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)

We report here the first demonstration of dengue virus infection and vasoactive cytokine response of a cell of the mast cell/basophil lineage. Infection of KU812 cells was dependent on dengue-specific antibody and gave rise to infectious virions. This antibody-enhanced dengue virus infection triggered a four- to fivefold increase in the release of interleukin-1beta (IL-1beta) and a modest increase for IL-6 but not for an alternate cytokine, granulocyte-macrophage colony-stimulating factor. The results suggest a potential role for mast cells/basophils in the pathogenesis of dengue virus-induced disease.
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PMID:Release of vasoactive cytokines by antibody-enhanced dengue virus infection of a human mast cell/basophil line. 1088 55

In the present study we show the capacity of an extract of the fern Polypodium leucotomos (PLE) to partially inhibit the production of cytokines showing a Th1 pattern (IL-2, IFN-gamma and TNF-alpha) in human PHA-stimulated peripheral blood mononuclear cells. The percentage of inhibition was 24% for IL-2, 72% for INF-gamma and 53% for TNF-alpha. With regard to Th2 cytokines, the addition of PLE resulted in a significant increase (33%) in IL-10 production. Surprisingly, the production of the inflammatory cytokine IL-6 was completely abolished (100% inhibition) by PLE at all doses tested. In a second experiment in vivo we show that, the topical application of PLE to the skin of hairless albino mice (Skh-1) significantly diminished the mast cell infiltrate as well as the number of blood vessels triggered by chronic ultraviolet B (UVB) irradiation. These data show that PLE moderately inhibits the immunological Th1 responses, thus explaining the immunosuppressive as well as the anti-inflammatory and antioxidant activities reported in other studies carried out with PLE. The clear inhibitory effect on TFN-alpha and IL-6 production strongly suggest that this may be the mechanism by which PLE: (a) inhibits angiogenesis in vivo in the mouse model described here, and (b) prevents Langerhans' cells depletion caused by solar irradiation in humans. Taken together, these data suggest that PLE works through the induction of suppressive/anti-inflammatory cytokines such as IL-10 and/or TGF-beta which in turn appear to allow the partial deactivation of macrophages or other accessory cells. These features suggest that PLE could be useful in the treatment of autoaggressive/inflammatory conditions due to an exacerbation of Th1 responses.
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PMID:An extract of the fern Polypodium leucotomos (Difur) modulates Th1/Th2 cytokines balance in vitro and appears to exhibit anti-angiogenic activities in vivo: pathogenic relationships and therapeutic implications. 1092 72

Reactive oxygen species (ROS) are known to modulate activities of a host of kinases, phosphatases and transcription factors. Rutin and chlorogenic acid (CGA) are the major polyphenolic antioxidants present in the small molecular fraction of smokeless tobacco leaf extracts, as ascertained by reverse-phase high-pressure liquid chromatography (HPLC) and mass spectrometry. Levels of intracellular ROS in resting versus antigen-immunoglobulin E (IgE)-challenged murine mast cells were measured at 510 nm by fluorescence-activated cell sorting (FACS) using carboxy-dichlorofluorescein (DCFH-DA). Enhanced ROS production was observed in IgE-sensitized mast cells following antigenic challenge. Rutin and CGA reduced ROS levels in antigen-IgE-activated mast cells. Concomitantly, they also profoundly inhibited histamine release by these activated mast cells. In contrast, rutin and CGA augmented the inducible cytokine messages, i.e. interleukin (IL)-10, IL-13, interferon-gamma (IFN-gamma), IL-6 and tumour necrosis factor-alpha (TNF-alpha) in IgE-sensitized mast cells following antigen challenge. This study indicates that tobacco polyphenolic antioxidants that quench intracellular ROS, differentially affect two effector functions of antigen-IgE-activated mast cells. This model system may be employed to determine the molecular target of polyphenols. The potential role of these polyphenolic antioxidants on IgE-mediated allergy in vivo depends on a balance of their differential effects on mast cell activation.
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PMID:Naturally occurring polyphenolic antioxidants modulate IgE-mediated mast cell activation. 1092 74

