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)

Temporal and topographic expression of matrix metalloproteinases (MMPs) after perivascular electric injury was studied in wild-type (WT) and urokinase-deficient (u-PA-/-) mice. Neointima formation after injury of the femoral artery was significantly reduced in u-PA-/- mice as compared to WT mice (area of 0.002+/-0.0007 mm2 versus 0.008 + 0.002 mm2 at 3 weeks after injury; p <0.001), associated with impaired cellular migration (nuclear cell counts of 44+/-5 versus 82+/-9in cross-sectional areas; p <0.001). Zymographic and/or microscopic analysis indicated that MMP expression gradually increased to reach a maximum at 1 to 2 weeks after vascular injury. In general, MMP levels were lower in u-PA-/- than in WT mice. In non-injured arteries, MMP-2 (gelatinase A) and MMP-3 (stromelysin-1) were produced mainly by adventitial fibroblasts and/or non-contractile smooth muscle cells (SMC). One week after injury, MMP-2 and MMP-3 levels were enhanced due to an increased number and size of producing cells; 2 to 3 weeks after injury, MMP-2 and MMP-3 were produced also by some contractile SMC, which stained with alpha-actin antiserum. MMP-9 (gelatinase B), MMP-12 (metalloelastase) and MMP-13 (collagenase-3) were found in macrophages located mainly in the adventitia. Immunogold electron microscopic examination revealed that MMP-2 was located predominantly in association with the cell surface of fibroblasts or SMC, while MMP-9 and MMP- 12 were located in well defined storage granules within macrophages. MMP-2, MMP-3 and MMP-13, but not MMP-9 or MMP-12, were also found extracellularly, associated with elastin-containing structures (MMP-2), with the basement membrane and occasionally with collagen fibres (MMP-3), or with proteoglycans, collagen and elastin (MMP-13). The temporal and topographic expression pattern of MMPs after vascular injury, coinciding with smooth muscle cell migration and neointima formation, thus is compatible with a role in vascular remodeling.
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PMID:Temporal and topographic matrix metalloproteinase expression after vascular injury in mice. 1036 56

During progesterone-induced decidualization of estradiol (E2)-primed human endometrial stromal cells (HESCs), the interstitial-type extracellular matrix (ECM) of the follicular phase endometrium is transformed in the luteal phase to a mixture of residual interstitial- and new basal laminar-type components. This transformation is accelerated by reduced proteolytic activity of HESCs undergoing decidualization (DZ). In cultured HESCs, progestins, but not E2, induce the expression of several DZ markers, and E2 enhances these effects despite the lack of response to E2 alone. Using this well-characterized in vitro DZ model we evaluated the expression of plasminogen activators (PAs), which degrade ECM components that undergo rapid turnover, and matrix metalloproteinases (MMPs), which degrade the bulk of ECM components. Medroxyprogesterone acetate (MPA) inhibited the catalytic activity of urokinase-type PA (uPA) and tissue-type PA (tPA) as well as the expression of such MMPs as interstitial collagenase (MMP-1) and stromelysin-1 (MMP-3). Moreover, E2 + MPA elicited greater inhibitory effects on the expression of all of these proteases. Progestin inhibition of PA activities reflected reciprocal upregulation in the output of the PA inhibitor PAI-1, which produced large molar excesses of PAI-1 compared with the PAs in HESC-conditioned medium. By contrast, the tissue inhibitor of the MMPs, TIMP1, as well as gelatinase A (MMP-2), was constitutively expressed by the HESCs. In the absence of implantation, menstruation-associated degradation of the functional endometrial ECM is triggered by withdrawal of circulating ovarian steroids. This process was evaluated in cultured HESCs that were first decidualized during 10 days of exposure to E2 + MPA, and then withdrawn to steroid-free medium with and without the antiprogestin RU 486. As expected, steroid withdrawal reversed progestin-inhibited PA activity as well as the expression of MMP-1 and MMP-3 and progestin-enhanced PAI-1; much greater reversal was observed in medium supplemented with RU 486. Unlike the changes in PAI-1, neither TIMP1, nor MMP-2 expression was affected by withdrawal to steroid-free or to RU 486-medium. By altering the composition of the ECM of the luteal phase endometrium, progestin-elicited inhibition of the PAs, uPA and tPA, as well as that of the MMPs, MMP-1 and MMP-3, modulates trophoblast adhesion, migration and differentiation. Conversely, steroid withdrawal elicited increases in uPA, MMP-1 and MMP-3 activities would promote endometrial sloughing by degrading the mixture of decidual cell-derived basement membrane-like proteins and interstitial components that comprise the stromal ECM of the perimenstrual endometrium.
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PMID:Implications of decidualization-associated protease expression in implantation and menstruation. 1040 70

