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)

The endogenous nucleoside adenosine is thought to play a role in the pathophysiology of asthma by stimulating mast cells. We previously showed that the human mast cell line HMC-1 expresses A2A and A2B receptors, and that both receptors activate adenylate cyclase via Gs-protein but that only A2B receptors are also coupled to phospholipase C via Gq proteins. Stimulation of A2B but not A2A receptors induced production of interleukin-8 (IL-8) from HMC-1 cells. The mechanism by which adenosine promotes IL-8 synthesis has not been defined. In this study, we tested the hypothesis that mitogen-activated protein kinase (MAPK) signaling pathways are involved in this process. Stimulation of HMC-1 with the stable adenosine analog NECA (5'-N-ethylcarboxamidoadenosine) activated p21(ras) and both p42 and p44 isoforms of extracellular signal-regulated kinase (ERK). NECA (10 microM) induced a 1.9 +/- 0. 06-fold increase in ERK activity, whereas 10 microM of the selective A2A agonist CGS 21680 (4-((N-ethyl-5'-carbamoyladenos-2-yl)-aminoethyl)-phenylpropionic acid) had no effect. NECA, in parallel with the activation of ERK, also stimulated the p46 isoform of c-Jun N-terminal kinase (MEK) and p38 MAPK. Furthermore, the selective MAPK/ERK kinase 1 inhibitor PD 98059 (2'-amino-3'-methoxyflavone), and p38 MAPK inhibitors SB 202190 (4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole) and SB 203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H- imidaz ole) blocked A2B receptor-mediated production of IL-8. These results indicate that extracellular adenosine can regulate ERK, c-Jun N-terminal kinase, and p38 MAPK signaling cascades and that activation of ERK and p38 MAPK pathways are essential steps in adenosine A2B receptor-dependent stimulation of IL-8 production in HMC-1.
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PMID:Role of p38 mitogen-activated protein kinase and extracellular signal-regulated protein kinase kinase in adenosine A2B receptor-mediated interleukin-8 production in human mast cells. 1010 Oct 31

Stimulation of RAW 264.7 cells with the Ca(2+)-ATPase inhibitor thapsigargin increased histamine production. Immunoblot analyses revealed that thapsigargin increased the expression of 74-kDa histidine decarboxylase protein although rat mast cell line RBL-2H3 cells express both 74- and 53-kDa histidine decarboxylase proteins. The inhibition of histamine production by the mitogen-activated protein kinase-extracellular signal-regulated kinase kinase (MEK) inhibitors PD98059 (2'-amino-3'-methoxyflavone) and U0126 (1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene) and by the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole) was correlated with the inhibition of the expression of thapsigargin-induced 74-kDa histidine decarboxylase protein. The synthetic glucocorticoid dexamethasone inhibited thapsigargin-induced histamine production and 74-kDa histidine decarboxylase protein expression. The thapsigargin-induced activation of p42/p44 MAP kinase and p38 MAP kinase was also inhibited by dexamethasone. These findings indicate that the induction of histamine production by thapsigargin in RAW 264.7 cells is due to the increased expression of 74-kDa histidine decarboxylase protein and that dexamethasone inhibits thapsigargin-induced histidine decarboxylase protein expression and histamine production via inhibition of MAP kinase activation.
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PMID:Expression of 74-kDa histidine decarboxylase protein in a macrophage-like cell line RAW 264.7 and inhibition by dexamethasone. 1133 61

