Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.17 (MMP-3)
 3,419 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We recently reported enhanced tumor growth and stimulation of vascular endothelial growth factor (VEGF) expression in rat mammary carcinoma cells transfected with a human tissue inhibitor of metalloproteinases-1 (hTIMP-1) cDNA (1). In the present study, we examined if the composition of the stroma was altered in the tumors with the highest hTIMP-1 production. Immunohistological examination revealed increased amounts of the basement membrane (BM) components, type IV collagen and laminin, in the hTIMP-1 overexpressing tumors compared to that of the control. In vitro studies also revealed upregulation of type IV collagen and laminin gene expression associated with the hTIMP-1 overexpression. Endogenous RNA levels of rat TIMP-1 and the rat matrix metalloproteinases (MMPs), MMP-2, MMP-3, and MMP-9, were not affected by the hTIMP-1 transfection, suggesting that the increase in BM deposition was not a result of decreased collagenolytic activity. This is the first report to show an association between overexpression of TIMP-1 and increased tumor BM matrix production through stimulation of type IV collagen and laminin gene expression.
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PMID:Stimulatory effect of endogenous tissue inhibitor of metalloproteinases-1 (TIMP-1) overexpression on type IV collagen and laminin gene expression in rat mammary carcinoma cells. 964 40

Cardiac rupture is a fatal complication of acute myocardial infarction lacking treatment. Here, acute myocardial infarction resulted in rupture in wild-type mice and in mice lacking tissue-type plasminogen activator, urokinase receptor, matrix metalloproteinase stromelysin-1 or metalloelastase. Instead, deficiency of urokinase-type plasminogen activator (u-PA-/-) completely protected against rupture, whereas lack of gelatinase-B partially protected against rupture. However, u-PA-/- mice showed impaired scar formation and infarct revascularization, even after treatment with vascular endothelial growth factor, and died of cardiac failure due to depressed contractility, arrhythmias and ischemia. Temporary administration of PA inhibitor-1 or the matrix metalloproteinase-inhibitor TIMP-1 completely protected wild-type mice against rupture but did not abort infarct healing, thus constituting a new approach to prevent cardiac rupture after acute myocardial infarction.
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PMID:Inhibition of plasminogen activators or matrix metalloproteinases prevents cardiac rupture but impairs therapeutic angiogenesis and causes cardiac failure. 1050 7

We have devised a new drug screening assay to discover anti-cancer drugs which inhibit Ras-mediated cellular signals, by utilizing a Ras-responsive element (RRE)-driven reporter gene system. We found that hypothemycin, an anti-bacterial, reduces RRE-dependent transcription. Treatment of tumor cells with hypothemycin resulted in reduced expression of Ras-inducible genes, including MMP (matrix metalloproteinase)-1, MMP-9, transforming growth factor-beta (TGF-beta), and vascular endothelial growth factor (VEGF), but not that of the constitutively expressed gene, MMP-2. The results of zymography demonstrated that hypothemycin reduced the production of MMP-9 and MMP-3, another Ras-inducible MMP, in the culture medium. Hypothemycin selectively inhibits anchorage-independent growth of Ras-transformed cells in comparison with anchorage-dependent growth. These findings suggest that hypothemycin inhibits Ras-mediated cellular signaling. Daily treatment of tumor-bearing mice with hypothemycin resulted in significant inhibition of tumor growth. Since MMP-1, MMP-3 and MMP-9 play important roles in tumor invasion and TGF-beta and VEGF are involved in tumor angiogenesis, hypothemycin is considered to be an example of a new class of antitumor drugs, whose antitumor efficacy can be at least partly attributed to inhibition of Ras-inducible genes.
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PMID:Antitumor efficacy of hypothemycin, a new Ras-signaling inhibitor. 1059 43

