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

Good production of tumor necrosis factor (TNF) in the rabbit was obtained using Propionibacterium acnes IID 912 as a priming agent and subsequent administration of lipopolysaccharide. The physicochemical characteristics of rabbit TNF were very similar to those of murine TNF. The molecular weight of rabbit TNF was 39,000 as estimated by gel filtration, and 18,000 by SDS-PAGE. The isoelectric point was determined as pH 4.0 by isoelectric focusing. Rabbit TNF was stable within the pH range of 5.5 to 11.0, and was stable at 56 degrees C for 8 hr. It was digested by trypsin, pancreatic protease and elastase, but was resistant to neuraminidase. The amino acid sequence of rabbit TNF was determined as Ser-Ala-Ser-Arg-Ala-Leu- .... Monoclonal antibody against rabbit TNF completely inhibited both the in vivo and in vitro activity of rabbit TNF. However, this antibody could not inhibit the action of murine TNF. Antitumor activity of rabbit TNF was shown against murine and human cancer cells in vivo and in vitro, and rabbit TNF was also capable of distinguishing malignant cells from normal cells.
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PMID:Purification and partial amino acid sequence of rabbit tumor necrosis factor. 403 Jan 39

The molecular basis by which transforming growth factor (TGF)-beta 1 protects certain tumor cells from tumor necrosis factor (TNF) cytotoxicity was investigated. When pretreated, with TGF-beta 1, -beta 2, and -beta 3, murine L929S fibroblasts developed resistance to TNF cytotoxicity. Time course experiments revealed that TGF-beta 1 initially induced both cellular protein-tyrosine phosphorylation and simultaneous secretion of a novel extracellular matrix TNF-resistance triggering (TRT) protein(s), which closely preceded the acquisition of TNF-resistance. TGF-beta 2 and -beta 3 also increased tyrosine phosphorylation. However, both molecules failed to stimulate TRT secretion. The increased levels of phosphorylation, particularly to 9 specific protein tyrosine kinase inhibitor-sensitive cellular proteins, appeared to alter the TNF killing pathway. TGF-beta 1-induced TRT secretion required participation of unknown serum factors. TRT adhered strongly to polystyrene plates and resisted treatment with heat (60 degrees C, 30 min), collagenase, alpha 2-macroglobulin, heparin, antibodies against TGF-beta s, and limited trypsin digestion. Notably, TRT promoted TNF-resistance via activation of tyrosine and serine/threonine kinase functions in L929S. Thus, the molecular pathway involves TGF-beta 1-mediated initiation of a rapid tyrosine phosphorylation of cellular protein substrates (which alters TNF cytotoxic pathway), and a simultaneous secretion of TRT, which in turn signals the cells to maintain the levels of phosphorylation, thereby sustaining the TNF-resistance.
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PMID:Transforming growth factor-beta 1 induction of novel extracellular matrix proteins that trigger resistance to tumor necrosis factor cytotoxicity in murine L929 fibroblasts. 753 77

We generated > 10(7) mast cells by culturing 10(7) cord blood mononuclear cells for > 10 weeks in the presence of Steel factor, interleukin-6 and prostaglandin E2. 99% of the cultured cells had tryptase-positive granules, while 18% had chymase-positive granules. Cultured mast cells contained 3.6 micrograms histamine and 3.5 micrograms tryptase per 10(6) cells. Cells sensitized with 1 microgram/ml human IgE released 58.5% histamine and 1.55 ng tumor necrosis factor (TNF)-alpha per 10(6) cells when challenged with 1 microgram/ml antihuman IgE, whereas the control cells spontaneously released 3.7% histamine and 0.18 ng TNF-alpha. Analysis for surface antigens revealed that cultured mast cells expressed the following CD molecules: 9, 13, 14, 29, 33, 38, 43, 44, 45RA, 45RB, 46, 47, 48, 49d, 50, 51, 53, 54, 55, 58, 59, 60, 61 and 117 (c-Kit). Taken together, these cultured cells seem to be functionally mature mast cells.
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PMID:Characterization of cord-blood-derived human mast cells cultured in the presence of Steel factor and interleukin-6. 754 4

