Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.23 (MMP)
 4,246 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Addition of fibronectin fragments to bovine articular cartilage explant cultures results in enhanced release of metalloproteinases and rapid cartilage proteoglycan (PG) degradation and loss. The chondrolysis begins with rapid PG degradation which markedly slows after 1 week. Preliminary observations suggest that catabolic cytokines mediate chondrolytic activities of the fibronectin fragments. The objectives of this work were to investigate the correlations between: (a) release of specific cytokines; (b) release of the metalloproteinase (MMP), stromelysin-1 (MMP-3); (c) release of the tissue inhibitor of MMPs, TIMP-1, and; (d) degradation and release of PG from cultured cartilage. We report that human articular cartilage cultured with an amino-terminal 29-kDa fragment (Fn-f) at 0.1 microM, released enhanced levels of TNF-alpha, IL-1beta, and IL-1alpha with peaks at Days 2, 3, and 9, respectively. MMP-3 release was elevated with a peak at Day 6 and a profile similar to that for the Fn-f-induced cartilage PG depletion. IL-6 release was enhanced within 2 days and continued at the same level throughout the culture period but this did not lead to enhanced release of TIMP-1, a known activity of IL-6. These data suggest that in the early chondrolytic events induced in cultured cartilage by Fn-f, enhanced MMP-3 release and maximal degradation and release of PG from cultured cartilage are kinetically associated with elevated release of the catabolic cytokines, TNF-alpha, IL-1beta, and IL-1alpha. Further, a later period of slowing PG loss and slowing MMP-3 release is associated with greatly slowed release of these cytokines, but prolonged release of IL-6. This model of cartilage damage may be useful for studies of the interplay between cytokines and the effects of combinations of cytokines on cartilage homeostasis.
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PMID:Association of proteoglycan degradation with catabolic cytokine and stromelysin release from cartilage cultured with fibronectin fragments. 890 Apr 7

Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed on cancer cell membranes and activates the zymogen of MMP-2 (gelatinase A). We have recently isolated MT1-MMP complexed with tissue inhibitor of metalloproteinases 2 (TIMP-2) and demonstrated that MT1-MMP exhibits gelatinolytic activity by gelatin zymography (Imai, K., Ohuchi, E., Aoki, T., Nomura, H., Fujii, Y., Sato, H., Seiki, M., and Okada, Y. (1996) Cancer Res. 56, 2707-2710). In the present study, we have further purified to homogeneity a deletion mutant of MT1-MMP lacking the transmembrane domain (DeltaMT1) and native MT1-MMP secreted from a human breast carcinoma cell line (MDA-MB-231 cells) and examined their substrate specificities. Both proteinases are active, without any treatment for activation, and digest type I (guinea pig), II (bovine), and III (human) collagens into characteristic 3/4 and 1/4 fragments. The cleavage sites of type I collagen are the Gly775-Ile776 bond for alpha1(I) chains and the Gly775-Leu776 and Gly781-Ile782 bonds for alpha2(I) chains. DeltaMT1 hydrolyzes type I collagen 6.5- or 4-fold more preferentially than type II or III collagen, whereas MMP-1 (tissue collagenase) digests type III collagen more efficiently than the other two collagens. Quantitative analyses of the activity of DeltaMT1 and MMP-1 indicate that DeltaMT1 is 5-7.1-fold less efficient at cleaving type I collagen. On the other hand, gelatinolytic activity of DeltaMT1 is 8-fold higher than that of MMP-1. DeltaMT1 also digests cartilage proteoglycan, fibronectin, vitronectin and laminin-1 as well as alpha1-proteinase inhibitor and alpha2-macroglobulin. The activity of DeltaMT1 on type I collagen is synergistically increased with co-incubation with MMP-2. These results indicate that MT1-MMP is an extracellular matrix-degrading enzyme sharing the substrate specificity with interstitial collagenases, and suggest that MT1-MMP plays a dual role in pathophysiological digestion of extracellular matrix through direct cleavage of the substrates and activation of proMMP-2.
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PMID:Membrane type 1 matrix metalloproteinase digests interstitial collagens and other extracellular matrix macromolecules. 899 57