Matrix metalloproteinases (MMPs, matrixins) are a family of homologous zinc endopeptidases that may play a very important role in many physiological and pathological processes, e.g., the initiation of angiogenesis. Two new matrixin inhibitors were synthesized and characterized. A thiol inhibitor MAG-283 had IC(50) values of 480, 3, 280, 14, 1.1, and 2.3 nM against human interstitial collagenase (MMP-1), gelatinase A (MMP-2), stromelysin (MMP-3), matrilysin (MMP-7), neutrophil collagenase (MMP-8), and gelatinase B (MMP-9), respectively. A sulfodiimine inhibitor YLL-224 had IC(50) values of 180, 63, 4500, 210, 5.9, and 44 nM against MMP-1, -2, -3, -7, -8, and -9, respectively. Human skin microvascular endothelial cells were treated with these two compounds in culture. These inhibitors at very low micromolar concentrations suppressed proliferation of the endothelial cells stimulated by acidic fibroblast growth factor and vascular endothelial growth factor. They also partially blocked cell invasion through type IV collagen. These results suggested a correlation between the anti-metalloenzyme activity and the effects of these inhibitors on the growth and invasion of endothelial cells.
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PMID:New thiol and sulfodiimine metalloproteinase inhibitors and their effect on human microvascular endothelial cell growth. 1092 54

To assess the possible involvement of vascular endothelial growth factor (VEGF) in the pathology of osteoarthritic (OA) cartilage, we examined the expression of VEGF isoforms and their receptors in the articular cartilage, and the effects of VEGF on the production of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in OA chondrocytes. Reverse transcriptase-polymerase chain reaction analyses demonstrated that mRNAs for three VEGF isoforms (VEGF(121), VEGF(165), and VEGF(189)) are detectable in all of the OA and normal (NOR) cartilage samples. However, the mRNA expression of their receptors (VEGFR-1 = Flt-1, VEGFR-2 = KDR and neuropilin-1) was recognized only in the OA samples. The protein expression of VEGFR-1 and VEGFR-2 in OA chondrocytes was also demonstrated by immunohistochemistry of the OA cartilage tissue and cultured OA chondrocytes. In situ hybridization and immunohistochemistry indicated that VEGF is expressed in the chondrocytes in the superficial and transitional zones of OA cartilage. A linear correlation was obtained between VEGF immunoreactivity and Mankin scores in the cartilage (r = 0.906, P < 0.001). The production levels of VEGF determined by enzyme-linked immunosorbent assay were significantly 3.3-fold higher in OA than in NOR samples (P < 0.001). Among MMP-1, -2, -3, -7, -8, -9, and -13, TIMP-1 and -2 measured by their sandwich enzyme immunoassay systems, the production of MMP-1 and MMP-3 but not TIMP-1 or TIMP-2 was significantly enhanced by the treatment of cultured OA chondrocytes with VEGF (P < 0.05), whereas no such effect was obtained with cultured NOR chondrocytes. These results demonstrate that VEGF and its receptors are expressed in OA cartilage, and suggest the possibility that VEGF is implicated for the destruction of OA articular cartilage through the increased production of MMPs.
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PMID:Vascular endothelial growth factor isoforms and their receptors are expressed in human osteoarthritic cartilage. 1250

Matrix metalloproteinases (MMPs) constitute a large family of extracellular matrix degrading proteases implicated in a number of physiological and pathological processes, including angiogenesis. However, the relative importance of the individual MMPs in vessel formation is poorly understood. Using the three-dimensional rat aortic model, the role of the MMPs in angiogenesis in vitro was investigated both by the use of synthetic MMP inhibitors, and by a study of the expression of nine MMPs and three of their endogenous inhibitors (the TIMPs) during vessel formation. Inhibition of microvessel growth in this model by the MMP inhibitor Marimastat demonstrated the requirement of the MMPs for angiogenesis in both collagen and fibrin matrices (half-maximal inhibition at 5 and 80 nM, respectively). The profile of MMP expression was seen to be modified by both matrix composition and exogenous growth factors. For example, whilst the gelatinase MMP-2 and stromelysin MMP-3 were present at high levels in fibrin culture, the stromelysin MMP-11 and membrane-type-1-MMP were more highly expressed during vessel formation in collagen. The angiogenic basic fibroblast growth factor (bFGF) upregulated the expression of the gelatinases (MMP-2 and MMP-9), the stromelysins (MMP-3, MMP-10 and MMP-11) and the interstitial collagenase MMP-13, whereas vascular endothelial growth factor (VEGF) led to a marked increase in expression of MMP-2 only. Together, the environment-dependent upregulation in expression of a number of MMPs during angiogenesis, and the total inhibition of vessel growth observed at nanomolar concentrations of synthetic MMP inhibitors, suggests a major collective role of these enzymes in angiogenesis, and provides a basis for further development of MMP inhibitors for anti-angiogenic therapy.
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PMID:The role of the matrix metalloproteinases during in vitro vessel formation. 1283 Oct 62