In the present study, we have investigated the pro-opiomelanocortin (POMC)-derived neuropeptide alpha-MSH for its ability to modulate activation of human mast cells. The in vitro ability of purified human skin mast cells to secrete various types of mast cell mediators was monitored in response to alpha-MSH at the mRNA and at the protein level. Picomolar concentrations of alpha-MSH induced a dose-dependent release of histamine from isolated human skin mast cells and from skin punch biopsies. However, no effect of alpha-MSH was seen regarding the expression of IL-1, IL-6, IL-8, TGF-beta, and TNF-alpha. Melanocortin receptor MC-1 was identified at the transcriptional level by RT-PCR analysis but not at the protein level, whereas, in leukemic human mast cells (HMC-1), the mRNAs and the proteins for the MC-1 and MC-5 receptor were identified. These results suggest that alpha-MSH may selectively induce acute inflammatory effects via secretion of histamine.
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PMID:alpha-Melanocyte stimulating hormone acts as a selective inducer of secretory functions in human mast cells. 1107 48

PGE(2) is an endogenously synthesized inflammatory mediator that is over-produced in chronic inflammatory disorders such as allergic asthma. In this study, we investigated the regulatory effects of PGE(2) on mast cell degranulation and the production of cytokines relevant to allergic disease. Murine bone marrow-derived mast cells (BMMC) were treated with PGE(2) alone or in the context of IgE-mediated activation. PGE(2) treatment alone specifically enhanced IL-6 production, and neither induced nor inhibited degranulation and the release of other mast cell cytokines, including IL-4, IL-10, IFN-gamma, and GM-CSF. IgE/Ag-mediated activation of BMMC induced the secretion of IL-4, IL-6, and GM-CSF, and concurrent PGE(2) stimulation synergistically increased mast cell degranulation and IL-6 and GM-CSF, but not IL-4, production. A similar potentiation of degranulation and IL-6 production by PGE(2), in the context of IgE-directed activation, was observed in the well-established IL-3-dependent murine mast cell line, MC/9. RT-PCR analysis of unstimulated MC/9 cells revealed the expression of EP(1), EP(3), and EP(4) PGE receptor subtypes, including a novel splice variant of the EP(1) receptor. Pharmacological studies using PGE receptor subtype-selective analogs showed that the potentiation of IgE/Ag-induced degranulation and IL-6 production by PGE(2) is mediated through EP(1) and/or EP(3) receptors. Our results suggest that PGE(2) may profoundly alter the nature of the mast cell degranulation and cytokine responses at sites of allergic inflammation through an EP(1)/EP(3)-dependent mechanism.
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PMID:Prostaglandin E2 selectively enhances the IgE-mediated production of IL-6 and granulocyte-macrophage colony-stimulating factor by mast cells through an EP1/EP3-dependent mechanism. 1108 97

Mast cells become activated in multiple diseases wherein thrombin generation is often clinically apparent, but the effect of thrombin on cytokine release by mast cells remains unexplored. Thus, we examined IL-6 and TNFalpha release by thrombin-challenged mast cells. Thrombin and the protease-activated receptor (PAR)-1 peptide TRAP(14) induced these cells to secrete IL-6 in a dose-dependent fashion. Mast cells secreted > or =2800 pg IL-6/10(6) cells over 24 h, but only low levels of serotonin and no significant TNFalpha. Furthermore, at near-background levels of allergen, threshold doses of alpha-thrombin synergistically enhanced the IL-6 response (by up to 100-fold), but high-dose costimulation led to a simple additive response. Both the PI(3)- and sphingosine-kinase signaling pathways contributed importantly to the thrombin response. Our data thus clearly demonstrate that low-level thrombin and FcepsilonRI signaling can synergize to augment mast cell IL-6 responses, and that thrombin also differentially induces cytokine secretion by mast cells.
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PMID:Thrombin induces IL-6 but not TNFalpha secretion by mouse mast cells: threshold-level thrombin receptor and very low level FcepsilonRI signaling synergistically enhance IL-6 secretion. 1110 85

Zymosan-induced peritonitis was investigated in mast cell-deficient WBB6F1 mice and in Balb/c mice pretreated with mast cell stabilizer (cromolyn) or antagonists of histamine receptors (mepyramine, triprolidine, cimetidine, or ranitidine). The inherited mast cell deficiency in W/Wv knockouts of WBB6F1 mice impaired significantly the level of histamine and plasma exudation (measured 30 min after stimulation) as well as the influx of exudatory leukocytes, accumulation of plasma and exudate chemoattractants, and the release of proinflammatory cytokines (TNF-alpha, IL-1beta, and IL-6) measured at 6 h of inflammation. All of those factors were fully restored after selective intraperitoneal reconstitution of W/Wv mice with bone marrow-derived mast cells from their control +/+ counterparts. Cromolyn pretreatment of Balb/c mice reduced exclusively the early plasma exudation and histamine influx. Blocking of histamine receptors inhibited not only the early plasma exudation but also temporarily diminished primary leukocyte influx and levels of MCP-1 and IL-1beta. In conclusion, mast cells play an important role in the initiation of zymosan-induced peritonitis and modulate its further course.
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PMID:Role of mast cells in zymosan-induced peritoneal inflammation in Balb/c and mast cell-deficient WBB6F1 mice. 1120 65

