Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Matrix metalloproteinases (MMP) responsible for degradation of connective tissue are found in most tissues. The MMP are regulated at the levels of transcription, zymogen activation by plasmin or membrane-type- (MT) MMP, and control of enzyme activity by tissue inhibitors of metalloproteinases (TIMP). Whole bovine skeletal muscle showed multiple MMP activities on gelatin zymography and also expressed mRNA encoding MMP-1, -2, -9, -14, and -16, tissue inhibitors of metalloproteinase (TIMP)-1, -2, and -3 and plasminogen activator and its receptor. Purified intramuscular fibroblasts and myogenic cell culture derived from satellite cells expressed most or all of these elements. Statistical analysis (n = 35) revealed a strong positive correlation among the mRNA levels of several elements of the MMP system, including MMP-2, MMP-14, TIMP-1, -2, and -3 (r = 0.614 to 0.930, P < 0.0001). Our results provide an extensive profile of an extracellular proteolytic cascade involving MMP in skeletal muscle and suggest that 1) the activation cascades of muscle MMP may be initiated by both plasmin and membrane-type MMP; 2) a group of genes involved in the same "arm" of zymogen activation are coexpressed in this tissue; and 3) skeletal muscle cells, in addition to the intramuscular fibroblasts, express an extensive complement of MMP and related proteins.
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PMID:Coordinate expression of matrix-degrading proteinases and their activators and inhibitors in bovine skeletal muscle. 1120 21

Extracellular proteolysis is an absolute requirement for new blood vessel formation (angiogenesis). This review examines the role of the matrix metalloproteinase (MMP) and plasminogen activator (PA)-plasmin systems during angiogenesis. Specifically, a role for gelatinases (MMP-2, MMP-9), membrane-type 1 MMP (MMP-14), the urokinase-type PA receptor, and PA inhibitor 1 has been clearly defined in a number of model systems. The MMP and PA-plasmin systems have also been implicated in experimental vascular tumor formation, and their role during this process will be examined. Antiproteolysis, particularly in the context of angiogenesis, has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization.
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PMID:Role of the matrix metalloproteinase and plasminogen activator-plasmin systems in angiogenesis. 1145 38

Cross-linked fibrin is deposited in tissues surrounding wounds, inflammatory sites, or tumors and serves not only as a supporting substratum for trafficking cells, but also as a structural barrier to invasion. While the plasminogen activator-plasminogen axis provides cells with a powerful fibrinolytic system, plasminogen-deleted animals use alternate proteolytic processes that allow fibrin invasion to proceed normally. Using fibroblasts recovered from wild-type or gene-deleted mice, invasion of three-dimensional fibrin gels proceeded in a matrix metalloproteinase (MMP)-dependent fashion. Consistent with earlier studies supporting a singular role for the membrane-anchored MMP, MT1-MMP, in fibrin-invasive events, fibroblasts from MT1-MMP-null mice displayed an early defect in invasion. However, MT1-MMP-deleted fibroblasts circumvented this early deficiency and exhibited compensatory fibrin-invasive activity. The MT1-MMP-independent process was sensitive to MMP inhibitors that target membrane-anchored MMPs, and further studies identified MT2-MMP and MT3-MMP, but not MT4-MMP, as alternate pro-invasive factors. Given the widespread distribution of MT1-, 2-, and 3-MMP in normal and neoplastic cells, these data identify a subset of membrane-anchored MMPs that operate in an autonomous fashion to drive fibrin-invasive activity.
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PMID:Matrix metalloproteinases (MMPs) regulate fibrin-invasive activity via MT1-MMP-dependent and -independent processes. 1182 4

Fischer rat thyroid (FRT) cells organize a matrix of extracellular fibronectin (FN) fibrils, which undergoes extensive remodeling according to cell culture confluence. In non-confluent cells FN forms a fibrillar array associated with the ventral cell surface. However, basal FN is progressively removed in confluent cultures and substituted by non-fibrillar FN deposits at lateral cell domains in regions of cell-cell contacts. FRT cells secrete and expose on the plasma membrane the tissue-type plasminogen activator and, in serum-free cultures, plasminogen induces a rapid loss of FN fibrils. Incubation with plasmin inhibitors greatly reduces this effect. FRT cells also express annexin II, a plasminogen receptor, suggesting that plasmin activity is associated with the pericellular enviroment. This is in agreement with the observation that a great reduction in FN degradation is observed if the cells are pre-incubated with carboxypeptidase B, which prevents plasminogen binding to the cells. A gelatinolytic activity with a molecular weigth equivalent to MMP-2 has been demonstrated by zymography of culture media, and the presence of MMP-2 and MT1-MMP on the cell plasma membrane has been detected by immunofluorescence. These results indicate that in the FN remodeling process, occurring during FRT epithelium maturation, both plasmin-dependent (tPA activated) and plasmin-independent proteolytic activities are involved.
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PMID:The role of proteases in fibronectin matrix remodeling in thyroid epithelial cell monolayer cultures. 1192 11

