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)

Antibodies to collagenous and noncollagenous components of glomerular basement membrane (GBM) have been detected by immunoblotting in some sera from patients with various kinds of glomerulonephritis. A half proportion of patients with rapidly progressive glomerulonephritis (RPGN), chronic focal glomerulonephritis (CFGN), idiopathic membranous glomerulonephritis (MGN). IgA nephropathy and lupus nephritis (LE-GN) had IgG antibodies to heterogenous components in acid insoluble fraction of pepsin digested GBM. This acid insoluble fraction represented a complex of collagen and noncollagenous proteins of GBM. Following digestion of acid insoluble fraction with bacterial collagenase, the triple helical collagenous components of GBM were destroyed and released most likely of noncollagenous proteins. Antibodies to this noncollagenous proteins were found in only some patients with chronic glomerulonephritis (17.6%) and lupus nephritis (21.4%). Upon reaction with human placenta derived type IV collagen, different frequencies of antibody response were found in patients of different groups. However, all these reactive sera showed a similar immunoblotting pattern. The relationship between antibody response to antigenic components from human GBM or human placenta and pathogenesis of renal disease is unclear. However, the occurrence of spontaneous autoantibody response to some exposed GBM self antigens may mediate further renal destruction resulting in chronic ongoing stage of the disease.
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PMID:Heterogeneity of antibody response to glomerular basement membrane antigen in patients with different forms of glomerulonephritis. 140 75

Decorin, a small collagen-binding dermatan sulfate proteoglycan, is widely distributed as a component of extracellular matrices. Using a solid phase binding assay, we showed that decorin bound C1q at physiologic pH and ionic strength. The interaction did not require divalent cations and was time and temperature dependent reaching equilibrium in 4 h at 37 degrees C. Binding was specific and saturable with an apparent dissociation constant of 7.6 x 10(-9) M. Decorin was shown to bind pepsin-derived fragments containing the collagenous domain of C1q and collagenase-derived fragments containing the globular domain of C1q. Because these fragments share a short sequence of amino acids, this finding suggests that decorin binds to a region of C1q located near the junction of the two domains. Competition studies using purified preparations of the decorin core protein and the glycosaminoglycan chains showed that only the former inhibited binding of decorin to C1q indicating that the interaction is mediated by the decorin core protein. Decorin was shown to inhibit the hemolytic activity of purified C1 as well as C1 in normal human serum. Approximately 50% inhibition was observed at a decorin concentration of 2 micrograms/ml. Inhibition was not observed if C1 was bound to Ag-complexed antibody. Furthermore, neither the core protein nor the glycosaminoglycan chain of decorin inhibited C1, indicating that the intact proteoglycan is necessary for functional activity.
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PMID:The proteoglycan decorin binds C1q and inhibits the activity of the C1 complex. 143 Nov 41

Human vascular smooth muscle cells have been used to assess the implied role of connective tissue microfibrils as cellular ligands. Preparations of intact high-M(r) microfibrillar assemblies of collagen VI and of fibrillin, respectively, were isolated from foetal bovine skin and used as ligands in cell attachment and spreading assays. Intact collagen VI microfibrils were capable of mediating cell attachment and partial spreading. Cell attachment assays using ligands composed of defined collagen VI fragments generated by pepsin or bacterial collagenase digestions demonstrated that both the triple-helical and non-collagenous domains of collagen VI had cell adhesion activity, although at reduced levels relative to intact microfibrils. Fibronectin was identified as a modulator of intact collagen VI microfibril-mediated cell attachment. These observations are indicative of complex multiple interactions between collagen VI microfibrils and smooth muscle cells. Purified fibrillin-containing microfibrils were also shown to support smooth muscle cell adhesion. Both pepsin-resistant and pepsin-sensitive domains of fibrillin exhibited some cell attachment activity, but at reduced levels relative to the intact fibrillin microfibrils. These data provide the first direct evidence of a physiological role for intact microfibrillar assemblies in cell-matrix interactions, and the involvement of integrin cell surface receptors containing the beta 1 subunit.
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PMID:Attachment of human vascular smooth muscles cells to intact microfibrillar assemblies of collagen VI and fibrillin. 147 46

