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)

Progelatinase A was purified as a complex with TIMP-2 from the conditioned medium of a human glioblastoma cell line. The TIMP-2/progelatinase complex was resistant to the activation by p-aminophenylmercuric acetic acid (APMA), and showed less than 10% of the activity of the TIMP-2-free active enzyme. When the complex was incubated with stromelysin in the presence of APMA, the 64-kDa progelatinase was effectively converted to the 57-kDa mature enzyme, increasing its gelatinolytic activity about 8-fold. These results suggest that stromelysin is a natural activator of TIMP-2-bound progelatinase A.
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PMID:Activation of TIMP-2/progelatinase A complex by stromelysin. 132 Aug 76

The basal levels of mRNAs encoding two metalloproteinases, collagenase and stromelysin, were increased as a function of in vitro serial subcultivation (cellular aging) of human fibroblasts. Procollagenase and prostromelysin synthesis and secretion were also greater in the old cultures (late passage). In contrast, the steady-state expression of mRNA for an inhibitor of metalloproteinases, tissue inhibitor of metalloproteinase-1 (TIMP-1), in late-passage cultures was lower than that in young cell cultures (early passage). Each mRNA was analyzed using total RNA preparations isolated from normal fibroblast cultures at different phases of the in vitro life span and from cultures derived from donors with the premature senescence syndromes characterized as Werner syndrome, progeria (Hutchinson-Gilford) syndrome, or Cockayne syndrome. In normal cell cultures expression of metalloproteinase mRNAs was increased after the culture had completed greater than 90% of the in vitro life span, and the reduction in TIMP-1 mRNA expression occurred after the culture had completed greater than 74% of the in vitro lifespan. In Werner syndrome cultures expression of metalloproteinase and TIMP-1 mRNAs was similar to the level of expression observed in late-passage cell cultures. Levels of metalloproteinase and TIMP-1 mRNA expression in progeria and Cockayne syndromes were similar to those of early-passage cell cultures. To determine if young and old cells were each responsive to mediators of metalloproteinase synthesis, cultures were treated with phorbol ester or cytokines. 12-O-tetradecanoylphorbol-13-acetate treatment increased the steady-state levels of all three mRNAs in young, old, and Werner syndrome cultures and increased procollagenase levels in all cultures. Early- and late-passage cell cultures also responded to cytokines. Interleukin-1 alpha treatment increased collagenase and stromelysin mRNA levels while transforming growth factor-beta reduced the steady-state levels of both transcripts. Neither cytokine affected the steady-state level of TIMP-1 mRNA. The results indicate that in vitro cellular aging is associated with changes in expression of mRNAs encoding proteins that mediate inflammatory responses and connective tissue remodeling.
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PMID:Differential expression of metalloproteinase and tissue inhibitor of metalloproteinase genes in aged human fibroblasts. 132 16

The enzymes that comprise the family of matrix metalloproteinases (MMPs) share the capacity to degrade extracellular matrix components. A large body of evidence indicates that certain members of this metalloproteinase gene family play critical roles in determining the malignant phenotype of solid tumors. We previously have derived transformed cell lines with vastly different metastatic potentials by transfecting different combinations of oncogenes into primary rat embryo cells. Conditioned medium from those cell lines was assayed by Western blot analysis for the production of four separate matrix metalloproteinases to see whether a correlation could be found between protease expression and the metastatic phenotype. The transformed rat embryo cell lines with high metastatic potential were found to produce high levels of the stromelysin 1 (MMP-3) and stromelysin 2 (MMP-10) proteases, while the nonmetastatic lines produced low or undetectable levels of these two enzymes. No correlation was seen between the metastatic phenotype of the cell lines and the level of expression of two other matrix metalloproteinases, the M(r) 72,000 type IV collagenase (MMP-2) and the M(r) 92,000 gelatinase (MMP-9). These data suggest that the differential regulation of the stromelysin proteases may contribute to the difference seen in the metastatic potential of these cell lines.
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PMID:Expression of matrix metalloproteinase genes in transformed rat cell lines of high and low metastatic potential. 132 87