Decorin (DCN) is a ubiquitous proteoglycan comprised of a core protein attached to a single dermatan/chondroitin sulphate glycosaminoglycan chain. It may play a role in regulation of collagen fibrillogenesis and function as a reservoir of transforming growth factor beta (TGF-beta) in the extracellular milieu. We have examined the susceptibility of DCN to five different matrix metalloproteinases (MMPs): MMP-1 (tissue collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-7 (matrilysin) and MMP-9 (gelatinase B). MMP-2 and MMP-3 digest DCN into seven major fragments in a similar pattern. The N-terminal sequence of the two fragments generated by MMP-2 and MMP-3 is Leu211-Lys-Gly-Leu-Asn, but that of the others is Asp1-Glu-Ala-Ser-Gly. MMP-7 cleaves DCN into three major fragments which have the N-termini Asp1-Glu-Ala-Ser-Gly, Glu2-Ala-Ser-Gly-Ile and Leu244-His-Leu-Asp-Asn. Activities of MMP-1 and MMP-9 against DCN are negligible. The values of Km for the MMPs capable of degrading DCN are very similar (10-12 microM), but the kcat/Km value for MMP-7 (30.5 microM-1.h-1) is 4.5-fold higher than those for MMP-2 and MMP-3. Incubation of a DCN-TGF-beta1 complex with MMP-2, -3 or -7 results in release of TGF-beta1 from the complex. These data indicate proteolytic degradation of DCN by MMP-2, MMP-3 and MMP-7, and suggest the possibility that, under pathophysiological conditions, the digestion by the MMPs may induce tissue reactions mediated by TGF-beta1 released from DCN in the connective tissues.
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PMID:Degradation of decorin by matrix metalloproteinases: identification of the cleavage sites, kinetic analyses and transforming growth factor-beta1 release. 914 53

Matrix metalloproteinases (MMP) consisting of at least 16 different molecules are thought to be involved in the degradation of extracellular matrix (ECM) macromolecules under various pathologic conditions. Among them, MMP-7 (matrilysin) is unique in that it has high specific activity against various ECM components such as cartilage proteoglycan. In the present study, we examined the expression and tissue localization of MMP-7 in articular cartilages of human osteoarthritis (OA). Immunohistochemistry using a monoclonal antibody specific to MMP-7 demonstrated that the proteinase is localized to the OA chondrocytes mainly in the superficial and transitional zones in 92% of the OA cases examined (36 of 39 cases). On average, approximately 30% of the total chondrocytes (29.1%+/-30.2%) were immunostained in the positive OA cartilage samples. In contrast, MMP-7 staining was found in 8% of the normal cartilage cases (1 of 12 cases), and only a few chondrocytes (0.15%+/-0.67%) in the superficial zone were immunostained. There was a linear correlation between degree (%) of the immunostained chondrocytes and Mankin scores (rho [rho] = 0.84). Immunoblot analysis of the culture media from the cartilage explants demonstrated MMP-7 in 65% of the OA cases (15 of 23 cases) and 8% of the normal specimens (1 of 12 cases). Reverse transcription-PCR demonstrated the specific amplicon in 68% of the OA cartilage cases (17 of 25 cases), whereas only 18% of the control (2 of 11 cases) amplified the product. In situ hybridization revealed that the chondrocytes in OA cartilage express MMP-7 mRNA. MMP-7 gene expression in cultured OA chondrocytes was enhanced by the treatment with interleukin-1alpha and/or tumor necrosis factor-alpha. These data demonstrate for the first time that MMP-7 is overexpressed in human OA cartilage and suggest that cytokine-induced MMP-7 may play an important role in the degradation of ECM macromolecules in the OA cartilage.
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PMID:Expression of matrix metalloproteinase 7 (matrilysin) in human osteoarthritic cartilage. 946 Nov 24

The membrane-type 1 matrix metalloproteinase (MT1-MMP) has been reported to mediate the activation of pro-gelatinase A (proMMP-2), which is associated with tumor proliferation and metastasis. MT1-MMP can also digest extracellular matrix (ECM) such as interstitial collagens, gelatin, and proteoglycan and thus may play an important role in pathophysiological digestion of ECM. We studied the inhibitory effect of various hydroxamate MMP inhibitors, including known inhibitors such as BB-94, BB-2516, GM6001, and Ro31-9790, on a deletion mutant of MT1-MMP lacking the transmembrane domain (DeltaMT1) to further characterize the enzyme and develop a selective inhibitor for MT1-MMP. The evaluation of the inhibitory activities of various hydroxamates reveals general structural profiles affecting selectivities toward MMPs. In particular, a longer side chain at the P1' position is preferable for the binding to MMP-2, -3, and -9 and MT1-MMP. For the P2' position, an alpha-branched alkyl group is critical for the binding toward DeltaMT1, while the introduction of a bulky group at the alpha-position of hydroxamic acid seems to diminish the activity against DeltaMT1. Summation of the data on the sensitivity of DeltaMT1 to various hydroxamate inhibitors indicates that (1) the volume of the S1' subsite of DeltaMT1 is similar to that of MMP-2, -3, and -9, which is bigger than that of MMP-1, and (2) the S1 and S2' subsites are narrower than those in other MMPs. On the basis of these results, the hydroxamates with a P1' phenylpropyl and P2' alpha-branched alkyl group were synthesized and evaluated for inhibitory activity. These inhibitors (1h,i) showed strong activity against DeltaMT1 over MMP-1, but no selectivity between DeltaMT1 and MMP-9. These results are explained using molecular modeling studies conducted on MT1-MMP.
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PMID:Inhibition of membrane-type 1 matrix metalloproteinase by hydroxamate inhibitors: an examination of the subsite pocket. 954 12

