Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.35 (matrix metalloproteinase 9)
 2,207 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the influence of basic fibroblast growth factor (FGF-2) and vascular endothelial growth factor (VEGF) on the release of collagenase type IV activity and the production of extracellular matrix (ECM) molecules using C6 astrocytoma cells in monolayer culture. Collagenase type IV activity was significantly increased in a dose dependent manner in the low cell density group by treatment with FGF-2 and VEGF but significantly decreased in a dose dependent fashion in the high cell density group. These results were corroborated using Western blot technique with an antibody to gelatinase A. Addition of exogenous laminin and fibronectin to the media decreased collagenase type IV activity in a dose dependent fashion with the minimum concentration of 0.1 microgram/ml. Laminin and fibronectin reached a concentration of 0.1 microgram/ml in only the high cell density group after treatment with the growth factors tested. These findings indicate that C6 astrocytoma cells appear to have two regulatory mechanisms for collagenase type IV activity which are dependent on cell density. In a low cell density, C6 astrocytoma cells respond to the dominant effect of FGF-2 and VEGF by increasing the release of collagenase IV activity. In a high cell density collagenase type IV activity is decreased due to it's down regulation by released ECM molecules in response to FGF-2 and VEGF. These regulatory mechanisms may be crucial to the understanding of the coordination of tumor-associated angiogenesis by malignant glial cells.
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PMID:The importance of cell density in the interpretation of growth factor effects on collagenase IV activity release and extracellular matrix production from C6 astrocytoma cells. 982 Nov 6

Glomerulopathic light chains (LCs) are associated with two distinct mesangiopathies: AL (light-chain-related) amyloidosis and light-chain deposition disease (LCDD) with immunomorphologic features that are well documented in the literature. Even though both conditions are caused by monoclonal LCs, these entities differ dramatically in their morphologic expressions. In AL amyloidosis the mesangial matrix is replaced by amyloid fibrils, while in LCDD the matrix increases as a consequence of deposition of excess extracellular matrix (ECM). The immunomorphologic mesangial alterations observed in biopsy material are closely reproduced in vitro when mesangial cells grown on an artificial matrix are incubated with monoclonal light chains obtained from the urine of patients with either condition. This article summarizes previously reported data, reports new findings, and focuses on integrating all the available information on the subject. When mesangial cells are incubated with LCDD-LCs, production of ECM proteins (collagen IV, laminin, fibronectin, and tenascin) is increased, with maximum effect at 72 hours post LC treatment. A concomitant decrease in collagenase IV activity further accentuates the accumulation of mesangial matrix. These effects are mediated through transforming growth factor-beta (TGF-beta) activation. In contrast, when mesangial cells are incubated with Am-LCs, a decrease in ECM protein production and a stimulatory effect on collagenase IV is observed, which results in matrix degradation and facilitates amyloid deposition. The decreased TGF-beta documented in the literature in this setting precludes adequate matrix repair. These findings substantiate the morphologic alterations observed in renal biopsy specimens and in the in vitro model. Using this in vitro model, it is then possible to delineate the LC interactions with putative receptors at the mesangial cell surface that regulate mesangial cell pathobiologic responses and mesangial matrix homeostasis.
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PMID:Glomerulopathic light chain-mesangial cell interactions modulate in vitro extracellular matrix remodeling and reproduce mesangiopathic findings documented in vivo. 1036 4

Human T cells produce and release fibronectin degrading neutral serine proteases with a molecular weight of 50 kD, 70-80 kD (doublet) and 95 kD and have a cell associated 400 kD fibronectin degrading enzyme. In addition, human T cells produce proteases with m.w. 50, 70-80 kD and 400 kD which degrade laminin. CD 4+ T lymphocytes from a non-malignant cloned human T cell line produce a 92 kD gelatinase (MMP 9) and malignant T cell lines release, in addition to the 92 kD gelatinase, low amounts of a 72 kD gelatinase (MMP 2). Purification of the enzymatic activities using benzamidine sepharose yields a 50 kD and a 70 kD band of which the 50 kD band has fibronectin degrading capacity. The purified enzymes do not react with monoclonal antibodies to various previously characterized proteolytic enzymes present in T cells. T lymphocytes from a non-malignant cloned human T cell line produce high amounts of the 50 and 70-80 kD proteases directly after stimulation with anti-CD 3 monoclonal antibodies whereafter the production of these enzymes declines with time. The expression of the 400 kD fibronectin-degrading protease is downregulated by crosslinking of alpha 4 beta 1-integrin receptors on T cells using monoclonal antibodies. Thus, T lymphocytes produce several matrix degrading enzymes with multiple substrate specificities. The expression of these enzymes is controlled partly by lymphocyte activation signals or by direct signalling via beta 1-integrins.
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PMID:Spectrum of extracellular matrix degrading enzymes in normal and malignant T lymphocytes. 1047 Jan 39

