Proteinase-activated receptor-2 (PAR-2) expression has been observed on numerous cell types. However, little is known about the functional expression of PAR-2 in human mast cells. In the current study, the actions of a PAR-2 agonist trans-cinnamoyl-Leu-Ile-Gly-Arg-Leu-Orn-amide (tc-LIGRLO) on tryptase release from dispersed human colonic mast cells were examined. The results showed that tc-LIGRLO was able to induce a fold increase in tryptase release over the basal level following a 15 min incubation of colonic mast cells, whereas tc-OLRGIL did not have any effect on tryptase release. The potency of tc-LIGRLO appeared greater than that of anti-IgE and calcium ionophore A23187 (CI) in induction of tryptase release. Extending the incubation time to 30 min had no significant effect on the actions of tc-LIGRLO or anti-IgE. In the time course study, it was observed that the tryptase release from mast cells induced by tc-LIGRLO started at 1 min and peaked at 3 min following incubation. The above-mentioned results indicate that tc-LIGRLO is a potent stimulus of tryptase release from human mast cells, which strongly suggests that PAR-2s are expressed in human mast cells.
Cells, Cultured ; Humans ; Mast Cells ; drug effects ; metabolism ; Receptor, PAR-2 ; agonists ; Tryptases ; metabolism

AIMTo examine the ability of calcium ionophore (CI) to induce tryptase and histamine release from human mast cells and its mechanisms.

METHODSEnzymatically dispersed cells from human colons were challenged with CI, and the cell supernatants after challenge were collected. Tryptase release was determined with a sandwich ELISA procedure and histamine release was measured using a glass fibre-based fluorometric assay.

RESULTSCI was able to induce a concentration dependent release of histamine and tryptase from human colon mast cells following 15 min incubation. The maximum of induced histamine and tryptase release were approximately 5.3 and 2.8 fold more than the levels of spontaneous release, respectively. CI at the concentrations higher than 1.0 micromol/L was able to induce significantly more histamine than tryptase release from mast cells. The time course revealed that the action of CI on mast cells started from 10 s, peaked at 6 min and lasted at least 15 min following incubation. Pertussis toxin and metabolic inhibitors were able to inhibit mast cell response to CI.

CONCLUSIONHuman colon mast cells were able to release tryptase and histamine in response to CI. The process seemed to be associated with the activation of a G-protein coupled receptor on the membrane of mast cells and requires cell energy supply.

Calcium Ionophores ; pharmacology ; Cells, Cultured ; Colon ; cytology ; Histamine ; metabolism ; Humans ; Mast Cells ; drug effects ; metabolism ; secretion ; Tryptases ; metabolism

Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling.
Cell Degranulation ; Cell Line ; *Exocytosis ; Humans ; Mast Cells/*drug effects/*metabolism ; Mitogen-Activated Protein Kinases/*metabolism ; Reactive Oxygen Species/*metabolism ; Trichomonas vaginalis/*metabolism ; Virulence Factors/*metabolism

Epigallocatechin gallate (EGCG) is a principle phenolic antioxidant found in a variety of plants, including green and black tea. The anti-allergic effect of EGCG is unknown. The purpose of this study is to investigate the effects of EGCG on compound 48/80-induced mast cell activation and passive cutaneous anaphylaxis. For this, the influences of EGCG on the compound 48/80-induced cutaneous reaction were measured in vivo and the effects of EGCG on the compound 48/80-induced mast cell activations were examined in vitro. Results are below: as 1) EGCG significantly inhibited compound 48/80-induced passive cutaneous anaphylaxis, 2) the compound 48/80-induced degranulation, calcium influx and histamine release of rat peritoneal mast cells (RPMCs) were significantly inhibited by the pretreatment with EGCG, and 3) the compound 48/80-mediated inhibition of cAMP level in RPMCs was significantly increased by the pretreatment with EGCG. These results suggested that EGCG, the most abundant polyphenol in green tea, inhibits the compound 48/80-induced mast cell activation and the increase of vascular permeability, and potentially serve as effective therapeutic tools for allergic diseases.
Animals ; Antioxidants/*pharmacology ; Catechin/*analogs & derivatives/pharmacology ; Cyclic AMP/metabolism ; Histamine Release/*drug effects ; Mast Cells/*drug effects/metabolism ; Passive Cutaneous Anaphylaxis/*drug effects ; Rats ; Research Support, Non-U.S. Gov't ; p-Methoxy-N-methylphenethylamine/*antagonists & inhibitors

OBJECTIVETo observe the effect of Tongxie Yaofang (TY) on the number of mast cells (MCs) and the expression of cytokines in rats with visceral hypersensitivity, and to explore roles of TY in treating visceral hypersensitivity and its possible mechanism.