Membrane type 3 matrix metalloproteinase (MT3-MMP), an activator for the zymogen of MMP-2 (proMMP-2, or progelatinase A), is known to be expressed in human placenta, brain, lung and rat vascular smooth muscle cells, but information about its biochemical properties is limited. In the present study, we expressed and purified a truncated form of MT3-MMP lacking the transmembrane and intracytoplasmic domain (DeltaMT3) and characterized the enzyme biochemically. DeltaMT3 digested type III collagen into characteristic 3/4- and 1/4-fragments by cleaving the Gly781-Ile782 and Gly784-Ile785 bonds of alpha1(III) chains. Although DeltaMT3 did not have such an activity against type I collagen, it attacked the Gly4-Ile5 bond of the triple helical portion of alpha2(I) chains, leading to removal of the crosslink containing N-terminal telopeptides. By quantitative analyses of the activities of DeltaMT3 and a similar deletion mutant of MT1-MMP (DeltaMT1), DeltaMT3 was approximately fivefold more efficient at cleaving type III collagen. DeltaMT3 also digested cartilage proteoglycan, gelatin, fibronectin, vitronectin, laminin-1, alpha1-proteinase inhibitor and alpha2-macroglobulin into almost identical fragments to those given by DeltaMT1, although carboxymethylated transferrin digestion by DeltaMT3 generated some extra fragments. The activity of DeltaMT3 was inhibited by tissue inhibitor of metalloproteinases-2 (TIMP-2) and TIMP-3 in a 1 : 1 stoichiometry, but not by TIMP-1. ProMMP-2 was partially activated by DeltaMT3 to give the intermediate form. These results indicate that, like MT1-MMP, MT3-MMP exhibits proteolytic activities against a wide range of extracellular matrix molecules. However, differences in the proMMP-2 activation and tissue distribution suggest that MT3-MMP and MT1-MMP play different roles in the pathophysiological digestion of extracellular matrix.
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PMID:Characterization of a truncated recombinant form of human membrane type 3 matrix metalloproteinase. 1041 55

The treatment of cartilage with mediators initiates the breakdown of proteoglycan followed by collagen. This is accompanied by the modulation of different proteinases and inhibitors that include members of the MMP family and TIMPs. We have evidence that a chondrocyte membrane-associated metalloproteinase cleaves aggrecan. This activity is rapidly induced after stimulation with IL-1 and OSM and is not inhibited by TIMPs-1 and -2 but is inhibited by synthetic MMP inhibitors. This same combination of cytokines also upregulates the collagenases with the subsequent release of collagen fragments, and there is a close correlation between the amount of collagen released and collagenase activity produced. Collagen release can be prevented after treatment with specific inhibitors of MAP kinases, inhibitors of MMP transcription, synthetic metalloproteinase inhibitors, TIMPs and treatment of cartilage with agents that upregulate TIMPs. The results from bovine cartilage culture models show that collagen release occurs when TIMP levels are low, collagenases are upregulated and then subsequently activated.
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PMID:The regulation of MMPs and TIMPs in cartilage turnover. 1041 24

