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)

Injury to a peripheral nerve is followed by a remodeling process consisting of axonal degeneration and regeneration. It is not known how Schwann cell-derived basement membrane is preserved after injury or what role matrix metalloproteinases (MMPs) and their inhibitors play in axonal degeneration and regeneration. We showed that the MMPs gelatinase B (MMP-9), stromelysin-1 (MMP-3), and the tissue inhibitor of MMPs (TIMP)-1 were induced in crush and distal segments of mouse sciatic nerve after injury. TIMP-1 inhibitor activity was present in excess of proteinase activity in extracts of injured nerve. TIMP-1 protected basement membrane type IV collagen from degradation by exogenous gelatinase B in cryostat sections of nerve in vitro. In vivo, during the early phase (1 d after crush) and later phase (4 d after crush) after injury, induction of TNF-alpha and TGF-beta 1 mRNAs, known modulators of TIMP-1 expression, were paralleled by an upregulation of TIMP-1 and gelatinase B mRNAs. At 4 days after injury, TIMP-1, gelatinase B, and TNF-alpha mRNAs were localized to infiltrating macrophages and Schwann cells in the regions of nerve infiltrated by elicited macrophages. TIMP-1 and cytokine mRNA expression was upregulated in undamaged nerve explants incubated with medium conditioned by macrophages or containing the cytokines TGF-beta 1, TNF-alpha, and IL-1 alpha. These results show that TIMP-1 may protect basement membrane from uncontrolled degradation after injury and that cytokines produced by macrophages may participate in the regulation of TIMP-1 levels during nerve repair.
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PMID:Basement membrane and repair of injury to peripheral nerve: defining a potential role for macrophages, matrix metalloproteinases, and tissue inhibitor of metalloproteinases-1. 897 86

Both astrocytes in the central nervous system and fibroblasts in somatic tissues are not only the major sources of extracellular matrix components but also of matrix metalloproteinases (MMPs), a family of enzymes directly involved in extracellular matrix breakdown. We have analyzed the regulation of the expression of MMPs and TIMPs (tissue inhibitors of metalloproteinases) in human primary astrocytes stimulated with oncostatin M (OSM) and other extracellular mediators in comparison with normal human dermal fibroblasts. It was found that OSM induced/enhanced transcription of MMP-1 (interstitial collagenase) and MMP-3 (stromelysin 1) in astrocytes, and MMP-1, MMP-9 (gelatinase B), and TIMP-1 in fibroblasts. Analysis of the signal transduction leading to activation of the MMP-1 gene revealed the presence of an OSM-responsive element (OMRE) encompassing the AP-1 binding site and the signal transducer and activator of transcription (STAT) binding element, which mediate activation by OSM. OMRE is also present in the TIMP-1 gene promoter and, although there are some differences in these two motifs, both appear to be targets for the simultaneous action of OSM-induced nuclear effectors. The induced enhancement of transcription by synergistically acting AP-1 and STAT binding elements in response to OSM is Raf-dependent. Cross-talk between the mitogen-activated protein kinase and JAK-STAT pathways is required to achieve maximal induction of the OMRE-driven transcription by OSM.
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PMID:The mitogen-activated protein kinase and JAK-STAT signaling pathways are required for an oncostatin M-responsive element-mediated activation of matrix metalloproteinase 1 gene expression. 899 20

This study was designed to investigate possible involvement of type IV collagenolytic matrix metalloproteinases (MMPs; 72-kDa type IV collagenase [MMP-2], 92-kDa type IV collagenase [MMP-9]), and the respective specific tissue inhibitors of these MMPs (TIMP-2 and TIMP-1) in the development of adult respiratory distress syndrome (ARDS). We determined the concentrations of these enzymes in the bronchoalveolar lavage fluid (BALF) from patients with ARDS using newly developed sensitive one-step sandwich enzyme immunoassay methods. BALF obtained from the 17 patients and eight healthy volunteer control subjects were also used for the analysis of the number of the cellular component. Concentrations of the 7S portion of type IV collagen and laminin in the BALF were measured as markers of basement membrane disruption. In the BALF from the ARDS patients, the concentrations of MMP-2 (66.7 +/- 57.0 ng/ml versus < 7.0 ng/ml for controls, p < 0.01) and MMP-9 (118.0 +/- 309.3 ng/ml versus 9.0 +/- 9.5 ng/ml for controls, p < 0.05), and the specific inhibitor of MMP-9 (TIMP-1) (161.0 +/- 145.0 ng/ml versus < 50 ng/ml for controls, p < 0.01) were significantly higher compared with those for healthy control subjects. In the ARDS patients, the concentrations of MMP-2 correlated both with those of 7S collagen and laminin; MMP-9 with the concentration of 7S collagen and the number of neutrophils. These findings suggest that the increased concentration of collagenolytic MMPs in lung plays a role in the pathogenesis of ARDS.
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PMID:Higher concentrations of matrix metalloproteinases in bronchoalveolar lavage fluid of patients with adult respiratory distress syndrome. 900 Dec 87

