Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10145 (IL-8)
23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recombinant mouse mast cell protease 6 (mMCP-6) was generated to study the role of this tryptase in inflammatory reactions. Seven to forty-eight hours after the i.p. injection of recombinant mMCP-6 into BALB/c, mast cell-deficient WCB6F1-Sl/Sl(d), C5-deficient, or mMCP-5-null mice, the number of neutrophils in the peritoneal cavity of each animal increased significantly by >50-fold. The failure of the closely related recombinant tryptase mMCP-7 to induce a comparable peritonitis indicates that the substrate specificities of the two tryptases are very different. Unlike most forms of acute inflammation, the mMCP-6-mediated peritonitis was relatively long lasting and neutrophil specific. Mouse MCP-6 did not induce neutrophil chemotaxis directly in an in vitro assay, but did promote chemotaxis of the leukocyte in the presence of endothelial cells. Mouse MCP-6 did not induce cultured human endothelial cells to express TNF-alpha, RANTES, IL-1alpha, or IL-6. However, the tryptase induced endothelial cells to express large amounts of IL-8 continually over a 40-h period. Neither enzymatically active mMCP-7 nor enzymatically inactive pro-mMCP-6 was able to induce endothelial cells to increase their expression of IL-8. Although the mechanism by which mMCP-6 induces neutrophil accumulation in tissues remains to be determined, the finding that mMCP-6 induces cultured human endothelial cells to selectively release large amounts of IL-8 raises the possibility that this tryptase regulates the steady state levels of neutrophil-specific chemokines in vivo during mast cell-mediated inflammatory events.
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PMID:Induction of a selective and persistent extravasation of neutrophils into the peritoneal cavity by tryptase mouse mast cell protease 6. 946 53

CD43 has been shown to be involved in the regulation of cellular adhesion and activation of leukocytes, but its functional significance for mast cell biology has been poorly defined. We demonstrate here that mAb engagement of surface CD43 on human leukemic (HMC-1) mast cells initiates a signaling cascade which involves protein kinase C, while tyrosine kinases appear to play a minor role, as evidenced by effects of different kinase inhibitors on homotypic aggregation induced via CD43. Furthermore, administration of an activating anti-CD43 mAb is shown to induce and promote TNF-alpha- and to enhance IL-8-secretion from HMC-1 cells, but it does not initiate histamine, tryptase, or LTC4 release, suggesting that the intracellular pathways leading to aggregation and release of certain mast cell mediators are differentially regulated. Additionally, engagement of CD43 on HMC-1 cells leads to down-regulation of CD43 surface expression, implying that CD43 may be potentially involved in its own regulation.
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PMID:Signal transduction via CD43 (leukosialin, sialophorin) and associated biological effects in human mast cell line (HMC-1). 947 99

Short-term exposure to ozone at peak ambient levels induces neutrophil influx and impairs lung function in healthy humans. In order to investigate the mechanisms contributing to neutrophil recruitment and to examine the role of T-cells in the acute inflammatory response, we exposed 12 healthy humans to 0.2 parts per million (ppm) of ozone and filtered air on two separate occasions for 2 h with intermittent periods of rest and exercise (minute ventilation = 30 L x min(-1)). Fibreoptic bronchoscopy was performed 6 h after the end of exposures. Total protein, tryptase, histamine, myeloperoxidase, interleukin (IL)-8 and growth-related oncogene-alpha (Gro-alpha) were measured and total and differential cell counts were performed in bronchoalveolar lavage (BAL) fluid. Flow cytometry was performed on BAL cells to study total T-cells, T-cell receptors (alphabeta and gammadelta), T-cell subsets (CD4+ and CD8+ cells) and activated T-cell subsets (CD25+). Using immunohistochemistry, neutrophils, mast cells, total T-cell numbers, T-cell subsets, CD25+ T-cells and leukocyte endothelial adhesion molecules including P-selectin, E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 were quantified in the bronchial biopsies. Paired samples were available from nine subjects. Following ozone exposure there was a threefold increase in the proportion of polymorphonuclear neutrophils (PMNs) (p=0.07) and epithelial cells (p=0.05) in BAL fluid. This was accompanied by increased concentrations of IL-8 (p=0.01), Gro-alpha (p=0.05) and total protein (p=0.058). A significant positive correlation was demonstrated between the two chemokines and proportion of PMNs in BAL fluid. After ozone exposure there was a significant decrease in the CD4/CD8 ratio (p=0.05) and the proportion of activated CD4+ (p=0.01) and CD8+ T-cells (p=0.04). However, no significant changes were demonstrable in any of the inflammatory markers studied in the biopsies. Short-term exposure of healthy humans to 0.2 ppm ozone induced a neutrophil influx in peripheral airways at 6 h post exposure, but no apparent inflammatory response in proximal airways. This response seems to be mediated at least in part by interleukin-8 and growth-related oncogene-alpha.
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PMID:Effects of 0.2 ppm ozone on biomarkers of inflammation in bronchoalveolar lavage fluid and bronchial mucosa of healthy subjects. 965 69