Gel electrophoretic analysis of the avian tectorial membrane under non-reducing conditions reveals the presence of 2 major proteins with apparent molecular masses of 195 and 41 kDa on 8.25% gels. Under reducing conditions, 6 polypeptides with apparent molecular masses of 146, 60, 56, 43, 35 and 31 kDa are consistently observed. None of these six polypeptides observed under reducing conditions are sensitive to digestion with collagenase, and all, except for the 43 kDa component, are degraded by treatment with cold acidic pepsin. The 60, 56 and 43 kDa polypeptides bind the peroxidase conjugated lectins from Canavalia ensiformis and Triticum vulgaris, indicating the presence of mannose, N-acetyl glucosamine and/or sialic acid. The 146, 60 and 56 kDa bands undergo a shift in electrophoretic mobility after treatment of native tectorial membranes with the enzyme neuroaminidase. Fibronectin and Type II collagen cannot be detected in the avian tectorial membrane by either immunoblotting or immunofluorescence techniques. Polyclonal antisera raised against the different polypeptides after partial purification by one dimensional gel electrophoresis confirm that these proteins are all components of the tectorial membrane, and show that they are restricted to the otolithic and tectorial membranes within the inner ear. Analysis of a wide variety of other tissue types indicates that the 60, 43 and 35 kDa components can only be detected within the inner ear, and that the antisera recognising the 146 and 31 kDa components only show cross-reactivity within the head, with the anti-146 kDa antibodies staining the mucus ducts supplying the olfactory epithelium and the anti-31 kDa antibodies staining granular elements in the cells of the respiratory epithelium. The results suggest that certain of the tectorial membrane components may be novel matrix molecules unique to the inner ear, and that some of the other proteins may be antigenically related to mucins.
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PMID:The protein composition of the avian tectorial membrane. 149 Aug 98

Mesangial cells serve many functions in the glomerulus, including regulation of glomerular ultrafiltration coefficient, matrix production, and eicosanoid generation. The glomerulus is a vascular bed, and the mesangial cell is continually exposed to rhythmic alterations in intraglomerular pressure. Since increased intraglomerular pressure has been implicated as a potential causative agent in the ultimate development of nephrosclerosis, we sought to determine the effect of continuous stretch-relaxation upon parameters of mesangial cell growth and function. Early passage (2-4) cultured rat mesangial cells were plated onto either rigid-bottom or flexible-bottom culture plates coated with type I collagen. After cell attachment, the cells on flexible supports were exposed to continuous stretch-relaxation for 72 to 96 hours at a rate of 100 cycles/minutes at an applied pressure of 7 to 8 KPa (53 to 61 mm Hg). Cellular morphology was altered by continuous stretch-relaxation, with the majority of mesangial cells presenting stellate or straplike morphology. Fluorescein isothiocyanate-labeled phalloidin staining indicated an increase in density of actin filaments running the long axis of the cell. Stretch-relaxation resulted in an approximately 50% increase in cell number. Prostaglandin production, assessed as irPGE2 production, was increased by stretching in mesangial cells from 28 +/- 1 to 49 +/- 4 pg/10(6) cells (N = 12; p less than 0.005). Mechanical stretch/relaxation increased the percentage of protein representing collagenous proteins from 47 +/- 6% to 70 +/- 4%, as assessed by collagenase susceptibility (p less than 0.025). Analysis of pepsin-resistant proteins synthesized indicated that stretch/relaxation resulted in increases in the relative amounts of types I and III collagens produced/cell. Additionally, stretch/relaxation selectively increased the relative amount of type I-homotrimers produced. Thus, when mesangial cells are exposed to cyclic stretch/relaxation, they exhibit significant alterations in morphology, growth, prostaglandin and collagen production.
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PMID:Continuous stretch-relaxation in culture alters rat mesangial cell morphology, growth characteristics, and metabolic activity. 157 48

In vitro and in vivo degradation of collagen suture was investigated focussing on the change in the mechanical properties and weight. The in vitro hydrolysis was carried out for catguts using collagenase (pH 7.4) and pepsin (pH 1.6), simulating the in vivo environments. The kinetic study on the weight loss of the fibre at the collagenase hydrolysis suggested that the degradation proceeded gradually from the surface of the fibre into the core. The enzymatic hydrolysis was different from the non-enzymatic acidic hydrolysis which resulted in almost homogeneous degradation throughout the cross-section of the fibre from the beginning of the hydrolysis reaction. The rate of weight loss with enzymatic hydrolysis was in good agreement with that predicted under the assumption of continuous erosion from the surface. When the collagen sutures were implanted in the subdermal tissue of rabbits, severe infiltration of macrophages and neutrophils was observed at 4 wk post-implantation, probably because of the degradation products from the implanted sutures. Comparison of the tensile strength decrease with the weight loss observed at the in vivo degradation revealed that enzymatic and non-enzymatic hydrolysis occurred concurrently in the subcutaneous tissue.
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PMID:Degradation of collagen suture in vitro and in vivo. 163 19

We have previously reported that pericytes derived from retinal and brain microvessels aggregate into nodules soon after reaching confluence. Nodule formation involves a reorganization of the cells resulting in the presence of sparse cells, confluent monolayers, multilayers, sprouts, and nodules within the same culture dish. Extracellular calcification occurs only within the nodules, demonstrating that pericytes are capable of undergoing osteogenic differentiation in culture and that this differentiation is related to nodule formation. Using immunofluorescence we have now studied the distribution of laminin, type IV collagen, type X collagen, and tenascin in pericyte cultures during nodule formation. These matrix macromolecules were also identified by a combination of biochemical techniques, including Northern blot hybridization, immunoblotting and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A molecule that seems to be related to type X collagen was demonstrated by the presence of a pepsin-resistant, collagenase-sensitive polypeptide of molecular weight approximately 45 kDa. The production of laminin, type X-related collagen, and tenascin by pericytes has not been previously reported. Our results suggest that the synthesis or distribution or both of these molecules is dependent on the state of pericyte differentiation. The expression of laminin, type IV collagen, and type X-related collagen was maximal in multilayer areas, sprouts, and nodules. Tenascin appeared homogeneously distributed in monolayer and multilayer areas; when calcified nodules were present, the anti-tenascin serum preferentially decorated a discrete area circumscribing the nodules. Tenascin and type X collagen have been found transiently in vivo preceding calcification; their possible role in this process is not known. Our results also suggest an association between laminin, type IV collagen, and calcification. The in vitro experimental system described here may help to clarify the role of matrix macromolecules in the calcification process.
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PMID:Differentiation of pericytes in culture is accompanied by changes in the extracellular matrix. 171 27

