Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carrageenans, a family of polysulphated carbohydrates, are able to inhibit the binding to cells of growth factors such as transforming growth factor 1 (TGF 1), fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor (PDGF) and so modulate cell invasion and proliferation. We studied the effects of carrageenans on the proliferation and on the uPA/PAI-1 system in breast epithelial cells. Carrageenans were able to inhibit the proliferation of both normal breast epithelial cells (NBEC) and breast epithelial cancer cell lines (MDA-MB-231 and MCF-7) but could only inhibit the uPA activity in the MDA-MB-231 cells. Moreover, carrageenans inhibited FGF-2 binding in all three cell types, suggesting that they regulate cell proliferation and uPA/PAI-1 system through two distinct mechanisms. These molecules could be considered as potentially useful anti-cancer agents.
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PMID:Regulation of cell proliferation and urokinase plasminogen activation of human breast epithelial cells by carrageenans. 959 6

Repair of demyelination in the CNS requires that oligodendrocyte precursors (OPs) migrate, divide and then myelinate. Repair of axon damage requires axonal regeneration. Limited remyelination and axon regeneration occurs soon after injury, but usually ceases in a few days. In vivo and in vitro experiments have shown that astrocytic environments are not very permissive for migration of OPs or for axonal re-growth. Yet remyelination and axon sprouting early after injury occurs in association with astrocytes, while later astrocytes can exclude remyelination and prevent axon regeneration. A large and changing cast of cytokines are released following CNS injury, so we investigated whether some of these alone or in combination can affect the ability of astrocytes to support migration of OPs and neuritic outgrowth. Interleukin (IL) 1alpha, tumour necrosis factor alpha, transforming growth factor (TGF) beta, basic fibroblast growth factor (bFGF), platelet-derived growth factor and epidermal growth factor alone exerted little or no effect on migration of OPs on astrocytes, whereas interferon (IFN) gamma was inhibitory. The combination of IL-1alpha + bFGF was found to be pro-migratory, and this effect could be neutralized by TGFbeta. We also examined neuritic outgrowth from dorsal root ganglion explants in three-dimensional astrocyte cultures treated with cytokines and found that IL-1alpha + bFGF greatly increased axon outgrowth and that this effect could be blocked by TGFbeta and IFNgamma. All these effects were absent or much smaller when OP migration or axon growth was tested on laminin, so the main effect of the cytokines was via astrocytes. The cytokine effects did not correlate with expression on astrocytes of laminin, fibronectin, tenascin, chondroitin sulphate proteoglycan, N-cadherin, polysialyated NCAM (PSA-NCAM), tissue plasminogen activator (tPA) or urokinase (uPA).
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PMID:Cytokine-induced changes in the ability of astrocytes to support migration of oligodendrocyte precursors and axon growth. 974 68

The vascular endothelial growth factor (VEGF) family has recently expanded by the identification and cloning of three additional members, namely VEGF-B, VEGF-C, and VEGF-D. In this study we demonstrate that VEGF-B binds selectively to VEGF receptor-1/Flt-1. This binding can be blocked by excess VEGF, indicating that the interaction sites on the receptor are at least partially overlapping. Mutating the putative VEGF receptor-1/Flt-1 binding determinants Asp63, Asp64, and Glu67 to alanine residues in VEGF-B reduced the affinity to VEGF receptor-1 but did not abolish binding. Mutational analysis of conserved cysteines contributing to VEGF-B dimer formation suggest a structural conservation with VEGF and platelet-derived growth factor. Proteolytic processing of the 60-kDa VEGF-B186 dimer results in a 34-kDa dimer containing the receptor-binding epitopes. The binding of VEGF-B to its receptor on endothelial cells leads to increased expression and activity of urokinase type plasminogen activator and plasminogen activator inhibitor 1, suggesting a role for VEGF-B in the regulation of extracellular matrix degradation, cell adhesion, and migration.
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PMID:Vascular endothelial growth factor B (VEGF-B) binds to VEGF receptor-1 and regulates plasminogen activator activity in endothelial cells. 975 30

