Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary and passaged human synovial fibroblasts isolated from rheumatoid pannus were treated with recombinant interleukin-1 (IL-1) alpha or beta, tumor necrosis factor-alpha (TNF), or phorbol myristate acetate (PMA) to determine the effects of these stimuli on the relative expression of stromelysin, collagenase, and tissue inhibitor of metalloproteinases (TIMP). The steady-state mRNA levels for these genes and glyceraldehyde-3-phosphate dehydrogenase were determined on Northern blots. Immunoblot analyses of the conditioned media using monoclonal antibodies generated against recombinant human stromelysin, collagenase, or TIMP showed that protein levels reflected the corresponding steady-state mRNA levels. The results revealed that 1) stromelysin and collagenase were not always coordinately expressed; 2) IL-1 was more potent than TNF or PMA in the induction of stromelysin expression; 3) neither IL-1 nor TNF significantly affected TIMP expression; 4) PMA induced both metalloproteinase and TIMP expression; and 5) the combination of IL-1 plus TNF had a synergistic effect on stromelysin expression. Dose response and time course experiments demonstrated that the synergistic effect of IL-1 plus TNF occurred at saturating concentrations of each cytokine and lasted for 7 days. In summary, the ability of IL-1 and TNF to preferentially induce stromelysin and collagenase expression, versus TIMP, may define a pivotal role for these cytokines in the pathogenesis of rheumatoid arthritis.
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PMID:Discoordinate expression of stromelysin, collagenase, and tissue inhibitor of metalloproteinases-1 in rheumatoid human synovial fibroblasts. Synergistic effects of interleukin-1 and tumor necrosis factor-alpha on stromelysin expression. 169 73

Immature female Sprague-Dawley rats were primed with 20 IU eCG at 28 days of age and treated with 10 IU hCG 48 h later. Ovulation followed at 12-14 h. Ovaries were extracted at various times after hCG by use of Triton X-100 and 10 mM CaCl2 (Triton extract) followed by heating to 60 degrees C for 6 min with 0.1 M CaCl2 in 50 mM Tris/0.15 M NaCl, pH 7.5 (heat extract). These extracts were tested for their ability to inhibit tissue metalloproteinases by use of the small uterine metalloproteinase (UMP) of the rat. The ovary contains three plasma-derived inhibitors (alpha 1-macroglobulin [alpha 1 M], alpha 2-macroglobulin [alpha 2 M], and alpha 1 inhibitor3 [alpha 1I3]) and one tissue-derived inhibitor of the tissue inhibitor of metalloproteinases (TIMP) family. alpha 1 I3 was shown to inhibit UMP and rat collagenase. The concentration of the tissue inhibitor rose 5-fold from 0.6 micrograms UMP blocked per gram wet tissue in ovaries not primed with eCG to 3.2 micrograms UMP blocked at 8 h after hCG. Over this same time interval, the sum of alpha 1M + alpha 2M per gram of ovary rose 7-fold from 3.2 to 22.4 micrograms UMP inhibited and alpha 1I3 rose 2-fold from 4.4 to 10.7 micrograms UMP inhibited. The increases in the tissue inhibitor are interpreted to be due to increased synthesis by the tissue, whereas the changes in alpha-macroglobulins are postulated to be due to increased vascularity and increased permeability of the vessels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A tissue inhibitor of metalloproteinases and alpha-macroglobulins in the ovulating rat ovary: possible regulators of collagen matrix breakdown. 172 97

A specific high-titre polyclonal antiserum to recombinant human prostromelysin was raised in a sheep and shown by immunoblotting to detect latent prostromelysin, high and low Mr active forms and the C-terminal domain. This antiserum was used to demonstrate by indirect immunofluorescence that latent and active high Mr prostromelysin bind to reconstituted collagen fibrils, and to other extracellular matrix components in tissues ex vivo but that active low Mr stromelysin does not. Isolation of the C-terminal domain was carried out to demonstrate that stromelysin binding was through this domain. By use of an antiserum to the tissue inhibitor of metalloproteinases (TIMP) it was shown that TIMP is unable to bind to reconstituted collagen fibrils. TIMP, however, will bind when active high Mr stromelysin is present but not if latent prostromelysin is bound. We conclude that stromelysin has different binding specificities from those previously documented for collagenase; only active collagenase binds to reconstituted collagen fibrils. However, TIMP binds to the active forms of both stromelysin and collagenase when these are bound to the collagen fibrils. These results have important implications for the interpretation of immunolocalization data in establishing the roles of metalloproteinases and their inhibitors in vivo.
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PMID:Binding of latent and high Mr active forms of stromelysin to collagen is mediated by the C-terminal domain. 177 6