We report on the effect of prolonged hyperglycaemic (11 and 30 mM D-glucose) culture conditions on human mesangial cell matrix metalloproteinases (MMPs), plasminogen activators and their inhibitors. The results indicate that hyperglycaemic conditions modulate the potential proteolytic activity of the enzymes secreted by confluent cultures of these cells. Gelatinase A (MMP-2) activity was always higher in cultures maintained under hyperglycaemic than under normoglycaemic conditions (4 mM D-glucose). In contrast, gelatinase B (MMP-9) activity was decreased under the same conditions. Matrilysin (MMP-7) activity was decreased by up to 100% under hyperglycaemic conditions. Reverse transcriptase-PCR and Western-blotting analyses indicate that in all cases both the transcripts and the protein level were correlated with enzymic activity. One tissue inhibitor of metalloproteinases, TIMP-2, was barely detectable under hyperglycaemic conditions (30 mM D-glucose). In contrast, TIMP-1 increased during the initial 2 weeks of culture in hyperglycaemic conditions and remained elevated to the end of the experiment (4 weeks). Under normoglycaemic conditions TIMP-1 decreased after 2 weeks of culture. Hyperglycaemic conditions also decreased markedly the activity of tissue plasminogen activator (t-PA). This seemed to be due to increased synthesis of its inhibitor, plasminogen activator inhibitor 1, under these conditions rather than to decreased expression of the t-PA enzyme.
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PMID:Modulation of neutral protease expression in human mesangial cells by hyperglycaemic culture. 900 62

Extracellular matrix (ECM) adhesion and proteolysis play important roles in embryonic development. In previous work (Behrendtsen et al. [1992] Development 114:447-456) we showed that gelatinase B activity is rate-limiting for trophoblast-mediated invasion and degradation of ECM in culture. In the present study, we show that metalloproteinases (MMPs) have distinct roles in migration along ECM as opposed to invasion through ECM. We investigated the role of ECM proteolysis in the differentiation and migration of parietal endoderm (PE), the first embryonic migratory cell type, adhering to ECM surfaces. Gelatinase B was the major MMP of PE; mRNA and protein were detected in PE of 7.5- and 8.5-day embryos. Using cultures of inner cell masses (ICMs) isolated from mouse blastocysts, we found that inhibitors of metalloproteinases, specifically, tissue inhibitor of metalloproteinases (TIMP)-1 and a peptide hydroxamic acid stimulated outgrowth and differentiation of PE from ICMs cultured on fibronectin, but inhibitors of plasminogen activators did not. TIMP-1 increased the number of PE cells and mean distance migrated and increased expression of the PE differentiation marker vimentin; the increase in cell number was not at the expense of other cell types. The stimulatory effect of TIMP-1 was most marked on low concentrations of substrate fibronectin, decreasing as concentrations of fibronectin increased. TIMP-1 also stimulated the outgrowth of PE in blastocyst cultures and in ICM/trophectoderm co-cultures; in ICM/trophectoderm co-cultures TIMP-1 stimulated PE differentiation on higher concentrations of fibronectin than was permissive for ICMs cultured alone. These data indicate that metalloproteinase inhibitors preserved the migration-inducing status of the ECM. We conclude that metalloproteinases have distinct roles in invasive activity through ECM barriers and migratory activity along ECM surfaces.
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PMID:Metalloproteinases regulate parietal endoderm differentiating and migrating in cultured mouse embryos. 902 62