The chondrocytes of articular cartilage synthesize a number of proteinases which are capable of degrading the component molecules of this specialized extracellular matrix. The use of class-specific proteinase inhibitors indicates that major activities responsible for catabolism of proteoglycan (aggrecan) and collagen are attributable to zinc-dependent metalloproteinases. In this study, we have compared the mRNA expression profiles of two matrix metalloproteinases (MMP-3 and MMP-13) and five disintegrin-metalloproteinases (ADAM-10, ADAM-9, ADAM-15, TNF-alpha-converting enzyme and decysin) by chondrocytes (human, porcine and bovine) from fresh cartilage and in cartilage explant cultures and isolated cells cultured in monolayer or in agarose gels. Such cultures were maintained in the presence or absence of interleukin-1 (IL-1) or all-trans-retinoic acid, two agents which promote cartilage matrix degradation in vitro. Whereas transcripts for all metalloproteinases examined were detected in chondrocytes from human osteoarthritic cartilage in monolayer cultures, mRNAs for ADAM-15 and decysin were not present in fresh osteoarthritic human cartilage or explant cultures. Similarly, expression of porcine and bovine metalloproteinase mRNAs varied with different culture conditions. Novel cDNA sequences obtained for porcine and bovine MMP-3 and MMP-13, porcine ADAM-10, porcine and bovine ADAM-9 and porcine TACE confirmed expression of mRNAs for these molecules by articular chondrocytes. Quantitative RT-PCR analysis was used to determine the effects of IL-1 and retinoic acid on metalloproteinase mRNA levels in human chondrocytes cultured in monolayer and in porcine chondrocytes cultured in agarose. For the MMPs, IL-1 treatment resulted in an approximately two to threefold increase in human and porcine MMP-3 and MMP-13 mRNAs, while retinoic acid treatment caused a statistically significant increase in human MMP-3 mRNA levels, but no significant change in transcript levels for porcine MMP-3 nor human or porcine MMP-13. The mRNA levels for ADAM-15 were elevated in human monolayer chondrocytes exposed to IL-1 or retinoic acid, while transcripts levels for TNF-alpha converting enzyme were increased in response to retinoic acid. In contrast, ADAM-9 mRNA levels were decreased in human monolayer chondrocytes exposed to IL-1 or retinoic acid. The results demonstrate that chondrocyte metalloproteinase expression can vary dependent on cell environment in situ and in vitro, and information on chondrocyte MMP and ADAM gene expression following cytokine (IL-1) or retinoid stimulation.
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PMID:Effects of culture conditions and exposure to catabolic stimulators (IL-1 and retinoic acid) on the expression of matrix metalloproteinases (MMPs) and disintegrin metalloproteinases (ADAMs) by articular cartilage chondrocytes. 1042 42

The involvement of immune complexes during experimental arthritis in induction of metalloproteinases (MMP)-induced neoepitopes in aggrecan in cartilage, as well as the role of stromelysin-1 (SLN-1) in the induction of this neoepitope, was investigated. Passive immune complex arthritis was induced, and generation of the MMP-specific cleavage product (VDIPEN) was studied by immunolocalization. The role of SLN-1 was studied with use of SLN-1-deficient (SLN-1KO) mice. VDIPEN expression was studied in vitro by exposing the cartilage to IL-1 and subsequent activation of latent MMPs. Immune complex arthritis was characterized by an acute inflammation, with influx of mainly polymorphonuclear cells into the joint cavity. Expression of VDIPEN neoepitopes was consistently found in areas extensively depleted from proteoglycans. SLN-1KO mice did not show expression of the VDIPEN neoepitope, although inflammation and proteoglycan depletion was comparable to wild-type mice. In addition, erosions of cartilage were absent in SLN-1KO mice, but were present in wild-type mice, suggesting an important role for SLN-1 in cartilage destruction. In vitro studies showed that SLN-1 is also pivotally involved in IL-1-induced MMP activity. Stimulated polymorphonuclear neutrophils were able to activate latent MMPs present in the cartilage. Neutrophil elastase was also capable of activating IL-1-induced latent MMPs, which identifies elastase as a possible activator for latent VDIPEN-inducing MMPs. This study suggests that IC are important in the activation of latent MMPs in cartilage, possibly through polymorphonuclear neutrophil activation on the cartilage edge. SLN-1 is a pivotal enzyme in overall MMP-activity in cartilage during immune complex-mediated arthritis.
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PMID:Active matrix metalloproteinases are present in cartilage during immune complex-mediated arthritis: a pivotal role for stromelysin-1 in cartilage destruction. 1055 93

Compared to degenerated nerves, the ability of normal adult peripheral nerve to support axonal regeneration is poor and may be attributed to the inhibition of endoneurial laminin by chondroitin sulfate proteoglycan (CSPG). In cryoculture assays, neuritic growth of neonatal and adult peripheral neurons was increased on sections of normal nerve by pretreatment with CSPG-degrading enzymes, including the matrix metalloproteinases MMP-2 and MMP-9. Axonal regeneration is known to occur within the Schwann cell basal laminae of degenerated nerve. Similarly, deconvolution microscopy revealed that neuritic growth on nerve tissue sections occurred principally on the lumenal surface of enzymatically modified basal laminae. Compared to normal nerve, there was a marked increase in the neurite-promoting activity of the degenerated nerve, and this activity was not increased significantly by subsequent MMP treatment. Additionally, the expression and activation of MMP-2 and MMP-9 were elevated in degenerated nerve, suggesting that degradation of inhibitory CSPG by the MMPs contributes to the growth-promoting properties of degenerated nerve.
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PMID:MMP-2 and MMP-9 increase the neurite-promoting potential of schwann cell basal laminae and are upregulated in degenerated nerve. 1092 58


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