Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to determine the relative activity of basic fibroblast growth factor (bFGF), vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), platelet-derived growth factor (PDGF), platelet-derived endothelial cell growth factor (PD-ECGF), hepatocyte growth factor (HGF), and interleukin-8 (IL-8) in regulating endothelial cell division, migration, degradation of the extracellular matrix (ECM), morphogenesis, and survival. Human umbilical vein endothelial cells (HUVEC) were treated with different concentrations of the six cytokines. bFGF was the most potent mitogen followed by VEGF/VPF and PD-ECGF. VEGF/VPF and bFGF also enhanced the survival of the endothelial cells in serum-free medium. Interstitial collagenase (MMP-1) and urokinase plasminogen activator (uPA) were significantly upregulated only by bFGF. HGF, bFGF, and VEGF/VPF induced chemotactic migration of the endothelial cells, but only HGF (scatter factor) enhanced nondirectional motility. The organization of endothelial cells to form tubes on Matrigel was induced by bFGF and, to a lesser extent, by VEGF/VPF and IL-8. Permeability across endothelial cell monolayers was induced only by VEGF/VPF. These data demonstrate that different angiogenic molecules differentially regulate distinct steps in the process of angiogenesis, suggesting that any given molecule may be necessary but in itself insufficient for establishment of a viable vasculature.
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PMID:Regulation of distinct steps of angiogenesis by different angiogenic molecules. 949 33

To identify proteins that are lost during the establishment of the transformed phenotype of a tumor cell, we have prepared a subtracted cDNA library with mRNA from normal human fibroblasts and from their matched SV40 transformed counterparts. More than 40 clones were obtained that showed a dramatic reduction in their relative expression after oncogenic transformation. The proteins encoded by these clones could be grouped into four distinct classes: extracellular matrix proteins (fibronectin, beta ig-h3, collagen VI), enzymes (collagenase, urokinase), cytoskeletal proteins (vinculin, SM22) and regulatory proteins (beta-glycan, integrin-associated protein, myosin kinase, IGFBP-5). Six novel gene products were discovered during these experiments, including a novel serine protease, a zyxin-like protein, an ankyrin-like protein and a GTP-binding protein. Only four of all the transformation-sensitive cDNAs were consistently down-regulated when a variety of cell lines derived from spontaneous mesenchymal tumors was investigated: beta ig-h3, collagen VI, the novel ankyrin-like protein, and IGFBP-5. It is likely that these gene products play an important role in the maintenance of the normal phenotype.
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PMID:Down-regulated proteins of mesenchymal tumor cells. 951 34

Knee laxity has been shown to increase during human pregnancy, and the laxity of the rabbit medial collateral ligament also increases during pregnancy. To determine whether the changes in tissue function could be related to alterations in the regulation of gene expression for a subset of relevant molecules in ligaments, RNA was isolated from the medial collateral(MCL) and anterior cruciate(ACL) ligaments of first time pregnant adolescent rabbits. Levels of mRNA for matrix molecules (collagen types I and III and the proteoglycans biglycan, decorin, versican and lumican), proteinases and inhibitors (collagenase, urokinase, PAI-1 and TIMP-1, -2 and -3), growth factors (bFGF, IGF-I, TGF-beta1 and ET-1), cytokines (IL-1beta and TNF) and enzymes responsible for important tissue mediators (COX-2 and iNOS) were assessed by semi-quantitative RT-PCR. In the MCL, levels of transcripts for all of the matrix molecules, growth factors and TIMPs 1 and 2 were significantly depressed at 29 days of pregnancy compared to age-matched non-pregnant controls. In contrast, transcripts for PAI-1 were elevated during pregnancy, while those for collagenase (MMP-1), urokinase, TIMP-3, IL-1beta, TNF, COX-2 and iNOS were not statistically altered. mRNA transcript levels rebounded by 7 days post-partum for most genes studied, indicating that the changes were rapidly reversible. For some molecules, transcript levels were again depressed at 18 days post-partum, indicating that regulatory mechanisms were still not stabilized. Analysis of mRNA from the ACL also revealed changes in the pattern of gene expression, with some similarities and differences from the MCL noted. These results indicate that pregnancy induces reversible changes in mRNA for matrix molecules in ligaments, but differences in responsiveness exist between different ligaments. The complexity of the changes observed indicates that there is probably no simple cause and effect relationship between laxity changes and the molecular alterations during pregnancy.
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PMID:Pregnancy induces complex changes in the the pattern of mRNA expression in knee ligaments of the adolescent rabbit. 962 50

