNOS protein. FGF2 stimulated eNOS protein in a time- and concentration-dependent manner, which also depended on cell density. FGF2 provoked sustained (5min to 12h) whereas VEGF only stimulated transient (5min) ERK2/1 phosphorylation. FGF2 was 1.7-fold more potent in stimulating ERK2/1 phosphorylation than VEGF. FGF2 and VEGF only transiently activated JNK1/2 and AKT1 within 5min; however, FGF2 was a stronger stimulus than VEGF. FGF2 and VEGF did not significantly activate p38MAPK at 5min; however, VEGF stimulated p38MAPK phosphorylation at 60min. VEGF but not FGF2 significantly stimulated c-SRC phosphorylation. Inhibitors of MEK-ERK2/1 (PD98059), JNK1/2 (SP600125) and PI3K (wortmannin), but not p38MAPK (SB203580) and SRC (PP2), decreased the FGF2-increased eNOS protein expression. Thus, the FGF2-induced eNOS protein expression requires activation of multiple signalling pathways including ERK2/1, JNK1/2 and PI3K/AKT1. Differences in intensity and temporal patterns of activation of these pathways by FGF2 and VEGF may account for their differential effects on eNOS expression in OFPAE cells.
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PMID:Differential activation of multiple signalling pathways dictates eNOS upregulation by FGF2 but not VEGF in placental artery endothelial cells. 1857 18

We previously reported that basic fibroblast growth factor (FGF-2) stimulates the release of vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the effect of platelet-derived growth factor-BB (PDGF-BB) on FGF-2-induced VEGF release in MC3T3-E1 cells. PDGF-BB significantly enhanced the FGF-2-stimulated VEGF release. The amplifying effect of PDGF-BB was dose dependent in the range between 0.1 and 30 ng/ml. AG1295, a selective inhibitor of PDGF receptor kinase, which reduced the autophosphorylation of PDGF receptor-(R), suppressed the enhancement by PDGF-BB without affecting the FGF-2 effect. PDGF-BB failed to strengthen the FGF-2-induced phosphorylation of p44/p42 MAP kinase or SAPK/JNK. The amplification by PDGF-BB of FGF-2-stimulated VEGF release was reduced by PD98059, a specific inhibitor of MEK, or SP600125, a specific inhibitor of SAPK/JNK. These results strongly suggest that PDGF-BB potentiates FGF-2-stimulated VEGF release at a point downstream from p44/p42 MAP kinase and SAPK/JNK in osteoblasts.
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PMID:Potentiation by platelet-derived growth factor-BB of FGF-2-stimulated VEGF release in osteoblasts. 1860 Mar 99

Hypoxia-inducible factor-1 (HIF-1) is the central mediator of cellular responses to low oxygen and vital to many aspects of cancer biology. In a search for HIF-1 inhibitors, we identified a quassinoid 6alpha-tigloyloxychaparrinone (TCN) as an inhibitor of HIF-1 activation from Ailantus altissima. We here demonstrated the effect of TCN on HIF-1 activation induced by hypoxia or CoCl2. TCN showed the potent inhibitory activity against HIF-1 activation induced by hypoxia in various human cancer cell lines. This compound markedly decreased the hypoxia-induced accumulation of HIF-1alpha protein dose-dependently, whereas it did not affect the expressions of HIF-1beta and topoisomerase-I. Furthermore, TCN prevented hypoxia-induced expression of HIF-1 target genes for vascular endothelial growth factor (VEGF) and erythropoietin. Further analysis revealed that TCN strongly inhibited HIF-1alpha protein synthesis, without affecting the expression level of HIF-1alpha mRNA or degradation of HIF-1alpha protein. Moreover, the levels of phosphorylation of extracellular signal-regulated kinase-1/2 (ERK1/2), mitogen-activated protein (MAP) kinase-interacting protein kinase-1 (MNK1) and eukaryotic initiation factor 4E (eIF4E) were significantly suppressed by the treatment of TCN, without changing the total levels of these proteins. Our data suggested that TCN may exhibit anticancer activity by inhibiting HIF-1alpha translation through the inhibition of eIF4E phosphorylation pathway and thus provide a novel mechanism for the anticancer activity of quassinoids. TCN could be a new HIF-1-targeted anticancer agent and be effective on mammalian target of rapamycin (mTOR)-targeted cancer therapy, in which mTOR inhibition increases eIF4E phosphorylation.
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PMID:A quassinoid 6alpha-tigloyloxychaparrinone inhibits hypoxia-inducible factor-1 pathway by inhibition of eukaryotic translation initiation factor 4E phosphorylation. 1863 43

