Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, we have investigated the distribution of the enzyme nucleoside triphosphate diphosphohydrolase-1 (NTPDase1; EC 3.6.1.5) in a subset of pig tissues by biochemical activity and Western blotting with antibodies against porcine NTPDase1. The highest expression of this enzyme was found in vascular endothelium, smooth muscle, spleen and lung. The complete cDNA of NTPDase1 from aorta endothelial cells was sequenced using primer walking. The protein consists of 510 amino acids, with a calculated molecular mass of 57 756 Da. The amino-acid sequence indicated seven putative N-glycosylation sites and one potential intracellular cGMP- and cAMP-dependent protein kinase phosphorylation site. As expected, the protein has a very high homology to other known mammalian ATPDases and CD39 molecules, and includes all five apyrase conserved regions. Expression of the complete cDNA in COS-7 cells confirmed that NTPDase1 codes for a transmembrane glycoprotein with ecto-ATPase and ecto-ADPase activities. Two proteolytic products of NTPDase1, with molecular mass of 54 and 27 kDa, respectively, were consistently present in proteins from transfected COS-7 cells and in particulate fractions from different tissues. A trypsin cleavage site, giving rise to these two cleavage products, was identified. In order to remain enzymatically active, the two cleavage products have to interact by non-covalent interactions.
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PMID:Distribution, cloning, and characterization of porcine nucleoside triphosphate diphosphohydrolase-1. 1086 13

Coronary microvascular endothelial cells exert (patho)physiological effects on the function of cardiac myocytes, which may be studied experimentally using pure cell populations. As an essential pre-requisite to the investigation of cells from gene-modified mice, we studied the phenotypic properties of coronary microvascular endothelial cells isolated from normal mice, and biochemically characterized the superoxide production by these cells. Microvascular endothelial cells were isolated from devitalized mouse ventricular tissue after sequential digestion with collagenase, trypsin and DNase. Coronary microvascular endothelial cells were separated from cardiac myocytes and other cells by differential centrifugation, plating and culture. Mouse coronary microvascular endothelial cells showed an irregular "cobblestone" morphology at confluence, were >98% positive for CD31 by FACS analysis, and were also positive for VE-cadherin and endothelial-type nitric oxide synthase (eNOS) by confocal microscopy. The cells took up fluorescently labelled, acetylated low-density lipoprotein, but were negative for a alpha -smooth muscle actin, desmin and cytokeratin. Unlike human endothelial cells, mouse coronary microvascular endothelial cells only weakly expressed von Willebrand factor. Immunoblotting showed that the mouse cells expressed components of a phagocyte-type NADPH oxidase. They exhibited NADPH-dependent O(2)(-)-generating activity, which was increased by angiotensin II but completely inhibited by diphenyleneiodonium. Thus, mouse coronary microvascular endothelial cells express both eNOS and NADPH oxidase, interactions between which may play a role in endothelial cell pathophysiology.
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PMID:Phenotypic properties and characteristics of superoxide production by mouse coronary microvascular endothelial cells. 1144 17

Ca(2+)-dependent adhesion molecules, cadherins, are critically involved in the barrier formation of epithelial layers. Adhesive strength depends on both the plasmalemmal concentration and adhesive affinity (affinity for trans interaction) of cadherins. In the present study we used recombinant vascular endothelial cadherin, VE-cadherin, as a reference to quantify the surface concentration of VE-cadherin in mouse microvascular endothelial cells by linear interpolation and regression analysis of immunosignals obtained with cell lysates dotted on nitrocellulose membranes. The affinity of trans interaction was determined by a novel mobility shift assay, in which soluble dimeric VE-cadherin ectodomains pass through a VE-cadherin affinity column. By these approaches we determined the trypsin-sensitive surface concentration of VE-cadherin to be 5 x 10(3) dimers/microm(2) cell surface and the dissociation constant K(D) to be about 0.8 x 10(-4) M. The low affinity of trans interaction in combination with high plasmalemmal concentration of VE-cadherins fulfils theoretical predictions for regulation of adhesion by a transmembrane cooperative linkage mechanism, in which the degree of lateral mobility (translational entropy) of cadherins in the plasma membrane determines the number of adhesive bonds and, hence, the strength of intercellular adhesion.
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PMID:Plasmalemmal concentration and affinity of mouse vascular endothelial cadherin, VE-cadherin. 1245 22

