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)

The proteolytic erosion of the temporal bone is the key event in the pathognomonic course of cholesteatoma progression. The molecular mechanisms of bone resorption, endangering the ossicles, the inner ear, the facial nerve, large vessels or the brain, are not understood. Recently, a new family of proteolytic enzymes, the matrix-metalloproteinases (MMP's) has been described and identified, which seems to play a pivotal role in matrix- and bone homeostasis and inflammatory osteolytic diseases, e.g. osteoarthritis and periodontitis. These enzymes are sophisticatedly controlled by specific inhibitors and activation cascades. We investigated whether human cholesteatoma tissue expresses MMP's and MMP-inhibitors. By immunocytochemistry of cholesteatoma-cryosections, the expression of MMP-2 (72 kD collagenase), MMP-9 (92 kD collagenase), and MMP-3 (stromelysin-1) could be seen to be strictly confined to the basal and suprabasal cell layer of the cholesteatoma epithelium. The neutrophil collagenase (MMP-8) showed a more disseminated expression in the epithelium and the granulation tissue as well. The tissue inhibitor of metalloproteases, TIMP-1, could be detected only in very limited areas of the granulation tissue in a quite randomized manner. Therefore, a derailment in favor of proteolysis of the normally tightly controlled MMP-system might be postulated. The results indicate that members of the MMP-family could play an active role in the molecular mechanisms of cholesteatoma invasion into the temporal bone. This offers new insights into the pathophysiology of the disease and of potential therapeutic approaches.
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PMID:Expression of matrix-metalloproteinases and their inhibitors in human cholesteatomas. 879 Jul 47

The potential therapeutic effects of insulin-like growth factor-1 (IGF-1) and sodium pentosan polysulfate (PPS) were evaluated in an anterior cruciate ligament-deficient canine model of osteoarthritis (OA). A control group of animals received no treatment or surgery (N). The remaining four groups of animals received anterior cruciate transection and either no treatment (OA), intra-articular IGF-1 (IGF-1), intra-muscular PPS (PPS), or a combination of intra-articular IGF-1 and intra-muscular PPS (IGF-1/PPS). All therapy was begun 3 weeks after surgery and continued for 3 weeks. At 6 weeks, articular cartilage from the femoral condyle was evaluated for anatomy, histology (Mankin grade) and biochemistry. Anatomically, only cartilage from dogs in the IGF-1/PPS group approximated that found in N. Mankin scores indicated less severe disease in both PPS and IGF-1/PPS groups compared with the OA group. Consistent with histology, the level of active neutral metalloproteinase was lower in cartilage from the PPS group compared with the OA group. Active and total neutral metalloproteinase, tissue inhibitor of metalloproteinases (TIMP), total collagenase, uronate and hydroxyproline contents were all near normal in the IGF-1/PPS group. In a model of mild OA, therapeutic intervention with IGF-1 and PPS appeared to successfully maintain cartilage structure and biochemistry. From these data, it is hypothesized that proteinase activity was successfully blocked by PPS, and that this allowed the observed growth factor induced effects. As we unravel the various factors that regulate cartilage metabolism, it is becoming apparent that combinations of agents will be needed to effectively control cartilage repair in OA. The addition of PPS to IGF-1 shows promise as a therapeutic intervention and introduces a new rational approach to therapy of OA.
Osteoarthritis Cartilage 1993 Apr
PMID:Treatment of canine osteoarthritis with insulin-like growth factor-1 (IGF-1) and sodium pentosan polysulfate. 888 86

The aim of this study was to investigate the relationship between location and size of osteophytes and cartilage loss in an instability-induced experimental model for osteoarthritis. Osteoarthritis was induced in murine knee joints by injection of highly purified bacterial collagenase, causing joint instability. The size of the osteophytes and the cartilage loss were measured at different locations in the joint using image analysis on histological sections of total kees. Cartilage damage did not occur without osteophytes. Osteophytes were located on both medial and lateral sides, independent of the location of cartilage damage, but the size of the osteophytes was related to the amount of cartilage damage on the corresponding side. Cartilage loss on the lateral tibial plateau correlated well with the size of lateral osteophytes, in particular with the osteophyte at the margin of the lateral tibial plateau. Cartilage loss on the medial tibial plateau appeared to have a good correlation with the size of medial osteophytes, which was most pronounced for the osteophyte on the medial margin of the tibial plateau. This side-specific correlation between cartilage damage and osteophyte formation suggests compartmentalization of the osteoarthritic process.
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PMID:The relation between cartilage damage and osteophyte size in a murine model for osteoarthritis in the knee. 889 76