Synovial fluid basic calcium phosphate crystals (BCP) are often found in severely degenerated joints. Crystalline BCP is a growth factor stimulating fibroblast mitogenesis and acting as a competence factor similar to platelet-derived growth factor. In human fibroblasts (HF), the synthesis of collagenase and stromelysin is coordinately induced after stimulation with a variety of cytokines and growth factors. We sought to determine whether BCP, like other growth factors, might induce proteases that would damage articular tissue. Northern blot analysis of mRNA for collagenase and stromelysin in HF stimulated with BCP was performed. Secreted enzymes were analyzed by immunoblot using a monoclonal antibody to collagenase and by immunoprecipitation using a polyclonal antibody to stromelysin. Stromelysin activity was confirmed using casein substrate gels. A significant, dose-dependent accumulation of collagenase and stromelysin message was evident after 4 h and continued for at least 24 h in BCP-stimulated cultures. Forty-nine and 54 kD proteins immunoreacting with collagenase antibody were identified in the conditioned media (CM) from BCP-stimulated cultures while 50 and 55 kD proteins were identified by immunoprecipitation with stromelysin antibody. Collagenase activity was increased significantly in the CM from BCP treated cells; casein substrate gels showed casein degrading bands at molecular weights consistent with stromelysin. BCP stimulates coordinate induction of collagenase and stromelysin which may mediate the joint destruction associated with these crystals.
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PMID:Basic calcium phosphate crystals cause coordinate induction and secretion of collagenase and stromelysin. 132 76

The action of three matrix metalloproteinases (MMPs), 72- and 95-kDa gelatinases (MMP-2 and MMP-9) and PUMP (MMP-7), and a cysteine proteinase, cathepsin B, were investigated on aggrecan the major proteoglycan of cartilage. All the enzymes cleaved aggrecan although the activity of the 95-kDa gelatinase was very low. Specific cleavage sites were investigated following incubation with a purified aggrecan G1-G2 domain fragment (150 kDa). Both gelatinases produced 110-kDa G2 and 56-kDa G1 products by a single cleavage at an Asn-Phe bond within the interglobular domain close to the G1 domain. This was similar to the action of stromelysin (MMP-3) (Fosang, A. J., Neame, P. J., Hardingham, T. E., Murphy, G., and Hamilton, J. A. (1991) J. Biol. Chem. 266, 15579-15582). Cathepsin B also produced two fragments from a single cleavage at a Gly-Val bond only three amino acids C-terminal to the metalloproteinase cleavage site. PUMP cleaved at the metalloproteinase Asn-Phe site, but in addition produced a low yield of a smaller G2 fragment (56 kDa) corresponding to cleavage between Asp441 and Leu442 (human sequence), within the interglobular domain, close to the G2 domain. The apparent difference in size between the two G2 fragments released by PUMP (110 and 56 kDa) was much greater than predicted from the peptide length between the cleavage sites (100 amino acids). However, keratanase digestion greatly reduced the size of the 110-kDa G2 fragment, while producing only a small reduction in size of the 56-kDa product, showing that there was approximately 30-40 kDa of keratan sulfate attached to the interglobular domain between the PUMP cleavage sites. This new structural information on aggrecan may account for the previously observed stiffness of the interglobular domains when viewed by rotary shadowing electron microscopy (Paulsson, M., Morgelin, M., Wiedemann, H., Beardmore-Gray, M., Dunham, D. G., Hardingham, T. E., Heinegard, D., Timpl, R., and Engel, J. (1987) Biochem. J. 245, 763-772). These results show that in spite of a high keratan sulfate content the interglobular domain provides important sites for cleavage by different proteinases, including several members of the matrix metalloproteinase family.
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PMID:The interglobular domain of cartilage aggrecan is cleaved by PUMP, gelatinases, and cathepsin B. 132 52

The vEts oncoprotein and its progenitor cEts1(p68) belong to a growing family of transcription factors that are related by the conserved ets domain. We show here that the ets domain and adjacent COOH-terminal amino acids are required for DNA binding by cEts1(p68). vEts differs from cEts1(p68) in both the COOH-terminal sequence and an amino acid substitution in the ets domain. The change in the COOH-terminal sequence markedly decreases its affinity for specific DNA, and the ets domain mutation further diminishes binding. vEts does not trans-activate through the ets (PEA3) motif in vivo. Surprisingly, vEts still efficiently trans-activates the promoters of two genes, stromelysin and collagenase, that are found to be overexpressed in transformed cells. The AP1 motifs of both promoters are required for efficient activation. vEts does not bind to the AP1 motif, even in the presence of cJun and cFos. The DNA-binding domain of Ets1 is required for activation through the AP1 element. Activation is inhibited by the expression of the glucocorticoid and retinoic acid receptors, suggesting that activation by Ets does not involve reversal of negative regulators of AP1. We suggest that activation is by an indirect mechanism involving activation of endogenous genes. Our results show that vEts differs from its progenitor cEts1(p68) in its trans-activating properties. The findings suggest that activation of the Jun and Fos oncoprotein pathway is important for transformation by Ets.
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PMID:Oncogenic conversion alters the transcriptional properties of ets. 132 27

