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

The purpose of this study was to determine the effects of mast cell coculture on human orbital fibroblasts. Thyroid-associated ophthalmopathy is characterized by infiltration of lymphocytes and mast cells and connective tissue activation in the orbit, leading to a disordered accumulation of hyaluronan and intense inflammation. Here, we report that HMC-1, an established human mast cell line, can activate human orbital fibroblasts to produce increased levels of prostaglandin E2 (PGE2) and hyaluronan when cocultured. HMC-1 cells up-regulate, in these fibroblasts, the expression of PG endoperoxide H synthase-2 (EC 1.14.99.1, PGHS-2), the inflammatory cyclooxygenase. This induction, at a pretranslational level, underlies the increase in PGE2 synthesis. The up-regulation can be attenuated with dexamethasone (10 nM), and the increase in PGE2 production can be inhibited by SC 58125, a specific PGHS-2 inhibitor. Moreover, anti-interleukin-4 receptor antibodies can block prostanoid production in the fibroblasts elicited by HMC-1 cells, suggesting that this cytokine might represent a molecular conduit for mast cell/fibroblast cross-talk. HMC-1 cells also increased hyaluronan synthesis, as was evidenced by a 2-fold increase in [3H]glucosamine incorporation into the macromolecule. To our knowledge, these findings are the first demonstrating the ability of mast cells to activate orbital fibroblasts, and the findings suggest a potential role for these cell-cell interactions in the pathogenesis of thyroid-associated ophthalmopathy.
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PMID:HMC-1 mast cells activate human orbital fibroblasts in coculture: evidence for up-regulation of prostaglandin E2 and hyaluronan synthesis. 1043 7

1. We investigated the role of arachidonic acid metabolism and assessed the participation of mast cells and leukocytes in neurogenic inflammation in rat paw skin. We compared the effect of lipoxygenase (LOX) and cyclo-oxygenase (COX) inhibitors on oedema induced by saphenous nerve stimulation, substance P (SP), and compound 48/80. 2. Intravenous (i.v.) pre-treatment with a dual COX/LOX inhibitor (RWJ 63556), a dual LOX inhibitor/cysteinyl-leukotriene (CysLt) receptor antagonist (Rev 5901), a LOX inhibitor (AA 861), a five-lipoxygenase activating factor (FLAP) inhibitor (MK 886), or a glutathione S-transferase inhibitor (ethacrynic acid) significantly inhibited (40 to 60%) the development of neurogenic oedema, but did not affect cutaneous blood flow. Intradermal (i.d.) injection of LOX inhibitors reduced SP-induced oedema (up to 50% for RWJ 63556 and MK 886), whereas ethacrynic acid had a potentiating effect. 3. Indomethacin and rofecoxib, a highly selective COX-2 inhibitor, did not affect neurogenic and SP-induced oedema. Surprisingly, the structurally related COX-2 inhibitors, NS 398 and nimesulide, significantly reduced both neurogenic and SP-induced oedema (70% and 42% for neurogenic oedema, respectively; 49% and 46% for SP-induced oedema, respectively). 4. COX-2 mRNA was undetectable in saphenous nerves and paw skin biopsy samples, before and after saphenous nerve stimulation. 5. A mast cell stabilizer, cromolyn, and a H(1) receptor antagonist, mepyramine, significantly inhibited neurogenic (51% and 43%, respectively) and SP-induced oedema (67% and 63%, respectively). 6. The co-injection of LOX inhibitors and compound 48/80 did not alter the effects of compound 48/80. Conversely, ethacrynic acid had a significant potentiating effect. The pharmacological profile of the effect of COX inhibitors on compound 48/80-induced oedema was similar to that of neurogenic and SP-induced oedema. 7. The polysaccharide, fucoidan (an inhibitor of leukocyte rolling) did not affect neurogenic or SP-induced oedema. 8. Thus, (i) SP-induced leukotriene synthesis is involved in the development of neurogenic oedema in rat paw skin; (ii) this leukotriene-mediated plasma extravasation might be independent of mast cell activation and/or of the adhesion of leukocytes to the endothelium; (iii) COX did not appear to play a significant role in this process.
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PMID:Cyclo-oxygenase and lipoxygenase pathways in mast cell dependent-neurogenic inflammation induced by electrical stimulation of the rat saphenous nerve. 1126 53

