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)

From collagenase digests of human thyroid, endothelial cells were separated from follicular cells by their greater adherence to gelatin-coated plates. Endothelial cells were further purified using fluorescence-activated cell sorting, selecting for cells expressing factor VIII-related antigen. Isolated cells were negative for thyroglobulin and calcitonin when examined by immunostaining. The receptor for the angiopoietins, Tie-2, was expressed by the cells, and expression was increased by agents that elevate cAMP. Nitric oxide synthase (NOS) 3, the endothelial form of NOS, was expressed by the cells and similarly regulated. Cells responded strongly to the mitogen fibroblast growth factor (FGF)-2 in growth assays but only weakly to vascular endothelial growth factor (VEGF). VEGF was, however, able to stimulate nitric oxide release from the cells consistent with their endothelial origin. The FGF receptor (FGFR1) was full length (120 kDa) and immunolocalized to the cytosol and nucleus. Thyrotropin (TSH) did not regulate FGFR1, but its expression was increased by VEGF. Thrombospondin, a product of follicular cells, was a growth inhibitor, but neither TSH nor 3,5,3'-triiodothyronine had direct mitogenic effects. Thyroid follicular cell conditioned medium contained plasminogen activator activity and stimulated the growth of the endothelial cells, but when treated with plasminogen to produce the endothelial-specific inhibitor, angiostatin, growth was inhibited. Human thyroid endothelial cell cultures will be invaluable in determining the cross talk between endothelial and follicular cells during goitrogenesis.
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PMID:Isolation and characterization of human thyroid endothelial cells. 1962 78

Expression of 12 matrix metalloproteinases (MMPs) after exposure of human melanoma cell lines C32TG and Mewo to nitric oxide (NO) was investigated by the reverse transcription-polymerase chain reaction. Expression of the mRNA of MMP-1, -3, -10 and -13 in C32TG cells was transcriptionally enhanced in a dose-dependent manner by exposure to an NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP) and mRNA expression of MMP-1 and -10 was similarly enhanced in Mewo cells. Exposure of C32TG cells to NO increased the MMP-1 protein concentration in the culture medium. Testing with the luciferase gene fused to the 1.5 Kbp 5'-flanking region of the human MMP-1 gene showed that exposure to NO upregulated MMP-1 promoter activity in C32TG cells. Endogenous NO production after introduction of inducible NO synthase cDNA also enhanced MMP-1 promoter activity in C32TG cells. Deletion and mutational analysis identified a critical AP-1 binding site required for NO regulation of MMP-1. A neighboring Ets motif from the AP-1 site in the promoter region acted as an accessory to enhance MMP-1 expression. Electromobility shift analysis using the AP-1 binding site showed that NO enhanced the AP-1 binding ability of nuclear factors in C32TG cells. PD98059, a selective MEK inhibitor and SB202190, a p38 MAPK inhibitor, attenuated the MMP-1 mRNA expression enhanced by NO. Thus, MMP-1 was transcriptionally enhanced by NO via MAPK (ERK and p38) pathways. The results of our study suggest that the increased expression of MMPs in response to NO may be associated with tumor progression under inflammation.
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PMID:Induction of matrix metalloproteinase gene transcription by nitric oxide and mechanisms of MMP-1 gene induction in human melanoma cell lines. 1245 29