During early pregnancy, placentation occurs in a relatively hypoxic environment that is essential for appropriate embryonic development. Intervillous blood flow increases around 10 to 12 weeks of gestation and results in exposure of trophoblast cells to increased oxygen tension. Before this time, low oxygen appears to prevent trophoblast differentiation toward an invasive phenotype. Using human villous explants of 5-8 weeks' gestation, we found that low oxygen tension triggered trophoblast proliferation, fibronectin synthesis, alpha(5) integrin expression, and gelatinase A activity. These biochemical markers were barely detectable under oxic conditions. We therefore examined the placental expression of hypoxia-inducible factor-1 (HIF-1), a master regulator of oxygen homeostasis, and determined that expression of HIF-1alpha subunit during the first trimester of gestation parallels that of TGFbeta(3), an inhibitor of extravillous trophoblast differentiation. Expression of both molecules is high in early pregnancy and falls around 9 weeks of gestation, when placental pO(2) levels are believed to increase. Increasing oxygen tension induced a similar decrease in expression in cultured explants. Moreover, antisense inhibition of HIF-1alpha expression in hypoxic explants inhibited expression of TGFbeta(3), arrested cell proliferation, decreased alpha(5) expression and gelatinase A activity, and triggered biochemical markers of an invasive trophoblast phenotype such as alpha(1) integrin and gelatinase B expression. These data suggest that the oxygen-regulated early events of trophoblast differentiation are in part mediated by TGFbeta(3) through HIF-1 transcription factors.
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PMID:Hypoxia-inducible factor-1 mediates the biological effects of oxygen on human trophoblast differentiation through TGFbeta(3) 1071 24

Digestion of type V collagen by the gelatinases is an important step in tumor cell metastasis because this collagen maintains the integrity of the extracellular matrix that must be breached during this pathological process. However, the structural elements that provide the gelatinases with this unique proteolytic activity among matrix metalloproteinases had not been thoroughly defined. To identify these elements, we examined the substrate specificity of chimeric enzymes containing domains of gelatinase B and fibroblast collagenase. We have found that the addition of the fibronectin-like domain of gelatinase B to fibroblast collagenase is sufficient to endow the enzyme with the ability to cleave type V collagen. In addition, the substitution of the catalytic zinc-binding active site region of fibroblast collagenase with that of gelatinase B increased the catalytic efficiency of the enzyme 3- to 4-fold. This observation led to the identification of amino acid residues, Leu(397), Ala(406), Asp(410), and Pro(415), in this region of gelatinase B that are important for its efficient catalysis as determined by substituting these amino acids with the corresponding residues from fibroblast collagenase. Leu(397) and Ala(406) are important for the general proteolytic activity of the enzyme, whereas Asp(410) and Pro(415) specifically enhance its ability to cleave type V collagen and gelatin, respectively. These data provide fundamental information about the structural elements that distinguish the gelatinases from other matrix metalloproteinases in terms of substrate specificity and catalytic efficiency.
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PMID:Identification of structural elements important for matrix metalloproteinase type V collagenolytic activity as revealed by chimeric enzymes. Role of fibronectin-like domain and active site of gelatinase B. 1082 38