Our previous studies demonstrated that a synthetic peptide encompassing residues 185-203 of the noncollagenous (NC1) domain of the alpha3 chain of type IV collagen, named tumstatin, inhibits in vitro melanoma cell proliferation and migration. In the present study, B16F1 melanoma cells were stably transfected to overexpress the complete tumstatin domain (Tum 1-232) or its C-terminal part, encompassing residues 185-203 (Tum 183-232). Tumstatin domain overexpression inhibited B16F1 in vitro cell proliferation, anchorage-independent growth, and invasive properties. For studying the in vivo effect of overexpression, representative clones were subcutaneously injected into the left side of C57BL6 mice. In vivo tumor growth was decreased by -60% and -56%, respectively, with B16F1 cells overexpressing Tum 1-232 or Tum 183-232 compared to control cells. This inhibitory effect was associated with a decrease of in vivo cyclin D1 expression. We also demonstrated that the overexpression of Tum 1-232 or Tum 183-232 induced an in vivo down-regulation of proteolytic cascades involving matrix metalloproteinases (MMPs), especially the production or activation of MMP-2, MMP-9, MMP-13, as well as MMP-14. The plasminogen activation system was also altered in tumors with a decrease of urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA) and a strong increase of plasminogen activator inhibitor-1 (PAI-1). Collectively, our results demonstrate that tumstatin or its C-terminal antitumor fragment, Tum 183-232, inhibits in vivo melanoma progression by triggering an intracellular transduction pathway, which involves a cyclic AMP (cAMP)-dependent mechanism.
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PMID:In vivo overexpression of tumstatin domains by tumor cells inhibits their invasive properties in a mouse melanoma model. 1553 Aug 61

During pathologic vessel remodeling, vascular smooth muscle cells (VSMCs) embedded within the collagen-rich matrix of the artery wall mobilize uncharacterized proteolytic systems to infiltrate the subendothelial space and generate neointimal lesions. Although the VSMC-derived serine proteinases, plasminogen activator and plasminogen, the cysteine proteinases, cathepsins L, S, and K, and the matrix metalloproteinases MMP-2 and MMP-9 have each been linked to pathologic matrix-remodeling states in vitro and in vivo, the role that these or other proteinases play in allowing VSMCs to negotiate the three-dimensional (3-D) cross-linked extracellular matrix of the arterial wall remains undefined. Herein, we demonstrate that VSMCs proteolytically remodel and invade collagenous barriers independently of plasmin, cathepsins L, S, or K, MMP-2, or MMP-9. Instead, we identify the membrane-anchored matrix metalloproteinase, MT1-MMP, as the key pericellular collagenolysin that controls the ability of VSMCs to degrade and infiltrate 3-D barriers of interstitial collagen, including the arterial wall. Furthermore, genetic deletion of the proteinase affords mice with a protected status against neointimal hyperplasia and lumen narrowing in vivo. These studies suggest that therapeutic interventions designed to target MT1-MMP could prove beneficial in a range of human vascular disease states associated with the destructive remodeling of the vessel wall extracellular matrix.
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PMID:MT1-matrix metalloproteinase directs arterial wall invasion and neointima formation by vascular smooth muscle cells. 1614 77

Bone matrix turnover is regulated by matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), and the plasminogen activation system, including tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), and plasminogen activator inhibitor type-1 (PAI-1). We previously demonstrated that 1.0g/cm(2) of compressive force was an optimal condition for inducing bone formation by osteoblastic Saos-2 cells. Here, we examined the effect of mechanical stress on the expression of MMPs, TIMPs, tPA, uPA, and PAI-1 in Saos-2 cells. The cells were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum and with or without continuously compressive force (0.5-3.0g/cm(2)) for up to 24h. The levels of MMPs, TIMPs, uPA, tPA, and PAI-1 gene expression were estimated by determining the mRNA levels using real-time PCR, and the protein levels were determined using ELISA. The expression levels of MMP-1, MMP-2, MMP-14, and TIMP-1 markedly exceeded the control levels at 1.0g/cm(2) of compressive force, whereas the expression levels of MMP-3, MMP-13, TIMP-2, TIMP-3, TIMP-4, tPA, uPA, and PAI-1 markedly exceeded the control levels at 3.0g/cm(2). These results suggest that mechanical stress stimulates bone matrix turnover by increasing these proteinases and inhibitors, and that the mechanism for the proteolytic degradation of bone matrix proteins differs with the strength of the mechanical stress.
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PMID:Effect of compressive force on the expression of MMPs, PAs, and their inhibitors in osteoblastic Saos-2 cells. 1651 40

