Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The AP-1 consensus sequences (TGAGTCA) are the major 12-O-tetradecanoylphorbol113-acetate (TPA) responsive elements shared by several TPA inducible genes, such as c-sis, c-fos, c-myc, collagenase, stromelysin, hMTIIA and SV40. However, the role of AP-1 binding sites, which are present in the introns 3, 5, and 11 of ODC gene, in the regulation of TPA-induced ornithine decarboxylase (ODC) gene transcription are unknown. We determined the TPA responsiveness of the AP-1 sequences in the introns of ODC gene in CV-1 cells which induce ODC activity and mRNA in response to TPA treatment. ODC introns containing AP-1 sequences were inserted into the chloramphenicol acetyltransferase (CAT) reporter gene. Transient transfection of CV-1 cells with the intron-CAT constructs followed by TPA treatment did not induce CAT activity. However, when flanking regions of the AP-1 site in intron 3 were narrowed down to 74 bp, TPA induced CAT activity by 5- to 7-fold. The TPA-inducibility could be eliminated by mutation of the AP-1 site (TGAGTCA-->TGATGCCA or TGATGA) in 74 bp of intron 3. These results indicate that the AP-1 sequences in the intact ODC introns may not be responsive to TPA. The flanking sequences of the AP-1 site may be crucial to determine whether the AP-1 site is accessible to the TPA-induced transcriptional factor(s).
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PMID:Lack of 12-O-tetradecanoylphorbol-13-acetate responsiveness of ornithine decarboxylase introns which have AP-1 consensus sequences. 765 80

Platelet-activating factor (PAF), a potent lipid mediator involved in inflammatory and immune responses, accumulates rapidly in response to injury in a variety of tissues, including the corneal epithelium. However, the precise role of this compound in the cascade of events following insult has not been defined. Here we examined the effect of PAF on gene expression in the epithelial cells of rabbit corneas in organ culture. We found that incubation with 100 nM methylcarbamoyl PAF, a nonhydrolyzable analog of PAF, produced rapid transient 2.8- and 3.5-fold increases in the expression of c-fos and c-jun, respectively, at 1 hr, followed by increased expression of the collagenase type I gene beginning at 3 hr and peaking at 14-fold by 8 hr. Addition of the protein-synthesis-inhibitor cycloheximide superinduced c-fos and c-jun, strongly potentiating the PAF effect, but inhibited the induction of collagenase type I expression, suggesting the existence of a transcriptional factor linking the two events. BN-50730, a selective antagonist of intracellular PAF-binding sites, blocked the expression of the immediate-early genes as well as the increase in collagenase type I mRNA. Our results suggest that one of the functions of PAF may be to enhance the breakdown of the extracellular matrix as a part of the remodeling process during corneal wound healing after injury. Pathologically, a PAF-induced overproduction of collagenase may be a factor in the development of corneal ulcers, as well as other pathophysiological conditions such as cartilage destruction in arthritis. If so, inhibitors of this signal-transduction pathway may be useful as tools for further investigation and, eventually, as therapeutic agents to treat such disorders.
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PMID:Platelet-activating factor induces collagenase expression in corneal epithelial cells. 837 47