METHODSTotally 30 male adult Sprague Dawley (SD) rats were randomly divided into the blank control group, the model group, and the TY treatment group, 10 in each group. The irritable bowel syndrome (IBS) rat model was established by combining colorectal distention with restraint stress in the TY treatment group and the model group. The visceral hypersensitivity was assessed by abdominal withdrawal reflex (AWR). From the 2nd day of successful modeling, rats in the treatment group were admiministered with TY at the daily dose of 4 g/kg for 4 successive weeks. Equal volume of normal saline was given to rats in the model group for 4 successive weeks. No treatment was given to rats in the blank control group. Four weeks later the number of MCs was counted by using toluidine blue staining. The expression of interleukin-4 (IL-4) and interleukin-9 (IL-9) both in colonic mucosa and serum were measured by enzyme linked immunosorbent assay (ELISA), and the expression of protease-activated receptor type 2 (PAR-2) was detected by Western blot.

RESULTSCompared with the blank control group, the visceral sensitivity was significantly elevated, the number of MCs in the ileocecal junction increased, and the expression of IL-4, IL-9, and PAR-2 in serum and the colonic mucosa significantly increased (P < 0.05). Compared with the model group, the visceral sensitivity significantly decreased, the number of MCs reduced, and the expression of PAR-2 in the colonic mucosa significantly reduced (all P < 0.05), and the expression of IL-4 in colonic mucosa and IL-9 in serum were obviously reduced in the TY treatment group (P < 0.05).

CONCLUSIONTY might improve the visceral hypersensitivity by acting on MCs related cytokines and reducing degranulation of MCs.

Animals ; Cytokines ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Intestines ; drug effects ; metabolism ; pathology ; Irritable Bowel Syndrome ; drug therapy ; metabolism ; pathology ; Male ; Mast Cells ; drug effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVESince human mast cell is an important source of cytokines, it is of importance to understand the effects of anti-allergic drugs on cytokines modulation in mast cells. In the present study, we aimed at observing whether IL-4 could be released from human mast cell line (HMC-1) after the stimulation of PMA + A23187, and the effects of systemic glucocorticosteroid, dexamethasone, topical glucocorticosteroid, budesonide and H1 antagonist, desloratadine on IL-4 release and mRNA expression.

METHODSHMC-1 was stimulated with 25 ng/ml phorbol 12-myristate 13-acetate (PMA) and 2.5 x 10(-7) mol/L ionomycin (A23187) and cultured for 6 hours, 12 hours and 24 hours respectively in the presence or absence of 10(-6)-10(-10) mol/L concentrations of test drugs. Culture supernatants were collected and the levels of IL-4 were assayed by enzyme-linked immunosorbent assays (ELISA). The mRNA expression of IL-4 was measured by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSHMC-1 expressed IL-4 mRNA and the resulting protein production of IL-4 released after being stimulated with PMA plus A23187. Dexamethasone, budesonide and desloratadine had potent inhibitory effect on IL-4 release at any concentrations and time points, with significant deference (P < 0.05) compared to the control cells. The inhibitory effect did not show time-dependent and concentration-dependent manner. Desloratadine and budesonide showed neither up-regulatory nor down-regulatory effects on IL-4 mRNA expression at the test concentrations, however, desloratadine could down-regulate IL-4 mRNA expression.

CONCLUSIONSHMC-1 could express and produce IL4 after stimulation. Dexamethasone, budesonide and desloratadine all had inhibitory effects on IL-4 release from HMC-1. In addition, desloratadine could also inhibit the IL-4 mRNA expression.