Tobacco smoking is an important risk factor for the development of severe periodontitis. Recently, we showed that nicotine affected mineralized nodule formation, and that nicotine and lipopolysaccharide stimulated the formation of osteoclast-like cells by increasing production of macrophage colony-stimulating factor (M-CSF) and prostaglandin E2 (PGE2) by human osteoblastic Saos-2 cells. In the present study, we examined the effects of nicotine on the expression of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), the plasminogen activation system including the component of tissue-type plasminogen activator (tPA), urokinase-type PA (uPA), and PA inhibitor type 1 (PAI-1), alpha7 nicotine receptor, and c-fos. We also examined the effect of the nicotine antagonist D-tubocurarine on nicotine-induced expression of MMP-1. Gene expression was examined using real-time polymerase chain reaction (PCR) to estimate mRNA levels. In addition, expression of the MMP, TIMP, uPA, tPA, and PAI-1 proteins was determined by Western blotting analysis. Nicotine treatment caused expression of MMP-1, 2, 3, and 13, but not MMP-14, to increase significantly after 5 or 10 d of culture; MMP-14 expression did not change through day 14. Enhancement of MMP-1 expression by nicotine treatment was eliminated by simultaneous treatment with D-tubocurarine. In the presence of nicotine, expression of uPA, PAI-1, or TIMP-1, 2, 3, or 4 did not change over 14 d of culture, whereas expression of tPA increased significantly by day 7. Nicotine also increased expression of the alpha7 nicotine receptor and c-fos genes. These results suggest that nicotine stimulates bone matrix turnover by increasing production of tPA and MMP-1, 2, 3, and 13, thereby tipping the balance between bone matrix formation and resorption toward the latter process.
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PMID:Nicotine treatment induces expression of matrix metalloproteinases in human osteoblastic Saos-2 cells. 1715 81

In degrading the extracellular matrix, matrix metalloproteinases (MMP) and the plasminogen activator (PA) system may play a critical role in extensive remodeling that occurs in the bovine mammary gland during development, lactation, and involution. Therefore, the aim of our study was to investigate the mRNA expression of MMP-1, MMP-2, MMP-14, MMP-19, tissue inhibitor of metalloproteinases (TIMP)-1, TIMP-2, urokinase-type PA, tissue-type PA, urokinase-type PA receptor, and PA inhibitor-1 by quantitative PCR and to localize with immunohistochemistry MMP-1, MMP-2, MMP-14, and TIMP-2 proteins in the bovine mammary gland during pubertal mammogenesis, lactogenesis, galactopoiesis, and involution. Expression of mRNA for each of the studied factors was relatively lower during galactopoiesis and early involution but was markedly increased during mammogenesis and late involution, 2 stages in which tissue remodeling is especially pronounced. The localization of proteins for MMP-1, MMP-14, and TIMP-2 showed a similar trend with strong staining intensity in cytoplasm of mammary duct and alveolar epithelial cells during pubertal mammogenesis and late involution. Interestingly, MMP-2 protein was localized only in the cytoplasm of endothelial cells during late involution. Our study demonstrated clearly that expression of extracellular matrix-degrading proteinases coincides with a concomitant expression of their inhibitors. High expression levels of MMP, TIMP, and PA family members seem to be a typical feature of the nonlactating mammary gland.
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PMID:Expression and localization of extracellular matrix-degrading proteinases and their inhibitors in the bovine mammary gland during development, function, and involution. 1723 51

The corpus luteum (CL) offers the opportunity to study high proliferative processes during its development and degradation processes during its regression. We examined the mRNA expression of matrix metalloproteases (MMP)-1, MMP-2, MMP-9, MMP-14, MMP-19, tissue inhibitor of MMP (TIMP)-1, TIMP-2, tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), uPA-receptor (uPAR), PA-inhibitors (PAI)-1, PAI-2 in follicles 20 h after GnRH application, CLs during days 1-2, 3-4, 5-7 and 8-12 of the oestrous cycle as well as after induced luteolysis. Cows in the mid-luteal phase were injected with Cloprostenol and the CLs were collected at 0.5, 2, 4, 12, 24, 48 and 64 h after PGF2alpha injection. Real-time RT-PCR determined mRNA expressions. Expression from 20 h after GnRH to day 12: MMP-1, MMP-2, MMP-14 and tPA showed a clear expression, but no regulation. TIMP-1 and uPAR mRNA increased when compared with the follicular phase. TIMP-2, MMP-9, MMP-19 and uPA increased from the follicular phase to days 8-12. PAI-1 and PAI-2 expression increased from days 1-7 and decreased to days 8-12. Induced luteolysis: MMP-1, MMP-2, MMP-9, MMP-14, MMP-19 and TIMP-1 all increased at different time points and intensities, whereas TIMP-2 was constantly decreased from 24 to 64 h. The plasminogen activator system and their inhibitors were up-regulated from 2 to 64 h, tPA was already increased after 0.5 h. Immunohistochemistry for MMP-1, MMP-2, MMP-14: an increased staining for MMP-1 and MMP-14 was seen in large luteal cells beginning 24 h after PGF2alpha application. MMP-2 showed a strong increase in staining in endothelial cells at 48 h.
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PMID:Expression and localisation of extracellular matrix degrading proteases and their inhibitors during the oestrous cycle and after induced luteolysis in the bovine corpus luteum. 1770 71


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