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)

Matrilysin (PUMP-1) is a member of the matrix metalloproteinase (MMP) family of extracellular matrix degrading enzymes that has been found to be overexpressed in human prostate cancer. The rat ventral prostate (RVP) following castration has been used as a model for both tissue involution and apoptosis. Northern analysis and in situ hybridization were used to determine the time course and localization of matrilysin during 8 days of RVP involution. Northern analysis revealed that the 1.2 kb matrilysin mRNA was undetectable in normal RVP. An increase in the steady-state levels of matrilysin mRNA was observed 5 days after castration, and the levels began to decline by 8 days after castration. The mRNAs for tissue inhibitor of metalloproteinase-1 and urokinase-type plasminogen activator also showed a time-dependent induction during the course of involution. Localization of matrilysin by in situ hybridization indicated that the mRNA was produced by epithelial cells of the involuting RVP. The matrilysin message was observed in a small number of glands within the whole RVP. Matrilysin protein was present in the RVP and peaked 3 days after castration. The combination of proteinase genes expressed in the RVP following castration indicate that the MMP and serine protease families of enzymes may interact during tissue remodeling of the RVP following castration.
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PMID:Matrilysin expression in the involuting rat ventral prostate. 882 84

We describe a new principle for assessment of the activity of proteolytic enzymes of all classes and show the application of this principle for the quantitative assay of bacterial collagenase and human matrix metalloproteinases (MMPs). Central to this new principle is the presence of a proenzyme that can be activated into an active enzyme by a single proteolytic event. The regular activation sequence in the proenzyme is replaced using protein engineering by an artificial sequence recognized by the proteinase to be determined. The latter can act as an activator for the newly engineered proenzyme. In the present paper a simple colorimetric assay for the determination for MMPs is described based on this principle. With the aid of protein engineering, a modified pro-urokinase has been prepared in which the activation sequence normally recognized by plasmin (Pro-Arg-Phe-Lys upward arrowIle-Ile-Gly-Gly) has been replaced by a sequence expected to be recognized and hydrolysed by many MMPs (Arg-Pro-Leu-Gly upward arrowIle-Ile-Gly-Gly). The active urokinase resulting from activation of the modified pro-urokinase by a MMP could be measured either directly, using a specific chromogenic peptide substrate for urokinase, or indirectly via urokinase-catalysed plasminogen activation. The response of the assay to equal molar quantities of active MMPs decreases in the order MMP-2>MMP-9>MMP-1>MMP-3>MMP-7. The detection limit for MMP-9 was below 15 pM, corresponding to 3. 75x10(-15) mol per assay. Using the assay, increased MMP activity was detected in synovial tissue extracts from rheumatoid arthritis patients compared with those from osteoarthritis patients, and in stomach tumour extracts as compared with normal stomach tissue extracts.
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PMID:Modified proenzymes as artificial substrates for proteolytic enzymes: colorimetric assay of bacterial collagenase and matrix metalloproteinase activity using modified pro-urokinase. 916 91

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

The role of extracellular proteolysis in inflammatory demyelination, originally hypothesized as a mechanism for myelin degradation, is increasingly recognized as a pathogenetic step and as a target for therapy in human demyelinating disease. The activation of ubiquitous plasminogen by urokinase (u-PA) and tissue-type plasminogen activator (t-PA), which is associated with various neuropathologies, including multiple sclerosis (MS), is the key initiator of the activation cascade of the four classes of matrix metalloproteinases (MMPs): collagenases, stromelysins, membrane-type metalloproteinases and gelatinases. Spatiotemporal protein and mRNA expression of gelatinase B (MMP-9) and matrilysin (MMP-7) have been documented respectively in MS lesions and in the central nervous system (CNS) of animals developing experimental autoimmune encephalomyelitis (EAE). A close interaction between disease-promoting cytokines and extracellularly acting proteases is deduced from in vitro experiments. Cytokines regulate the balance between the proteases and their respective specific inhibitors at the transcriptional level, while proteolysis is a reciprocal mechanism to enhance (by activation) or downmodulate (by degradation) the specific activities of cytokines. In acute inflammation the contribution of chemokines is hierarchically organised, interleukin-8 (IL-8) and related CXC-chemokines inducing a rapid influx of neutrophils in the acute lesions and an instantaneous exocytosis of gelatinase B granules. This results in sudden and extensive damage to the CNS. In chronic disease involving autoimmune processes CC-chemokines that act mainly on mononuclear cell types appear to be more strictly regulated. As MMPs modify matrix components, promoting extravasation of lymphocytes and monocytes/macrophages and have the potential to generate encephalitogenic peptides from myelin basic protein, novel treatments for demyelinating diseases may be predicted by specific inhibition of these enzymes. Here we review plasminogen activators and the MMP family, in the context of their role in CNS inflammation and demyelination and highlight studies in which intervention in these protease cascades are and may be used to treat demyelinating diseases.
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PMID:Plasminogen activators and matrix metalloproteases, mediators of extracellular proteolysis in inflammatory demyelination of the central nervous system. 1037 31

