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:3.4.24.35 (matrix metalloproteinase 9)
2,207 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

T cell homing into extravascular sites requires penetration across the subendothelial basal lamina, a specialized nonfibrillar connective tissue structure that anchors endothelial cells to parenchymal surfaces. Herein, we show that normal human T cells express gelatinases A and B, two matrix metalloproteinases active against the major basal lamina constituents, collagen types IV and V. Expression is confirmed at both the mRNA and protein levels. Gelatinase B is expressed constitutively, whereas gelatinases A and B expression is induced by T cell activation. In vitro migration of resting T cells across a basal lamina equivalent is mediated by gelatinase B, because it is specifically blocked by GM6001, a hydroxamic acid inhibitor of matrix metalloproteinases. Inhibition of T cell homing by interference with gelatinase function may represent a useful approach to the treatment of T cell-mediated autoimmune diseases.
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PMID:T cell gelatinases mediate basement membrane transmigration in vitro. 772 95

The regulatory effect of endogenously synthesized eicosanoid metabolites on the expression of tissue inhibitor of metalloproteinases (TIMP), interstitial collagenase, and 92-kDa gelatinase by human macrophages was examined. TIMP and metalloproteinase production were stimulated with three agonists that produce distinct patterns of eicosanoid synthesis: lipopolysaccharide (10 micrograms/ml), denatured collagen (10 micrograms/ml), or zymosan (1 mg/ml). Indomethacin (3 micrograms/ml) or MK886 (3 microM), a specific inhibitor of 5-lipoxygenase, was used to examine the role of endogenous metabolites of arachidonic acid. Regardless of the agonist used, TIMP production by macrophages was inhibited 65% by indomethacin, synthesis of interstitial collagenase was reduced 70%, and expression of 92-kDa gelatinase was decreased 40%. In contrast, inhibition of leukotriene synthesis had no effect on metalloproteinase or TIMP production. The agonist-stimulated increase in TIMP and collagenase production was directly correlated to the cumulative prostaglandin E2 level induced by the agonist used. However, if response to an agonist was poor, the exogenous addition of prostaglandin E2 could not increase TIMP or collagenase production more than twofold, indicating an important permissive effect of the agonist on the regulation of each protein's expression. The mechanism of indomethacin inhibition of TIMP and collagenase production was studied by labeling the cells with [35S]-methionine and performing immunoprecipitation using specific antiserum. Indomethacin markedly inhibited the lipopolysaccharide-induced biosynthesis of both TIMP and collagenase. Northern analysis revealed parallel suppression of TIMP and collagenase steady-state mRNA levels by indomethacin, indicating pretranslational control. The regulation of inflammatory-cell TIMP and interstitial collagenase expression by prostaglandin E2 suggests that therapy inhibiting the cellular response to prostaglandins may be useful in cutaneous and systemic disease states involving macrophage-mediated connective-tissue destruction.
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PMID:Agonist-induced expression of tissue inhibitor of metalloproteinases and metalloproteinases by human macrophages is regulated by endogenous prostaglandin E2 synthesis. 779 41

Immunohistochemical studies of prostate carcinoma reveal that most primary carcinomas, including high-grade tumors, are surrounded by a basal lamina composed of laminin, type IV collagen, and entactin. In addition to the expected laminin subchains A, B1, B2, subchains M and S are also found. Tenascin, found around normal glands, is seen in 60% of carcinomas. The basal cells of the normal gland express several integrin alpha units including alpha 2,3,4,5,6, and v. Both beta 1 and beta 4 subunits are observed. These integrin units are polarized at the base of the cells where they codistribute with the surrounding extracellular matrix. The integrin alpha 6 beta 4 is associated with hemidesmosomal-like structures, as detected by transmission electron microscopy (TEM). In carcinoma, the beta 4 is not observed and the alpha 6 and beta 1 subunits are variably expressed. The integrin expression in carcinoma is diffuse in the cytoplasmic membrane and not restricted to the basal aspects of the cell. In addition, type VII collagen and the BP 180 protein which are associated with hemidesmosomes are lost, although the BP 230, plectin, and HD1 proteins are variably expressed. Using immunohistochemistry and northern analysis we observed three metalloproteinases in prostate carcinoma--matrilysin, gelatinase A, and gelatinase B. Western blotting and zymogram analysis reveal that of these three, only matrilysin appears to be present in its active form. Recent in situ hybridization studies reveal focal expression of the matrilysin mRNA in 25/33 primary carcinomas. Matrilysin also appears to be highly expressed in prostatic ducts and atrophic glands. Expression of the three metalloproteinases is also seen in prostatic intraepithelial neoplasia lesions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Adhesion molecules, extracellular matrix, and proteases in prostate carcinoma. 782 96