The ets-1 proto-oncogene is a member of the transcriptional factor family and was identified by homology to the v-ets oncogene. It was recently demonstrated that Ets-1 protein interacts with the promoter region of the genes coding for proteinases, including matrix metalloproteinase-1 (MMP-1), MMP-3, and urokinase-type plasminogen activator, suggesting that it may play an important role in the regulation of MMP expression. The role of the ets-1 proto-oncogene in advanced glomerular diseases, where extracellular matrix accumulation is observed, remains undefined. In this study, the expression of ets-1 mRNA and protein during the progression of rat crescentic glomerulonephritis was examined using immunohistochemical analysis, reverse transcription-PCR, and in situ hybridization. Passive accelerated anti-glomerular basement membrane-induced nephritis was induced in rats by intravenous injection of nephrotoxic serum. Rats were euthanized on day 7, 14, 21, 28, or 42. Immunohistochemical analysis demonstrated significant upregulation of Ets-1 protein expression in glomeruli and the interstitium in anti-glomerular basement membrane-induced nephritis. The numbers of Ets-1-positive cells were increased 8.8-fold on day 21 in glomeruli (1.2+/-0.1 cells/glomerular cross-section, P<0.001) and sixfold on day 28 in the interstitium (21+/-1.3 cells/mm(2), P<0.001), compared with control samples. Ets-1 protein was predominantly localized in glomerular epithelial cells, endothelial cells, and interstitial cells. A small number of vascular endothelial cells, macrophages, and T cells also expressed Ets-1 protein. MMP-3 deposition was upregulated and positive cells in the interstitium often coexpressed Ets-1, whereas only a few glomerular cells were positive for both MMP-3 and Ets-1 protein. The expression of ets-1 mRNA was also markedly increased in diseased kidneys. The distribution of ets-1 mRNA was similar to that of the protein. These results indicate that overexpression of the ets-1 proto-oncogene by phenotypically altered renal cells might be associated with the pathogenesis of rat crescentic glomerulonephritis.
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PMID:Renal expression of the Ets-1 proto-oncogene during progression of rat crescentic glomerulonephritis. 1109 47

Calcium antagonists (CAs) are widely prescribed for patients with cardiovascular diseases. CAs have been reported to inhibit smooth muscle cell (SMC) proliferation in addition to their effects on vascular tone. To determine whether CAs potentially affect vascular remodeling, we measured the expression of matrix-degrading enzymes in growth factor-stimulated SMC. Human cultured SMC were stimulated with 10 ng/ml of platelet-derived growth factor (PDGF)-BB with or without a calcium antagonist, diltiazem. In the cell counting assay, diltiazem (10-5 M) alone had no effect on the proliferation of quiescent SMC, however 10-6-10-5 M of diltiazem dose-dependently inhibited PDGF-stimulated SMC proliferation. The inhibitory effects of diltiazem on SMC proliferation were further confirmed by a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and flow cytometry. In Western blotting, matrix metalloproteinase (MMP)-1 (tissue collagenase) but not MMP-2 (72-kDa gelatinase) expression was upregulated by PDGF and phorbol ester (TPA), which were reduced by diltiazem in a dose-dependent manner. The downregulation of MMP-1 expression was consistent with the reduction of collagenolytic activity measured by a FITC-conjugated type I collagen breakdown assay. PDGF-stimulated c-Jun/AP-1 expression, a major transcriptional factor for MMP-1, was not affected by diltiazem. In contrast, intracellular calcium ions measured with a fluorometric assay of Fluo-3AM-loaded cells revealed that the PDGF-stimulated increase in the intracellular calcium content was dose-dependently reduced by diltiazem. Our data suggest that diltiazem inhibits not only proliferation but also MMP-1 expression and collagenolytic activity in PDGF-stimulated SMC. The administration of CAs potentially influences the process of vascular remodeling, and this possibility should be further verified in vivo.
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PMID:Diltiazem, a calcium antagonist, inhibits matrix metalloproteinase-1 (tissue collagenase) production and collagenolytic activity in human vascular smooth muscle cells. 1160 28