Mast cells are found frequently in close proximity to blood vessels, and endothelial cells are likely to be exposed to high concentrations of their granule mediators. We have investigated the proinflammatory actions of the major mast cell product tryptase on HUVEC. Addition of purified tryptase was found to stimulate thymidine incorporation, but induced little alteration in cell numbers, suggesting it is not a growth factor for HUVEC. Expression of ICAM-1, VCAM-1, and E-selectin was not altered following incubation with tryptase, but the potent granulocyte chemoattractant IL-8 was released in a dose-dependent fashion in response to physiologically relevant concentrations, with maximal levels in supernatants after 24 h. The actions of tryptase on HUVEC were inhibited by heat inactivation of the enzyme, or by preincubating with the protease inhibitors leupeptin or benzamidine, suggesting a requirement for an intact catalytic site. Reverse-transcription PCR analysis indicated up-regulation of mRNA for IL-8 as well as for IL-1 beta in response to tryptase or TNF-alpha. However, tryptase was a more selective stimulus than TNF-alpha and did not induce increased expression of mRNA for granulocyte-macrophage CSF or stimulate the release of this cytokine. Leukocyte accumulation in response to tryptase may be mediated in part through the selective secretion of IL-8 from endothelial cells.
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PMID:The role of mast cell tryptase in regulating endothelial cell proliferation, cytokine release, and adhesion molecule expression: tryptase induces expression of mRNA for IL-1 beta and IL-8 and stimulates the selective release of IL-8 from human umbilical vein endothelial cells. 971 64

Mast cells are traditionally viewed as effector cells of immediate type hypersensitivity reactions. There is, however, a growing body of evidence that the cells might play an important role in the maintenance of tissue homeostasis and repair. We here present our own data and those from the literature elucidating the possible role of mast cells during wound healing. Studies on the fate of mast cells in scars of varying ages suggest that these cells degranulate during wounding, with a marked decrease of chymase-positive cells, although the total number of cells does not decrease, based on SCF-receptor staining. Mast cells contain a plethora of preformed mediators like heparin, histamine, tryptase, chymase, VEGF and TNF-alpha which, on release during the initial stages of wound healing, affect bleeding and subsequent coagulation and acute inflammation. Various additional vasoactive and chemotactic, rapidly generated mediators (C3a, C5a, LTB4, LTC4, PAF) will contribute to these processes, whereas mast cell-derived proinflammatory and growth promoting peptide mediators (VEGF, FGF-2, PDGF, TGF-beta, NGF, IL-4, IL-8) contribute to neoangiogenesis, fibrinogenesis or re-epithelization during the repair process. The increasing number of tryptase-positive mast cells in older scars suggest that these cells continue to be exposed to specific chemotactic, growth- and differentiation-promoting factors throughout the process of tissue remodelling. All these data indicate that mast cells contribute in a major way to wound healing. their role as potential initiators of or as contributors to this process, compared to other cell types, will however have to be further elucidated.
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PMID:Mast cells and their mediators in cutaneous wound healing--active participants or innocent bystanders? 1020 16

The effects of the mucolytic agent, dithioerythritol (DTE), and the temperature at which sputum processing is conducted on cellular and biochemical markers in induced sputum was assessed. Samples from healthy and atopic asthmatic subjects were treated with either DTE or phosphate-buffered saline (PBS) at 22 or 37 degrees C and compared for cell counts and concentrations of histamine, tryptase, eosinophil cationic protein (ECP), free interleukin (IL)-8, immunoglobulin (Ig)A, IL-8/IgA complexes and secretory component (SC). In addition, the influence of DTE on in vitro mediator release from blood eosinophils, basophils and bronchoalveolar lavage (BAL) mast cells was studied. Processing with DTE improved cytospin quality and increased the cell yield and measurable ECP, tryptase, IgA and SC, but reduced levels of histamine in PBS-treated samples and had no effect on IL-8. Cell counts or mediator levels were similar when sputum was processed at 22 or 37 degrees C, even though DTE induced blood basophils and BAL mast cells to release histamine at 37 degrees C. In spiking experiments, recovery of added ECP, tryptase, total IL-8 and histamine from sputum was similar in DTE- and PBS-processed sputum, but reduced for free IL-8 in PBS-treated samples. In conclusion, dithioerythritol improves cell and mediator recovery without causing cell activation when sputum processing is conducted at room temperature. The extent of recovery depends on the mediator studied.
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PMID:The effect of processing on inflammatory markers in induced sputum. 1023 43