Previously we reported that suppression of type I collagenase synthesis in human melanoma cells with antisense RNA significantly reduced proteolysis of type I and type IV collagen matrices (Durko et al., 1997, Biochim. Biophys. Acta 1356, 271). Because plasmin is a major activator of the type I collagenase, we assessed the impact of type I collagenase suppression on the urokinase/plasmin system of proteolysis. Gel zymography revealed the appearance of two new caseinolytic bands of Mr 81-83000 in conditioned media of type I collagenase-depleted, but not of wild-type cells and these were identified as plasmin bands. This increased extracellular plasmin activity coincided with reduced membrane-associated plasminogen levels and decreased expression of the urokinase-type plasminogen activator receptor at both the mRNA (up to 83% reduction) and cell-surface (up to 48% reduction) levels, while urokinase mRNA levels remained unchanged. The results indicate that in these cells the urokinase/plasmin system is regulated by type I collagenase levels.
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PMID:Suppression of type I collagenase expression by antisense RNA in melanoma cells results in reduced synthesis of the urokinase-type plasminogen activator receptor. 964 28

In the present study, the time-dependent collagenolytic potential and mRNA transcription of extracellular matrix (ECM)-degrading components, transforming growth factor beta1 (TGFbeta1), and both basic fibroblast growth factor (bFGF) and FGF receptors (FGFR) in bovine cumulus-oocyte complexes (COCs) were investigated during 24 h of in vitro maturation (IVM). COCs were collected from 2- to 6-mm follicles, cultured in maturation medium, and sequentially removed at 3-h intervals for analysis. From 285 oocytes matured under these conditions, 114 (40.0%) developed to blastocysts on Day 9 after fertilization. Gelatin zymograms revealed protease activity at about 55 kDa for COCs matured for at least 3 h and two additional proteolytic zones at about 70 kDa after at least 9 h of IVM. The mRNAs of ECM-degrading components urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI1), matrix metalloproteinase 1 (MMP1), and tissue inhibitor of metalloproteinases 1 (TIMP1), as well as TGFbeta1, bFGF, and FGFR, were detected during IVM in a factor-specific pattern: all transcript levels found at COC 0 generally increased after 3 h of maturation and either remained high or decreased thereafter. On the basis of the chosen reverse transcription-polymerase chain reaction technique, one could suggest relative higher mRNA concentrations for TIMP1, PAI1, and both growth factors compared to uPA, MMP1, and FGFR. Our results suggest a finely tuned extracellular proteolysis during IVM of bovine COCs, for which the concerted action of modulating growth factors like bFGF and TGFbeta1 may be essential.
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PMID:Growth factors and components for extracellular proteolysis are differentially expressed during in vitro maturation of bovine cumulus-oocyte complexes. 974 28

Membrane binding of urokinase type plasminogen activator (u-PA) is thought to play a pivotal role in connective tissue remodeling and invasive processes. We compare the ability of different matrix-metalloproteinases involved in connective tissue turnover to cleave pro-urokinase type plasminogen activator between the catalytic domain and the receptor binding part to investigate a potential role for matrix-metalloproteinases in the regulation of membrane-associated proteolytic activity. We employed several forms of human stromelysin-1 (full length, C-truncated, and recombinant catalytic domain), rabbit C-truncated stromelysin-1, the human gelatinases A and B and the human catalytic domain of neutrophil collagenase. The gelatinases and the collagenase did not separate the receptor binding domain of pro-urokinase type plasminogen activator from the catalytic domain, whereas all stromelysin-1 forms cleaved the glutamic acid 143-leucine 144 bond of pro-urokinase type plasminogen activator. This reaction could be inhibited by specific inhibitors of matrix metalloproteinases and was not affected by inhibitors of serine proteinases. The M(r) 31000 cleavage product with leucine 144 as N-terminus displayed no proteolytic activity towards the pro-urokinase type plasminogen activator substrate pyroGlu-Gly-Arg-pNA-HCI (S2444), but it could be activated by an additional treatment with plasmin. Comparison between full length stromelysin-1 and its C-truncated forms, showed that both exhibited the same cleavage properties towards pro-urokinase type plasminogen activator. Thus, the cleavage of pro-urokinase type plasminogen activator by stromelysin-1 is not influenced by the presence or absence of the C-terminal domain. The recombinant catalytic domain of MMP-3 generated pro-urokinase type plasminogen activator, whereas incubation of pro-urokinase type plasminogen activator with the native forms of human or rabbit stromelysin-1 led to a moderate activation of pro-uPA due to an additional cleavage that is catalyzed by a serine proteinase.
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PMID:The cleavage of pro-urokinase type plasminogen activator by stromelysin-1. 980 93

Normal as well as neoplastic cells traverse extracellular matrix barriers by mobilizing proteolytic enzymes in response to epidermal growth factor (EGF)-EGF receptor (EGFR) or hepatocyte growth factor/scatter factor (SF)-c-Met interactions. The plasminogen activator-plasminogen axis has been proposed to play a key role during cell invasion, but the normal development of plasminogen activator- as well as that of plasminogen-deficient mice supports the existence of alternate proteolytic systems that permit cells to traverse extracellular matrix barriers. To characterize the role that matrix-degrading proteinases play in EGF- or SF-stimulated invasion, a human squamous carcinoma cell line (UM-SCC-1) was triggered atop the matrices of type I collagen or human dermal explants in a three-dimensional culture system. During EGF- or SF-induced invasion, UM-SCC-1 cells expressed urokinase-type plasminogen activator (uPA) and uPA receptor as well as the matrix metalloproteinases (MMPs), membrane-type MMP-1, collagenase 1, stromelysin 1, and gelatinase B. Despite the presence of a positive correlation between uPA receptor-uPA expression and growth factor-stimulated invasion, UM-SCC-1 invasion was not affected by inhibitors directed against the plasminogen activator-plasminogen axis. In contrast, both recombinant and synthetic MMP inhibitors completely suppressed invasion by either EGF- or SF-stimulated cells without affecting either proteinase expression or cell motility across collagen-coated surfaces. These data demonstrate that MMPs, but not the plasminogen activator-plasmin system, can directly regulate the ability of either EGF- or SF-stimulated tumor cells to invade interstitial matrix barriers.
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PMID:Role of the plasminogen activator and matrix metalloproteinase systems in epidermal growth factor- and scatter factor-stimulated invasion of carcinoma cells. 982 36

