Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelin-1 (ET-1) is a potent vasoconstrictor postulated to play a role in hypertension, ischemia-reperfusion, and atherosclerosis. In addition to these contributions, it has been also proposed to induce leukocyte-endothelial cell interactions. The aim of the present study was to assess the mechanisms of action of ET-1 on leukocyte recruitment in vivo. Intravital microscopy of the rat mesenteric postcapillary venules was used. Ten minutes after 1 nM ET-1 superfusion, a significant increase in leukocyte rolling (77.5 +/- 22.6 vs. 20.5 +/- 4.5 cells/min) and adhesion (15.5 +/- 2.9 vs. 3.0 +/- 0.8 cells/100 micrometer) but not emigration was observed. These effects were found not to be mediated by mast cell activation. No platelet-endothelial cell interactions were detected in this in vivo system and furthermore, flow cytometry analysis revealed no increase of P-selectin expression in rat platelets on ET-1 stimulation. Pretreatment of animals with an anti-rat P-selectin monoclonal antibody (mAb) dramatically reduced leukocyte rolling and adhesion by 100 and 94% respectively when compared with control mAb-treated animals. At this dose of ET-1, a very transient decrease in shear rate was detected, arteriolar diameter was significantly reduced but venular diameter remained unchanged. A similar mechanical reduction in blood flow did not induce leukocyte recruitment. Thus this study demonstrates that ET-1 can directly cause significant leukocyte rolling and adhesion adding to its potential pathophysiological role in the development of disease states of the cardiovascular system.
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PMID:Endothelin-1 causes P-selectin-dependent leukocyte rolling and adhesion within rat mesenteric microvessels. 1056 36

Although the etiology of urticaria is mostly unclear, there are a number of recent new insights into the underlying pathomechanisms and causes. Dermal mast cell numbers and endothelial cell adhesion molecule and cytokine expression are also increased in uninvolved skin, while serum P-selectin levels are elevated, suggesting a systemic activation of the cutaneous inflammatory system in urticaria. In all adults, but not children with indolent mastocytosis, we found activating point mutations of c-kit, the mast cell growth factor receptor, in lesional cutaneous mast cells. In acute urticaria, IgE-dependent mechanisms are only rarely involved (0.9%), in contrast to generally held beliefs, whereas acute upper respiratory infections (39.3%) and drug intolerance (9.2%) are more frequent. In chronic urticaria, pseudoallergies to food (73%) and more rarely chronic inflammatory gastrointestinal diseases (11%) play a major role, with avoidance or elimination of the eliciting factors leading to long term remission. On the basis of recent findings, autoantibodies must be viewed mostly as secondary rather than causative in chronic urticaria.
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PMID:[Urticaria. New developments and perspectives]. 1087 66

Endothelial surface expression of P-selectin and subsequent leukocyte rolling in venules can be induced by mast cell-derived histamine and binding of thrombin to protease-activated receptor-1 (PAR1). We hypothesized that activation of endothelial PAR2 by mast cell tryptase or other proteases also contributes to inflammatory responses. Leukocyte rolling flux and rolling velocity were assessed by intravital microscopy of the cremaster muscles of wild-type mice following perivenular micropipette injections of a control (LSIGRL) or PAR2-activating (SLIGRL) oligopeptide. Injection of SLIGRL increased mean rolling leukocyte flux fraction from 34 +/- 11 to 71 +/- 24% (p < 0.05) and decreased mean rolling velocity from 63 +/- 29 to 32 +/- 2 micrometer/s (p < 0.05). No significant changes occurred with control peptide injection. To further evaluate the role of PAR2 in inflammatory responses, PAR2-deficient mice were generated by gene targeting and homologous recombination. Perivenular injections of SLIGRL resulted in only a small increase in rolling leukocyte flux fraction (from 21 +/- 8 to 30 +/- 2%) and no change in rolling velocity. Leukocyte rolling after surgical trauma was assessed in 9 PAR2-deficient and 12 wild-type mice. Early (0-15 min) after surgical trauma, the mean leukocyte rolling flux fraction was lower (10 +/- 3 vs 30 +/- 6%, p < 0.05) and mean rolling velocity was higher (67 +/- 46 vs 52 +/- 36 micrometer/s, p < 0.01) in PAR2-deficient compared with control mice. The defect in leukocyte rolling in PAR2-deficient mice did not persist past 30 min following surgical trauma. These results indicate that activation of PAR2 produces microvascular inflammation by rapid induction of P-selectin-mediated leukocyte rolling. In the absence of PAR2, the onset of inflammation is delayed.
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PMID:Delayed onset of inflammation in protease-activated receptor-2-deficient mice. 1108 91