We have previously reported that transforming growth factor-beta (TGF-beta) stimulates the synthesis of vascular endothelial growth factor (VEGF) through p44/p42 mitogen-activated protein (MAP) kinase, p38 MAP kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) in osteoblast-like MC3T3-E1 cells. In order to investigate whether Rho-kinase is involved in the TGF-beta-stimulated VEGF synthesis in these cells we examined the effects of Rho-kinase inhibitors on the VEGF synthesis. TGF-beta time-dependently induced the phosphorylation of myosin phosphatase targeting subunit (MYPT-1) which is a well known substrate of Rho-kinase. Y27632 and fasudil, Rho-kinase inhibitors, significantly reduced the TGF-beta-stimulated VEGF synthesis as well as the MYPT-1 phosphorylation. Y27632 and fasudil failed to affect the TGF-beta-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase or Smad2. On the contrary, Y27632 as well as fasudil markedly suppressed the TGF-beta-induced phosphorylation of SAPK/JNK. Taken together, our results strongly suggest that Rho-kinase regulates TGF-beta-stimulated VEGF synthesis via SAPK/JNK activation in osteoblasts.
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PMID:Rho-kinase inhibitors decrease TGF-beta-stimulated VEGF synthesis through stress-activated protein kinase/c-Jun N-terminal kinase in osteoblasts. 1899 57

We hypothesized that oxidative stress from hyperbaric oxygen (HBO(2), 2.8 ATA for 90 min daily) exerts a trophic effect on vasculogenic stem cells. In a mouse model, circulating stem/progenitor cell (SPC) recruitment and differentiation in subcutaneous Matrigel were stimulated by HBO(2) and by a physiological oxidative stressor, lactate. In combination, HBO(2) and lactate had additive effects. Vascular channels lined by CD34(+) SPCs were identified. HBO(2) and lactate accelerated channel development, cell differentiation based on surface marker expression, and cell cycle entry. CD34(+) SPCs exhibited increases in thioredoxin-1 (Trx1), Trx reductase, hypoxia-inducible factors (HIF)-1, -2, and -3, phosphorylated mitogen-activated protein kinases, vascular endothelial growth factor, and stromal cell-derived factor-1. Cell recruitment to Matrigel and protein synthesis responses were abrogated by N-acetyl cysteine, dithioerythritol, oxamate, apocynin, U-0126, neutralizing anti-vascular endothelial growth factor, or anti-stromal cell-derived factor-1 antibodies, and small inhibitory RNA to Trx reductase, lactate dehydrogenase, gp91(phox), HIF-1 or -2, and in mice conditionally null for HIF-1 in myeloid cells. By causing an oxidative stress, HBO(2) activates a physiological redox-active autocrine loop in SPCs that stimulates vasculogenesis. Thioredoxin system activation leads to elevations in HIF-1 and -2, followed by synthesis of HIF-dependent growth factors. HIF-3 has a negative impact on SPCs.
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PMID:Hyperbaric oxygen stimulates vasculogenic stem cell growth and differentiation in vivo. 1902 21

To support the role of interferon (IFN)-alpha and sorafenib combination therapy against renal cell carcinoma (RCC), the effects of IFN-alpha and sorafenib on tumor growth, vascular endothelial growth factor (VEGF) production, and phosphorylation levels of extracellular signal-regulated kinase (ERK) and mitogen-activated protein/ERK kinase (MEK) were examined using several cultured RCC cell lines (ACHN, Caki-1, Caki-2, SMKT-R1, SMKT-R2, SMKT-R3 and SMKT-R4). IFN-alpha or sorafenib alone inhibited the proliferation of all the cell lines except Caki-2, while combined treatment with the two agents showed enhanced inhibitory effects compared to treatment with each agent alone. VEGF production was inhibited by IFN-alpha alone in ACHN and SMKT-R2 cells and by sorafenib alone in ACHN, Caki-1, SMKT-R1 and SMKT-R2 cells. However, sorafenib increased VEGF production by Caki-2 cells. Interestingly, combined treatment with the two agents suppressed VEGF production by SMKT-R1 and SMKT-R2 cells more strongly than IFN-alpha or sorafenib alone. Although phosphorylated ERK (p-ERK) was increased after 30 min of treatment with IFN-alpha alone, no difference was observed between control and IFN-alpha-treated cells after 2 h. Sorafenib decreased p-ERK in ACHN, Caki-1, SMKT-R1 and SMKT-R2 cells, but increased p-ERK in Caki-2, SMKT-R3 and SMKT-R4 cells, after 2 h. Combined treatment with IFN-alpha and sorafenib decreased p-ERK compared to treatment with each agent alone in all cell lines except Caki-2. However, IFN-alpha did not inhibit the p-ERK increase induced by sorafenib in Caki-2 cells. Phosphorylated MEK showed similar patterns to p-ERK after the various treatments. In conclusion, combined treatment with IFN-alpha and sorafenib suppressed cell proliferation and VEGF production more strongly than treatment with each agent alone in several RCC cell lines.
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PMID:Antitumor effects of a combination of interferon-alpha and sorafenib on human renal carcinoma cell lines. 1912 70


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