T1/ST2 is a member of the interleukin (IL)-1 receptor superfamily, possessing three immunoglobulin domains extracellularly and a Toll/IL1R (TIR) domain intracellularly. The ligand for T1/ST2 is not known. T1/ST2 is expressed on Type 2 T helper (Th2) cells, and its role appears to be in the regulation of Th2 cell function. Here, we have investigated T1/ST2 signal transduction, using either transient overexpression of T1/ST2 or a cross-linking monoclonal antibody to activate cells. We demonstrate that T1/ST2 does not activate the transcription factor NF-kappaB when overexpressed in murine thymoma EL4 cells, or in the mast cell line P815 treated with the anti-T1/ST2 antibody. However, a chimera comprising the extracellular domain of the type 1 IL-1 receptor and the intracellular domain of T1/ST2 activates NF-kappaB both by overexpression and in response to IL-1. This artificial activation requires the IL1RAcP recruited via the extracellular portion (IL1R1) of the chimera. T1/ST2 is, however, able to activate the transcription factor activator protein-1 (AP-1), increase phosphorylation of c-Jun, and activate the MAP kinases c-Jun N-terminal kinase (JNK), p42/p44 and p38. Anti-T1/ST2 also induces the selective expression of IL-4 but not IFN-gamma in naive T cells. Importantly, this effect is blocked by prior treatment with the JNK inhibitor SP600125 confirming that JNK as a key effector in T1/ST2 signaling. The lack of effect on NF-kappaB when T1/ST2 is homodimerized identifies T1/ST2 as the first member of the IL-1 receptor superfamily so far studied that is apparently unable to activate NF-kappaB, consistent with evidence indicating the lack of a role for NF-kappaB in Th2 cell function.
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PMID:Characterization of signaling pathways activated by the interleukin 1 (IL-1) receptor homologue T1/ST2. A role for Jun N-terminal kinase in IL-4 induction. 1236 75

Thrombin activates mast cells to release inflammatory mediators through a mechanism involving protease-activated receptor-1 (PAR-1). We hypothesized that PAR-1 activation would induce mast cell adhesion to fibronectin (FN). Fluorescent adhesion assay was performed in 96-well plates coated with FN (20 microg/ml). Murine bone marrow cultured mast cells (BMCMC) were used after 3-5 wk of culture (>98% mast cells by flow cytometry for c-Kit expression). Thrombin induced beta-hexosaminidase, IL-6, and matrix metalloproteinase-9 release from BMCMC. Thrombin and the PAR-1-activating peptide AparafluoroFRCyclohexylACitY-NH(2) (cit) induced BMCMC adhesion to FN in a dose-dependent fashion, while the PAR-1-inactive peptide FSLLRY-NH(2) had no effect. Thrombin and cit induced also BMCMC adhesion to laminin. Thrombin-mediated adhesion to FN was inhibited by anti-alpha(5) integrin Ab (51.1 +/- 6.7%; n = 5). The combination of anti-alpha(5) and anti-alpha(4) Abs induced higher inhibition (65.7 +/- 7.1%; n = 5). Unlike what is known for FcepsilonRI-mediated adhesion, PAR-1-mediated adhesion to FN did not increase mediator release. We then explored the signaling pathways involved in PAR-1-mediated mast cell adhesion. Thrombin and cit induced p44/42 and p38 phosphorylation. Pertussis toxin inhibited PAR-1-mediated BMCMC adhesion by 57.3 +/- 7.3% (n = 4), indicating that G(i) proteins are involved. Wortmannin and calphostin almost completely inhibited PAR-1-mediated mast cell adhesion, indicating that PI-3 kinase and protein kinase C are involved. Adhesion was partially inhibited by the mitogen-activated protein kinase kinase 1/2 inhibitor U0126 (24.5 +/- 3.3%; n = 3) and the p38 inhibitor SB203580 (25.1 +/- 10.4%; n = 3). The two inhibitors had additive effects. Therefore, thrombin mediates mast cell adhesion through the activation of G(i) proteins, phosphoinositol 3-kinase, protein kinase C, and mitogen-activated protein kinase pathways.
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PMID:Thrombin induces mast cell adhesion to fibronectin: evidence for involvement of protease-activated receptor-1. 1237 Mar 92

Recently we have isolated four active components from Tanshen (the root of Salvia miltiorrhiza Bunge, Labiatae) responsible for the anti-allergic activities. In this study, the molecular mechanism of action of tanshinones for the inhibition of mast cell degranulation was investigated by testing their effects on the signaling components of the high affinity IgE receptor FcepsilonRI. Activation of FcepsilonRI produced immediate tyrosine phosphorylation of Syk, mitogen-activated protein kinase extracellular signal-regulated kinase, ERK1/ERK2 (p44, p42), and phospholipase Cgamma2 (PLCgamma2). 5,16-Dihydrotanshinone-I possessed the strongest inhibitory effects on mast cell degranulation and markedly reduced FcepsilonRI-mediated tyrosine phosphorylation of ERK and PLCgamma2. This suggests that tanshinones possibly exert their anti-allergic activities by affecting FcepsilonRI-mediated tyrosine phosphorylation of ERK and PLCgamma2. Abbreviations. FcepsilonRI:high affinity IgE receptor ERK:extracellular signal regulated kinase PLC: phospholipase C
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PMID:Tanshinones inhibit mast cell degranulation by interfering with IgE receptor-mediated tyrosine phosphorylation of PLCgamma2 and MAPK. 1499 99