Considerable evidence has implicated matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases, in the degradation of extracellular matrix (ECM) during the metastatic process. Most MMPs are secreted as inactive zymogens and are activated extracellularly. Over expression of MMP-1, -2, -3. -7, -9, -13, and MT1-MMP has been demonstrated in human colorectal cancers. The degree of over expression of some MMPs has been noted to correlate with stage of disease and/or prognosis. An unresolved debate has centered on whether MMPs are produced by the stromal cells surrounding a tumor or by the colorectal cancer cells themselves. MMP-7 is produced abundantly by colorectal cancer cells. The presence of a mutation in the APC gene results in nuclear accumulation of the beta-Catenin/TCF complex, which serves as a transcriptional factor that upregulates MMP-7 expression. Increased expression of MMP-3 in colorectal cancer correlates with low levels of microsatelite instability and poor prognosis. Increased levels of MMP-9 (produced primarily by inflammatory cells) have been demonstrated early in the transition from colon adenoma to adenocarcinoma. In contrast to other MMPs, overexpression of MMP-12 is associated with increased survival in colorectal cancer, presumably as a result of an inhibitory effect on angiogenesis. Based on the assumption that MMPs were responsible for metastasis, several orally active, low molecular weight inhibitors of MMPs (MMPIs) have been developed. These MMPIs have been effective in controlling cancer progression in animals, but have failed to prolong survival in phase III clinical trials in patients with advanced cancer. MMPIs have not yet been evaluated in patients with colorectal cancer.
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PMID:Role of matrix metalloproteinases (MMPs) in colorectal cancer. 1500 Jan 52

p21SNFT (21 kDa small nuclear factor isolated from T cells) is a human basic leucine zipper transcription factor that can repress AP-1-mediated transcription. We show here that overexpression of p21SNFT in HepG2 cells leads to repression of matrix metalloproteinase-1 by 70-80%. p21SNFT interacted with Jun at the matrix metalloproteinase-1 promoter -88 Ets/AP-1 enhancer element, where Jun is known to activate transcription via interaction with Fos and Ets proteins. When p21SNFT/Jun dimers bound the element in the presence of Ets, DNA was protected differently than when Fos was paired with Jun. The data suggest a difference in overall conformation between p21SNFT-containing and Fos-containing complexes that may be involved in the repression of matrix metalloproteinase-1 by p21SNFT. Overexpression of p21SNFT led to a reduction in invasiveness of HepG2 cells through type I collagen and reconstituted basement membrane, an effect similar to that obtained via direct immunodepletion of matrix metalloproteinase-1. The results indicate that the mechanism of repression of matrix metalloproteinase-1 by p21SNFT may be exploited in inhibiting pathological matrix remodeling during cancer progression in vivo.
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PMID:Transcriptional repression of MMP-1 by p21SNFT and reduced in vitro invasiveness of hepatocarcinoma cells. 1546 42

It is now becoming clear that matrix metalloproteinases (MMPs) play a key role in tumor development and growth. MMPs are overexpressed in a variety of premalignant tumor tissues, including colorectal adenoma. Little is known about the mechanisms underlying the overexpression of MMPs in adenoma tissues. E1AF, an Ets family transcriptional factor, has been shown to play an important role in the expression of MMPs and cyclooxygenase-2 (COX-2) in advanced colorectal cancers. The aim of this study was to examine the E1AF expression and determine whether it is correlated with the expression of MMPs, COX-2 and inducible nitric oxide synthase (iNOS) in human colorectal adenoma and submucosal cancer (pT1). Using the semi-quantitative RT-PCR, 90 colorectal tumors, including 63 adenomas and 27 cancers (pT1), were analyzed for the expression of E1AF, MMPs, COX-2 and iNOS. Immunohistochemical analysis and in vitro transfection assays were also performed. E1AF mRNA was detected in 43 (47.8%) of the 90 colorectal tumors. E1AF overexpression was significantly correlated with histopathology. E1AF expression was correlated significantly with the expression of MMP-1 and MMP-7. Overexpression of COX-2 and iNOS mRNA expression was observed in 42.2% and 66.7% of the 90 colorectal tumors, respectively. COX-2 was correlated significantly with size, gender, histopathology and E1AF. iNOS was correlated significantly with size, histopathology, E1AF and COX-2. The correlation of E1AF expression with COX-2 and iNOS expression was also demonstrated by immunohistochemistry. Northern blot analysis of transfectants showed the effect of E1AF on COX-2 expression as well as iNOS on E1AF/COX-2 expression in colon cancer cell lines. The results suggest that E1AF, in conjunction with the expression of MMP-1, MMP-7, COX-2 and iNOS, plays an important role in the early stage of colorectal carcinogenesis.
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PMID:Association of Ets-related transcriptional factor E1AF expression with overexpression of matrix metalloproteinases, COX-2 and iNOS in the early stage of colorectal carcinogenesis. 1569 37