The in vitro release of matrix-degrading proteinases from breast cancer cells is associated in part with shed membrane vesicles. To determine whether shed vesicles might play a similar role in ovarian cancer cells, we analyzed the shedding phenomenon in vivo and in vitro as well as the enzymatic content of their vesicles. This is the first time that an immunoelectron microscopical analysis revealed membrane vesicles carrying tumor-associated antigen alpha-Folate Receptor (alpha-FR), circulating in biological fluids (ascites and serum) of an ovarian carcinoma patient. These vesicles were trapped in a fiber network with characteristic fibrin periodicity. An ovarian cancer cell line (CABA I) established from ascitic fluid cells of this patient, grew in Matrigel and formed tubular structures suggesting invasive capability. Immunofluorescence analysis demonstrated strong cytoplasmic staining of CABA I cells with anti-matrix metalloproteinase-9 (MMP-9) and anti-urokinase-type plasminogen activator (uPA) antibodies. CABA I cells shed membrane vesicles, which were morphologically similar to those identified in vivo, as determined by electron microscopy. Gelatin zymography of vesicles isolated both in vivo and in vitro revealed major gelatinolytic bands of the MMP family, identified as the zymogen and active forms of gelatinase B (MMP-9) and gelatinase A (MMP-2). By casein-plasminogen zymography we observed high-molecular weight (HMW)-uPA and plasmin bands. Incubation of purified vesicles from CABA I cells with Matrigel led to cleavage of Matrigel components. Taken together, our results point to a possible role of shed vesicles, both in vivo and in vitro, in proteolysis that mediates invasion and spread of ovarian epithelial carcinoma cells.
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PMID:Matrix-degrading proteinases are shed in membrane vesicles by ovarian cancer cells in vivo and in vitro. 1041 Nov 5

Kaposi's sarcoma (KS) cells are considered to be of endothelial origin. KS lesions are characterized by hyperproliferation and an invasive phenotype. We have determined that KS cell cultures constitutively secrete multiple forms of several matrix metalloproteinases (MMPs) and an altered form of urokinase plasminogen activator (uPA) by zymogram and Western analysis of the culture media. MMPs are a family of secreted endoproteinases which degrade components of the extracellular matrix. Their enhanced expression and activity are strongly correlated with cellular processes involving tissue remodeling and invasion. The KS cells secrete increased levels of gelatinase A and B and a high molecular weight uPA in vitro when compared with non-KS endothelial or epithelial cells. Multiple forms of gelatinases A and B were observed on gelatin zymograms. Caseinolytic bands observed were confirmed by Western blot analysis to be due to stromelysin activity, whereas matrilysin was not detected by casein zymography. Western blot analysis also detected secretion of interstitial collagenase and high molecular weight uPA. Gelatinolytic activity with the mobility of gelatinase B was detected on gelatin zymograms, but not by Western analysis. This unusual constitutive expression pattern of MMPs and uPA by KS cells in vitro is characterized by elevated levels of gelatinase A, gelatinase B, interstitial collagenase, stromelysin and a high molecular weight form of uPA, and the lack of expression of matrilysin. These secreted MMPs, taken together, are capable of digesting a broad range of components of the extracellular matrix. This unusual pattern is likely to contribute to the characteristic hyperproliferative and invasive phenotype of KS lesions.
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PMID:Expression of multiple matrix metalloproteinases and urokinase type plasminogen activator in cultured Kaposi sarcoma cells. 1044 93