Aspirin-induced asthma (AIA) is a distinct clinical entity characterised by hypersensitivity to aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) typically occurring in the form of asthma and severe rhinosinusitis. Its prevalence is about 10%, but AIA probably is underdiagnosed. The diagnosis can only be established with certainty by challenge tests, using increasing doses of aspirin. The crucial cell in AIA is the eosinophil, while the role of mast cell is more elusive. At the biochemical level, AIA is distinguished by profound underlying arachidonic acid disturbances. An overproduction of leukotrienes was observed in patients with aspirin hypersensitivity at baseline and following aspirin challenge. In some patients altered prostaglandin release following aspirin was encountered. The inhibition of COX-1, but not COX-2, was shown to precipitate post-challenge symptoms precipitated by aspirin. The new insights into eicosanoid molecular biology and genetics have recently emerged. The patients with aspirin-sensitive asthma require often prolonged oral, inhaled and nasal corticotherapy. Antileukotrienes also can be used. Aspirin and NSAIDs should be avoided. Nevertheless, highly specific COX-2 inhibitors are well tolerated. Aspirin desensitisation, followed by daily aspirin treatment, is a valuable therapeutic option.
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PMID:[Asthma with hypersensitivity to aspirin]. 1452 72

Recent studies have suggested that dual inhibitors of cyclooxygenase (COX) and lipoxygenase (LO) may be more beneficial in the treatment of inflammatory diseases in which platelet-leukocyte interaction dominates the underlying inflammatory process, than inhibitors of COX or LO alone. In this study, we examined oxygenated xanthones, shown previously to inhibit platelet and neutrophil activation, with respect to the potency of COX inhibition. 1,3,6,7-Tetrahydroxyxanthone (norathyriol) was the most potent. Norathyriol suppressed thromboxane B(2) (TXB(2)) and leukotriene B(4) (LTB(4)) formation in calcium ionophore (A23187)- and formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated rat neutrophils. Norathyriol was 3-4 times more active against LTB(4) formation than against TXB(2) formation (IC(50) about 2.8 vs. 10 microM, respectively). Norathyriol also inhibited prostaglandin D(2) (PGD(2)) formation in A23187-stimulated rat mast cells (IC(50) 3.0+/-1.2 microM) and in arachidonic acid (AA)-activated mast cell lysate. Norathyriol was a more effective inhibitor of 5-LO activity than of COX, as shown also by analyses of enzyme activities in a cell-free system, of COX and 5-LO metabolic capacity in neutrophils and of ex vivo TXB(2) and LTB(4) formation in A23187-stimulated neutrophils. Moreover, norathyriol inhibited COX-2 and 12-LO with IC(50) values (19.6+/-1.5 and 1.2+/-0.1 microM, respectively) similar to those required for the inhibition of COX-1 and 5-LO (16.2+/-1.5 and 1.8+/-0.4 microM, respectively). Inhibition of 15-LO by norathyriol was slightly less active. Norathyriol had no effect on A23187-induced AA release from neutrophils and did not affect phospholipase A(2) (PLA(2)) activity in a cell-free system. These results indicate that norathyriol inhibits the formation of PGs and LTs in neutrophils probably through direct blockade of COX and 5-LO activities. Norathyriol, a single molecule with multiple targets, might provide a potential therapeutic benefit in the treatment of inflammatory diseases.
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PMID:Inhibition of the arachidonic acid cascade by norathyriol via blockade of cyclooxygenase and lipoxygenase activity in neutrophils. 1508 66