Activated mast cells generate multiple cytokines but it is not known if these can be differentially regulated by pharmacological agents. We report here that the glucocorticoid dexamethasone (DEX) preferentially inhibited Ag-induced expression of IL-4 and IL-6 mRNA relative to TNF-alpha mRNA in RBL-2H3 cells. Likewise, the drug more readily inhibited release of IL-4 than TNF-alpha protein. SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK), enhanced Ag-induced TNF-alpha mRNA expression without affecting IL-4 or IL-6 mRNA. At the protein level, SB203580 exerted little effect on TNF-alpha release but inhibited IL-4 release; notably, the ratio of TNF-alpha : IL-4 increased markedly with the concentration of SB203580, confirming the differential regulation of these cytokines. PD98059, an inhibitor of MAPK kinase (MEK), a component of the p44/42 MAPK pathway, partially inhibited Ag-induced expression of mRNA for all three cytokines while cyclosporin A inhibited Ag-induced IL-4 and IL-6 mRNA more readily than TNF-alpha mRNA. Ag activation of the cells led to phosphorylation of p38 and p44/42 MAPK but this was not influenced by DEX. In conclusion, mast cell cytokines can be differentially regulated pre- and post-translationally by DEX and SB203580 but there does not appear to be a direct mechanistic link between the actions of these two drugs.
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PMID:Differential regulation of mast cell cytokines by both dexamethasone and the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. 1519 47

NO is a cell-derived radical reported to inhibit mast cell degranulation and subsequent allergic inflammation, although whether its action is nonspecific or occurs via specific molecular mechanisms remains unknown. To examine this question, we set out to determine whether NO inhibits mast cell cytokine production, and, if so, whether it also alters FcepsilonRI-dependent signal transduction. As hypothesized, the radical inhibited IgE/Ag-induced IL-4, IL-6, and TNF production. Although NO did not influence phosphorylated JNK, p38 MAPK, or p44/42 MAPK, it did inhibit phosphorylation of phospholipase Cgamma1 and the AP-1 transcription factor protein c-Jun, but not NF-kappaB or CREB. NO further completely abrogated IgE/Ag-induced DNA-binding activity of the nuclear AP-1 proteins Fos and Jun. These results show that NO is capable of inhibiting FcepsilonRI-dependent mast cell cytokine production at the level of gene regulation, and suggest too that NO may contribute to resolution of allergic inflammation.
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PMID:Nitric oxide inhibits IgE-dependent cytokine production and Fos and Jun activation in mast cells. 1555 87

SC-236 [4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-l] benzenesulfonamide; C16H11ClF3N3O2S] is a highly selective cyclooxygenase (COX)-2 inhibitor. However, the exact mechanism that accounts for the anti-inflammatory effect of SC-236 is not completely understood. The aim of the present study was to elucidate whether and how SC-236 modulates the inflammatory reaction in a stimulated human mast cell (HMC) line, HMC-1. SC-236 inhibited the expression of tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, vascular endothelial growth factor, COX-2, inducible nitric-oxide synthase, and hypoxia-inducible factor-1alpha in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated HMC-1. SC-236 suppressed nuclear factor (NF)-kappaB activation induced by PMACI, leading to suppression of IkappaB-alpha phosphorylation and degradation. SC-236 also suppressed strong induction of NF-kappaB promoter-mediated luciferase activity. In addition, SC-236 suppressed PMACI-induced phosphorylation of the mitogen-activated protein kinase p38, the extracellular-regulated kinase p44, and the c-Jun N-terminal kinase and induced expression of mitogen-activated protein kinase phosphatase-1. These results provide new insight into the pharmacological actions of SC-236 as a potential molecule for therapy of mast cell-mediated inflammatory diseases.
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PMID:Cyclooxygenase-2 inhibitor SC-236 [4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-l] benzenesulfonamide] suppresses nuclear factor-kappaB activation and phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and c-Jun N-terminal kinase in human mast cell line cells. 1578 48