In addition to the known 94-kd gelatinase (matrix metalloproteinase 9, MMP-9), HL-60 leukemia cells release a hither-to undescribed 45-kd metalloproteinase into the culture medium. This enzyme cleaves the synthetic substrate Pro-Gln-Gly-Ile-Ala-Gly-Gln-Arg, which represents the cleavage site for collagenases in collagen type I not between isoleucine and alanine--the typical cleavage site for collagenases--but between alanine and glycine. The enzymatic activity was purified through a combination of zinc-chelate-Sepharose column chromatography, precipitation with Fractogel TSK-AF Red and gelatin-Sepharose, and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Microsequence analysis of the NH2-terminus of the purified 45-kd proteinase revealed the sequence Asp-Ile-Ser-Lys-Tyr-Thr-Thr-Thr-, which could not be found in other proteins when searched in several protein data bases. Incubation of the enzyme immobilized on nitrocellulose membranes with polyclonal antibodies to collagenase and stromelysin or gelatinases revealed no cross-reactivity. The proteolytic activity was not increased by treatment with trypsin, 8M urea, acid, or organomercurials. The proteinase, which was inhibited by chemical inhibitors of metalloproteinases, such as phenanthrolene or EDTA, is able to degrade several matrix constituents, such as collagen type IV, fibronectin, gelatin, and proteoglycans. In contrast to all known MMPs, the proteolytic activity of the 45-kd enzyme was not abolished upon incubation with recombinant tissue inhibitors of matrix metalloproteinases (TIMP) 1 or 2. Thus, the novel enzyme may influence extracellular matrix (ECM) turnover in vivo because its activity is not influenced by specific inhibitors of MMPs.
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PMID:Leukemic cells (HL-60) produce a novel extracellular matrix-degrading proteinase that is not inhibited by tissue inhibitors of matrix metalloproteinases (TIMPs). 782 72

Type XIV collagen is a newly described member of the fibril-associated collagens with interrupted triple helices (FACITs). Expression of this collagen has been localized to various embryonic tissues, suggesting that it has a functional role in development. All FACITs thus far described (types IX, XII, XIV, and XVI) contain a highly homologous carboxyl-terminal triple helical domain designated COL1. We have studied the capacity of various matrix metalloproteinases (interstitial collagenase, stromelysin, matrilysin, and 92-kDa gelatinase) to degrade the COL1 domain of collagen XIV. We found that only 92-kDa gelatinase cleaves COL1. Furthermore, digestion of whole native collagen XIV by the 92-kDa gelatinase indicates that this enzyme specifically attacks the carboxyl-terminal triple helix-containing region of the molecule. COL1 is cleaved by 92-kDa gelatinase at 30 degrees C, a full 5-6 degrees C below the melting temperature (Tm) of this domain; native collagen XIV is also degraded at 30 degrees C. In comparison to interstitial collagenase degradation of its physiologic native type I collagen substrate, the 92-kDa enzyme cleaved COL1 (XIV) with comparable catalytic efficacy. Interestingly, following thermal denaturation of the COL1 fragment, its susceptibility to 92-kDa gelatinase increases, but only to a degree that leaves it several orders of magnitude less sensitive to degradation than denatured collagens I and III. These data indicate that native COL1 and collagen XIV are readily and specifically cleaved by 92-kDa gelatinase. They also suggest a role for 92-kDa gelatinase activity in the structural tissue remodeling of the developing embryo.
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PMID:Degradation of the COL1 domain of type XIV collagen by 92-kDa gelatinase. 783 60