Human ovarian adenocarcinoma cells N.1 secrete an autocrine activity that stimulates active cell death under serum-reduced conditions. To substitute the autocrine activity by a single physiological component, 28 cytokines, growth factors and biomodulators were tested [interleukin 1alpha (IL-1alpha), IL-1beta, IL-2, IL-3, IL-4, IL-6, IL-10, IL-11, stem cell factor (SCF), platelet-derived growth factor (PDGF), acid fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-1), IGF-2, insulin, macrophage colony-stimulating factor (M-CSF), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), oncostatin, RANTES (regulated on activation normal T cell expressed and secreted), angiogenin, leukaemia inhibitory factor (LIF), erythropoietin (EPO), interferon alpha (INF-alpha), INF-gamma, transferrin, tumour necrosis factor alpha (TNF-alpha, TNF-beta and bovine serum albumin for control reasons]. In these experiments, only TNF-alpha and TNF-beta rapidly induced apoptosis. TNF-alpha and TNF-receptor 1 were expressed by N.1 cells, and the secretion of TNF-alpha was verified by enzyme-linked immunosorbent assay (ELISA). Autocrine factor-triggered apoptosis was inhibited when conditioned supernatant was preincubated with anti-TNF-alpha antibody. These findings suggested that the apoptosis-inducing component of the N.1 autocrine activity was TNF-alpha. In the presence of antisense c-myc oligonucleotides, induction of cell death by autocrine factor was partly inhibited. Autocrine factor and TNF-alpha stimulated transcription of the invasiveness-related protease plasminogen activator/urokinase mRNA (upa) with similar kinetics. When N.1 cells were exposed to purified plasminogen activator/urokinase protein (uPA), cell matrix contact was disrupted. Thus, uPA might serve a physiological role during TNF-induced apoptosis by affecting the interactions between cells and the basal membrane, thereby facilitating anoikis. This mechanistic study, which was restricted to a single human ovarian carcinoma model cell line (N.1), provides evidence that N.1 maintains the capacity to undergo c-myc-dependent apoptosis by the TNF-TNF-receptor pathway, and no additional pharmacological stimuli for induction of apoptosis are required.
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PMID:Autocrine self-elimination of cultured ovarian cancer cells by tumour necrosis factor alpha (TNF-alpha). 976 76

Ras activates a multitude of downstream activities with roles in cellular proliferation, invasion and metastasis, differentiation, and programmed cell death. In this work we have evaluated the requirement of extracellular signal-regulated protein kinase (ERK), c-Jun NH2-terminal kinase kinase (JNKK), and c-Jun/AP-1 activities in transformation and extracellular matrix invasion of ras oncogene expressing NIH 3T3 fibroblasts by expressing stable mutant genes that constitutively inhibit these activities. Whereas the inhibition of ERK activity reverts the transformed and invasive phenotype, the inhibition of the JNK pathway and AP-1 trans-activating activities by JNKK[K129R] and c-Jun(TAM67) had no effect on the ability of the ras oncogene-expressing cells to grow in soft agar or invade Matrigel basement membrane. Thus an elevated JNK activity and/or c-Jun/AP-1 trans-activating activity are not absolute requirements for ras transformation or invasion through basement membrane, and the dependence on AP-1 activity for transformation is cell-specific. However, inhibition of JNK kinase (JNKK) in ras-transformed cells with normally elevated JNK activity switches the protease-dependent invasive phenotype from a urokinase plasminogen activator (uPA)-dependent to a cathepsin L (CL)-dependent invasive phenotype. Conversely, treatment of ras-transformed cells of low constitutive JNK activity with the JNK stimulator, anisomycin, converts the protease mRNA levels from those characteristic of a CL-dependent to a uPA-dependent phenotype. These protease phenotypes can be duplicated in untransformed NIH 3T3 cells that express platelet-derived growth factor receptors and m1 muscarinic receptors that selectively stimulate the ERK or JNK pathways, respectively. It is concluded that high ERK activity is required for both protease phenotypes, whereas the JNK pathway and c-Jun/AP-1 activity are not required for transformation but regulate a switch between uPA and CL protease phenotypes in both transformed and untransformed cells. In ras-transformed NIH 3T3 fibroblasts, the uPA- and CL-dependent protease phenotypes are redundant in their ability to invade through basement membrane.
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PMID:Role of mitogen-activated protein kinases and c-Jun/AP-1 trans-activating activity in the regulation of protease mRNAs and the malignant phenotype in NIH 3T3 fibroblasts. 987 19