Integrin alpha(4)beta(1) on the surface of T lymphocytes interacts with vascular cell adhesion molecule-1 (VCAM-1) and fibronectin during migration of lymphocytes from the blood to sites of inflammation. Migrating lymphocytes actively modify their environment through a number of mechanisms including proteolysis of the extracellular matrix by matrix metalloproteinases (MMP) synthesized by the cells. In this study, expression of MMP upon alpha(4)beta(1)-mediated adhesion of leukocytes to two major ligands, the IIICS-1 domain of fibronectin and VCAM-1, has been examined. Adhesion of T lymphoblastoid Jurkat cells to the CS-1 peptide induced expression of mRNA for two MMPs, gelatinase A (MMP-2) and gelatinase B (MMP-9). As evaluated by relative RT-PCR and Northern blot analyses, the level of mRNA was upregulated about 4- to 5-fold for both MMPs compared to control cells maintained in suspension. With time, both enzymes were detected in conditioned media and inside the cells, and their identities were verified by Western blotting and gelatin zymography. Adhesion of Jurkat cells to the second major alpha(4)beta(1) ligand, VCAM-1, upregulated mRNA for MMP-2 (3.5-fold) and failed to induce expression of mRNA for MMP-9. Accordingly, only MMP-2 protein was detected in conditioned media of cells adherent to VCAM-1. Occupancy of alpha(4)beta(1) on the surface of suspended cells with soluble CS-1 peptide or VCAM-1 did not upregulate synthesis and release of MMPs. A similar pattern of induction of MMPs after adhesion to CS-1 and VCAM-1 was observed in T lymphocytes isolated from human blood. These results demonstrate that adhesion of T lymphocytes through alpha(4)beta(1) to different ligands, which bind to similar or overlapping sites in the integrin, induces intracellular events leading to distinct patterns of MMPs biosynthesis.
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PMID:Differential induction of gelatinase B (MMP-9) and gelatinase A (MMP-2) in T lymphocytes upon alpha(4)beta(1)-mediated adhesion to VCAM-1 and the CS-1 peptide of fibronectin. 1101 Aug 12

We have isolated a novel 75-kDa gelatinase from a chicken macrophage cell line, HD11. Biochemical and immunological characterization of the purified enzyme demonstrated that it is distinct from the chicken 72-kDa gelatinase A (MMP-2). The enzyme is capable of specific gelatin binding and rapid gelatin cleavage. Incubation with an organomercurial compound (p-aminophenylmercuric acetate) induces proteolytic processing and activation of this enzyme, and the resultant gelatinolytic activity is sensitive to both zinc chelators and tissue inhibitors of metalloproteinases. A full-length cDNA for the enzyme has been cloned, and sequence analysis demonstrated that the enzyme possesses the characteristic multidomain structure of an MMP gelatinase including a cysteine switch prodomain, three fibronectin type II repeats, a catalytic zinc binding region, and a hemopexin-like domain. The 75-kDa gelatinase is produced by phorbol ester-treated chicken bone marrow cells, monocytes, and polymorphonuclear leukocytes, cell types that charac- teristically produce the 92-kDa mammalian gelatinase B (MMP-9). The absence of a 90-110-kDa gelatinase in these cell types indicates that the 75-kDa gelatinase is likely the avian counterpart of gelatinase B. However, the protein is only 59% identical to human gelatinase B, whereas all previously cloned chicken MMP homologues are 75-90% identical to their human counterparts. In addition, the new 75-kDa chicken gelatinase lacks the type V collagen domain that is found in all mammalian gelatinase Bs. Furthermore, the secreted enzyme appears structurally distinct from known gelatinase Bs and the activated enzyme can cleave fibronectin, which is not a substrate for mammalian gelatinase B. Thus the results of this study indicate that a second MMP gelatinase exists in chickens, and although it is MMP-9/gelatinase B-like in its overall domain structure and expression pattern, it appears to be biochemically divergent from mammalian gelatinase B.
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PMID:The isolation, characterization, and molecular cloning of a 75-kDa gelatinase B-like enzyme, a member of the matrix metalloproteinase (MMP) family. An avian enzyme that is MMP-9-like in its cell expression pattern but diverges from mammalian gelatinase B in sequence and biochemical properties. 1101 Sep 69