Rhein, the active metabolite of diacerein, inhibits interleukin-1 activity. Consequently, collagenase production in articular cartilage is reduced. Rhein dose-dependently inhibits superoxide anion production, chemotaxis and phagocytic activity of neutrophils, and macrophage migration and phagocytosis. Articular cartilage damage is reduced by diacerein in animal models of osteoarthritis. Diacerein does not alter renal or platelet cyclooxygenase activity and may therefore be tolerated by patients with prostaglandin-dependent renal function. In clinical trials of < or = 6 months' duration, oral diacerein 50mg twice daily was associated with improvement in 57 to 85% of patients with osteoarthritis. Pain scores and measures of joint function were generally reduced compared with baseline and placebo. Diacerein had similar efficacy to NSAIDs, but a slower onset of action, in comparative trials of < or = 2 months' duration conducted in patients with osteoarthritis. The predominant adverse effects of diacerein are diarrhoea and related disorders.
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PMID:Diacerein. 901 Jun 51

A distinctive cell was identified from sites of rheumatoid arthritis cartilage injury. Similar cells are not found in lesions of osteoarthritis cartilage. We have designated them as pannocytes (PCs). Their rhomboid morphology differs from the bipolar shape of fibroblast-like synoviocytes or the spherical configuration of primary human articular chondrocytes. Chondrocytes are short-lived, whereas the original PC line grew for 25 passages before becoming senescent. Features in common with cultured primary chondrocytes include maximal proliferation in response to transforming growth factor-beta a catabolic response to interleukin-1 beta, collagenase production, and mRNA for the induced lymphocyte antigen and inducible nitric oxide synthase. Despite the presence of the inducible nitric oxide synthase message, PCs do not produce NO either constitutively or when cytokine stimulated. Each of the mesenchymal cells, fibroblast-like synoviocytes, primary chondrocytes, and PCs have the gene for type I collagen, but the type II collagen gene is detected only in primary chondrocytes. PCs can be distinguished from fibroblast-like synoviocytes and primary chondrocytes by their morphology, bright VCAM-1 staining, and growth response to cytokines and growth factors. Their prolonged life span in vitro suggests that PCs might represent an earlier stage of mesenchymal cell differentiation, and they could have a heretofore unrecognized role in rheumatoid arthritis joint destruction.
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PMID:Pannocytes: distinctive cells found in rheumatoid arthritis articular cartilage erosions. 906 Aug 47

We demonstrate the direct involvement of increased collagenase activity in the cleavage of type II collagen in osteoarthritic human femoral condylar cartilage by developing and using antibodies reactive to carboxy-terminal (COL2-3/4C(short)) and amino-terminal (COL2-1/4N1) neoepitopes generated by cleavage of native human type II collagen by collagenase matrix metalloproteinase (MMP)-1 (collagenase-1), MMP-8 (collagenase-2), and MMP-13 (collagenase-3). A secondary cleavage followed the initial cleavage produced by these recombinant collagenases. This generated neoepitope COL2-1/4N2. There was significantly more COL2-3/4C(short) neoepitope in osteoarthritis (OA) compared to adult nonarthritic cartilages as determined by immunoassay of cartilage extracts. A synthetic preferential inhibitor of MMP-13 significantly reduced the unstimulated release in culture of neoepitope COL2-3/4C(short) from human osteoarthritic cartilage explants. These data suggest that collagenase(s) produced by chondrocytes is (are) involved in the cleavage and denaturation of type II collagen in articular cartilage, that this is increased in OA, and that MMP-13 may play a significant role in this process.
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PMID:Enhanced cleavage of type II collagen by collagenases in osteoarthritic articular cartilage. 911 97