Replicative senescence is characterized by numerous phenotypic alterations including loss of proliferative capacity and numerous changes in gene expression such as impaired serum inducibility of the immediate early gene c-fos and increased expression of collagenase. Transcription of c-fos in response to mitogens depends on the activation of a multiprotein complex formed on the c-fos serum response element (SRE), which includes the transcription factors serum response factor (SRF) and ternary complex factor (TCF). TCF is activated after phosphorylation by the Extracellular signals Regulated Kinase 1 and 2 (ERK1/2), two kinases of the Raf/MEK/ERK signaling pathway. We have previously demonstrated that collagenase expression is under positive regulation by the transcription factor FKHRL1 and that this transcription factor is under negative regulation by the phosphatidylinositol 3-kinase(PI3K)/Akt(PKB) pathway. Although total activity of ERK and Akt was similar in total cell lysates from early and late passage fibroblasts our data indicate that in senescent cells neither ERK nor Akt are able to phosphorylate efficiently their nuclear targets. Our findings suggest that although they can be fully activated in the cytosol of both early and late passage cells, the Raf/MEK/ERK and the PI3K/Akt pathways, which are essential for cellular proliferation, are down regulated in the nuclei of senescent cells.
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PMID:Role of the Raf/MEK/ERK and the PI3K/Akt(PKB) pathways in fibroblast senescence. 1247 Aug 26

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

Several members of the ETS family of transcription factors contribute to tumorigenesis in many different tissues, including breast epithelium. The ESX gene is an epithelial-specific Ets member that is particularly relevant to breast cancer. ESX is amplified in early breast cancers, it is overexpressed in human breast ductal carcinoma in situ, and there may be a positive feedback loop between the HER2/neu proto-oncogene and ESX. Despite this progress in our understanding of ESX, its ability to regulate tumor-related gene expression and to modulate breast cell survival, remain unknown. Here we show that HA-ESX stimulates the collagenase and HER2/neu promoters, but fails to activate an intact stromelysin promoter. However, HA-ESX activates, in a dose-dependent manner, a heterologous promoter containing eight copies of the Ets binding site derived from the stromelysin gene (p8Xpal-CAT). Analysis of the ability of constructs encoding nine Ets family members to activate the HER2/neu promoter revealed three patterns of gene activation: (1) no effect or repressed promoter activity (Elk-1 and NET); (2) intermediate activity (ER81, GABP, ESX, and HA-Ets-2); and, (3) maximal activity (Ets-1, VP-16-Ets-1, and EHF). Based on these observations, we also determined whether ESX is capable of conferring a survival phenotype upon immortalized, but nontransformed and ESX negative MCF-12A human breast cells. Using a colony formation assay, we found that HA-ESX and HA-Ets-2, mediated MCF-12A cell survival rates that approached those generated by oncogenic V12 Ras, whereas empty vector resulted in negligible colony formation. By contrast, in immortalized and transformed T47D breast cancer cells, which express both HER2/neu and ESX, we found that antisense and dominant-negative HA-ESX inhibited T47D colony formation, whereas control vector allowed formation of many colonies. These results are significant because they show that HA-ESX is able to differentially activate several malignancy-associated gene promoters, and that ESX expression is required for cellular survival of nontransformed MCF-12A and transformed T47D human mammary cells.
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PMID:The epithelial-specific ETS transcription factor ESX/ESE-1/Elf-3 modulates breast cancer-associated gene expression. 1271 34

Signal transduction events in monocyte matrix metalloproteinase (MMP) production have been shown to include a PGE(2)-cAMP-dependent step. To determine earlier pathway components, we examined the role of mitogen-activated protein kinases (MAPKs) in the regulation of monocyte MMP-1 and MMP-9, two major MMPs induced by LPS. Stimulation with LPS resulted in the activation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) and mitogen-activated kinase p38. The p38-specific inhibitor SB203580 suppressed p38 activity and MMP-1 mRNA and protein, but increased ERK activity and MMP-9 mRNA and protein. In contrast, the MAPK kinase 1/2-specific inhibitor PD98059 inhibited MMP-1 and MMP-9. However, both MAPK inhibitors decreased the production of cyclooxygenase-2 and PGE(2), but only the inhibition of MMP-1 by SB203580 was reversed by PGE(2) or dibutyryl cAMP. Examination of the effect of these MAPK inhibitors on the promoters of MMP-1 and MMP-9 revealed that PD98059 inhibited the binding of transcription factors to all of the MMP promoter-specific complementary oligonucleotides tested. However, SB203580 only inhibited the binding of MMP-1-specific CREB and SP 1 oligonucleotides, which was reversed by PGE(2). Additionally, SB203580 enhanced transcription factor binding to the oligonucleotides complementary to a NF-kappaB site in the promoter of MMP-9. Thus, LPS induction of MMP-1 production by monocytes is regulated by both ERK1/2 and p38, whereas MMP-9 stimulation occurred mainly through the ERK1/2 pathway. Moreover, p38 regulates MMP-1 mainly through a PGE(2)-dependent pathway, whereas ERK1/2-mediated MMP-1 and MMP-9 production involves the activation of additional MMP promoter sites through a PGE(2)-independent mechanism.
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PMID:Differential regulation of lipopolysaccharide-induced monocyte matrix metalloproteinase (MMP)-1 and MMP-9 by p38 and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinases. 1279 56