Proteolytic enzymes acting at physiologic pH (neutral proteases) are involved in both the formation and modeling of new bone and the remodeling of mature bone. In endochondral ossification systems such as growth-plate calcification, fracture healing, osteophyte formation, and demineralized bone matrix-induced osteogenesis, neutral proteases are predominantly involved in modifying proteins and proteoglycans in the extracellular matrix in preparation for calcification. These enzymes are of low molecular weight (below 30,000 Mr), are poorly charged, metal ion dependent, and appear to become active only after being released from chondrocytes. These neutral proteases may be distributed to the extracellular matrix in association with matrix vesicles that are derived from chondrocyte plasma membranes. A similar mechanism of calcification may also exist during malignant osteogenesis in an osteosarcoma; however, the cell producing the neutral protease in this lesion is the osteoblast and the matrix being synthesized is osteoid. In remodeling bone, osteoblasts secrete neutral collagenase (as an inactive enzyme) and produce not only additional proteases capable of activating the collagenase but also a collagenase inhibitor. Osteoblast collagenase or neutral protease may act to remove unmineralized osteoid from bone surfaces, thus facilitating its subsequent degradation by osteoclasts. The production of all these factors by osteoblasts appears to be regulated by calciotropic hormones (e.g., parathyroid hormone, 1,25-dihydroxyvitamin D, and calcitonin), possibly in a concerted fashion. Other possible functions of neutral proteases involve direct actions on cells or on specific molecules (growth factors) residing in the extracellular matrix.
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PMID:Neutral proteases in regenerating bone. 184 59

This study examines the role of interleukin-6 (IL-6) in connective tissue metabolism. Effects of different preparations of IL-6 on production of collagenase and tissue inhibitor of metalloproteinases-1/erythroid potentiating activity production are studied in human fibroblasts, synoviocytes, and articular chondrocytes. In contrast to interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha), IL-6 does not stimulate the production of collagenase, nor does it modulate the stimulatory effects of IL-1 beta and TNF alpha on the production of this proteinase. Furthermore, IL-6 has no detectable effect on prostaglandin E2 production, an additional proinflammatory response induced by IL-1 beta and TNF alpha. IL-6, however, is identified as a potent inducer of de novo synthesis of tissue inhibitor of metalloproteinases-1/erythroid potentiating activity in all types of connective tissue cells examined. These results define new biological activities of IL-6 and provide further insight into the regulation of connective tissues by cytokines.
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PMID:Interleukin-6 induces the synthesis of tissue inhibitor of metalloproteinases-1/erythroid potentiating activity (TIMP-1/EPA). 184 8

The purification and cloning of a novel metalloproteinase inhibitor (MI or TIMP-2) related to tissue inhibitor of metalloproteinases (TIMP) has been recently described by our laboratory (DeClerck, Y.A., Yean, T. D., Ratzkin, B.J., Lu, H.S., and Langley, K.E. (1989) J. Biol. Chem. 264, 17445-17453; Boone, T.C., Johnson, M.J., DeClerck, Y.A., and Langley, K.E. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 2800-2804). We have transfected Chinese hamster ovary cells with a vector containing human MI/TIMP-2 cDNA and purified recombinant-derived MI/TIMP-2 (rMI/rTIMP-2) from the conditioned medium of such cells. We have investigated the inhibitory activity of rMI/rTIMP-2 toward rabbit fibroblast interstitial collagenase. The inhibition of activated collagenase by rMI/rTIMP-2 is stoichiometric and consistent with the formation of a 1:1 molar ratio complex. In addition to blocking the activated enzyme, rMI/rTIMP-2 inhibits the conversion of 52-kDa procollagenase to the 42-kDa active enzyme initiated by organomercurials. When plasmin is used as activator, rMI/rTIMP-2 does not inhibit the plasmin-mediated conversion of the 52-kDa proenzyme to the 46-kDa inactive intermediate but blocks further conversion of the 46-kDa intermediate to the 42-kDa active enzyme. The data indicate that rMI/rTIMP-2 blocks the autoproteolytic activation of procollagenase. Also, rMI/rTIMP-2 forms complexes with the 52-kDa procollagenase, the 46-kDa intermediate, and with the 42-kDa activated enzyme which are stable to sodium dodecyl sulfate (SDS), such that the complexes can be visualized by SDS-polyacrylamide gel electrophoresis. It appears that the formation of a SDS-stable complex with procollagenase requires an initial conformational change of the procollagenase brought about by organomercurials or by plasmin cleavage. The data suggest that MI/TIMP-2 may be able to control the extracellular action of certain metalloproteinases not only at the level of the activated enzyme but also at the level of proenzyme activation.
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PMID:Inhibition of autoproteolytic activation of interstitial procollagenase by recombinant metalloproteinase inhibitor MI/TIMP-2. 184 92