This study was aimed at investigating the influence of cathepsin D (CD) expression by cancer cells and stromal cells on breast cancer prognosis. This is a study of 1348 node-positive (NPBC) and node-negative (NNBC) breast cancers diagnosed between 1980 and 1986 and with a minimum follow-up of 5.2 years. CD expression was assessed by immunohistochemistry on archival material using a polyclonal antibody. The expression by cancer and stromal cells was assessed separately and correlated with distant metastasis free (DMFS) and overall survival (OS). Cancer cells expressed CD (more than 10% cells expressing CD) in 38.9% of cases and reactive stromal cells in 43.6%. CD expression by reactive stromal cells, and not cancer cells, correlated with several factors of poor prognosis by cancer cells. A strong association was also found with expression of other proteases (stromelysin-3, gelatinase A, and urokinase Plasminogen Activator) by these same reactive stromal cells. CD expression by cancer cells did not predict DMFS or OS but, by univariate analysis, CD expression by reactive stromal cells was associated with earlier recurrence and shorter survival in NNBC (p = 0.0425) and NPBC patients submitted to adjuvant chemotherapy (p = 0.0234). However, CD expression by reactive stromal cells remained a significant predictor of recurrence by multivariate analyses only in a subgroup of NPBC submitted to adjuvant chemotherapy. Overall, those data support the concept that proteases produced by reactive stromal cells are under cancer cell stimulation and that CD by stromal cells, and not cancer cells, influences the prognosis, but only in a subgroup of patients with breast cancer.
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PMID:Cathepsin D expression by cancer and stromal cells in breast cancer: an immunohistochemical study of 1348 cases. 1048 41

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 have previously reported a constitutively activated form of the Flt-1 kinase (BCR-FLTm) molecularly engineered based on the structural backbone of the activated tyrosine kinase BCR-ABL. Here we show that it can induce not only growth stimulation but also tubulogenic differentiation of non-tubulogenic NP31 (non parenchymal) sinusoidal endothelial cells of rat liver in basement membrane matrix. Tubules formed in vitro were accompanied by fenestration structures and allowed circulation when transplanted into syngeneic animals. This biological response was not observed in other activated forms of kinases constructed in a similar fashion, which include Trk (BCR-TRK), KDR (BCR-KDR), and the parental BCR-ABL. Interestingly, formation of fine tubules was accomplished with lower but not higher expression levels of BCR-FLTm. Compared to NP cells in primary culture NP31 is deficient in expression of alpha1 integrin subunit, which was restored by expression of BCR-FLTm that had tubulogenic ability. Matrix-induced tyrosine phosphorylation of an adaptor protein Shc with recruitment of Grb-2 was observed even when tubulogenesis was nearly completed at G1 stage of the cell cycle in 2-3 weeks. Activation of matrix metalloproteinase 2 (MMP-2) and expression of urokinase type plasminogen activator (uPA) was observed with cellular invasion into matrix at the depth of 200-300 microm. Inhibitors for MAP kinase activator MEK1 and for serine proteases showed deleterious effects on the tubulogenesis. We suppose that matrix ligand-induced integrin signals cooperate with a low level of Flt-1 kinase activity to promote tubulogenic behaviors of endothelial cells in this system.
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PMID:An oncogenic form of the Flt-1 kinase has a tubulogenic potential in a sinusoidal endothelial cell line. 1072 21

Proteases contribute to tumor invasion and metastasis via their potential to degrade basement membranes and extracellular matrix. Our aim was to compare the level of several proteases: urokinase-type plasminogen activator (u-PA), matrix metalloproteinase 2 (MMP-2; 72-kDa type IV collagenase, also known as gelatinase A), MMP-11 [also known as stromelysin 3 (STR3)], and cathepsins B and L in resected non-small cell lung cancer. Between June 1996 and March 1998, samples of lung tumor tissues were taken from 119 surgically treated patients. Thirty out of the 119 tumor samples were matched with corresponding adjacent normal tissue. u-PA was measured by a commercially available immunoluminometric assay. Metalloproteinases and cathepsins have been evaluated at the RNA level by Northern blot and quantified with a PhosphorImager. Expression of these proteases was compared to the following clinicopathological parameters: pathological diagnosis, tumor size, exposure to asbestos, radiotherapy, neo-adjuvant chemotherapy, tumor-node-metastasis stage, lymph node involvement, presence of metastasis. u-PA, MMP-2, MMP-11/STR3, and cathepsin B were significantly increased in tumor (the tumor:normal ratio was on average increased by 5.4-, 2.2-, 83.5-, and 2.2-fold, respectively). The tumor:normal ratio of MMP-11/ STR3 was found to be significantly linked to the lymph node involvement (P < 0.05). Our results suggest that several proteases are involved in the invasive potential of non-small cell lung cancer and that the quantification of MMP-11/ STR3 could represent an useful prognostic marker.
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PMID:Overexpression level of stromelysin 3 is related to the lymph node involvement in non-small cell lung cancer. 1074 38