TGF-beta1 has been implicated in glomerular extracellular matrix accumulation, although the precise cellular mechanism(s) by which this occurs is not fully understood. The authors have previously shown that the Smad signaling pathway is present and functional in human glomerular mesangial cells and plays a role in activating type I collagen gene expression. It also was determined that TGF-beta1 activates ERK mitogen-activated protein kinase in mesangial cells to enhance Smad activation and collagen expression. Here, it was shown that TGF-beta1 rapidly induces cytoskeletal rearrangement in human mesangial cells, stimulating smooth muscle alpha-actin detection in stress fibers and promoting focal adhesion complex assembly and redistribution. Disrupting the actin cytoskeleton with cytochalasin D (Cyto D) selectively decreased basal and TGF-beta1-induced cell-layer collagen I and IV accumulation. The balance of matrix metalloproteinases (MMP) and inhibitors was altered by Cyto D or TGF-beta1 alone, increasing MMP activity, increasing MMP-1 expression, and decreasing tissue inhibitor of matrix metalloproteinase-2 expression. Cyto D also decreased basal and TGF-beta1-stimulated alpha1(I) collagen mRNA but did not inhibit TGF-beta-stimulated alpha1(IV) mRNA expression. A similar decrease in alpha1(I) mRNA expression caused by the actin polymerization inhibitor latrunculin B was partially blocked by the addition of jasplakinolide, which promotes actin assembly. The Rho-family GTPase inhibitor C. difficile toxin B or the Rho-associated kinase inhibitor Y-27632 also blocked TGF-beta1-stimulated alpha1(I) mRNA expression. Cytoskeletal disruption reduced Smad2 phosphorylation but had little effect on mRNA stability, TGF-beta receptor number, or receptor affinity. Thus, TGF-beta1-mediated collagen I accumulation is associated with cytoskeletal rearrangement and Rho-GTPase signaling.
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PMID:Cytoskeletal rearrangement and signal transduction in TGF-beta1-stimulated mesangial cell collagen accumulation. 1287 50

Matrix metalloproteinases (MMPs) are the proteases involved in the degradation of the extracellular matrix. MMP-1 is thought to be one of the key enzymes in fibrolysis, a process closely related to tissue remodeling. In the present study, we investigated MMP-1 secretion from human pancreatic periacinar myofibroblasts in response to pro-inflammatory cytokines IL-1beta and TNF-alpha. We also attempted to clarify the intracellular signaling pathways mediating the cytokine-induced MMP-1 secretion. MMP-1 secretion was measured by an enzyme-linked immunosorbent assay. MMP-1 molecules were analyzed by Western blotting. MMP-1 mRNA expression was evaluated by Northern blotting. IL-1l and TNF-alpha stimulated the MMP-1 secretion in a dose- and time-dependent manner. Ninety percent of MMP-1 was secreted as inactive form (pro-MMP-1). The effects of IL-1beta and TNF-alpha were significantly inhibited by PD98059 MEK/ERK inhibitor). In contrast, SB203580 (p38 MAPK inhibitor), GF109203X (PKC inhibitor), and PDTC (NF-kappaB inhibitor) did not alter the MMP-1 secretion induced by IL-1beta and TNF-alpha. These effects were also observed at them RNA level. In conclusion, in human pancreatic periacinar myofibroblasts, MMP-1 secretion was regulated by the pro-inflammatory cytokines via the MEK/ERK cascade. Thus, human pancreatic periacinar myofibroblasts may play an important role in the remodeling of damaged pancreatic tissue in chronic pancreatitis via MMP-1 secretion.
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PMID:Pro-inflammatory cytokine-induced matrix metalloproteinase-1 (MMP-1) secretion in human pancreatic periacinar myofibroblasts. 1452 52