Uterine cervical adenocarcinoma typically is an aggressive neoplasm with a propensity for early invasion and dissemination; however, the regulatory mechanism of invasive activity of cervical adenocarcinoma cells has not been fully understood. In this study, biological effects of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha on invasion and proteinase expression of human cervical adenocarcinoma OMC-4 cells were investigated. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into the reconstituted basement membrane were stimulated by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. Their effects on tumor cell migration were also confirmed by wound assay. The zymography of tumor-conditioned medium showed that the treatment of OMC-4 cells with EGF and TGF-alpha resulted in the increase of matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (uPA). Matrilysin (MMP-7), also secreted by OMC-4 cells, was not affected by these growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion of cervical adenocarcinoma cells, which may be associated with their stimulatory effects on tumor cell motility and the induction of type IV collagenase and uPA secreted by tumor cells.
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PMID:Effects of EGF and TGF-alpha on invasion and proteinase expression of uterine cervical adenocarcinoma OMC-4 cells. 1064 Sep 3

We investigated late-onset anastomotic stenosis in an implanted prosthetic graft. Rupture of the pseudointima and hemorrhaging from the vasa vasorum were observed at the border of the collagenous tissue and fibrin layer. An immunohistological study showed that the fibrin layer was positive for tPA, but weakly positive for PAI-1. Some neutrophils and monocyte/macrophages in the fibrin layer were immunostained for tPA, uPA, uPAR, and MMP-1, -2 and -3. Some spindle-shaped cells surrounding the graft were immunostained for uPA, uPAR, MMP-1, -2, -3, -7 and -9, and TIMP-1 and -2. The endothelial cells of some microvessels were positive for MMP-1 and -2, and tPA. Some multi-nucleated giant cells were immunostained for MMP-7 and-9, tPA, PAI-1, uPA, and uPAR. Overexpressed MMPs and PAs possibly caused instability of the pseudointima.
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PMID:Rupture of pseudointima in an implanted vascular prosthesis: immunohistological study of plasminogen activators and matrix metalloproteinases. 1095 41

The matrix metalloproteinase (MMP) and fibrinolytic (plasminogen/plasmin) systems cooperate in many (patho)physiological processes requiring extracellular proteolysis. The effect of MMP-3 (stromelysin-1), MMP-7 (matrilysin), MMP-9 (gelatinase B) or MMP-12 (metalloelastase) on cellular fibrinolytic activity was studied with the use of smooth muscle cells (SMC) and fibroblasts derived from mice with specific inactivation of these genes. Activation of cell-bound plasminogen by two-chain urokinase-type plasminogen activator (tcu-PA) was not significantly different with SMC or fibroblasts from the gene-deficient mice (78% to 140% of wild-type). For all cell types, very limited conversion of plasminogen to angiostatin-like kringle-containing fragments was observed (< 3% of the total cell-bound plasminogen). Activation of plasminogen in solution by cell-associated tcu-PA was also comparable for SMC or fibroblasts of the different genotypes (54% to 160% of wild-type). In vitro SMC migration on scrape wounded collagen-coated surfaces was comparable for wild-type, MMP-7(-/-), MMP-9(-/-) and MMP-12(-/-) SMC, but was significantly reduced for MMP-3(-/-) SMC (P < .005 vs. wild-type). Serum-free conditioned medium of MMP-3(-/-) and MMP-7(-/-) SMC or fibroblasts induced similar lysis of fibrin films as wild-type cells. These findings indicate that several interactions that have been described between these MMPs and the plasminogen/plasmin system in a purified system do not significantly affect plasmin-mediated cellular fibrinolytic activity under cell culture conditions.
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PMID:Matrix metalloproteinase deficiencies do not impair cell-associated fibrinolytic activity. 1132 16