We have characterized a transcriptional enhancer of the human urokinase-type plasminogen activator (uPA) gene and found a regulatory element required for co-operation between a PEA3--AP-1 element and an AP-1 site in the enhancer. We designated this regulatory element co-operation mediator (COM). Both the PEA3--AP-1 element, the AP-1 site and the COM are required for efficient phorbol ester induction of transcription from the uPA promoter in the HepG2 hepatoma cell line. We show that the COM is also required for co-operation between the PEA3--AP-1 element and a glucocorticoid response element, both in the presence or absence of TPA, indicating that the COM is generally capable of mediating synergism between inducible enhancer elements. The COM contains multiple overlapping binding sites for nuclear proteins, designated uPA enhancer factors 1-4 (UEF-1-4). We have identified putative binding sites for UEF-1, -2 and -3. The UEF-1 and -3 sites in the uPA enhancer are highly conserved between species. We demonstrate the binding of UEF-3 to the NIP element, a previously characterized regulatory element in the human interleukin-3 and stromelysin promoters, suggesting that this factor plays a role in regulation of a variety of genes.
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PMID:A regulatory element that mediates co-operation between a PEA3-AP-1 element and an AP-1 site is required for phorbol ester induction of urokinase enhancer activity in HepG2 hepatoma cells. 133 May 39

We established two cell lines of human smooth muscle cells (SMC) by transfection of cells from the aortic intima and aortic media with origin-minus simian virus 40 (ori-minus SV40) DNA. Ori-minus SV40 DNA very efficiently immortalized human smooth muscle cells in culture. Proteins that these cell lines produced included type I, III, IV, and V collagens, fibronectin, and human matrix metalloproteinases (MMP)-1 (tissue collagenase), -2 ("type IV collagenase"), and -3 (stromelysin). The protein production in these cell lines generally mimicked that of normal SMC, but the immortalization stimulated the cell line of medial SMC to produce excessive MMP-2 and to secrete MMP-9 (92-kDa gelatinase). However, since these cell lines did not show a fully malignant phenotype, we concluded that, in addition to the degradation of extracellular matrix macromolecules, including basement membrane components by MMP-2, -3, and/or -9, some additional factors must be involved for the malignancy of fully transformed cells and that these immortalized human aortic SMC, which share many characteristics with normal SMC, will prove useful to study the role(s) of metalloproteinases in atherosclerosis.
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PMID:Immortalization of human aortic smooth muscle cells with origin-minus simian virus 40 DNA. 133 71

Collagenase production by rodent osteoblasts in response to calciotropic hormones has led to the hypothesis that bone cells play a major role in bone resorption by degrading the surface osteoid layer, thereby exposing the underlying mineralized matrix to osteoclastic action. Many studies suggest, however, that this model might not apply to bone resorption in the human. Human osteoblasts have been shown to produce gelatinase-A (72 kDa) and TIMP-1 (tissue inhibitor of metalloproteinases), but previous investigators have been unable to demonstrate the synthesis of collagenase by human osteoblasts either constitutively or in response to bone resorptive agents. In the present study the ability of human osteoblasts to produce the matrix metalloproteinases (MMPs) collagenase, gelatinase and stromelysin, and their specific inhibitors TIMPs-1 and 2, was examined using highly sensitive and specific antisera and by zymography. Semi-quantitative histomorphometric data showed that cells cultured on either glass or a type I collagen substratum constitutively synthesized gelatinase-A and TIMP-1. On type I collagen, however, a small proportion of unstimulated cells produce both collagenase (7%) and gelatinase-B (95 kDa; 3%). Treatment of cells with either parathyroid hormone (PTH), 1,25-dihydroxy-vitamin D3 (1,25(OH)2D3), or partially purified mononuclear cell conditioned medium (MCM), stimulated the synthesis of collagenase, gelatinase-B and stromelysin; MCM was 2- to 3-fold more potent than either PTH or 1,25(OH)2D3. Zymography using SDS/PAGE on conditioned media from cells cultured on type I collagen films revealed the presence of active gelatinase-A and that MCM stimulated progelatinase-B synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human osteoblasts in culture synthesize collagenase and other matrix metalloproteinases in response to osteotropic hormones and cytokines. 133 77

This study was performed to characterize the matrix metalloproteinases (MMPs) produced during the degradation of cotton-wrapped cartilage, implanted into the murine air pouch. One, two or three weeks following cartilage implantation, proteins were extracted from the granulation tissue and MMP activities were measured. Although collagenase-, gelatinase- and stromelysin-like activities were detected at each time point, gelatinase activity was by far the most prominent. These enzymes were inhibited by EDTA, but not by NEM or PMSF, indicating that these proteinases were metalloproteinases. Gelatin zymography revealed several lysis zones amongst which a major 92-kDa band shifted to 83- and 68-kDa species during the course of implantation. The emergence of these species coincided with enhanced gelatinolytic activity and collagen loss from the implanted cartilage.
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PMID:Gelatinase is the main matrix metalloproteinase involved in granuloma-induced cartilage degradation. 133 18


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