The finding that osteoblasts synthesize collagenase has led to the hypothesis that bone cells play a major role in bone resorption by degrading the surface osteoid layer, thereby preparing the underlying mineralized bone for osteoclastic action. To further understand the mechanisms regulating osteoid removal, mouse calvarial osteoblasts were cultured on 14C-labelled type I collagen films and the abilities of (i) bovine bone matrix extracts and (ii) purified or recombinant human growth factors, to modify their collagenolytic behaviour were investigated. EDTA/Tris-HCl extracts of bone matrix containing growth factor activity, exerted a dose-dependent inhibition of type I collagenolysis by osteoblasts stimulated with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3, 10 ng/ml). Inhibition was accompanied by a reduction in collagenase activity and an increase in free TIMP (tissue inhibitor of metalloproteinases) in the culture medium. Transforming growth factor-beta, epidermal growth factor, platelet-derived growth factor and the acidic and basic fibroblast growth factors all mimicked these effects. In contrast, insulin-like growth factors-I and -II did not inhibit type I collagenolysis, only partially inhibited collagenase activity, and did not stimulate TIMP production by either 1,25(OH)2D3-treated or untreated cells. These findings provide additional evidence for the tight control exerted on the proteolytic activity of osteoblasts and the importance of TIMP in its regulation. They suggest strongly that the conversion (coupling) of the initial resorptive phase of the bone remodelling cycle to one of deposition, may be mediated by polypeptide growth factors either produced locally by osteoblasts, or released by proteolysis from the bone matrix.
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PMID:Bone-derived growth factors modulate collagenase and TIMP (tissue inhibitor of metalloproteinases) activity and type I collagen degradation by mouse calvarial osteoblasts. 184 30

We have examined the expression of murine tissue inhibitor of metalloproteinases (TIMP) in nonmetastatic and metastatic cell lines derived from SP1 murine mammary adenocarcinoma cells. We observed decreased levels of TIMP mRNA and activity in metastatic cells as compared to their nonmetastatic equivalents in the absence of fetal bovine serum. Lower levels of TIMP mRNA correlated to decreased levels of transcription of the TIMP gene. Net collagenase activity was higher in metastatic cells, but metastatic and nonmetastatic cells secreted similar levels of total collagenase (mainly type IV). This suggests that decreased TIMP gene expression results in increased net collagenase activity in malignant cells.
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PMID:Decreased expression of tissue inhibitor of metalloproteinases in metastatic tumor cells leading to increased levels of collagenase activity. 184 44

It has been postulated in a number of systems that increased metalloproteinase activity in different pathologies can be due to decreased levels of the specific inhibitor tissue inhibitor of metalloproteinases (TIMP). To date direct proof of such a mechanism has been lacking. We report that in metastatic variants which secrete increased levels of collagenase activity, this is due to decreased levels of TIMP activity and mRNA levels.
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PMID:Increased collagenase activity in metastatic cells as a result of decreased TIMP expression. 185 Dec 32

Mouse colon 26 tumor cells were shown to produce collagenase inhibitor in culture. The inhibitor was purified more than 2,000-fold from the culture medium by passage through DE-52 cellulose, CM-52 cellulose, Ultrogel AcA 54, Con A-Sepharose, and Sephadex G-50 Superfine columns. The inhibitor did not bind to Con A-Sepharose as do most other collagenase inhibitors. The inhibitor showed a single band (Mr = 20.5 k) on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and inhibitory activity against interstitial collagenases and gelatinases, except for bacterial collagenase. Double-immunodiffusion analysis using monospecific anti-serum against tissue inhibitor of metalloproteinases (TIMP) from bovine dental pulp showed that colon 26 inhibitor did not cross-react immunologically with the pulp inhibitor. NH2-Terminal protein sequence data were obtained for the first 36 residues of the colon 26 inhibitor, and the first 20 of them exhibited a sequence almost identical with that of a new TIMP recently designated as TIMP-2.
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PMID:Purification and characterization of a new tissue inhibitor of metalloproteinases (TIMP-2) from mouse colon 26 tumor cells. 166 27


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