Degradation of the extracellular matrix leads to the release of fragments, which elicit biological responses distinct from intact molecules. We have reported that alpha1:Ser(2091)-Arg(2108), a peptide derived from the alpha1-chain of laminin-1, triggers protein kinase C-dependent activation of MAPK(erk1/2), leading to the up-regulation of macrophage urokinase type plasminogen activator and matrix metalloproteinase (MMP)-9 expression. Since intact laminin-1 failed to trigger these events, we hypothesized that alpha1:Ser(2091)-Arg(2108) is cryptic or assumes a conformation not recognized by macrophages. Here we demonstrate that elastase cleavage of laminin-1 generates fragments, which stimulate proteinase expression by RAW264.7 macrophages and peritoneal macrophages. In contrast, fragments generated by MMP-2, MMP-7, or plasmin had no effect on macrophage proteinase expression. Elastase-generated laminin-1 fragments were fractionated by heparin-Sepharose chromatography. Heparin-binding fragments stimulated macrophages' proteinase expression severalfold greater than nonbinding fragments. The heparin binding fragments reacted with antibodies directed against regions of the alpha1-chain including alpha1:Ser(2091)-Arg(2108) and the globular domain. A peptide from the first loop of the globular domain (alpha1:Ser(2179)-Ser(2198)) triggered the phosphorylation of MAPK(erk1/2) and stimulated the expression of macrophage urokinase type plasminogen activator and MMP-9. Moreover, a heparin-binding fraction isolated from an aortic aneurysm contained fragments of alpha1-chain and stimulated macrophages' proteinase expression. Based on these data, we conclude that cryptic domains in the COOH-terminal portion of the alpha1-chain of laminin are exposed by proteolysis and stimulate macrophages' proteinase expression.
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PMID:Exposure of cryptic domains in the alpha 1-chain of laminin-1 by elastase stimulates macrophages urokinase and matrix metalloproteinase-9 expression. 1182 68

Invasion and dissemination of well-differentiated carcinomas are often associated with loss of epithelial differentiation and gain of mesenchymal-like capabilities of dedifferentiated tumor cells at the invasive front. However when analysing central areas of metastases of colorectal carcinomas one finds a regain of the differentiated epithelial growth patterns like in the primary tumor. More than 80% of these tumor have loss of function mutations in the APC tumor suppressor gene, leading to an overexpression of beta-catenine. In its nuclear pool beta-catenine acts as a transcription factor and is now considered as one of the main oncogenic proteins in colorectal carcinogenesis. We could define several molecules important for the processes of invasion and dissemination, like MMP-7, uPA, laminin-5, as target genes activated by nuclear beta-catenine. Moreover the characteristic phenotypic changes during tumor progression were associated with distinct expression patterns of beta-catenine and E-cadherin. Nuclear beta-catenine was found in dedifferentiated mesenchyme-like tumor cells at the invasive front, but strikingly, like in central areas of the primary tumors, was localized to the membrane and cytoplasm in polarized epithelial tumor cells in the metastases. This was accompanied by changes in the proliferative activity. Based on these data, we postulate that an important driving force for progression of well-differentiated colorectal carcinomas is the specific environment, initiating two transient phenotypic transition processes by modulating intracellular beta-catenine distribution in the tumor cells.
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PMID:[The Rudolf Virchow Prize 2001. The role of the oncoprotein beta-catenin ni the progression of colorectal cancers]. 1189 5

Acquired abdominal aortic aneurysms are usually associated with a mural thrombus through which blood continues to flow. Some early data suggest that aneurysmal evolution correlates with the biological activity of the thrombus. Our hypothesis was therefore that the thrombus could adsorb blood components and store, release, and participate in the activation of proteases involved in aneurysmal evolution. For this purpose, we have explored both the metalloproteinase and fibrinolytic systems in the thrombus and the wall of human aneurysms. We have first investigated blood clot formation and lysis in vitro. Spontaneous clotting induces a release of promatrix metalloproteinase (pro-MMP)-9 into the serum that was fourfold higher than in paired control plasma (P < 0.001). Fibrinolysis progressively released more MMP-9 in a time-dependent manner (P < 0.01). After selective isolation, we demonstrated that polymorphonuclear leukocytes are the main source of MMP-9 release during clot formation. Protease content was then analyzed in 35 mural thrombi and walls of human abdominal aortic aneurysms sampled during surgical repair. In 15 aneurysms, the liquid phase at the interface between the thrombus and the wall was sampled separately. Both thrombus and wall contained MMP-2 and MMP-9 but the ratio MMP-9/MMP-2 was higher in the thrombus than in the wall. The liquid interface also contained active MMP-9. Immunohistochemistry of the thrombus confirmed these findings, showing the presence of polymorphonuclear leukocytes at the luminal pole of the thrombus, co-localizing with MMP-9 storage. In contrast, MMP-3 and MMP-7 were only present in the aneurysmal wall. Plasminogen was present in the mural thrombus but plasmin activity was present in both thrombus and wall. In the liquid interface, plasmin-alpha(2)-anti-plasmin complexes were detected demonstrating in vivo the activation of plasminogen. In contrast, u-PA and t-PA were detectable only in the wall, suggesting that plasminogen present in the thrombus could be activated by factors secreted by the arterial wall. This was demonstrated in vitro, in which co-incubation of thrombus and wall extracts generated plasmin in the presence of a fibrin matrix and activated MMPs. In conclusion, our study strongly suggests that the mural thrombus, by trapping polymorphonuclear leukocytes and adsorbing plasma components could act as a source of proteases in aneurysms that may play a critical role in enlargement and rupture.
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PMID:Involvement of the mural thrombus as a site of protease release and activation in human aortic aneurysms. 1241 17


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