We describe a new principle for assessment of the activity of proteolytic enzymes of all classes and show the application of this principle for the quantitative assay of bacterial collagenase and human matrix metalloproteinases (MMPs). Central to this new principle is the presence of a proenzyme that can be activated into an active enzyme by a single proteolytic event. The regular activation sequence in the proenzyme is replaced using protein engineering by an artificial sequence recognized by the proteinase to be determined. The latter can act as an activator for the newly engineered proenzyme. In the present paper a simple colorimetric assay for the determination for MMPs is described based on this principle. With the aid of protein engineering, a modified pro-urokinase has been prepared in which the activation sequence normally recognized by plasmin (Pro-Arg-Phe-Lys upward arrowIle-Ile-Gly-Gly) has been replaced by a sequence expected to be recognized and hydrolysed by many MMPs (Arg-Pro-Leu-Gly upward arrowIle-Ile-Gly-Gly). The active urokinase resulting from activation of the modified pro-urokinase by a MMP could be measured either directly, using a specific chromogenic peptide substrate for urokinase, or indirectly via urokinase-catalysed plasminogen activation. The response of the assay to equal molar quantities of active MMPs decreases in the order MMP-2>MMP-9>MMP-1>MMP-3>MMP-7. The detection limit for MMP-9 was below 15 pM, corresponding to 3. 75x10(-15) mol per assay. Using the assay, increased MMP activity was detected in synovial tissue extracts from rheumatoid arthritis patients compared with those from osteoarthritis patients, and in stomach tumour extracts as compared with normal stomach tissue extracts.
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PMID:Modified proenzymes as artificial substrates for proteolytic enzymes: colorimetric assay of bacterial collagenase and matrix metalloproteinase activity using modified pro-urokinase. 916 91

Collagenase-3 (matrix metalloprotease-13) is a recently discovered human collagenase produced in normal articular cartilage chondrocytes and thought to be involved in the pathological process of osteoarthritis. We have sequenced and characterized 1.6 kb of the human collagenase-3 gene 5'-flanking region. The transcription start site was located 22 bp upstream from the ATG start codon. Sequence analysis of the 5'-flanking region revealed the presence of the consensus recognition sites for the TATA and CCAAT DNA-binding proteins, activator protein-1 and E26 transformation specific/polyoma virus enhancer, as well as three core motifs of hormone response elements. Transient transfection assays demonstrated that a small fragment of 133 bp, containing the activator protein-1 and E26 transformation specific/polyoma virus enhancer sites promoted transcription in normal and osteoarthritic human chondrocytes with significantly higher activity than the original 1.6 kb fragment. Nucleotide sequence comparison of the promoter region of human collagenase-3 revealed a stronger similarity to the mouse collagenase-1 promoter than to the human collagenase-1 promoter.
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PMID:Cloning, sequencing and characterization of the 5'-flanking region of the human collagenase-3 gene. 917 71

In this study we determined the efficiency of magnetization transfer magnetic resonance imaging (MT-MRI) to differentiate native and enzymatically degraded cartilage, using bovine sesamoid bones from the metacarpophalangeal joint as a model system. Gradual proteoglycan (PG) depletion was achieved by increasing incubation periods with testicular hyaluronidase. For native cartilage a Ms/Mo ratio of 0.303 +/- 0.09 (mean +/- SEM) was measured. Biochemically determined PG diminution up to 50% correlated strongly (r = 0.953) with changes in the Ms/Mo ratio. Further PG loss is not reflected in an equally drastic Ms/Mo increase, whereas subsequent treatment of PG-depleted cartilage samples with collagenase led to an additional rise in the Ms/Mo ratio. Proteoglycan depletion and the beginning destruction of the collagen structure were also assessed histochemically. Our study confirms that collagen contributes to the baseline MT effect observed in articular cartilage. However, the changes in the MT ratio in gradually PG-depleted cartilage with a largely intact collagen network indicate that PG contributes to the MT effect as well. Therefore MT-MRI might become a sensitive technique for the monitoring of subtle degradational changes in articular cartilage, the still inaccessible process in osteoarthritis.
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PMID:Can magnetization transfer magnetic resonance imaging follow proteoglycan depletion in articular cartilage? 921 83

Human articular chondrocytes modulated away from their original phenotype by serial subcultures in monolayer differentially express mRNAs for endopeptidases. The mRNAs for the cathepsins B and L are extremely low in differentiated cells, but are soon expressed in parallel with the loss of the differentiated state. In contrast, the mRNA for collagenase-1 is strongly expressed by differentiated chondrocytes and declines rapidly following phenotypic modulation. The mRNA for stromelysin-1 and the tissue inhibitor of metalloproteinases-2 is high and does not appreciably change after modulation. Chondrocyte activation induced by alteration of its original phenotype leads to the expression of endopeptidases in a way that markedly differs from that induced by cytokines. The results are relevant to cartilage catabolism in osteoarthritis and suggest a prominent role of fibroblastic metaplasia on the part of the chondrocytes as a mechanism of expressing catabolic endopeptidases.
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PMID:Differential expression of mRNAs for endopeptidases in phenotypically modulated ('dedifferentiated') human articular chondrocytes. 927 45


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