Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated undulin, an extracellular matrix protein associated with the surface of collagen fibrils, from chicken embryos. The protein showed a molecular mass of about 600 kDa and is composed of three 210-kDa subunits linked by reducible as well as non-reducible bonds. In contrast to human undulin which reportedly is devoid of collagenous sequences, the chicken protein contained a short triple-helical segment that was sensitive to digestion by bacterial collagenase. Screening of an expression library with affinity-purified antibodies yielded two cDNA clones specific for chicken undulin. Analysis of the amino acid sequence deduced from the nucleotide sequence of these clones showed that the human and the chicken protein shared 71% sequence identity. At the amino-terminus both polypeptides contained several similar repeats related to the type III modules found in fibronectin. Towards the carboxyl terminus, however, the two sequences diverged substantially from each other. While the human sequence terminated in a proline-rich segment, the chicken sequence continued with a domain related to von Willebrand factor, with a domain similar to the noncollagenous domain NC4 of type IX collagen and with a typical collagenous triple helix. A short segment of this sequence was found to be identical with the published sequence of a bovine peptide derived from type XIV collagen. Our protein must therefore represent chicken type XIV collagen. One way to explain these results is the possibility that undulin exists in at least two alternatively spliced variants, one lacking the collagenous domain, as described initially for human undulin, and one containing the triple-helical domain, as found in type XIV collagen.
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PMID:Type XIV collagen is a variant of undulin. 133 49

Primary ciliary muscle cell cultures derived from human donors (16-91 years) were established and characterized by comparing them with ciliary muscle in tissue sections using immunocytochemical and ultrastructural methods. Monoclonal antibodies against desmin, vimentin, alpha-actinin, smooth muscle (sm) specific alpha-actin and von Willebrand factor were used. In tissue sections of the ciliary body, ciliary muscle cells, vascular muscle cells, pericytes, endothelial cells and fibroblasts stain for vimentin. Both types of muscle cells and the pericytes stain for alpha-sm-actin, but only ciliary muscle cells stain for desmin. For tissue cultures, explants of the meridional and partly the reticular portion of the ciliary muscle were dissected and grown directly or after digestion of the explant with collagenase. Ten primary cell cultures with a typical hill-and-valley growth pattern similar to smooth muscle cells and two with a growth pattern similar to fibroblasts were established. All cultures could be subcultured up to the fifth passage. In fibroblast-like cultures 5-10% of the cells stained for alpha-sm-actin. Staining for desmin was not observed. In smooth muscle-like cultures, all cells stained positive for alpha-sm-actin. Desmin staining was not seen in growing non-confluent smooth muscle-like cultures. In confluent cultures, about 10% of the cells stained positive for desmin, preferentially in areas where the cells had formed hills. No culture stained for von Willebrand factor. Staining for alpha-actinin in smooth muscle-like cultures showed that the dense bands of the myofilaments were arranged in register, similar to the typical ciliary muscle cell morphology seen in tissue sections. Ultrastructurally, the smooth muscle-like cultures showed the typical morphology of cultured smooth muscle cells. We conclude that the smooth muscle-like cultures consist of ciliary muscle cells.
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PMID:Cell cultures of human ciliary muscle: growth, ultrastructural and immunocytochemical characteristics. 193 74

The use of microvascular endothelial cells derived from omental tissue has been advocated to seed vascular grafts with autologous endothelial cells in high density. The purpose of our study was to evaluate the precise origin of these cells. Therefore we have compared cellular characteristics of these cells with those of endothelial cells isolated by collagenase treatment of human umbilical veins. The omental cells were isolated from from omental tissue from four different patients by incubation in a collagenase-dispase solution. Part of the material was processed by Percoll density gradient centrifugation in an attempt to purify the isolates. Cellular characteristics of both types of cells were determined by studying the morphologic features of the cells and by determining the presence of von Willebrand factor, antigens EN-4 and PAL-E specific for endothelial cells, cytokeratins 8 and 18, vimentin and desmin, and uptake of diI-acetylated low-density lipoprotein. Epitheloid cells from omental tissue, isolated after collagenase treatment and either purified or nonpurified by Percoll density gradient centrifugation, differed from human umbilical vein endothelial cells with respect to the presence of surface microvilli, the expression of von Willebrand factor, EN-4 and PAL-E, and the presence of cytokeratins 8 and 18 and desmin. von Willebrand factor (in a granular staining pattern) and the presence of EN-4 and PAL-E were only detected in human umbilical vein endothelial cells. Vimentin was present in both cell types, whereas cytokeratins 8 and 18 and desmin were only present in cells derived from omentum. From these data we conclude that the so called microvascular endothelial cells from omentum are not endothelial but mesothelial in nature.
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PMID:Cells derived from omental fat tissue and used for seeding vascular prostheses are not endothelial in origin. A study on the origin of epitheloid cells derived from omentum. 173 9