In severe acute pancreatitis (SAP), the mechanisms leading to adult respiratory distress syndrome (ARDS) are usually attributed to the release of active enzymes and vasoactive substances from the pancreas. Thoracic duct drainage has been proposed as a means of removing the portion of these substances that drain through retroperitoneal lymphatics before they reach the systemic circulation. This technique was used in six patients with ARDS complicating SAP. The levels of proinflammatory cytokines (tumor necrosis factor-alpha [TNF alpha], interleukin-1 [IL-1], and interleukin-6 [IL-6]), neutrophil enzymes (myeloperoxidase and lactoferrin), and pancreatic enzymes (amylase, lipase and trypsin) were measured in plasma and lymph in the first 24 h of ARDS and then on Day 2, Day 4, and at the end of the drainage (Day 8). High plasma concentrations of these products were measured. A moderate lymph-to-plasma gradient was observed for IL-6, lipase, and trypsin, while similar levels in plasma and lymph were recorded for the other substances. Plasma levels of pancreatic enzymes were weakly correlated with the lung injury score and lymph level of cytokines. These results suggest that in patients with ARDS due to SAP, cytokines as well as pancreatic enzymes could contribute to the development of the lung injury, and that lymphatics are potential vectors of these mediators.
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PMID:Lymphatic release of cytokines during acute lung injury complicating severe pancreatitis. 758 88

A method for the isolation and long-term culture of human microvessel endothelial cells from mammary adipose tissue (HuMMEC) obtained at breast reduction surgery has been developed. Pure cultures of HuMMEC were isolated by sequential digestion of the fat with collagenase and trypsin followed by specific selection of microvessel fragments with Ulex europaeus agglutinin-1 coated magnetic beads (Dynabeads). The resulting cells formed contact-inhibited monolayers on gelatin and fibronectin substrates and capillary-like "tubes" on Matrigel; they also expressed von Willebrand factor, angiotensin-converting enzyme, and accumulated acetylated low density lipoprotein. Further immunofluorescence characterization revealed the presence of antigens for the endothelial cell specific monoclonal antibodies EN4 and H4-7/33. In addition, the origin of these cells was confirmed by the demonstration of the cell adhesion molecules, platelet endothelial cell adhesion molecule-1 (CD31), and endothelial leukocyte adhesion molecule-1 (ELAM-1/E-selectin) upon stimulation with tumor necrosis factor (TNF) alpha. HuMMEC were found to express-1 ELAM-1 at lower levels of TNF alpha (< 10 ng/ml) than required by human umbilical vein endothelial cells. These cells should provide a useful in vitro model for studying various aspects of microvascular biology and pathology.
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PMID:Isolation and characterization of microvessel endothelial cells from human mammary adipose tissue. 768 48

Fibroblasts prepared from the meninges of newborn mice or from mouse embryos, as well as fibroblast L929 cells, secreted an immunoreactive material (ir-kininogen) against rabbit anti-mouse low-molecular-weight kininogen antibody in response to dibutyryl cAMP. Western blots using a bradykinin-directed monoclonal, as well as a polyclonal anti-mouse low-molecular-weight kininogen antibody, showed that ir-kininogen had a molecular weight of 80,000 and that it contained a kinin moiety. N-terminal amino acid sequence of the ir-kininogen was consistent with that of mouse L-kininogen. The ir-kininogen produced by fibroblasts released a kinin by incubating with trypsin and mouse submandibular gland kallikrein, and it was identified as bradykinin by means of high-performance liquid chromatography, indicating that mouse fibroblasts produce and secrete a kininogen. Forskolin, prostaglandin E2 and tumor necrosis factor alpha stimulated the production of ir-kininogen by meningeal fibroblasts, whereas neither dibutyryl cAMP nor these agents influenced kininogen production by mouse hepatocytes in primary cultures. These results demonstrated that fibroblasts are a source of kininogen in the mouse, and that it is regulated by the inflammatory mediators, prostaglandin E2 and tumor necrosis factor. Therefore locally produced kininogen is implicated in pathogenesis of inflammation.
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PMID:Murine fibroblasts synthesize and secrete kininogen in response to cyclic-AMP, prostaglandin E2 and tumor necrosis factor. 769 48

Mesenchymal cell apoptosis is important during development, tissue homeostasis, and repair. We sought to determine whether type II alveolar epithelial cells influence mesenchymal cell apoptosis, using the model of tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis of endothelial cells. Apoptosis was quantified by morphology and confirmed by electrophoretic DNA size analysis. Endothelial cells exposed to 20 ng/ml of TNF-alpha for 16 h exhibited apoptosis in 14.4 +/- 1.4% (SE) of the cells, whereas serum-free conditioned media (CM) from primary cultures of rat type II cells reduced TNF-alpha-induced apoptosis by 52% to 7.5 +/- 0.9% (P < 0.01). Flow cytometric analysis of subdiploid DNA content per cell also showed that CM reduced the percentage of cells with TNF-alpha-induced DNA degradation by 48 +/- 1.7%. The protective effect of CM was concentration dependent and also was effective across a range of TNF concentrations. This CM factor was trypsin sensitive and stable at 65 degrees C for 1 h. It bound to a Mono-Q anion-exchange resin, eluting in a discrete peak at 1.18 M NaCl and pH 8.5. Therefore alveolar type II cells release a heat-stable peptide(s) that protects endothelial cells against apoptosis induced by TNF. Our results suggest that alveolar epithelial cells regulate the response of mesenchymal cells to factors that induce apoptosis during injury and repair.
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PMID:Alveolar epithelial cells regulate the induction of endothelial cell apoptosis. 794 82