Urticarial reactions are characterized by dermal capillary dilatation and edema, associated with a variably intense mixed inflammatory infiltrate consisting of neutrophils, eosinophils, T-helper lymphocytes, and activated macrophages. Mast cell numbers are moderately increased by a factor of 2.4, in contrast to mastocytosis where numbers are much higher (5-48-fold increase). In urticarial vasculitis there is in addition endothelial damage, leukocytoclasia, and fibrin and complement deposition. The emigration of leukocytes is regulated by vasoactive and chemotactic mediators released firom mast cells, inducing a sequential upregulation of endothelial adhesion molecules (P-selectin, E-selectin, ICAM-1, and VCAM-1), of beta2-integrins on leukocytes, and of cytokines on endothelial, epithelial, and infiltrating cells. In nonlesional skin, there is also an increase of mast cells and an upregulation of endothelial adhesion molecules, probably due to molecules in the circulation of which P-selectin and TNFalpha have so far been demonstrated. Whereas these data provide a molecular basis for the understanding of variations in mast cell-dependent pathology, they underline the fact that they are not diagnostic for different types of urticaria, except for urticarial vasculitis and mastocytosis.
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PMID:Adhesion molecules and cellular infiltrate: histology of urticaria. 1176

It is suggested that mast cells contribute to cell recruitment in inflammation through the upregulation of endothelial adhesion molecules. P-selectin and intercellular adhesion molecule(ICAM)-1 are two key adhesion molecules that have been associated indirectly with mast cell activity. The canine C2 mastocytoma cell line and primary cultures of canine carotid endothelial cells were used to establish a new in vitro model to help study the interaction between mast cells and endothelial cells. Carotid endothelial cells were incubated with mast cell mediators to uncover their effect on endothelial ICAM-1 and P-selectin expression. To assess the relative contributions of tumour necrosis factor (TNF)-alpha and histamine to such effect, an H1 antihistamine and a TNF-alpha blocking antibody were used. Prior to activation by mast cell mediators, P-selectin was expressed only within the cytoplasm, and ICAM-1 was constitutively expressed on the surface of the canine carotid endothelial cells. Both adhesion molecules were enhanced significantly and strongly upon mast cell activation at various time points. Unstored TNF-alpha was fully responsible for ICAM-1 upregulation. P-selectin was up-regulated by both preformed and newly synthesized mast cell mediators, but neither histamine nor TNF-alpha accounted for such an effect. Therefore,a new model is proposed in which the pro-inflammatory effect of mast cells on endothelial cells can be studied in vitro. In this model, it has been demonstrated that only TNF-alpha accounts for the overexpression of ICAM-1 induced by mast cells, and that mast cells up-regulate P-selectin expression through a histamine-independent mechanism.
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PMID:Mast cells induce upregulation of P-selectin and intercellular adhesion molecule 1 on carotid endothelial cells in a new in vitro model of mast cell to endothelial cell communication. 1194 Jan 18