Interleukin-9 (IL-9) is a Th2 cytokine whose overexpression is associated with asthma and T cell lymphomagenesis. All the IL-9 activities studied so far are mediated by a specific hemopoietin receptor that activates a Jak/STAT pathway. Searching for genes specifically modulated by IL-9, we observed that the 24P3 mRNA is strongly upregulated in BW5147 T lymphoma cells upon IL-9 stimulation. 24P3 is a member of the lipocalin family, and has been reported to bind N-formyl-Met-Leu-Phe, a potent neutrophil chemoattractant, and possibly other lipophilic mediators of inflammation. A similar 24P3 induction was observed in other T cell lymphomas (EL4 and TH201) in response to IL-9, as well as in EL4 cells stimulated with IL-6 or IL-1. By contrast, other IL-9-responsive cells such as mast cell line MC9 and B cell lymphoma A20 showed no 24P3 induction upon IL-9 stimulation. Experiments using IL-9R mutants indicated that STAT transcription factors, particularly STAT3, are involved in this process. However, 24P3 gene induction was slow, reaching a plateau from 36 to 72 hours after stimulation and was inhibited if cells were treated with cycloheximide during the first 8 hours of IL-9 stimulation, suggesting an indirect induction requiring new protein synthesis.
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PMID:Interleukin-9 induces 24P3 lipocalin gene expression in murine T cell lymphomas. 1128 60

Mature human mast cells are tissue-residing, key effector cells of immediate allergic reactions. Moreover, mast cells have been recognized as a potent cellular source of multiple cytokines, suggesting an important role in immunoregulation and host defense. Here, we report on the regulation of mature human mast cells isolated from intestinal tissues by stem cell factor (SCF) and interleukin (IL)-4. SCF is substantially necessary for mast cell survival and induces marginal mast cell proliferation in vitro, whereas IL-4 by itself has no effects on mast cell survival or proliferation. Most interestingly, in synergy with SCF, IL-4 strongly enhances mast cell proliferation. In the presence of SCF, mast cells predominantly produce pro-inflammatory cytokines including tumor necrosis factor (TNF)-alpha, IL-1beta, IL-6, IL-8, IL-16, and IL-18. Addition of IL-4 to the culture medium induces the expression of Th2-type cytokines (IL-3, IL-5 and IL-13), and a downregulation of pro-inflammatory cytokines, namely IL-6. Furthermore, SCF by itself supports the predominance of the tryptase/chymase double-positive mast cell subtype MCTC whereas the addition of IL-4 supports the chymase negative MCT subtype. In conclusion, SCF may primarily regulate resident mast cell survival, whereas IL-4 may promote local proliferation of mast cells and their expression of Th2-type cytokines.
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PMID:Regulation of human intestinal mast cells by stem cell factor and IL-4. 1129 28

To further characterize the development of mast cells from human hemopoietic pluripotent cells we have investigated the expression of telomerase activity in cultured human peripheral blood CD34+ cells, and CD34+ /CD117+ /CD13+ progenitor mast cells selected therefrom, with the idea that induction of telomerase is associated with clonal expansion of CD34+ /CD117+ /CD13+ cells. A rapid increase in telomerase activity preceded proliferation of both populations of cells in the presence of stem cell factor and either IL-3 or IL-6. The induction was transient, and telomerase activity declined to basal levels well before the appearance of mature mast cells. Studies with pharmacologic inhibitors suggested that this induction was initially dependent on the p38 mitogen-activated protein kinase and phosphatidylinositol 3'-kinase, but once cell replication was underway telomerase activity, but not cell replication, became resistant to the effects of inhibitors. Tumor mast cell lines, in contrast, expressed persistently high telomerase activity throughout the cell cycle, and this expression was unaffected by inhibitors of all known signaling pathways in mast cells even when cell proliferation was blocked for extended periods. These results suggest that the transient induction of telomerase activity in human progenitor mast cells was initially dependent on growth factor-mediated signals, whereas maintenance of high activity in tumor mast cell lines was not dependent on intracellular signals or cell replication.
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PMID:Induction of telomerase activity during development of human mast cells from peripheral blood CD34+ cells: comparisons with tumor mast-cell lines. 1135 19


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