The collagen of a primitive invertebrate, the sea-pen Veretillum Cnidaria, Octocorallia), was studied with respect to its molecular-chain composition. The soft extracellular tissues (mesoglea) were solubilized by limited pepsin proteolysis and the collagen was isolated by selective precipitation at 0.7 M NaCl under acidic conditions. The pepsinized molecules were 260 nm in length, as demonstrated by electron microscope studies of rotary-shadowed molecules and of the segment-long-spacing crystallites obtained by dialysis against ATP. SDS/PAGE of the extract produced two main bands susceptible to bacterial collagenase, designated as the alpha 1 and alpha 2 chain, which were differentiated clearly by their CNBr cleavage products and the higher glycosylation rate of the alpha 2 chain. The latter finding corresponds with the high hydroxylysine content of the alpha 2 chain. The alpha 1/alpha 2 chain ratio observed in SDS/PAGE and the fact that only one peak was obtained by concanavalin-A affinity chromatography of a non-denatured 0.7 M NaCl extract demonstrate the alpha 1 [alpha 2]2 molecular structure of this collagen. These results contrast with data on the structure of other coelenterates (i.e. [alpha]3 for sea anemone collagen molecules and alpha 1 alpha 2 alpha 3 for jellyfish collagen molecules). They are discussed in relation to the evolution of collagen.
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PMID:Characterization of heterotrimeric collagen molecules in a sea-pen (Cnidaria, Octocorallia). 173 Feb 24

SR 26831 ([[5-(2-chloro-benzyl-2-(terbutyloxycarbonyl)]-4,5,6,7- tetrahydrothieno(3,2-c)pyridine]N-oxide) is the first member of a new class of human leukocyte elastase inhibitors. SR 26831 inhibited in a dose-dependent manner elastases from human leukocytes or pancreas with IC50 values of 80 +/- 2.6 nM and 4.8 +/- 0.12 microM, respectively. Steady-state studies revealed that SR 26831 behaved like a noncompetitive, irreversible inhibitor of both types of enzymes. SR 26831 inhibited in a dose-dependent manner degradation of [3H]elastin and [3H]collagens (types I and IV) by human leukocyte elastase (IC50 values were between 1.2 and 1.8 microM). In this respect, SR 26831 was 3- to 20-fold more active than alpha-1-antitrypsin. SR 26831 was also highly selective for elastases inasmuch as it did not inhibit pepsin, collagenase, trypsin, alpha-chymotrypsin, factor Xa, plasmin, kallikrein, cathepsins B, C, D and G and thrombin. In the rabbit, SR 26831 was cleared rapidly from blood after i.v. injection, but affected intracellular leukocyte elastase activity shortly after either i.v. or p.o. administration. In the rat, i.v. or p.o. administration of SR 26831 prevented in a dose-dependent manner acute lung injury induced by intratracheal instillation of human leukocyte elastase. SR 26831 (1 mg/kg) was still efficient when it was administered 90 min before elastase instillation and was also able to limit further hemorrhage development in response to elastase, after it had begun. SR 26831 may therefore be of therapeutic value in the treatment of diseases such as rheumatoid arthritis or pulmonary emphysema thought to be due to the destructive action of leukocyte elastase.
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PMID:Biochemical and pharmacological activities of SR 26831, a potent and selective elastase inhibitor. 173 26

Bovine retinal pericytes (BRP) in culture synthesise a low Mr collagenous polypeptide which appears similar, but not identical, to bovine type X collagen and which we have called 'BRP collagen'. This polypeptide displays the following characteristics: (i) it is sensitive to digestion by bacterial collagenase and is resistant to pepsin digestion; (ii) it has an apparent Mr of 45 kDa (pepsinised form); (iii) it is recognised by specific antibodies to type X collagen using immunoblotting; (iv) it is present in the cell layer/matrix but not in the medium of pericyte cultures; and (v) it is not disulphide-bonded into higher Mr multimers. The latter two properties distinguish BRP collagen from bovine type X collagen. We have recently shown that pericytes calcify in vitro. We now report that this calcification is associated with an increased synthesis of BRP collagen.
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PMID:Identification and partial characterisation of a low Mr collagen synthesised by bovine retinal pericytes. Apparent relationship to type X collagen. 186 64


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