1. Myocardial injury caused by ischaemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, mast cell activation, and peroxidation of cell membrane lipids. These events are followed by myocardial cell alterations resulting eventually in cell necrosis. An enhanced formation of reactive oxygen species is widely accepted as a stimulus for tissue destruction and cardiac failure. 2. In this study, we have investigated the cardioprotective effects of M40403 in myocardial ischaemia-reperfusion injury. M40403 is a low molecular weight, synthetic manganese containing superoxide dismutase mimetic (SODm) that selectively removes superoxide anion. Ischaemia was induced in rat hearts in vivo by ligating the left anterior descending coronary artery. Thirty minutes after the induction of ischaemia, the ligature was removed and reperfusion allowed to occur for at least 60 min. M40403 (0.1-1 mg kg(-1)) was given intravenously 15 min before ischaemia. 3. The results obtained in this study showed that M40403 significantly reduced the extent of myocardial damage, mast cell degranulation and the incidence of ventricular arrhythmias. Furthermore, M40403 significantly attenuated, in a dose-dependent manner, neutrophil infiltration in the myocardium as well as the associated induction of lipid peroxidation. Calcium overload seen post-reperfusion of the ischaemic myocardium was also reduced by M40403. 4. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in cardiac tissue taken after reperfusion: this was attenuated by M40403. Moreover reperfused cardiac tissue sections showed positive staining for P-selectin and for anti-intercellular adhesion molecule (ICAM-1) in the vascular endothelial cells. M40403 treatment markedly reduced the intensity and degree of P-selectin and ICAM-1 in these tissues. No staining for nitrotyrosine, P-selectin or ICAM-1 was found in cardiac tissue taken at the end of the ischaemic period. 5. Overall, M40403 treatment reduced the morphological signs of myocardial cell injury and significantly improved survival. 6. Taken together, these results clearly indicate that M40403 treatment exerts a protective effect against ischaemia-reperfusion-induced myocardial injury, supporting a key role for superoxide anion in reperfusion injuries. This suggests that synthetic enzymes of SOD such as M40403, offer a novel therapeutic approach for the treatment of ischaemic heart disease where superoxide anion plays a dominant role.
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PMID:Protective effects of M40403, a selective superoxide dismutase mimetic, in myocardial ischaemia and reperfusion injury in vivo. 1211 Jun 15

Epidemiological studies suggestthat asthmatics are more affected by ozone than healthy people. This study tested three hypotheses (1) that short-term exposure to ozone induces inflammatory cell increases and up-regulation of vascular adhesion molecules in airway lavages and bronchial tissue 6 h after ozone exposure in healthy subjects; (2) these responses are exaggerated in subjects with mild allergic asthma; (3) ozone exacerbates pre-existent allergic airways inflammation. We exposed 15 mild asthmatic and 15 healthy subjects to 0.2 ppm of ozone or filtered air for 2 h on two separate occasions. Airway lavages and bronchial biopsies were obtained 6 h post-challenge. We found that ozone induced similar increases in bronchial wash neutrophils in both groups, although the neutrophil increase in the asthmatic group was on top of an elevated baseline. In healthy subjects, ozone exposure increased the expression of the vascular endothelial adhesion molecules P-selectin and ICAM- 1, as well as increasing tissue neutrophil and mast cell numbers. The asthmatics showed allergic airways inflammation at baseline but ozone did not aggravate this at the investigated time point. At 6 h post-ozone-exposure, we found no evidence that mild asthmatics were more responsive than healthy to ozone in terms of exaggerated neutrophil recruitment or exacerbation of pre-existing allergic inflammation. Further work is needed to assess the possibility of a difference in time kinetics between healthy and asthmatic subjects in their response to ozone.
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PMID:Effect of ozone on bronchial mucosal inflammation in asthmatic and healthy subjects. 1211 86

Intravital microscopic techniques were used to examine the mechanisms underlying bradykinin-induced leukocyte/endothelial cell adhesive interactions (LECA) and venular protein leakage (VPL) in single postcapillary venules of the rat mesentery. The effects of bradykinin superfusion to increase LECA and VPL were prevented by coincident topical application of either a bradykinin-B(2) receptor antagonist, a cell-permeant superoxide dismutase (SOD) mimetic or antioxidant, or inhibitors of cytochrome P-450 epoxygenase (CYPE) or protein kinase C (PKC) but not by concomitant treatment with either SOD, a mast cell stabilizer, or inhibitors of nitric oxide synthase, cyclooxygenase, xanthine oxidase, NADPH oxidase, or platelet-activating factor. Immunoneutralizing P-selectin or intercellular adhesion molecule-1 (ICAM-1) completely prevented bradykinin-induced leukocyte adhesion and emigration but did not affect VPL. On the other hand, stabilization of F-actin with phalloidin prevented bradykinin-induced leukocyte emigration and VPL but did not alter leukocyte adhesion. These data indicate that bradykinin induces LECA in rat mesenteric venules via a B(2)-receptor-initiated, CYPE-, oxidant- and PKC-mediated, P-selectin- and ICAM-1-dependent mechanism. Bradykinin also produced VPL, an effect that was initiated by stimulation of B(2) receptors and involved CYPE and PKC activation, oxidant generation, and cytoskeletal reorganization but was independent of leukocyte adherence and emigration.
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PMID:Bradykinin-induced proinflammatory signaling mechanisms. 1238 46