The Ets2 transcription factor is regulated by mitogen-activated protein (MAP) kinase phosphorylation of a single threonine residue. We generated by gene targeting a single codon mutation in Ets2 substituting Ala for the critical Thr-72 phosphorylation site (Ets2A72), to investigate the importance of MAP kinase activation of Ets2 in embryo and tumor development. Ets2(A72/A72) mice are viable and develop normally. However, combining the Ets2A72 allele with a deletion mutant of Ets2 results in lethality at E11.5 and shows that Ets2A72 is a hypomorphic allele. Mammary tumors caused by transgenic polyomavirus middle T antigen, activated Neu(Erbb2), or the combination of Neu and transgenic VEGF (Neu; VEGF-25) were all restricted in Ets2(A72/A72) females. The Ets2(A72/A72) restriction on Neu; VEGF-25 tumor growth was associated with increased p21Cip1 expression. The size of tumors transplanted into fat pads of mice with Ets2 targeted alleles was correlated directly with Ets2 activity and fewer stromal cells expressing matrix metalloproteinase 9 (MMP-9). Decreased MMP-3 and MMP-9 mRNAs were confirmed in Ets2(A72/A72) macrophages. Activation of Ets2 at Thr-72 acts in the stroma, downstream of vascular endothelial growth factor production, in part through the regulation of macrophage proteases to support the progression of Neu- and polyomavirus middle-T-initiated mammary tumors.
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PMID:Ets2-dependent stromal regulation of mouse mammary tumors. 1461 5

VEGF (vascular endothelial growth factor) is not only one of the most important angiogenesis factors, but is involved also in inflammatory processes. Recent studies have shown that VEGF as well as its receptor VEGFR-2 are expressed on osteoarthritic chondrocytes, but not on normal adult chondrocytes. Since mechanical overload is one of the causative factors for osteoarthritis, we studied its effect on VEGF expression on bovine cartilage disks that were compressed once with a strain of 50% and a strain rate of 1/second. Under these conditions, control disks (without pressure) were completely negative for VEGF expression as evidenced by immunocytochemical stainings as well as by enzyme-linked immunosorbent assay (ELISA) measurements. In contrast, 4 days after mechanical overload, the cartilage disks were positive in both detection methods. In addition, after mechanical overload chondrocytes were strongly immunopositive for hypoxia-inducible factor-1alpha (HIF-1alpha), the limiting protein of the dimeric transcription factor HIF-1 that is known to induce VEGF expression. Furthermore, the matrix metalloproteases MMP-1, MMP-3, and MMP-13, could be easily detected in pressure-treated disks by immunohistochemistry whereas staining in controls was low or undetectable. The tissue inhibitors of metalloproteinases (TIMP-1 and -2) could be detected in controls but not in samples treated with mechanical overload. To prove that increased MMP or decreased TIMP expression could be a result of the autocrine action of VEGF on chondrocytes, we repeated the experiments in the presence of a specific inhibitor for the kinase activity of the VEGFR-2. This inhibitor was effective to reduce mechanically induced MMP-1, -3, and -13 immunostaining and to restore TIMP expression. Taking together, these findings indicate that VEGF is induced in chondrocytes by mechanical overload and mediates destructive processes in osteoarthritis as an autocrine factor.
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PMID:Mechanical overload induces VEGF in cartilage discs via hypoxia-inducible factor. 1469 32