Two important realizations about pathophysiological mechanisms involved in allergic conjunctivitis have led to novel drug discovery efforts and new topical ocular medications for prevention and treatment of this prevent allergic disease. The first of these, interspecies and intraspecies mast cell heterogeneity, was established in the mid-1980's by investigators working in the field of asthma. It is now appreciated that secretory responses as well as effects of pharmacological agents differ depending upon the mast cell population studied. Two types of human mast cells, the tryptase containing (T) and the tryptase/chymase containing (TC) mast cells, have been characterized in a variety of tissues. Significantly, Irani et al. (1) demonstrated by immunohistochemical staining that the mast cells present in conjunctival tissues from patients with allergic conjunctivitis were 100% TC. Functional responses of human conjunctival mast cells to a variety of secretagogues (2) were consistent with their classification as TC or connective tissue type mast cells. Importantly, the studies by Miller et al. mentioned above allowed the harvesting and preparation of human conjunctival mast cells for use in drug screening studies. Utilization of these cells has led to the identification of Patanol, the most effective human conjunctival mast cell stabilizer available for topical use in allergic conjunctivitis (3). These same studies demonstrated the lack of mast cell stabilizing activity for cromolyn and nedocromil in these connective tissue type, TC containing, human conjunctival mast cells. Similar lack of effect was noted with these drugs on human skin mast cell degranulation (4). The second important discovery in the area of allergic conjunctivitis has been the demonstration that conjunctival epithelial cells may contribute to the perpetuation of the allergic response. A report from Gamache et al. (5) identified cytokines produced by human conjunctival epithelial cells following treatment with a number of stimuli. Significantly, Sharif et al. (6) subsequently identified functional histamine H1 receptors on these same cell types. Recently, Weimer et al. (7) have shown that exposure of human conjunctival epithelial cells to histamine leads to the production of pro-inflammatory cytokines IL-6 and IL-8. Importantly, treatment of the epithelial cells with drugs that possess histamine H1 antagonist properties prevents cytokine production. It is noteworthy that first generation anti-histamines antazoline and pheniramine are not potent inhibitors of histamine-stimulated cytokine synthesis in intact epithelial cells, while newer anti-histamines Emadine and levocabastine are more potent. Surprisingly, Patanol was more potent as an inhibitor of histamine-stimulated cytokine production by the epithelial cells than would be predicted from its histamine H1 antagonist affinity. These inhibitory effects on conjunctival epithelial cell production of pro-inflammatory cytokines may contribute to enhanced clinical activity noted with these recently approved drugs.
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PMID:A current appreciation of sites for pharmacological intervention in allergic conjunctivitis: effects of new topical ocular drugs. 1033 30