Matrix metalloproteinases are a growing family of neutral pH optima, zinc atom-dependent endopeptidases that collectively degrade all components of the extracellular matrix. This family of related proteases is further defined by their inhibition of protease activity by a class of low-molecular-weight endogenous inhibitors known as tissue inhibitors of metalloproteinases or TIMPs. Reverse zymography is an electrophoretic technique used to identify TIMP inhibitory activity within acrylamide gels. Previous methods have generally used biochemically complex sources of proteolytic activity (such as cell culture conditioned media) copolymerized with a proteinase substrate in the gel to identify the zones of inhibited proteolysis. We describe a novel system for reverse zymography using purified recombinant human gelatinase A or gelatinase B in place of conditioned media. These reverse zymograms using recombinant gelatinase have sensitivities for TIMPs that are favorable in comparison to immunoblotting techniques but have the benefit of visualizing multiple inhibitors simultaneously. We have developed and characterized these methods for the evaluation of inhibitors and have shown them to be highly sensitive, convenient, and reproducible. Both systems detect TIMPs 1, 2, and 3 simultaneously, but with differential sensitivities for TIMPs 1 and 2. Using gelatinase A the system can detect as little as 1 pg of rTIMP-2, but the limit of detection for rTIMP-1 is 40 pg. Gelatinase B shows less differential activity in that the limits of detection are 60 and 40 pg for TIMP-2 and TIMP-1, respectively. We demonstrate how these varied sensitivities of the gelatinases for the TIMPs can contribute to potential pitfalls in systems using uncharacterized reagents (i.e., conditioned media).
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PMID:Quantitative reverse zymography: analysis of picogram amounts of metalloproteinase inhibitors using gelatinase A and B reverse zymograms. 902 22

Scleritis is a sight-threatening inflammatory disorder of the eye characterized by the degradation of scleral matrix. Matrix metalloproteinases (MMPs) are ubiquitous proteolytic enzymes important in physiological and pathological processes, the activity of which is stringently controlled by the action of a family of natural antagonists, the tissue inhibitors of matrix metalloproteinases (TIMPs). We hypothesized that enhanced expression of MMPs, without the negative regulatory influence of TIMPs, may be a key feature of tissue destruction in inflammatory eye diseases, such as scleritis. The aim of this study was to localize and characterize cells expressing MMPs and TIMPs in sclera affected by necrotizing scleritis and, in a parallel study, to establish whether cytokines modulate MMP expression in cultured human scleral fibroblasts. In situ hybridization and immunohistochemical analyses indicated that resident scleral fibroblasts as well as inflammatory cells such as macrophages and T lymphocytes express stromelysin, gelatinase B, and TIMP-1 in necrotizing scleritis tissue. In addition, cytoplasmic immunoreactivity for tumor necrosis factor-alpha, an inducer of MMPs, was detected in infiltrating inflammatory cells. Cultured scleral fibroblasts stimulated with the combination of interleukin-1 alpha plus tumor necrosis factor-alpha increased TIMP-1 mRNA twofold above constitutive levels. By contrast, these cytokines induced a sevenfold increase in the steady-state levels of stromelysin mRNA. Using Western blotting, stromelysin and TIMP-1 protein production paralleled mRNA induction in cytokine-stimulated human scleral fibroblasts. Culture supernatants harvested from cytokine-stimulated human scleral fibroblasts were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis gelatin substrate zymography. Our results revealed a prominent 92-kd gelatinolytic band corresponding to gelatinase B, which was inducible with interleukin-1 alpha. These data provide evidence for our hypothesis, that an imbalance between enzyme/inhibitor ratios may be the underlying mechanism of the tissue destruction characteristic of scleritis. Our results demonstrate the potential involvement of MMPs and their modulation by cytokines produced by infiltrating inflammatory cells in destructive ocular inflammation.
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PMID:Increased expression of matrix metalloproteinases in vivo in scleritis tissue and in vitro in cultured human scleral fibroblasts. 903 78

We have studied the expression of gelatinase A, gelatinase B, interstitial collagenase, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in reactive lymphoid cells, as well as in a series of cell lines derived from neoplasms of B- and T-cell lineage. Using both Northern blot analysis and zymography, gelatinase B activity was detected by zymography in two Burkitt cell lines and in a tonsillar cell suspension, while gelatinase A and interstitial collagenase activities were not detected by either method. TIMP-1 expression was demonstrated by Northern blot analysis in the multipotential neoplastic K-562 cell line, the high grade Burkitt's B-cell lymphoma lines, isolated tonsillar B cells and at low levels in peripheral blood T cells, but was not expressed in any of the neoplastic T-cell lines or isolated peripheral blood B cells. In contrast, TIMP-2 expression was restricted to tissues containing cells of T-cell lineage with high levels being observed in the neoplastic T-cell lines and lower levels in normal peripheral blood T cells and hyperplastic tonsil. Expression of TIMP-1 and TIMP-2 was confirmed at the protein level by reverse zymography and immunofluorescence assays using antihuman TIMP polyclonal antibodies. Expression of gelatinase B by the high grade B-cell Burkitt's lymphoma cell lines is consistent with previous findings in large cell immunoblastic lymphomas and indicates that this enzyme may play an important role in high grade non-Hodgkin's lymphomas. TIMP expression correlated with cell lineage in that TIMP-1 was primarily observed in B cells and TIMP-2 was restricted to T cells.
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PMID:Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in reactive and neoplastic lymphoid cells. 905 54