VEGF (vascular endothelial growth factor), an important angiogenesis factor, appears also to be involved in inflammatory processes. Recent studies have shown that VEGF and its receptors (VEGFR) are expressed on osteoarthritic, but not on normal adult, chondrocytes. To elucidate possible functions of VEGF in osteoarthritic cartilage, the effects of VEGF were studied on immortalized human chondrocytes. Activated matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, tissue inhibitor of metalloproteinases (TIMP)-1, TIMP-2, interleukin (IL)-1beta, IL-6, and tumour necrosis factor-alpha (TNF-alpha) were measured in culture supernatants by enzyme-linked immunosorbent assays, nitric oxide with the Griess reagent, and cell proliferation by [3H]thymidine incorporation. VEGFR-2 mRNA was quantified by real-time reverse transcription-polymerase chain reaction and the protein was identified by immuno-gold electron microscopy. Intracellular signal transduction effects were determined by western blots and electrophoretic mobility shift assays. The chondrocyte cell lines C28/I2, C20/A4, and T/C28a2/a4 expressed functionally active VEGFR-2. VEGF stimulation induced receptor phosphorylation, activation of the mitogen-activated protein kinases ERK 1/2, and long-lasting activation of the transcription factor AP-1 (activator protein-1). VEGF increased secreted MMP-1, MMP-3, and especially MMP-13, which could be effectively reduced by an inhibitor of VEGFR-2 kinase activity. Interestingly, VEGF diminished the expression of TIMP-1 and especially TIMP-2. Under hypoxic conditions, as occur in cartilage, the reduction in TIMP levels was even greater. Furthermore, VEGF induced IL-1beta, IL-6, TNF-alpha, and nitric oxide expression to a small extent and stimulated the proliferation of immortalized chondrocytes. These findings indicate that VEGF is an autocrine stimulator of immortalized chondrocytes that mediates mainly destructive processes in osteoarthritis.
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PMID:Vascular endothelial growth factor (VEGF) induces matrix metalloproteinase expression in immortalized chondrocytes. 1499 3

Intervertebral disc herniation (HD) is one of the most common orthopaedic conditions. MRI analysis of HD has revealed a spontaneous resorption mechanism related with neo-vascularization. It appears that the interaction of activated macrophages with disc tissues leads to the generation of inflammatory cytokines. Moreover, inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) is required for the induction of angiogenesis inducing factors such as vascular endothelial growth factor (VEGF) or matrix degrading enzymes such as MMP-3, MMP-7 and plasmin. We hypothesized that these molecules play a crucial role during spontaneous HD resorption. In this study, we have examined the sequential expression of these molecules using a co-culture system which is composed of the interaction of activated macrophages and disc tissues as a model of the acute response of inflammation occurred in HD. We have also considered the mechanism of activating latent MMPs during HD resorption process. Current our results indicate that upregulation of both TNF-alpha mRNA and protein expressions occur first in the inflammation induced by HD. VEGF upregulation follows the increased level of TNF-alpha expression. Both plasmin and MMP-3 are upregulated at later time points. We also demonstrate that both TNF-alpha and VEGF induce upregulated expression of urokinase-type plasminogen activator (u-PA). Our previous work has demonstrated that TNF-alpha could upregulate the expression of VEGF, MMP-3 and MMP-7 in the co-culture system. It has been reported that plasmin could affect to activate latent MMPs. Based on these findings, we suggest that TNF-alpha acts as the initiator of inflammation following contact between macrophages and disc chondrocytes and that plasmin and u-PA play a crucial role in activation of MMPs. We propose a spontaneous HD resorption cascade. Further understanding of the resorption process may provide future novel therapies for HD.
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PMID:Sequential dynamics of inflammatory cytokine, angiogenesis inducing factor and matrix degrading enzymes during spontaneous resorption of the herniated disc. 1518 52


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