Organochlorine compounds have been demonstrated to have detrimental health effects in both wildlife and humans, an effect largely attributed to their ability to mimic the hormone estrogen. Our laboratory has studied cell signaling by environmental chemicals associated with the estrogen receptor (ER) and more recently via ER-independent mechanisms. Here, we show that the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolites induce a stress mitogen-activated protein kinase (MAPK) that leads to AP-1 activation. Through the use of a dominant negative c-Fos mutant, we show that DDT exposure induces the collagenase promoter in an AP-1-dependent manner. DDT stimulates an AP-1 complex shift at the DNA to one favoring c-Jun/c-Fos dimers through both increasing c-Jun levels and by post-translational activation of c-Jun and c-Fos in HEK 293 and human endometrial Ishikawa cells. DDT treatment induces phosphorylation of ERK and p38, while JNK phosphorylation levels are slightly decreased. Using pharmacological and molecular inhibitors of the various MAPKs, we implicate the p38 signaling cascade, and to a lesser extent ERK, as necessary pathways for AP-1-mediated gene expression induction by organochlorines. Taken together, these results demonstrate that organochlorines induce the collagenase promoter via sequential activation of the p38 kinase cascade and AP-1.
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PMID:Mechanism of AP-1-mediated gene expression by select organochlorines through the p38 MAPK pathway. 1460 93

Degradation of stromal collagens in the extracellular matrix is mediated largely by matrix metalloproteinase-1 (MMP-1; collagenase-1), and high constitutive levels of MMP-1 in breast cancer correlate with a poor prognosis and invasive disease. MMP-1 expression is, in part, controlled by the mitogen-activated protein kinase (MAPK) pathway(s), which may target several activator protein-1 (AP-1) and polyoma enhancing activity-3/E26 virus (PEA3/ETS) sites within the promoter. An additional ETS site in the MMP-1 promoter is conferred by a single nucleotide polymorphism (SNP) at -1607 bp, when two guanines (5'-GGAT-3'; '2G allele/SNP') are present instead of one guanine (5'-GAT-3'; '1G allele/SNP'). This SNP is adjacent to an AP-1 site at -1602 bp, and in the presence of the 2G allele (ETS site), these sites cooperate to induce higher levels of transcription. ERK 1/2 is one component of the MAPK pathway and is constitutively active in MCF-7/ADR breast cancer cells, which are 1G/2G heterozygotes. This study demonstrates that when these cells are treated with PD098059, an ERK-specific inhibitor, MMP-1 mRNA levels are significantly decreased, suggesting that high constitutive expression of MMP-1 in these cells results from continuous ERK 1/2 activation. Using transient transfection, we determined that this signaling pathway targets different AP-1/ETS sites, depending upon which allele is present. Furthermore, in these cells, the AP-1 site at -1602 bp enhances transcription in the presence of the 2G SNP, but represses transcription from the 1G SNP. Finally, inhibiting ERK signaling and MMP-1 expression blocks type I collagen degradation and reduces the invasive ability of the MCF-7/ADR cells. We conclude that ERK 1/2 signaling and the 2G SNP mediate high levels of MMP-1 expression, which may contribute to the invasive potential of these breast cancer cells.
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PMID:The 2G single nucleotide polymorphism (SNP) in the MMP-1 promoter contributes to high levels of MMP-1 transcription in MCF-7/ADR breast cancer cells. 1469 51


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