Budesonide ; pharmacology ; Cell Line ; Dexamethasone ; pharmacology ; Humans ; Interleukin-4 ; biosynthesis ; Loratadine ; analogs & derivatives ; pharmacology ; Mast Cells ; drug effects ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacology

For those with allergy, vaccination with a specific allergen has often been used as a major therapeutic measure. However, the universal application of this technique in clinics have been restricted due to its low success rates and the risk of active systemic anaphylactic shock (ASAS). In this regard, we constructed a fusion protein (OVA-DT), ovalbumin (OVA) fused with diphtheria toxin protein (DT), which may exert a specific cytotoxicity to cells bearing OVA-specific IgE. Its therapeutic effect was evaluated in mice (BALB/c) sensitized with OVA (Os-mice). OVA challenges to the OVA-sensitized mice (Os-mice) caused ASAS to death within 30 min, but OVA-DT treatment afforded mice complete protection. When OVA-DT was treated to the Os-mice, none showed the signs of ASAS when re-challenged 48 h after the treatment. OVA-DT itself was not found to be toxic or allergenic in normal mice. The effect of OVA-DT on the biological functions of mast cells was also studied. Binding of OVA-DT to OVA-specific IgE bearing mast cells and the inhibition of histamine release from these cells were observed. In addition, OVA-DT treatment inhibited the proliferation of OVA-specific B cells in mice. In Os-mice treated with OVA-DT, levels of anti-OVA IgG2a in serum and the production of IFN-gamma by splenic lymphocytes were found to increase, but the production of IL-4 by these cells decreased. Re-direction of cytokine profiles from OVA-specific Th2 to OVA-specific Thl is suggested. These results indicate that OVA-DT can protect Os-mice from ASAS due to OVA challenge, because it inactivates OVA-specific IgE-expressing cells, including mast cells and B cells.
Anaphylaxis/prevention | control* ; Animal ; B-Lymphocytes/immunology ; Female ; Histamine Release/drug effects ; IgE/metabolism ; Interferon Type II/biosynthesis ; Interleukin-4/biosynthesis ; Lymphocyte Transformation/drug effects ; Mast Cells/metabolism ; Mice ; Mice, Inbred BALB C ; Ovalbumin/immunology* ; Recombinant Fusion Proteins/therapeutic use*

BACKGROUNDStudy of the relationship between mast cells and atherosclerosis is mostly dependent on pathological observation and cytology experiments. To investigate the effects of mast cells degranulation on plaque and their possible mechanisms we used apolipoprotein E knockout mice which had been placed perivascular common carotid collar with mast cells degranulator compound 48-80.

METHODSForty apolipoprotein E knockout mice were fed a western-type diet and operated on with placement of perivascular right common carotid collar. Four weeks after surgery, the mice were intraperitoneally injected with compound 48-80 (0.5 mg/kg) or D-Hanks every other day for 4 times. The serum lipids and activity of tryptase were measured. Tissue sections were stained with hematoxylin and eosin. Corresponding sections were stained with toluidine blue and immunohistochemically with antibodies against macrophage-specific antigen, alpha-smooth muscle actin, interleukin-1beta and von Willebrand factor. Simultaneously, basic fibroblast growth factor was detected by in situ hybridization and immunofluorescence.

RESULTSNo pathological change was observed in common carotid non-collar placement but atherogenesis in common carotid collar placement of both groups. There was a significant increase in plaque area ((5.85+/-0.75) x 10(4) vs (0.86+/-0.28) x 10(4) microm(2), P<0.05), the degree of lumen stenosis ((81+/-15)% vs (41+/-12)%, P<0.05), the activity of tryptase in serum ((0.57+/-0.13) U/L vs (0.36+/-0.10) U/L, P<0.05), and the percentage of degranulated mast cells ((80.6+/-17.8)% vs (13.5+/-4.1)%, P<0.05). The expressions of macrophage-specific antigen, alpha-smooth muscle actin, interleukin-1beta, basic fibroblast growth factor and the density of neovessel in plaque were more in the compound 48-80 group than in the control group.