During liver fibrogenesis, hepatic stellate cells (HSC) proliferate and migrate under the influence of growth factors, including platelet-derived growth factor (PDGF) and basic-fibroblast growth factor (b-FGF). The plasminogen activation system regulates extracellular matrix (ECM) catabolism and cell movement. We evaluated the expression and biological functions of the plasminogen activation system in human HSC and its interaction with PDGF and b-FGF. Urokinase-plasminogen activator receptors (u-PAR) were measured by radioligand binding, cell cross-linking, immunoassay, and RNAse protection assay. u-PA and plasminogen activator inhibitors (PAIs) expression and activities were analyzed by zymography, immunoassay, and RNase protection assay. Cell migration and proliferation, studied in Boyden chambers and by microscopic counting, were evaluated after the addition of PDGF, b-FGF, and blockade with anti-u-PA, anti-u-PAR antibodies, and antisense oligodeoxynucleotides (aODN) against u-PAR mRNA. We have shown that HSC produce u-PAR, u-PA, and PAI-1. PDGF and b-FGF up-regulate u-PA and u-PAR, but not PAI-1, and exogenous addition of u-PA stimulates HSC proliferation, chemotaxis, and chemoinvasion. Inhibition of u-PA/u-PAR with antibodies against u-PA or u-PAR and with u-PAR aODN inhibit the proliferative, chemotactic, and chemoinvasive activity of PDGF and b-FGF. These findings indicate that u-PA and u-PAR are required for the mitogenic and chemoinvasive activity of PDGF and b-FGF on HSC.
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PMID:Functions of the fibrinolytic system in human Ito cells and its control by basic fibroblast and platelet-derived growth factor. 1005 91

Thickening of the glomerular basement membrane (GBM) results from excessive accumulation of extracellular matrix (ECM) proteins following glomerular injury. We studied the temporal relationship between the expression of growth factors, ECM accumulation, ECM degrading proteinases, and their inhibitors in a rat model of anti-GBM antibody (Ab) glomerulonephritis (GN) by the RNase protection assay and immunohistochemistry. There were two- or fourfold increases in the expression of transforming growth factor-beta(1) (TGF-beta(1)) and platelet-derived growth factor (PDGF) A and B chain mRNAs 4 days after anti-GBM Ab administration. These changes were temporally associated with increased accumulation of alpha1(III) and alpha2(IV) collagens, fibronectin, and heparan sulfate proteoglycan along the GBM. The increase in matrix accumulation was associated with little or no increases in the proteinases, urokinase plasminogen activator (u-PA) and transin, respectively. There was a 1.6x increase in the u-PA/28s mRNA ratio on day 4 in rats with anti-GBM Ab GN, but this was not associated with an increase in u-PA biologic activity. By comparison, the mRNAs of the proteinase inhibitors, plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metalloproteinase (TIMP) were 5x greater than that of control rats on day 4. PAI-1 mRNA correlate with increased biologic activity. These data demonstrate a temporal association between TGF-beta(1) and PDGF expression and matrix accumulation within the GBM in anti-GBM Ab GN. In addition, it suggest that this matrix accumulation results from an imbalance between matrix synthesis and degradation.
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PMID:Glomerular extracellular matrix accumulation in experimental anti-GBM Ab glomerulonephritis. 1064 7