Linear IgA bullous dermatosis (LAD) is an acquired, heterogeneous, subepidermal blistering disease characterized by linear IgA deposits at the dermoepidermal basement membrane zone (BMZ), often with circulating IgA antibodies to the BMZ. The pathogenetic mechanism, possibly related to the immunophenotype of infiltrating cells, as well as the potential role of cytokines in determining bullous lesions, have not yet been elucidated. An immunohistochemical study was performed with a large panel of monoclonal antibodies [to CD3, CD4, CD8, CD25, CD1a, CD30, CD54, CD50, endothelial leucocyte adhesion molecule-1, vascular cell adhesion molecule-1, myeloperoxidase (MPO), eosinophil cationic protein EG1 and EG2, tryptase, HLA-DR, human interleukin (IL)-3, human IL-5, human IL-8, human IL-4, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma and granulocyte/macrophage colony-stimulating factor] using the alkaline phosphatase-antialkaline phosphatase procedure on lesional and perilesional skin of nine patients (one male, eight female; age range 8 months-80 years) with clinical, histological and immunofluorescent proven LAD. The predominant infiltrating cells, distributed mostly inside and below the bullae, were neutrophils and eosinophils which showed intense activation (MPO +, EG1 +, EG2 +). The lymphocytic infiltrate, consisting principally of CD4 +, HLA-DR + and CD30 + T cells, had a predominantly perivascular distribution. Proinflammatory cytokines, such as TNF-alpha and IFN-gamma, showed a moderate focal expression on the dermal perivascular sites; IL-8 was found to have a particularly intense staining on all the epidermal cell layers and at perivascular and vascular sites. Other cytokines, such as IL-4 and IL-5, showed a prevalent intracytoplasmic staining on some cells of the dermal infiltrate (probably mastocytes and lymphocytes), and at the dermal-epidermal separation sites there was also an intense scattered distribution of IL-5. The specific tissue lesions of LAD may be the consequence of the IgA deposits at the BMZ and also of the release of these cytokines together with tissue damage enzymes derived from neutrophils or eosinophils.
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PMID:The role of lymphocytes, granulocytes, mast cells and their related cytokines in lesional skin of linear IgA bullous dermatosis. 1035 73

Tryptase and myeloperoxidase respectively represent 2 specific markers of activated mast cells or neutrophils. Therefore, establishing the levels of these enzymes may be useful to quantify the cell involvement in the tissues or fluids of different origins and in different pathologies. The aim of this study was to analyse the levels of these 2 markers in both the sera and blister fluids of patients affected with bullous pemphigoid. These levels were then correlated to the concentrations of 19 cytokines and 2 soluble adhesion molecules determined in the same samples and also with the log (anti-basement membrane zone antibody) titres, evaluated in the patients' sera. For these purposes, 15 patients with bullous pemphigoid (10 males and 5 females; median age: 84 years, range 66-87; median disease duration: 0 years, range 0-3: median number of skin lesions: 17, range 14-30; median anti-basement membrane zone antibody titre: 1:320, range 0.0-1:2560) and 15 normal subjects (11 males and 4 females, median age: 81 years, range 59-86) were analysed by means of commercially available kits. Results showed that blister fluid myeloperoxidase and tryptase levels were increased as compared with the respective sera (P<0.01) and several correlations were observed with cytokines and adhesion molecules. In fact, significant correlations of blister fluid tryptase levels were observed with IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, VEGF, RANTES and sICAM-1, while myeloperoxidase was correlated with IL-1beta, IL-13 and IL-15. The blister fluid tryptase levels were also significantly correlated with the anti-basement membrane zone antibody titres (R=0.53, P=0.05). In conclusion, these findings are in accord with an involvement of both mast cells and neutrophils in bullous pemphigoid and their recruitment may be mediated by different biological modulators. Our findings seem to indicate that the cytokine (IL-3, IFN-gamma and OSM) or adhesion molecule (sICAM-1) concentrations in blister fluid are logarithmically related to the anti-basement membrane zone antibody titers.
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PMID:Increased tryptase and myeloperoxidase levels in blister fluids of patients with bullous pemphigoid: correlations with cytokines, adhesion molecules and anti-basement membrane zone antibodies. 1077 87

Tryptase, the major product of human mast cell activation, is a potent stimulus of vascular leakage and neutrophil accumulation in vivo in animal studies, but the mechanisms of action remain unclear. Using HUVEC cultures we have sought to investigate the potential of tryptase to alter monolayer permeability or induce the release of neutrophil chemotactic activity. Tryptase (1-100 mU/ml) failed to alter the permeability of endothelial cell monolayers as assessed by albumin flux over 1 h. However, supernatants from endothelial cells treated with tryptase (1-50 mU/ml) for a 24-h period induced neutrophil migration across Transwell filters, with maximal migration observed at 10 mU/ml tryptase. Pretreatment of tryptase with the protease inhibitor leupeptin abolished the chemotactic activity, indicating a dependence on the catalytic site. Moreover, this effect was abolished by addition of an IL-8 neutralizing antibody, suggesting that IL-8 release makes an important contribution to the chemotactic activity. The interaction of mast cell tryptase with endothelial cells could be important in stimulating the ingress of neutrophils following mast cell activation in inflammatory disease.
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PMID:Human mast cell tryptase stimulates the release of an IL-8-dependent neutrophil chemotactic activity from human umbilical vein endothelial cells (HUVEC). 1088 36


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