(1) Intravenous injection of ioxaglate (4 g iodine kg(-1)), an iodinated radiographic contrast medium, caused a marked protein extravasation, pulmonary oedema and a decrease in the arterial partial oxygen pressure in rats. (2) All of these reactions to ioxaglate were reversed by the pretreatment with gabexate mesilate (10 and 50 mg kg(-1), 5 min prior to injection) or nafamostat mesilate (3 and 10 mg kg(-1)), in which the inhibition was complete after injection of nafamostat mesilate (10 mg kg(-1)). (3) Both gabexate mesilate and nafamostat mesilate inhibited the activity of purified human lung tryptase, although the latter compound was far more potent than the former. (4) Ioxaglate enhanced the nafamostat-sensitive protease activity in the extracellular fluid of rat peritoneal mast cell suspensions. (5) Tryptase enhanced the permeability of protein through the monolayer of cultured human pulmonary arterial endothelial cells. Ioxaglate, when applied in combination with rat peritoneal mast cells, also produced the endothelial barrier dysfunction. These effects of tryptase and ioxaglate were reversed by nafamostat mesilate. (6) Consistent with these findings, immunofluorescence morphological analysis revealed that tryptase or ioxaglate in combination with mast cells increased actin stress fibre formation while decreasing VE-cadherin immunoreactivity. Both of these actions of tryptase and ioxaglate were reversed by nafamostat mesilate. (7) These findings suggest that tryptase liberated from mast cells plays a crucial role in the ioxaglate-induced pulmonary dysfunction. In this respect, nafamostat mesilate may become a useful agent for the cure or prevention of severe adverse reactions to radiographic contrast media.
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PMID:A potent tryptase inhibitor nafamostat mesilate dramatically suppressed pulmonary dysfunction induced in rats by a radiographic contrast medium. 1264 98

We report here a direct modulation by mast cell tryptase of endothelial barrier function through activation of proteinase-activated receptor-2 (PAR-2). In cultured bovine aortic endothelial cells (BAECs), tryptase, trypsin and PAR-2 activating peptide impaired the barrier function as determined by the permeability of protein-conjugated Evans blue. The tryptase-induced barrier dysfunction was completely blocked by U73122, and partially reversed by xestospongin C, calphostin C or Y27632. The intracellular Ca(2+) was elevated by tryptase. It was notable that ioxaglate, a contrast material that degranulates mast cells, markedly increased the permeability when applied to BAECs in combination with mast cells, an action that was blocked by nafamostat, a potent tryptase inhibitor. Immunofluorescence analysis showed that actin stress fibre formation and disruption of VE-cadherin were observed after exposure to tryptase or ioxaglate in combination with mast cells. Therefore, it is suggested that mast cell tryptase impairs endothelial barrier function through activation of endothelial PAR-2 in a manner dependent on the phospholipase C activity.
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PMID:Involvement of proteinase-activated receptor-2 in mast cell tryptase-induced barrier dysfunction in bovine aortic endothelial cells. 1278 70

The effect of carbazochrome sodium sulfonate (AC-17), a hemostatic drug with capillary stabilising action, on the endothelial barrier dysfunction induced by a variety of vasoactive substances or agents that increase the vascular permeability was investigated in the monolayers of cultured porcine aortic endothelial cells (PAECs). The endothelial barrier function was determined by the transendothelial transport of albumin-conjugated Evans blue. AC-17 (0.1-1 M) reversed the barrier dysfunction induced by tryptase, thrombin and bradykinin without affecting the endothelial permeability enhanced by Ca(2+) ionophores such as ionomycin and A23187 or phorbol 12-myristate 13-acetate. Immunofluorescence analysis showed that AC-17 reversed the tryptase-induced formation of actin stress fibres and disruption of VE-cadherin in PAECs. On the other hand, AC-17 (0.1-10 M) reduced concentration-dependently the enhancement of [(3)H]inositol triphosphate formation from [(3)H]myo-inositol induced by bradykinin and thrombin.Therefore, it is suggested that AC-17 reduces the vascular hyperpermeability induced by a variety of vasoactive agents through inhibition of agonist-induced phosphoinositide hydrolysis.
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PMID:Carbazochrome sodium sulfonate (AC-17) reverses endothelial barrier dysfunction through inhibition of phosphatidylinositol hydrolysis in cultured porcine endothelial cells. 1292 65

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of antigenically diverse proteins is expressed on the surface of human erythrocytes infected with the malaria parasite P. falciparum, and mediates cytoadherence to the host vascular endothelium. In this report, we show that export of PfEMP1 is slow and inefficient as it takes several hours to traffic newly synthesized proteins to the erythrocyte membrane. Upon removal by trypsin treatment, the surface-exposed population of PfEMP1 is not replenished during subsequent culture indicating that there is no cycling of PfEMP1 between the erythrocyte surface and an intracellular compartment. The role of Maurer's clefts as an intermediate sorting compartment in trafficking of PfEMP1 was investigated using immunoelectron microscopy and proteolytic digestion of streptolysin O-permeabilized parasitized erythrocytes. We show that PfEMP1 is inserted into the Maurer's cleft membrane with the C-terminal domain exposed to the erythrocyte cytoplasm, whereas the N-terminal domain is buried inside the cleft. Transfer of PfEMP1 to the erythrocyte surface appears to involve electron-lucent extensions of the Maurer's clefts. Thus, we have delineated some important aspects of the unusual trafficking mechanism for delivery of this critical parasite virulence factor to the erythrocyte surface.
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PMID:Characterization of the pathway for transport of the cytoadherence-mediating protein, PfEMP1, to the host cell surface in malaria parasite-infected erythrocytes. 1462 10