Wound healing is a complex process involving the interactions of many different cell types, matrix components and biological factors, including proteinases and cytokines. This study compared the levels of proteinases (matrix metalloproteinases and plasminogen activators), proteinase inhibitors (tissue inhibitors of metalloproteinases and plasminogen activator inhibitors), inflammatory cytokines and growth factors in acute wound fluid samples collected from the surgical drains of elective breast (n = 24) and colorectal (n = 26) patients on the first postoperative day. Gelatin zymography was used to determine matrix metalloproteinase-2 and -9 levels, quenched fluorescence substrate hydrolysis was applied for total MMP activity and enzyme-linked immunoassays were used to quantitate other factors. Colorectal wound fluid samples showed significantly (p < 0.05) greater levels of the matrix metalloproteinases (MMP-1, 2, 3, and 9), tissue inhibitor of metalloproteinases-1, urokinase plasminogen activator receptor and the inflammatory cytokines (interleukin-1beta, -6, and tumor necrosis factor-alpha); e.g., matrix metalloproteinase-3 colon; median 275 (range 11-2.530) ng/ml; breast; 530-400. However, tissue plasminogen activator and growth factor levels (epidermal growth factor, platelet-derived growth factor, basic fibroblast growth factor, transforming growth factor-beta1) were significantly greater in breast samples; e.g., epidermal growth factor breast 468 (103-1, 444) pg/ml; colon 57(1-573). There was no difference in the levels of urokinase type plasminogen activator, plasminogen activator inhibitor-1 and -2, tissue inhibitor of metalloproteinases -2 or vascular endothelial growth factor. Acute wound fluid from different surgical wounds showed different profiles of proteinases, proteinase inhibitors, and cytokines. This may lead to differences in the rate of tissue remodeling and therefore healing in these two wounds in vivo.
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PMID:Proteinases, their inhibitors, and cytokine profiles in acute wound fluid. 1111 51

Emerging data suggest that urokinase-type plasminogen activator (UPA), beyond its role in pericellular proteolysis, may also act as a mitogen. We investigated the function of endogenous UPA in mediating the mitogenic effects of platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) on human vascular smooth muscle cells (SMC). Growth-arrested SMC constitutively expressed UPA, but UPA expression and secretion increased several times upon stimulation with either PDGF or bFGF. Inhibition of endogenous UPA with a polyclonal antibody significantly reduced DNA synthesis and proliferation of PDGF or bFGF stimulated SMC, this effect already being evident when the cells entered S-phase. The proliferative activity of endogenous UPA was dependent on a functional catalytic domain as demonstrated by inhibition experiments with a specific monoclonal antibody (394OA) and p-aminobenzamidine, respectively. In contrast, neither plasmin generation nor binding of UPA to its receptor (CD87) were required for UPA-mediated mitogenic effects. The results demonstrate that endogenous UPA is not only overexpressed in SMC upon stimulation with PDGF/bFGF, but also mediates the mitogenic activity of the growth factors in a catalytic-domain-dependent manner. Specific inhibition of this UPA domain may represent an attractive target for pharmacological interventions in atherogenesis and restenosis after angioplasty.
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PMID:The catalytic domain of endogenous urokinase-type plasminogen activator is required for the mitogenic activity of platelet-derived and basic fibroblast growth factors in human vascular smooth muscle cells. 1195 27

Genistein has been reported to be a natural chemopreventive in several types of human cancer. In our prior study, soy isoflavones were shown to induce cell cycle arrest and apoptosis of bladder cancer cells in the range of human urine excretion. This study was designed to identify the novel molecular basis underlying anti-angiogenic activities of soy isoflavones. An immortalized E6 and five human bladder cancer cell lines were studied by immunoassay, flow cytometry, functional activity, reverse transcription-polymerase chain reaction, immunoblotting, and transwell co-culture in vitro. The efficacy of soy isoflavones on angiogenesis inhibition in vivo was examined by nude mice xenograft and chick chorioallantoic membrane bioassay. Factors analyzed included angiogenic factors, matrix-degrading enzymes, and angiogenesis inhibitors. Genistein was the most potent inhibitor of angiogenesis in vitro and in vivo among the isoflavone compounds tested. It may also account for most of the reduced microvessel density of xenografts observed and the suppressed endothelial migration by soy isoflavones. Genistein exhibited a dose-dependent inhibition of expression/excretion of vascular endothelial growth factor165, platelet-derived growth factor, tissue factor, urokinase plasminogen activator, and matrix metalloprotease-2 and 9, respectively. On the other hand, there was an up-regulation of angiogenesis inhibitors-plasminogen activator inhibitor-1, endostatin, angiostatin, and thrombospondin-1. In addition, a differential inhibitory effect between immortalized uroepithelial cells and most cancer cell lines was also observed. Altogether, we discovered that tissue factor, endostatin, and angiostatin are novel molecular targets of genistein. The current investigation provides further evidence in support of soy-based foods as natural dietary inhibitors of tumor angiogenesis.
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PMID:The novel targets for anti-angiogenesis of genistein on human cancer cells. 1562 83


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