We report the purification of a protease from tumor cells undergoing apoptosis that is involved in activating DNA fragmentation. Initial studies revealed that two inhibitors of serine proteases, N-1-tosylamide-2-phenylethylchloromethyl ketone and carbobenzoxy-Ala-Ala-borophe (DK120), suppressed tumor necrosis factor or ultraviolet (UV) light-induced DNA fragmentation in the U937 histiocytic lymphoma as well as UV light-induced DNA fragmentation in the BT-20 breast carcinoma, HL-60 myelocytic leukemia, and 3T3 fibroblasts. The protease was purified by affinity chromatography with DK120 as ligand and showed high activity on a synthetic substrate preferred by elastase-like enzymes (Ala-Ala-Pro-Val p-nitroanilide), but was inactive on the trypsin substrate, N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester, or the chymotrypsin substrate, Ala-Ala-Pro-Phe p-nitroanilide. The activity of the DK120-binding protease purified from U937 cells undergoing apoptosis was increased approximately 10-fold over that recovered from normal cells. Further purification to homogeneity by heparin-Sepharose affinity chromatography followed by reverse phase high-performance liquid chromatography revealed a single band of 24 kD on a silver-stained sodium dodecyl sulfate gel. In addition to protease activity, the purified enzyme induced DNA fragmentation into multiples of 180 basepairs in isolated U937 nuclei. These findings suggest the 24-kD protease is a novel enzyme that activates DNA fragmentation in U937 cells undergoing apoptosis.
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PMID:Purification of a 24-kD protease from apoptotic tumor cells that activates DNA fragmentation. 796 87

Airway inflammation is often associated with the infiltration of activated neutrophils and subsequent protease release. Although aiding in the digestion and phagocytosis of foreign proteins and microorganisms, neutrophil proteases can indiscriminately damage healthy lung tissue. In the conducting airway, proteases, particularly neutrophil elastase, are counter-balanced by several antiproteases, including secretory leukocyte protease inhibitor (SLPI). SLPI can be produced locally by a number of cells including the airway epithelial cell. To examine the effects of neutrophil granule components on SLPI transcript levels, airway epithelial cells were treated (up to 96 h) with elastase, other proteases, or enzymes isolated from human sputum. We found that neutrophil elastase increased SLPI transcript levels in primary and transformed human airway epithelial cells in a time- and dose-dependent manner. Other neutrophil products, such as cathepsin G, myeloperoxidase, and lysozyme, had little or no effect on SLPI transcript levels. However, two nonneutrophil proteases, trypsin and pancreatic elastase, also increased SLPI transcript levels at higher doses than that required of neutrophil elastase. Two inflammatory cytokines, tumor necrosis factor-alpha and interleukin-8, produced little or no effect on SLPI transcript levels. This study demonstrates one way in which SLPI is regulated, via a protease that it inhibits, neutrophil elastase.
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PMID:Neutrophil elastase increases secretory leukocyte protease inhibitor transcript levels in airway epithelial cells. 810 97

Asthma is characterized by the presence of an inflammatory cell infiltrate in the bronchial mucosa consisting of activated mast cells, eosinophils, and T cells. Several cytokines are considered to play a pivotal role in this response, particularly interleukin (IL)-4, IL-5, IL-6, and tumor necrosis factor-alpha (TNF-alpha). In this study, we have used immunohistochemistry applied to thin glycol methacrylate sections of bronchial mucosal biopsies to define the cellular provenance of these cytokines in normal and asthmatic airways. Both the asthmatic and normal mucosa contained numerous cells staining positively for all four cytokines, with the majority identified as mast cells by their tryptase content. Eosinophils also accounted for some IL-5 immunostaining in the asthmatic biopsies. By using two monoclonal antibodies directed to different epitopes of IL-4, we provide tentative evidence for enhanced IL-4 secretion in asthma. Similarly, a sevenfold increase in the number of mast cells staining for TNF-alpha in the asthmatic biopsies suggests that this cytokine is also up-regulated in this disease. These findings clearly identify human mast cells as a source of IL-4, IL-5, IL-6, and TNF-alpha and add to the view that, along with T cells, mast cells may play an important role in initiating and maintaining the inflammatory response in asthma.
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PMID:Interleukin-4, -5, and -6 and tumor necrosis factor-alpha in normal and asthmatic airways: evidence for the human mast cell as a source of these cytokines. 817 9


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