We analyzed the effects of the Janus kinase 3 (Jak3)-specific inhibitor WHI-P131 (4-(4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline) and the Jak3/Syk inhibitor WHI-P154 (4-(3'-bromo-4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline) on the antigen-induced activation of mast cells. In the rat mast cell line RBL-2H3, both WHI-P131 and WHI-P154 inhibited the antigen-induced degranulation and phosphorylation of p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK and c-Jun N-terminal kinase (JNK). The phosphorylation of Gab2, Akt and Vav was also inhibited by WHI-P131 and WHI-P154, indicating that these inhibitors suppress the activation of phosphatidylinositol 3-kinase (PI3K). In bone marrow-derived mast cells (BMMCs) from Jak3-deficient (Jak3-/-) mice, degranulation and activation of MAPKs were induced by the antigen in almost the same extent as in BMMCs from wild-type mice. In addition, the antigen-induced degranulation and activation of MAPKs were inhibited by WHI-P131 and WHI-P154 in both groups of BMMCs, indicating that these compounds inhibit a certain step except for Jak3. The antigen-induced increase in the activity of Fyn, a probable tyrosine kinase of Gab2, was also inhibited by WHI-P131 and WHI-P154 in RBL-2H3 cells. In BMMCs from Jak3-/- mice, the antigen stimulation induced tyrosine phosphorylation of Fyn, which was inhibited by WHI-P131, as well as in BMMCs from wild-type mice and in RBL-2H3 cells. These findings suggest that Jak3 does not play a significant role in the antigen-induced degranulation and phosphorylation of MAPKs, and that WHI-P131 and WHI-P154 inhibit the PI3K pathway by preventing the antigen-induced activation of Fyn, thus inhibiting the antigen-induced degranulation and phosphorylation of MAPKs in mast cells.
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PMID:Inhibition of the antigen-induced activation of rodent mast cells by putative Janus kinase 3 inhibitors WHI-P131 and WHI-P154 in a Janus kinase 3-independent manner. 1585 29

Interleukin-8 (IL-8) is a potent proinflammatory chemokine that plays an important role in inflammation by activating and recruiting neutrophils, lymphocytes, and eosinophils. To demonstrate the effect of intracellular Ca(2+) on IL-8 production and related signaling, we stimulated human mast cell line HMC-1 with either calcium ionophore A23187 or thapsigargin. Increase of intracellular Ca(2+) resulted in inducing IL-8 gene expression and protein secretion, and addition of EGTA or BAPTA/AM before Ca(2+) stimulation inhibited the induction of IL-8 production. Intracellular Ca(2+) triggered the activation of mitogen-activated protein kinase (MAPK) in HMC-1, especially p42 and p44 isoforms of extracellular signal-regulated kinase (ERK) and p38 MAPK, but not c-Jun N-terminal kinase (JNK). Pretreatment of MAPK inhibitors (PD98059 and SB203580) markedly blocked Ca(2+)-induced IL-8 production from cells, and anti-inflammatory drugs, such as dexamethasone and cyclosporin A, partially inhibited the activation of ERK1/2. We determined that increased Ca(2+) activates the nuclear translocation of the transcription factor NF-kappaB. NF-kappaB inhibitors blocked the ability of Ca(2+) to induce IL-8 production, and the activation of NF-kappaB was required for intracellular Ca(2+)-induced up-regulation of IL-8. These results suggest that increased intracellular Ca(2+) stimulated p38 and ERK1/2 MAPK signaling cascades result in NF-kappaB activation and IL-8 production in HMC-1 cells. This study is the first to identify the intracellular signaling pathways involved in the Ca(2+)-mediated up-regulation of IL-8 synthesis and release from HMC-1 cells.
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PMID:Involvement of mitogen-activated protein kinase and NF-kappaB activation in Ca2+-induced IL-8 production in human mast cells. 1634 28


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