1. Based on in vitro chemotaxis experiments, it is widely held that CC chemokines, such as macrophage inflammatory protein-1alpha (MIP-1alpha) and macrophage chemotactic protein-1 (MCP-1) mainly support lymphocyte trafficking. 2. The objective of the present study was to examine the role of MIP-1alpha and MCP-1 in neutrophil recruitment in vivo by use of intravital microscopy of the mouse cremaster microcirculation. 3. MIP-1alpha and MCP-1 caused a dose-dependent increase in leukocyte rolling, adhesion and recruitment. Indeed, neutrophils comprised more than 85% of the leukocyte response to MIP-1alpha and MCP-1. An anti-P-selectin antibody reduced MIP-1alpha and MCP-1-provoked leukocyte rolling by more than 94%. Concomitantly, firm adhesion and extravasation of neutrophils in response to MIP-1alpha and MCP-1 challenge were significantly decreased by more than 78 and 84%, respectively. In contrast, an anti-E-selectin antibody had no influence on CC chemokine-induced neutrophil recruitment. 4. Flow cytometric analysis revealed that MIP-1alpha and MCP-1 had no effect on P-selectin expression on endothelial cells, suggesting that neutrophil recruitment elicited by CC chemokines in vivo is not mediated via a direct effect on the endothelium but rather via an indirect effect involving activation of an intermediary tissue cell. Indeed, it was found that MIP-1alpha-induced neutrophil accumulation was significantly decreased by 58% in mast cell-deficient mice. 5. These findings demonstrate that CC chemokines trigger P-selectin-dependent rolling and tissue recruitment of neutrophils via tissue mast cells in vivo and suggest that CC chemokines may also be important targets in neutrophil-mediated tissue damage in multicellular organs.
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PMID:CC chemokines induce P-selectin-dependent neutrophil rolling and recruitment in vivo: intermediary role of mast cells. 1259 24

Immune complex-induced tissue injury is mediated by inflammatory cell infiltration that is highly regulated by multiple adhesion molecules. To assess the relative contribution of adhesion molecules, including selectins and ICAM-1, in this pathogenetic process, the cutaneous passive Arthus reaction was examined in mice lacking E-selectin, P-selectin, or both L-selectin and ICAM-1 with anti-P- or E-selectin mAbs. Edema and hemorrhage were significantly reduced in P-selectin(-/-) mice compared with wild-type mice while they were not inhibited in E-selectin(-/-) mice. Combined E- and P-selectin blockade resulted in more significant reduction relative to L-selectin/ICAM-1(-/-) as well as P-selectin(-/-) mice. Remarkably, both E- and P-selectin blockade in L-selectin/ICAM-1(-/-) mice completely abrogated edema and hemorrhage. The inhibited edema and hemorrhage paralleled reduced infiltration of neutrophils and mast cells that expressed significant levels of P-selectin glycoprotein ligand-1. Similarly reduced infiltration of neutrophils and mast cells was observed in the peritoneal Arthus reaction and was associated partly with the decreased production of tumor necrosis factor-alpha and interleukin-6. The results of this study indicate that both endothelial selectins contribute predominantly to the Arthus reaction by regulating mast cell and neutrophil infiltration and that the full development of the Arthus reaction is mediated cooperatively by all selectins and ICAM-1.
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PMID:Relative contributions of selectins and intercellular adhesion molecule-1 to tissue injury induced by immune complex deposition. 1270 29


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