The antigen-induced release of histamine from sensitized guinea pig mast cells was dose-dependently reduced by endogenous (2-arachidonylglycerol; 2AG) and exogenous [(1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3-hydroxypropyl)cyclohexan-1-ol (CP55,940)] cannabinoids. The inhibitory action afforded by 2AG and CP55,940 was reversed by N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide (SR144528), a selective cannabinoid 2 (CB(2)) receptor antagonist, and left unchanged by the selective CB(1) antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). The inhibitory action of 2AG and CP55,940 was reduced by the unselective nitric-oxide synthase (NOS) inhibitor N-monomethyl-L-arginine methylester (l-NAME) and reinstated by L-arginine, the physiological substrate. The inhibitory action of 2AG and CP55,940 was also reduced by the unselective cyclooxygenase (COX) inhibitor indomethacin and the selective COX-2 blocker rofecoxib. Both 2AG and CP55,940 significantly increased the production of nitrite from mast cells, which was abrogated by L-NAME and N-(3-(aminomethyl)benzyl)acetamidine (1400W), a selective inducible NOS (iNOS) inhibitor. Nitrite production consistently paralleled a CP55,940-induced increase in the expression of iNOS protein in mast cells. Both 2AG and CP55,940 increased the generation of prostaglandin E(2) from mast cells, which was abrogated by indomethacin and rofecoxib and parallel to the CP55,940-induced expression of COX-2 protein. Mast cell challenge with antigen was accompanied by a net increase in intracellular calcium levels. Both cannabinoid receptor ligands decreased the intracellular calcium levels, which were reversed by SR144528 and l-NAME. In unstimulated mast cells, both ligands increased cGMP levels. The increase was abrogated by SR144528, l-NAME, indomethacin, and rofecoxib. Our results suggest that 2AG and CP55,940 decreased mast cell activation in a manner that is susceptible to a CB(2) receptor antagonist and to inhibition of nitric oxide and prostanoid pathways.
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PMID:The endocannabinoid 2-arachidonylglycerol decreases the immunological activation of Guinea pig mast cells: involvement of nitric oxide and eicosanoids. 1518 70

Recently, three different prostaglandin E2 synthases have been identified: microsomal prostaglandin E synthase (mPGES)-1, cytosolic PGES (cPGES), and mPGES-2; however, their role and connection to cyclooxygenase (COX)-2 in the gastric ulcer repair process remain unknown. Therefore, we examined mPGES-1, cPGES, and mPGES-2 expression and localization in the stomach in vitro and in vivo. Tissues were obtained from Helicobacter pylori (H. pylori)-infected patients and consisted of surgical resections of gastric ulcers, or biopsies of gastric ulcers or gastritis. mPGES-1 mRNA and protein expression levels were examined by real-time polymerase chain reaction (PCR) and Western blot analysis, respectively. mPGES-1, cPGES, and mPGES-2 localization were analyzed immunohistochemically. Induction of PGES expression in response to interleukin (IL)-1beta was examined in vitro in the cultured human gastric fibroblast line Hs262.St. Real-time PCR analysis of mPGES-1 mRNA expression in biopsy samples showed significantly higher expression levels in open than in closed gastric ulcer tissue. Western blot analysis showed mPGES-1 protein expression limited to open ulcer tissue, while mPGES-2 and cPGES immunoreactivities were seen in both open and closed ulcer tissue. Immunohistochemical analysis showed strong mPGES-1 expression in fibroblasts and macrophages of the ulcer bed, paralleling COX-2 expression. cPGES and mPGES-2 expression levels were seen in both fibroblasts of the ulcer bed and in epithelial cells. Furthermore, stronger cPGES and mPGES-2 immunoreactivities were seen in scattered mast cell-like cells and neuroendocrine-like cells, respectively. Induction of mPGES-1 expression in response to IL-1beta was seen in cultured gastric fibroblasts in vitro, and double immunostaining showed mPGES-1 coexpression with COX-2 in fibroblasts of the ulcer bed in vivo. In conclusion, mPGES-1, cPGES, and mPGES-2 are all expressed in gastric ulcer tissue, but only mPGES-1 parallels COX-2 expression in mesenchymal and inflammatory cells of the ulcer bed, suggesting a key role for this enzyme in the ulcer repair process.
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PMID:Microsomal prostaglandin E synthase (mPGES)-1, mPGES-2 and cytosolic PGES expression in human gastritis and gastric ulcer tissue. 1553 9