Wound healing in ligaments is a complex process which leads to functionally impaired scar tissue, even after extended time postinjury. To investigate the potential role of proteinases and inhibitors, as well as potential regulators of their expression, mRNA levels for collagenase, stromelysin, urokinase, PAI-1, and TIMPs 1 to 4 have been assessed by semiquantitative RT-PCR in RNA isolated from rabbit ligaments 3, 6, and 14 weeks postinjury. In addition, mRNA levels for IL-1, TNF, COX-2, and iNOS, potential regulators of proteinase/inhibitor expression, have been assessed. mRNA levels for the proteinases TIMP-1, -2, and -3 and PAI-1 were elevated early in scar tissue, but TIMP-4 mRNA levels exhibited a different pattern. In contrast, mRNA levels for the cytokines iNOS and COX-2 were either unchanged or depressed early after injury. The results indicate that alterations in mRNA levels for proteinases and inhibitors occurring early after injury are likely being influenced by factors other than IL-1, TNF, or products of COX-2 or iNOS.
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PMID:Temporal alterations in mRNA levels for proteinases and inhibitors and their potential regulators in the healing medial collateral ligament. 983 80

Matrix metalloproteinases have been implicated to play a vital role in glioma invasion as they degrade extracellular matrix to facilitate the subsequent migration of tumor cells into the surrounding brain tissue. The cytokine Interleukin-10 (IL-10) was detected recently in glial tumors in vivo. Expression of specific IL-10 mRNA as well as blood serum levels of IL-10 in glioma patients increased with malignancy suggesting a functional role of IL-10 in glioma progression. Moreover, glioma cell migration in vitro was enhanced in the presence of IL-10. We therefore investigated the expression of the matrix metalloproteinases (MMPs) stromelysin-1 (MMP-3), 72-kDa collagenase (MMP-2), 92-kDa collagenase (MMP-9), matrilysin (MMP-7) and the human macrophage metalloelastase (MMP-12). In addition, a possible relation between exposure of glioma cells to IL-10 and invasiveness of these cells due to MMP expression was analyzed. Experiments with Matrigel coated Boyden chambers revealed a pronounced dose dependent effect of IL-10 on glioma invasiveness. The synthetic MMP-inhibitor Marimastat markedly reduced cell invasion in the Boyden chambers confirming the significance of MMPs in the process of invasion. Subsequently, the expression level of MMPs and the serine protease uPA was investigated in 7 glioma cell lines (U373, GaMG, U251, GHE, SNB19, U138 and D54) by RT-PCR. In all but one cell line no enhancement of MMP expression by IL-10 was detected. Matrilysin in U373 cells was the only protease found to be upregulated in the presence of IL-10 dependent on cell density. The present data suggest that IL-10 related effects on the invasive properties of the cell lines are not directly mediated by an upregulation of matrix metalloproteinase expression.
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PMID:Expression of matrix metalloproteinases in human glioma cell lines in the presence of IL-10. 989 93

Proteolytic enzymes, postulated to create an avenue for cell migration by digestion of host extracellular matrix molecules, have been implicated in neoplastic glial cell migration. A similar process is likely to occur in the developing brain. Fetal rabbit brain fragments transplanted into the striatum of the neonatal Shiverer mouse give rise to cells which migrate from the graft site and differentiate into astrocytes and oligodendrocytes. Proteinase expression by transplanted brain cells was studied using immunohistochemistry and in situ hybridization. Immature donor cells expressed the mRNAs for matrix metalloproteinases (MMP) 1 (collagenase) and 3 (stromelysin). Northern blot analysis of rabbit brain showed that MMP-1 in particular is expressed in the immature rabbit cerebrum and down-regulated during maturation. Immature donor cells exhibited immunoreactivity for urokinase plasminogen activator. However, immunoreactivity was also present in maturing neurons. Donor and host astroglia in the vicinity of grafts were immunoreactive for MMP-2 and tissue-type plasminogen activator. This expression may represent a reactive phenomenon, not specifically related to cell migration, by mature astrocytes. Based upon our findings, MMP-1 appears to be a candidate for involvement in migration of immature brain cells in the cerebrum.
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PMID:Expression of extracellular matrix degrading enzymes during migration of xenografted brain cells. 1019 76


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