CONCLUSIONSPerivascular common carotid collar placement can promote atherosclerotic plaque formation in apolipoprotein E knockout mice. Compound 48-80 increases plaque area and the degree of lumen stenosis by the mechanism that compound 48-80 promotes proliferation of smooth muscle cells and aggregation of macrophages. Compound 48-80 promotes angiogenesis in plaque. The mechanism is potentially that compound 48-80 increases the expressions of basic fibroblast growth factor mRNA and protein in plaque. Compound 48-80 enhances the expression of interleukin-1beta in plaque.

Animals ; Apolipoproteins E ; genetics ; Atherosclerosis ; chemically induced ; genetics ; metabolism ; pathology ; Carotid Arteries ; drug effects ; pathology ; Fluorescent Antibody Technique ; Immunohistochemistry ; In Situ Hybridization ; In Vitro Techniques ; Male ; Mast Cells ; drug effects ; metabolism ; Mice ; Mice, Knockout ; p-Methoxy-N-methylphenethylamine ; pharmacology

OBJECTIVETo investigate the influence of Weichang Anwan on the treatment of IBS-D in model rats.

METHODAnimal model of compound diarrhea was induced by a lactose enriched diet in the Wistar rat, combining with restraint stress. At first, the best cycle of taking medicine was tested. In order to decide the best cycle of taking medicine, 24 female Wistar rats were randomly divided into normal control group, model group and 60 mg x kg(1) x d(-1) weichangan group. The rate of weight increase, the rate of diarrhea, the incubation period of diarrhea and the diarrhea index were observed. And then 45 female Wistar rats randomly divided into five groups: normal control group, model group and Weichang Anwan groups of high, medium and low doses( 80, 60, 40 mg x kg(-1) x d(-1)). The mast cells in mucous membrane were observed by light microscope. The level of NO in blood serum was checked by the method of nitrate reductase. 5-HT in blood serum was detected by fluorimetry. The level of SP in colon was measured by radioimmunoassay.

RESULTAfter taking Weichang Anwan for 4 days, the rate of weight increase in Weichangan group was higher than the model group's. And the rate of diarrhea was lower significantly. So the best cycle of taking medicine was 4 days. The levels of NO and 5-HT in blood serum decreased remarkably in the model group than those of the normal control group. At the same time, the amount of the mast cells and the level of SP in colon significantly increased. Compared with the model group, the levels of NO and 5-HT in blood serum increased remarkably in the groups of high doses and medium doses. Meanwhile, the amount of the mast cells and the level of SP in colon decreased significantly.

CONCLUSIONWeichang Anwan has the effect of antidiarrhea. It can adjust the levels of NO and 5-HT in blood serum and can inhibit the expression of SP in colon which can active the mast cell. Weichangan can also decrease the amount of the mast cells directly.

Animals ; Colon ; drug effects ; immunology ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Irritable Bowel Syndrome ; drug therapy ; immunology ; metabolism ; Mast Cells ; immunology ; Nitric Oxide ; blood ; Random Allocation ; Rats ; Rats, Wistar ; Serotonin ; blood ; Substance P ; metabolism

Ongoing effort to find novel antiasthmatic drugs led to the design and synthesis of a series of compounds bearing phenyl tetrazole group based on the SAR study. The important intermediate 3-(1H-tetrazol-5-yl) benzenamine was synthesized from m-nitroaniline via cyclization and hydrogenation. Followed by amidation, eight new target compounds were obtained. The structures of these compounds were confirmed with 1H NMR, ESI-MS and elemental analysis. Their non-specific and specific anti-histamine effects in the mast cell were determined. Compound NP03 could inhibit non-specific histamine release induced by compound 48/80 in mast cell of SD rats.
Animals ; Anti-Asthmatic Agents ; chemical synthesis ; chemistry ; pharmacology ; Histamine Release ; drug effects ; Mast Cells ; drug effects ; metabolism ; Molecular Structure ; Rats ; Rats, Sprague-Dawley ; Structure-Activity Relationship ; Tetrazoles ; chemical synthesis ; chemistry ; pharmacology ; p-Methoxy-N-methylphenethylamine ; pharmacology