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

Trichinella spiralis infection in rats induces hypermotility and an abnormal response to cholecystokinin (CCK) similar to motor disturbances observed in irritable bowel syndrome. Mast cell hyperplasia is also characteristic of this experimental model. The aim of our study was to correlate mast cell activity with the development of dysmotility and to demonstrate whether the mast cell stabilizer ketotifen [4-(1-methyl-4-piperidylidene)-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-10(9H)-one fumarate] could prevent the development of intestine hypermotility. Sprague-Dawley rats were infected with T. spiralis and, 5 days after infection, treated with the mast-cell stabilizer ketotifen (10 mg/kg/day). Twelve days after infection, intestinal spontaneous motor activity and response to CCK were evaluated by means of strain-gauge transducers. Immunohistochemistry for rat mast cell protease II (RMCPII), cyclooxygenase (COX)-2, and inducible nitric-oxide synthase (iNOS) was performed in intestinal specimens. In addition, RMCPII and myeloperoxidase were determined in serum. Infected control rats showed hypermotility, mast cell hyperplasia, increased RMCPII levels, increased myeloperoxidase, and overexpression of COX-2 and iNOS. In contrast, ketotifen-treated rats showed spontaneous intestinal motility and CCK response similar to the noninfected control rats. Mast cell hyperplasia and RMCPII were reduced in ketotifen-treated rats. Inflammatory parameters were less modified by ketotifen, but those animals that received the longest ketotifen treatment showed a slight amelioration in these parameters. These results indicate that mast cells are implicated in the development of hypermotility. The treatment with ketotifen prevented hypermotility and mast cell hyperplasia and diminished mucosal mast cell activity.
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PMID:Mast cell stabilizer ketotifen [4-(1-methyl-4-piperidylidene)-4h-benzo[4,5]cyclohepta[1,2-b]thiophen-10(9H)-one fumarate] prevents mucosal mast cell hyperplasia and intestinal dysmotility in experimental Trichinella spiralis inflammation in the rat. 1698 56

The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H(1) and H(2) and that the selective H(1) antagonist terfenadine reverted the histamine-induced inhibition of HuH-6 cell growth, whereas the selective H(2) antagonist ranitidine inhibited the histamine-induced cell growth of HA22T/VGH cells. We demonstrated that histamine down-regulated the expression of beta-catenin, COX-2 and survivin in HuH-6 cells and that this was associated with caspase-3 activation and PARP cleavage. On the contrary, in HA22T/VGH cells expression of survivin and beta-catenin increased after treatment with granule remnants and histamine. Overall, our results suggest that mediators stored in mast cell granules and histamine may affect the growth of liver cancer cells. However, mast cells and histamine may play different roles depending on the tumor cell features. Finally, these data suggest that histamine and histamine receptor agonists/antagonists might be considered as "new therapeutic" drugs to inhibit liver tumor growth.
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PMID:Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells. 1760 79

Various inflammatory mediators released from antigen-activated mast cells are considered to play a key role in the pathogenesis of food allergy. The aim of the present study was to determine the mechanisms underlying the antigen-induced anaphylactic responses in the rat colons. Wistar rats were sensitized by intraperitoneal injection of ovalbumin (OVA). The contractilities of isolated proximal colons of the sensitized rats were studied in the organ bath. OVA challenges of sensitized tissues induced prolonged contractile responses. The antigen-induced contractions were greatly reduced by mast cell stabilizer doxantrazole (10 microM). However, the contractions were resistant to histamine H1 receptor antagonist and prostaglandin D2 receptor antagonist. In contrast, non-selective cyclooxygenase (COX) inhibitor indomethacin (1 microM) significantly reduced the contractions by 61.0%. Furthermore, selective COX-1 inhibitor FR122047 (10 microM) as well as selective COX-2 inhibitor NS-398 (10 microM) significantly inhibited the contractions by 50.1% and 50.3%, respectively. Nevertheless, the transcript levels of COX-2 as well as COX-1 were not upregulated by OVA in the proximal colons of the sensitized rats. The present results indicate that de novo arachidonic acid metabolites synthesis by constitutive COX-1 as well as constitutive COX-2 within mast cells contribute to the altered smooth muscle contractilities in the colons under the anaphylactic condition.
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PMID:The pathophysiological roles of COX-1 and COX-2 in the intestinal smooth muscle contractility under the anaphylactic condition. 1848 May 53


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