"Proteinase-activated" receptor-2 (PAR-2) is a G protein-coupled transmembrane receptor with seven transmembrane domains activated by trypsin. It has been shown in the pancreatic tissue that PAR-2 is involved in duct/acinary cells secretion, arterial tonus regulation and capillary liquid content turnover under physiological conditions. These above mentioned structures play an important role during the development of acute pancreatitis and are profoundly influenced by a high concentration of trypsin enzyme after its secretion into the interstitial tissue from the basolateral aspect of acinar cells. Among the other factors, it is the increase of interstitial trypsin concentration followed rapidly by PAR-2 action on pancreatic vascular smooth muscle cells that initiates ischemic changes in pancreatic parenchyma and that finally leads to necrosis of the pancreas. Consequent reperfusion perpetuates changes leading to the acute pancreatitis development. On the contrary, PAR-2 action on both exocrine and duct structures seems to play locally a protective role during acute pancreatitis development. Moreover, PAR-2 action is not confined to the pancreas but it contributes to the systemic vascular endothelium and immune cell activation that triggers the systemic inflammatory response syndrome (SIRS) contributing to an early high mortality rate in severe disease.
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PMID:Acute pancreatitis: proteinase-activated receptor-2 as Dr. Jekyll and Mr. Hyde. 1634 48

Genomic and proteomic analysis of normal and diseased tissues have yielded an abundance of molecular information for diagnostic and potential therapeutic targets. Changing the target of analysis from poorly accessible cells within tissues to easily accessible vascular endothelium has theoretical advantages in tissue-specific targeting. In this study, we sought to map a large-scale proteome of microvascular endothelium in human non-small cell lung cancer (NSCLC) and normal lung tissues, and identify lung cancer-related endothelial cell (EC)-selective proteins. Endothelial cells were isolated within NSCLC tissues and adjacent-normal lung tissue of lung cancer patients by using CD31-immunomagnetic beads. The complex proteins from the ECs were separated by one-dimensional gel electrophoresis, and the proteins in each gel band were digested by trypsin. Peptides were separated by online reverse-phase liquid-chromatography and analyzed by electrospray ionization (ESI) ion trap tandem mass spectrometry. Approximately 600-1000 proteins were identified in each individual sample. Five patient cases of paired individual data, extracted from the protein identification data sets of both normal- and cancer-derived ECs, were analyzed by subtractive proteomics. An average of 300 proteins was specifically identified from each lung cancer-derived EC isolate, compared to normal lung-derived ECs. With the use of several comparative analyses, we identified among those 300 proteins, 16 common candidate proteins that were detected in at least 3 of 5 cases specific to lung cancer-derived ECs. Proteins selectively identified in cancer-derived ECs, including coatomer protein complex, subunit gamma (COPG), and peroxiredoxin 4 (PRDX4), were validated by Western blot analysis. In an additional experiment in which 16 cancer samples were analyzed by immunohistochemistry, PRDX4, thymopoietin (TMPO), and COPG were confirmed to be abundantly expressed in lung cancer-derived ECs and in cancerous lung cells. Further ongoing analysis of these 16 candidate proteins will determine their potential applicability to NSCLC-specific diagnosis and therapeutics.
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PMID:Proteomic profiling of endothelial cells in human lung cancer. 1822 Mar 33

To invade the decidua and myometrium, extravillous trophoblast must degrade an assortment of extracellular matrix (ECM) components. The uterine wall is rich in heparan sulphate proteoglycans (HSPG), which interact with collagen, laminin and fibronectin, and bind a variety of growth factors. HSPG are catabolised by heparanase, an enzyme that is highly expressed in the placenta. The aim of this study was to investigate the role of heparanase in first trimester trophoblast invasion. First trimester cytotrophoblasts (CTB) were isolated by trypsin digestion followed by centrifugation on a Percoll gradient. Cells were cultured on Matrigel to promote an extravillous phenotype. Heparanase expression was studied by immunohistochemistry and confocal microscopy. Trophoblast invasion was assessed using an in vitro transwell assay. A high level of heparanase was observed in isolated first trimester trophoblast; however, a function-blocking antibody did not inhibit invasion of primary CTB or the extravillous trophoblast cell line SGHPL-4 at 21% oxygen. In contrast to cancer cells, heparanase expression was not increased following culture at 3% oxygen, and trophoblast invasion was not retarded by the blocking antibody under these conditions. Heparanase expression was observed in stromal cells and vascular endothelium in first trimester parietal decidua. Expression was evident on the cell surface and in the nucleus of trophoblast and decidual cells. In conclusion, trophoblast heparanase is not required for invasion in vitro. Its abundant expression suggests another role during pregnancy, perhaps in controlling the availability of ECM-bound growth factors or acting as a transcription factor.
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PMID:Trophoblast-derived heparanase is not required for invasion. 1832 9


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