A method for long-term cultivation of large amounts of human microvascular endothelial cells from the omental tissue (human omental tissue microvascular endothelial cells, HOTMECs) was devised. The method originally described by Kern, Knedler, and Eckel was modified: HOTMECs were isolated by enzymatic dissociation with collagenase. For primary cultivation and passages, HOTMECs were plated either onto fibronectin-coated petri dishes or onto a human fibroblast extracellular matrix (HFB-ECM) prepared from the same tissue. Omental tissue (10-15 g) yielded 4-8 X 10(5) HOTMECs; more than 90% of the cells adhered to precoated dishes and grew in Waymouth's culture medium supplemented with 20% heat-inactivated fetal calf serum. Confluence was reached 3-5 days after seeding with an average of 1-2 X 10(6) cells/dish. Confluent HOTMEC layers were subcultured at a split ratio of 1:3 up to 11 passages by plating the cells onto dishes coated with HFB-ECM and maintained in long-term culture for up to 3 months. The endothelial origin of these cells was demonstrated as follows. The cells in culture showed the typical "cobblestone" growth pattern and synthesized von Willebrand factor (vWF) as determined by metabolic labeling. Using an indirect immunostaining technique, the cytoplasm of the HOTMECs stained for vWF. A monoclonal antibody specific for human endothelial cells bound exclusively to the cultured cells. The expression of thrombomodulin on the surface of the cultured cells was demonstrated by the activation of protein C by thrombin. In control experiments, these features could be detected on neither fibroblasts nor mesothelial cells.
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PMID:Microvascular endothelial cells from human omental tissue: modified method for long-term cultivation and new aspects of characterization. 282 81

Adult bovine aortic tissue was homogenized in a neutral phosphate buffer containing proteinase inhibitors. The insoluble residue was rehomogenized in Tris-buffered 6 mol/L guanidinium chloride (pH 7.4). An insoluble fibrillar protein, floating above the main pellet after recentrifugation, was harvested. This material agglutinated washed fixed human platelets in the presence of either normal human plasma or purified von Willebrand factor (vWF). No such reaction was seen when either buffer or plasma from patients with severe von Willebrand's disease was added instead. The extent of platelet agglutination was measured photometrically, similarly to the ristocetin cofactor assay. The agglutination reaction was strongest at neutral pH and was impaired after either addition of EDTA or previous digestion of the fibrillar material by collagenase or pepsin. By light microscopy platelets were seen to adhere onto isolated fibers. Amino acid composition, subunit polypeptides, substrate properties, and interaction with fibronectin of this fibrillar protein were comparable to those of collagen. Therefore, we tentatively denote the induction of platelet agglutination by vWF protein in the described test system as "vWF-collagen cofactor" activity. Comparison of this activity in 65 plasma samples, containing various concentrations of vWF, with ristocetin cofactor activity showed good correlation between results obtained in both tests (r = 0.91).
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PMID:Von Willebrand factor-dependent agglutination of washed fixed human platelets by insoluble collagen isolated from bovine aorta. 300 53

A new method for isolation and culture of endothelial cells from bovine coronary artery (BCoAEC) is presented. This method involves in situ perfusion and digestion of main coronary arteries with a collagenase solution. The isolated cells were cultured and maintained through many cell passages in Dulbecco's Modified Eagle's Medium supplemented with fetal bovine serum derived from either whole blood or plasma. Confirmation of these cells' endothelial origin was obtained by demonstration of typical morphologic and growth characteristics of endothelium, immunofluorescent staining with antibodies to von Willebrand factor (Factor VIII: vWF), and measurement of plasminogen activator (PA). In addition, production of PA was inhibited by enzymatically active thrombin as has been previously described with bovine aortic endothelial cells in culture.
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PMID:Bovine coronary artery endothelium: in vitro culture and production of plasminogen activator. 308 24

Colloidal gold is an electron-dense, lyophobic colloid that readily forms a stable electrostatic interaction with a variety of macromolecules. Monodispersed colloids ranging from 3-150 nm in diameter can be produced to provide the researcher with flexibility in selecting the optimally sized probe. Gold labeling of antibodies and lectins has been extensively used to study surface antigens and cell components. Recently, the use of gold labeling has been extended to study receptor-ligand binding, enzyme-substrate reactions, and transcellular pathways. Published applications include gold labeling of metabolites (low-density lipoproteins), enzymes (DNAase and RNAase, RNA polymerase, thrombin, collagenase, elastase), hormones (insulin, epidermal growth factor, glucagon), circulating plasma proteins (asialoglycoprotein, alpha 2-macroglobulin, factor VIII-von Willebrand factor), and endotoxins (tetanus toxin, cholera toxin). This broad spectrum of applications emphasizes the versatility and usefulness of colloidal gold as a probe in areas of cell biology related to receptors, endocytosis, transport, and functions of proteins.
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PMID:Colloidal gold: a pluripotent receptor probe. 635 33