An extracellular proteasome-like (EP) structure has been isolated from serum-free media conditioned by C6 astrocytoma cells. EP has a native molecular mass of 1000 kDa and is composed of three subunits, two isoelectric variants at 70 kDa and one at 65 kDa. The extracellular proteasome degraded collagen IV, alpha-casein, beta-insulin, and certain synthetic peptide substrates. A 68-kDa type IV collagenase, identified as the activated form of gelatinase A, was also isolated from this medium. The type IV collagenase activity of the proteasome was sensitive to serine protease inhibitors, while the 68-kDa collagenase IV represented the matrix metalloprotease gelatinase A. The general protease activity of the proteasome was sensitive to metalloprotease inhibitors. Western blot analysis indicates a sequence relationship between the 68-kDa type IV collagenase and either one or both of the 70-kDa isoelectric variants of the proteasome; however, the two enzymes appear to be distinct functionally. Comparison with known proteasomes indicates that EP represents a novel proteasome. The complexity of degradative enzymes in the extracellular microenvironment implies that complete inhibition of tumor growth requires at least a combination of serine and metalloprotease inhibitors.
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PMID:An extracellular proteasome-like structure from C6 astrocytoma cells with serine collagenase IV activity and metallo-dependent activity on alpha-casein and beta-insulin. 787 29

The 72-kDa gelatinase/type IV collagenase (MMP-2) is a member of the matrix metalloproteinase (MMP) family of enzymes. This enzyme is known to cleave type IV collagen as well as degrade denatured collagens. However, native interstitial collagens are reportedly resistant to MMP-2 and are thought to be susceptible only to the interstitial collagenases MMP-1 and MMP-8. In this study we report that both human and chicken MMP-2, free of tissue inhibitors of metalloproteinases (TIMPs) are capable of cleaving soluble, triple helical type I collagen generating the 3/4- and 1/4-length collagen fragments characteristic of vertebrate interstitial collagenases. MMP-2 cleaves at the same Gly-Ile/Leu bond in the collagen alpha chains as interstitial collagenases with kcat and Km values similar to that of MMP-1. MMP-2 also is capable of degrading reconstituted type I collagen fibrils. The closely related 92-kDa gelatinase/type IV collagenase (MMP-9) is unable to cleave soluble or fibrillar collagen under identical conditions indicating that the specific collagenolytic activity of MMP-2 is not a general property of gelatinases. That MMP-2, a potent gelatinase, also can cleave fibrillar collagen provides an alternative to the proposal that two enzymes, an interstitial collagenase and a gelatinase, are required for the complete dissolution of stromal collagen during cellular invasion.
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PMID:Matrix metalloproteinase-2 is an interstitial collagenase. Inhibitor-free enzyme catalyzes the cleavage of collagen fibrils and soluble native type I collagen generating the specific 3/4- and 1/4-length fragments. 789 Jul 17

Matrix metalloproteinase 7 (MMP-7) has been purified as an inactive zymogen of M(r) 28,000 (proMMP-7) from the culture medium of CaR-1 human rectal carcinoma cells. The NH2-terminal sequence of proMMP-7 is Lys-Pro-Lys-Pro-Gln-Glu, which is identical to that of matrilysin. The zymogen is activated by 4-aminophenylmercuric acetate (APMA), yielding an intermediate form of M(r) 21,000 and an active species of M(r) 19,000 which shows the new NH2-terminal sequence of Tyr78-Ser-Leu-Phe-Pro-Asn-Ser. Although trypsin fully activates the zymogen, the activation rate by plasmin or leukocyte elastase is confined to approximately 50%. ProMMP-7 can be activated by MMP-3 (stromelysin 1) to its full activity in a single-step mechanism and generates the same NH2 terminus obtained by APMA activation, whereas MMP-1 (tissue collagenase), MMP-2 (gelatinase A), and MMP-9 (gelatinase B) do not have such an effect. On the other hand, proMMP-1 is activated by MMP-7 to an activity similar to that obtained by APMA and the activation by MMP-7 is enhanced up to approximately 6.5 fold in the presence of APMA. This enhanced activity is donated by specific cleavage at the Gln80-Phe81 bond of proMMP-1. MMP-7 can also activate proMMP-9 up to approximately 50% of the full activity with a new NH2 terminus of Leu16-Arg-Thr-(Asn)-Leu. Incubation of proMMP-2 or proMMP-3 with MMP-7 results in no activation of these proMMPs. MMP-7 degrades type IV collagen, laminin-1, fibronectin, proteoglycan, type I gelatin, and insoluble elastin. These results suggest that in vivo MMP-7 may play a role in degradation of extracellular matrix macromolecules in concert with MMP-1, -3, and -9 under pathological conditions.
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PMID:Matrix metalloproteinase 7 (matrilysin) from human rectal carcinoma cells. Activation of the precursor, interaction with other matrix metalloproteinases and enzymic properties. 789 11