Tranilast is an anti-allergic agent that blocks the release of chemical mediators, such as histamine and leukotrienes from mast cells, and has been reported to suppress keloid and hypertrophic scar formation. Since matrix metalloproteinases (MMPs) play an essential role in tissue remodelling, this study was undertaken to determine whether tranilast suppresses MMP production from neutrophils after lipopolysaccharide (LPS) stimulation in-vitro. Neutrophils from five healthy donors (1 x 10(5) cells/mL) were stimulated with 1.0 microg mL(-1) LPS in the presence or absence of various concentrations of tranilast for 24 h. MMP-7, MMP-8, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 levels in the culture supernatants were assayed by ELISA. In addition, the influence of tranilast on MMP mRNA expression and transcriptional factor activation in cells cultured for 12 h and 4 h was also evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Tranilast inhibited MMP and TIMP-1 production from neutrophils when cells were treated with the agent at more than 5.0 x 10(-5) M. It also suppressed MMP mRNA expression and transcriptional factor activation induced in neutrophils by LPS stimulation. The results suggest that tranilast inhibits the formation of keloid scarring through the suppression of factors such as MMPs and TIMP, which are essential for tissue remodelling, from inflammatory cells.
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PMID:Effect of tranilast on matrix metalloproteinase production from neutrophils in-vitro. 1639 68

We investigated the effect of hepatocyte growth factor (HGF) on collagen metabolism in cultured fibroblasts from scleroderma (SSc) patients and discussed the possible mechanism of its effect. Synthesis of matrix metalloproteinase-1 (MMP-1) and collagen and mRNA levels of various cytokines were examined by enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively. Hepatocyte growth factor enhanced MMP-1 production and mRNA levels of MMP-1 and Ets-1 (a transcriptional factor of MMPs). In addition, HGF suppressed collagen synthesis and mRNA levels of procollagenalpha1(I) and connective tissue growth factor (CTGF) in SSc fibroblasts. Expression of transforming growth factor (TGF)-beta1 was not inhibited significantly in SSc or control fibroblasts. Hepatocyte growth factor also increased interferon (IFN)-gamma mRNA significantly in SSc and control fibroblasts. Addition of anti-HGF antibody neutralized these effects of HGF on MMP-1 and collagen synthesis. The results suggest that HGF can suppress collagen accumulation in SSc fibroblasts by increasing MMP-1 levels possibly via activation of Ets-1 and also by decreasing collagen synthesis, which may be partly related to inhibition of CTGF, and increasing IFN-gamma levels rather than the effect on TGF-beta1. The present study indicates that HGF may be a promising therapeutic agent for this intractable disease.
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PMID:Antifibrotic effects of hepatocyte growth factor on scleroderma fibroblasts and analysis of its mechanism. 1716 98

Nrf2 is a key transcriptional factor for antioxidant response element (ARE)-regulated genes. While its beneficial role has been described for stroke, its contribution to intracerebral hemorrhage (ICH)-induced early brain injury remains to be determined. Using wild-type (WT) and Nrf2 knockout (Nrf2(-/-)) mice, the role of Nrf2 in ICH induced by intracerebral injection of collagenase was investigated. The results showed that injury volume was significantly larger in Nrf2(-/-) mice than in WT controls 24 h after induction of ICH (P<0.05), an outcome that correlated with neurological deficits. This exacerbation of brain injury in Nrf2(-/-) mice was also associated with an increase in leukocyte infiltration, production of reactive oxygen species, DNA damage, and cytochrome c release during the critical early phase of the post-ICH period. In combination, these results suggest that Nrf2 reduces ICH-induced early brain injury, possibly by providing protection against leukocyte-mediated free radical oxidative damage.
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PMID:Role of Nrf2 in protection against intracerebral hemorrhage injury in mice. 1760 56


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