Relaxin participates in extracellular matrix (ECM) remodeling in many reproductive organs, including the ovary, by regulating proteolytic enzyme activity. Accumulated evidence indicates this action of relaxin is involved in ovarian follicle development and ovulation. Equine follicles are embedded in cortex that is at the center of the ovary and they must expand/emigrate to the fossa, the only site in the ovary for ovulation. Due to the tremendous expansion of the follicle in this species, we hypothesized that ovarian stromal remodeling would be extensive. Therefore, cultured equine ovarian stromal cell (EOSC) lines were obtained from stroma at the apex of large follicles and the effects of relaxin on gelatinases A and B, tissue inhibitors of matrix metalloproteinases (TIMPs), plasminogen activators (PAs) and PA inhibitor-1 (PAI-1) activities were assessed. Our results showed that equine relaxin increased the activity of total gelatinase A (both pro forms and mature forms) and latent progelatinase B present in conditioned medium, latent progelatinase A present in cell extracts, and TIMP-1 and TIMP-2 present in conditioned medium. This study also revealed that equine relaxin increased the urokinase-type PA activity in conditioned medium and cell extracts, tissue-type PA activity in ECM and PAI-1 activity in conditioned medium. These results suggest that relaxin may contribute to equine follicle growth and migration, and facilitate ovulation by modulating the degradation of ECM in ovarian stromal tissue.
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PMID:Effects of relaxin on matrix remodeling enzyme activity of cultured equine ovarian stromal cells. 1134 85

Previous studies have shown that matrix vesicles isolated from cultures of costochondral growth zone chondrocytes and treated with 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] can activate recombinant human latent transforming growth factor beta1 (rhTGF-beta1). It is unknown what enzyme or other factor in the extracellular organelles is responsible for the activation. This study tested the hypothesis that enzymes present in matrix vesicles can activate latent TGF-beta1 and that this is regulated by 1alpha,25(OH)2D3. To do this, we examined the ability of matrix vesicle extracts to activate small latent rhTGF-beta1. In addition, enzymes previously determined to be present in matrix vesicles were screened for their ability to activate small latent rhTGF-beta1. Recombinant human matrix metalloproteinase 2 (rhMMP-2; 72 kDa gelatinase), rhMMP-3 (stromelysin 1), purified human plasminogen, and purified urokinase (plasminogen activator) were each tested at varying concentrations. To assess the role of cell maturation, we used a cell culture model in which chondrocytes are derived from two distinct zones of rat costochondral cartilage, the resting zone and the growth zone. Matrix vesicles were isolated from these cultures and then tested. The results showed that extracts of matrix vesicles produced by both growth zone and resting zone chondrocytes were able to activate small latent rhTGF-beta1. The effects were dose and time dependent, with greater activity being found in extracts of matrix vesicles from the growth zone chondrocyte cultures. Only rhMMP-3 was able to activate small latent rhTGF-beta1, indicating that stromelysin-1, but not MMP-2, plasminogen, or urokinase, was involved. As observed in the extracts, the effect of rhMMP-3 was time and dose dependent. When anti-MMP-3 antibody was added to matrix vesicle extracts from both cell types, activation of small latent rhTGF-beta1 was dose-dependently blocked. Neither 1alpha,25(OH)2D3 nor 24R,25(OH)2D3 had a direct effect on activation of small latent rhTGF-beta1 by the extracts. However, when intact matrix vesicles were treated with 1alpha,25(OH)2D3, their ability to activate small latent rhTGF-beta1 was increased. Inhibition of phospholipase A2 with quinacrine blocked the 1alpha,25(OH)2D3-dependent effect. These results suggest that the ability of 1alpha,25(OH)2D3-treated matrix vesicles to activate small latent TGF-beta1 is via action of the secosteroid on the matrix vesicle membrane, not on the enzymes responsible for activating latent TGF-beta1. Because matrix vesicles isolated from growth zone chondrocytes have been shown to contain increased phospholipase A2 activity after treatment with 1alpha,25(OH)2D3, it is likely that this secosteroid promotes loss of membrane integrity through phospholipase A2-dependent formation of lysophospholipids, resulting in the release of MMP-3 into the matrix, where latent TGF-beta1 is stored. Taken together, the results of the current study show that matrix vesicles produced by growth plate chondrocytes contain MMP-3, that this enzyme is at least partially responsible for activation of small latent TGF-beta1 in the matrix, and that 1alpha,25(OH)2D3 regulates MMP release from matrix vesicles.
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PMID:Activation of latent transforming growth factor beta1 by stromelysin 1 in extracts of growth plate chondrocyte-derived matrix vesicles. 1145 Jul 4


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