Hepatic fibrosis occurs as a consequence of net accumulation of matrix proteins (particularly collagen types I and III) in liver. Current concepts of the pathogenesis of liver fibrosis place major emphasis on the activation of hepatic lipocytes (fat-storing or Ito cells) to a myofibroblast-like phenotype with a consequent increase in their synthesis of matrix proteins. While this is an important factor, there is increasing evidence to indicate that liver fibrosis is a dynamic pathologic process in which altered matrix degradation may also play a significant role. Extracellular degradation of matrix proteins is regulated by a family of enzymes called the matrix metalloproteinases, which is subdivided into three groups; collagenases which degrade interstitial collagens (types I, II and III), type IV collagenases/gelatinases which degrade basement membrane (type IV) collagen and gelatins and stromelysins which degrade a broad range of substrates including proteoglycans, laminin, gelatins and fibronectin. The extracellular activity of these enzymes is regulated by several mechanisms which include alterations in gene transcription and proenzyme synthesis, cleavage of secreted proenzymes to active forms, and specific inhibition of activated forms by tissue inhibitor(s) of metalloproteinases (TIMPs). In liver, current evidence indicates that activated hepatic lipocytes and Kupffer cells play a central role in synthesis of matrix metalloproteinases. Under defined conditions they synthesize interstitial collagenase, 72 kDa and 95 kDa type IV collagenase/gelatinase and possibly stromelysin. Moreover, lipocytes also contribute to regulation of the extracellular activity of these enzymes by secretion of TIMP-1 and alpha 2-macroglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Degradation of matrix proteins in liver fibrosis. 789 31

The 72-kDa (MMP-2, gelatinase A) and the 92-kDa (MMP-9, gelatinase B) matrix metalloproteinases have been associated with tumor cell invasion and metastasis. Immunohistological staining of MMP-2 and MMP-9, basal lamina collagen IV and TIMP-2 were performed on frozen sections of 83 invasive breast carcinomas. MMP-2 and MMP-9 were associated with neoplastic cell plasma membrane in 72% of cases and exhibited inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining was not correlated with presence of metastases at time of diagnosis or with disease outcome. TIMP-2 was detected in the peri-tumoral stroma and was present in 87% of cases. Residual benign breast tissue was negative for TIMP-2 staining. Neoplasms with diffuse TIMP-2 staining (24%) recurred significantly more frequently (75% recurred) than cases with focal (42% recurred) or absent (27% recurred) TIMP-2. Presence of collagen IV was negatively correlated with gelatinase staining. We conclude that up-regulation of MMP-2 and MMP-9 expression in breast tumor cells is reciprocally correlated to collagen IV staining. Clinical outcome, however, is more closely related to the presence of TIMP-2 than the corresponding MMPs. Enhanced TIMP-2 expression, therefore, may denote a stromal response to tumor invasion, indicative of aggressive behavior in a subset of breast carcinomas.
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PMID:Enhanced expression of tissue inhibitor of metalloproteinase-2 (TIMP-2) in the stroma of breast carcinomas correlates with tumor recurrence. 792 38


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