Here, we describe the production of recombinant human tissue inhibitor of metalloproteinases-1 (rTIMP-1) and wild-type and mutant human collagenase type I (rMMP-1) proteins in SF9 cells by the baculovirus expression system. Wild-type MMP-1, as well as the MMP-1 mutant lacking the C-terminal hemopexin-like domain [des-(248-450)-MMP-1], exhibit enzymatic activity upon cleavage of the prodomain by treatment with trypsin or 4-aminophenylmercuric acetate. Enzyme activity of both proteins can be inhibited by addition of rTIMP. Deletion of the complete active-site [des-(161-228)-MMP-1] within the catalytic domain, or mutation of a single His residue of the Zn2+ binding domain (His199), generates stable forms of MMP-1 proteins which are unable to digest collagen type I or beta-casein. In addition to co-immunoprecipitation analysis, we have established a rapid and sensitive ELISA assay using immobilized rTIMP to determine the structural requirements of MMP-1 to form complexes with its inhibitor. Only the activated and not the latent forms of wild-type and C-terminal mutant des-(248-450)-MMP-1 proteins are able to form complexes with TIMP. Neither mutation of His199, nor deletion mutants des-(161-228)-MMP-1 and des-(161-228/248-450)-MMP-1, interact with TIMP. This demonstrates that the C-terminal hemopexin domain of MMP-1, in contrast to the corresponding regions of gelatinase A and gelatinase B, does not interact with TIMP-1. In summary, we have shown that the integrity of the catalytic domain of MMP-1 and its ability to bind Zn2+ is absolutely required for complex formation with TIMP-1, which further underlines the importance of this region for proper regulation of enzymatic activity of MMP-1.
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PMID:The catalytic domain of activated collagenase I (MMP-1) is absolutely required for interaction with its specific inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1). 906 49

We have investigated the role of proteinases in the developmental program of bone, cartilage, tongue muscle and epithelial differentiation and remodeling in the mandibular arch during murine embryogenesis. Expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) was tissue-specific with little or no expression in the epithelium of tooth buds, tongue or oral cavity. Gelatinase A mRNA transcripts were strongly expressed in the perichondrium of Meckel's cartilage and mesenchymal areas of embryonic day 13-15 mandibles, whereas gelatinase B, collagenase-3, TIMP-1 and TIMP-2 mRNA were found primarily in the ossifying areas of the mandibles. The skeletal muscle of the tongue expressed stromelysin-3, TIMP-2 and TIMP-3 mRNA while stromelysin-3, TIMP-2 and gelatinase A were seen in the overlying connective tissue layer. Gelatinase A, gelatinase B, stromelysin-1, urokinase, TIMP-1 and TIMP-2 mRNA and protein activities were also detected in cultured mandibular explants. Culture of day 10 mandibular explants with a hydroxamic acid metalloproteinase inhibitor, but not with inhibitors of metalloendopeptidases (thiorphan and phosphoramidon), serine proteinases (aprotinin), cysteine proteinases (leupeptin) and urokinase (amiloride), altered mandibular morphogenesis dramatically. Development of the tongue (glossogenesis) and cartilage, but not bone or teeth was affected. Formation of the oral sulcus and fusion of the two epithelia of the medial sulcus were inhibited, and number and migration of myoblasts decreased. The resulting 'tongue-tied phenotype' indicates that MMPs are involved in epithelial morphogenesis and the migration of myoblasts to the region of the tongue. Development of the anterior segment of Meckel's cartilage was also inhibited and proteoglycan content of the cartilage was reduced by inhibiting MMPs. Our data suggest that matrix metalloproteinases play a pivotal role in the morphogenesis of structures derived from epithelium (oral sulcus), cranial paraxial mesoderm (tongue) and cranial neural crest (Meckel's cartilage).
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PMID:Matrix metalloproteinases regulate morphogenesis, migration and remodeling of epithelium, tongue skeletal muscle and cartilage in the mandibular arch. 910 68


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