The effect on platelet function of a monoclonal platelet antibody to platelet membrane glycoprotein I was tested. This antibody, AN51, inhibited ristocetin or bovine factor VIII-induced aggregation but did not modify ADP, collagen type I or type III, thrombin or arachidonic acid induced aggregations. Furthermore, the adhesion-aggregation of platelets induced by microfibrils was also inhibited by the antibody. Platelet adhesion to rabbit aorta subendothelium was impaired by the antibody. The persistent adhesion of platelets to collagenase-treated subendothelium was also inhibited. These findings strongly suggested that platelet membrane glycoprotein I could interact with a non-collagenic microfibrillar component of subendothelium. The binding of factor VIII/von Willebrand factor to platelet membrane in the presence of ristocetin was decreased in the binding site for factor VIII/von Willebrand factor to allow platelet adhesion to subendothelium.
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PMID:Monoclonal antibody to human platelet glycoprotein I. II. Effects on human platelet function. 679 59

Thrombogenicity of the vessel wall: role of the microfibrils and collagen. The study of platelet adhesion to rabbit aortic subendothelium preincubated with highly specific collagenase has revealed that platelets adhere to the microfibrils of the elastic lamina. To certify that an interaction between microfibrils and platelets can occur, microfibrils from two different origins were isolated: placental microfibrils extracted from the villi of human placenta, and aortic microfibrils extracted from adult bovine aorta. Both preparations were histologically homogeneous, and differed in their amino acid composition with an acidic character more pronounced for placental than for aortic microfibrils. Both preparations were able to induce platelet aggregation in plasma, but not after platelet isolation and resuspension in buffer. An interesting feature was the fact that when normal platelets were isolated, washed and resuspended in plasma from severe VWD patients, they were not aggregated by placental or aortic microfibrils. This defect was corrected after perfusion of cryoprecipitate to one patient. Moreover, monoclonal antibody directed against platelet glycoprotein Ib inhibited the aggregation of platelets to microfibrils, not to collagen; this suggested that an axis platelet GPI-FVIII/VWF-microfibrils could represent a pathway for platelet/subendothelium interaction. The adhesion of platelets to collagen seems to involve the staggering of a short amino acid sequence along a collagen fibre. This possibility arises from the requirement for the preservation of the quaternary structure of collagen in the induction of platelet adhesion/aggregation in vitro, and also from the identification and synthesis of a nonapeptide derived from type III collagen, which is also to specifically inhibit the aggregation of platelets by collagen, following its binding to platelet membrane.
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PMID:[Thrombogenicity of the vessel: role of microfibrils and of collagen]. 698 59

To examine potential mechanisms by which hematopoiesis may be regulated by endothelial cells within the bone marrow (BM) microenvironment, we have devised a technique for the in vitro study of the interaction of human BM microvascular endothelial cells (BMEC) with hematopoietic cells. Microvessels isolated by collagenase digestion of spicules obtained from filtered BM aspirate were plated on gelatin-coated plastic dishes, and colonies of endothelial cells grown from microvessel explants were further purified by Ulex europaeus lectin affinity separation. BMEC monolayers isolated by this technique grew in typical cobblestone fashion, stained positively with antibody to factor VIII/von Willebrand factor, and incorporated acetylated LDL. Immunohistochemical studies showed that BM microvessels and BMEC monolayers express CD34, PECAM, and thrombospondin. Incubation of resting BMEC with BM mononuclear hematopoietic cells resulted in the selective adhesion of relatively large numbers of CD34+ progenitor cells and megakaryocytes. The binding of purified BM-derived CD34+ progenitor cells to BMEC was dependent on divalent cations and was partially blocked by antibodies to CD34. IL-1 beta treatment of BMEC monolayers resulted in an increase of CD34+ progenitor cell adhesion by mechanisms independent of CD34 or divalent cations. BMEC exhibit specific affinity for CD34+ progenitor cells and megakaryocytes, suggesting that the BM microvasculature may play a role in regulating the trafficking, proliferation, and differentiation of lineage specific hematopoietic elements, and possibly of pluripotent stem cells within the CD34+ population.
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PMID:Isolation and characterization of human bone marrow microvascular endothelial cells: hematopoietic progenitor cell adhesion. 751 3


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