The extracellular matrix metalloproteases (MMPs) secreted by various human tumor cells play a crucial role in tumor cell invasion and metastasis, but their expression in malignant mesothelioma (MM) cells has not been examined. In this study, we have investigated the spectrum of MMPs and tissue inhibitors of metalloproteases (TIMPs) produced by 8 MM cell lines. Using RT-PCR, we found that all investigated MM cell lines expressed genes encoding mRNA for MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin-1), MMP-9 (gelatinase B) and TIMPs 1, 2 and 3. We also found that 6/8 MM cell lines expressed MMP-7 (matrilysin) and 3/8 MM cell lines expressed MMP-10 (stromelysin-2). MMP-11 (stromelysin-3) was not detected in any of the MM cell lines. Production of MMP-2 and MMP-9 was confirmed using gelatin zymography. In addition, all MM cell lines secreted a 66 kDa metalloprotease, while 3/8 MM cell lines secreted 46, 48, 51 and 63 kDa metalloproteases which specifically degraded the extracellular matrix components fibronectin, vitronectin and laminin. The 66 kDa protease was identified as MMP-3 by Western blot. Our results reveal a broad spectrum of MMPs and TIMPs produced by MM cells and indicate that different substrate specificities of MMPs may play a role in MM cell invasion.
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PMID:Expression and activity of matrix metalloproteases in human malignant mesothelioma cell lines. 1126 73

The matrix metalloproteinases gelatinase A (MMP-2) and gelatinase B (MMP-9) are implicated in the physiological and pathological breakdown of several extracellular matrix proteins. In the present study, we show that long-chain fatty acids (e.g. oleic acid, elaidic acid, and cis- and trans-parinaric acids) inhibit gelatinase A as well as gelatinase B with K(i) values in the micromolar range but had only weak inhibitory effect on collagenase-1 (MMP-1), as assessed using synthetic or natural substrates. The inhibition of gelatinases depended on fatty acid chain length (with C18 > C16, C14, and C10), and the presence of unsaturations increased their inhibitory capacity on both types of gelatinase. Ex vivo experiments on human skin tissue sections have shown that micromolar concentrations of a long-chain unsaturated fatty acid (elaidic acid) protect collagen and elastin fibers against degradation by gelatinases A and B, respectively. In order to understand why gelatinases are more susceptible than collagenase-1 to inhibition by long-chain fatty acids, the possible role of the fibronectin-like domain (a domain unique to gelatinases) in binding inhibitory fatty acids was investigated. Affinity and kinetic studies with a recombinant fibronectin-like domain of gelatinase A and with a recombinant mutant of gelatinase A from which this domain had been deleted pointed to an interaction of long-chain fatty acids with the fibronectin-like domain of the protease. Surface plasmon resonance studies on the interaction of long-chain fatty acids with the three individual type II modules of the fibronectin-like domain of gelatinase A revealed that the first type II module is primarily responsible for binding these compounds.
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PMID:Involvement of fibronectin type II repeats in the efficient inhibition of gelatinases A and B by long-chain unsaturated fatty acids. 1127 59

The integrin alpha v beta 6 is a fibronectin receptor that is undetectable on normal keratinocytes in situ, but is increased significantly in wound healing and in culture-established keratinocytes, suggesting that it may promote changes associated with cell motility. Using normal human oral keratinocytes we have shown that cultured cells express relatively high levels of alpha v beta 6 and this integrin has a functional role in both cell adhesion and migration towards fibronectin. We provide experimental evidence that the increased expression of alpha v beta 6 by normal human oral keratinocytes results in coordinate changes, which promote a more migratory phenotype. Thus increased expression of alpha v beta 6 results in a fibronectin-dependent increase in pro-matrix metalloproteinase 9, matrix metalloproteinase 9 activity increases normal human oral keratinocyte migration, and this may be further dependent on plasmin activation. The results suggest a key role for alpha v beta 6 in these processes and indicate a coordinated link between alpha v beta 6 expression and upregulation of matrix metalloproteinase 9. It appears that alpha v beta 6 may function in normal human oral keratinocyte migration through matrix-metalloproteinase-9-dependent and -independent mechanisms.
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PMID:alpha v beta 6 Integrin upregulates matrix metalloproteinase 9 and promotes migration of normal oral keratinocytes. 1140 78


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