Prostaglandin D2 (PGD2) is a major prostanoid, produced mainly by mast cells, in allergic diseases, including bronchial asthma. PGD2-induced vasodilatation and increased permeability are well-known classical effects that may be involved in allergic inflammation. Recently, novel functions of PGD2 have been identified. To date, D prostanoid receptor (DP) and chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2) have been shown to be major PGD2-related receptors. These two receptors have pivotal roles mediating allergic diseases by regulating the functions of various cell types, such as TH2 cells, eosinophils, basophils, mast cells, dendritic cells, and epithelial cells. This review will focus on the current understanding of the roles of PGD2 and its metabolites in TH2 inflammation and the pathogenesis of bronchial asthma.
Asthma/*etiology/immunology ; Basophils/physiology ; Eosinophils/physiology ; Humans ; Mast Cells/physiology ; Prostaglandin D2/*physiology ; Receptors, Immunologic/physiology ; Receptors, Prostaglandin/physiology ; Th2 Cells/*immunology

OBJECTIVETo probe into the mechanism of acupuncture analgesia.

METHODSType-I collagenase was injected to destroy the structure of collagen fibers in the acupoint. Paw withdrawing latency and mast cell degranulation rate in the acute adjuvant arthritis rat were investigated. Effects of acupuncture at "Zusanli" (ST 36) with twirling or thrusting-lifting manipulation on acupuncture analgesia and mast cells were compared when the structures of collagen fibers in the acupoint were destroyed or not.

RESULTSWhen the structures of collagen fiber were destroyed, the analgesic effects of both acupuncture manipulations were attenuated and the degranulation rate of mast cells caused by acupuncture were significantly inhibited.

CONCLUSIONCollagen fibers and mast cells in the acupoint play an important role in acupuncture analgesia. Collagen fibers participate in transmission and transform process of acupuncture signs from the acupoint to the target organ, and the degranulation of mast cells is positively correlated with acupuncture analgesia.

Acupuncture Analgesia ; Acupuncture Points ; Animals ; Cell Degranulation ; Collagen ; physiology ; Male ; Mast Cells ; physiology ; Rats ; Rats, Sprague-Dawley

Exocytosis is a vital function of many cell types including neuron, endocrine cell and immunocyte. Secretion in immunocytes involves a complex process of signal transduction, in which many factors still remain unknown. In the last 10 years, this area has become an international hot spot of investigation, resulting in many break-through progresses. This progress was made possible by combined efforts in molecular biology, cell biology and biophysics. This review focuses on notable new knowledge and some new techniques in functional study of secretion in immunocytes.
Exocytosis ; physiology ; Humans ; Ion Channels ; physiology ; Lymphocytes ; immunology ; secretion ; Mast Cells ; immunology ; secretion ; Membrane Proteins ; physiology ; Neutrophils ; immunology ; secretion ; SNARE Proteins ; Signal Transduction ; physiology ; Vesicular Transport Proteins

We have occasionally experienced eosinophilic abscess of the liver in patients with gastric carcinoma, suggesting that some eosinophil mobilizing (chemotactic and proliferative) factors might be produced by carcinoma cells. The aim of this study was to determine whether or not gastric carcinoma expresses the well-known eosinophil chemotactic factors (ECFs) and whether or not the expression is related to the histologic subtypes. Seventeen consecutive surgically removed tumor-bearing stomachs were collected: 7 signet ring cell type, 7 poorly differentiated tubular adenocarcinoma, and 3 moderately differentiated tubular adenocarcinoma. Hematoxylin-eosin stained sections were re-evaluated for eosinophil and mast cell infiltration. The expression of IL-2, IL-5 and granulocyte-macrophage colony stimulating factor (GM-CSF) were examined by immunocytochemical stain. There was no available frozen tissue for IL-2 and IL-5 in one case. Gastric carcinoma expressed IL-2 in all 16 cases, IL-5 in 12 of 16 cases and GM-CSF in 10 of 17 cases. Of particular interest, 7 of 10 GM-CSF-expressing carcinomas were signet ring cell type. Even in the remaining 3 cases, most GM-CSF-positive cells were signet ring cells scattered within tubular adenocarcinoma. No correlation of ECF expression between either eosinophil/mast cell infiltration or peripheral blood eosinophilia was identified. In conclusion, most gastric carcinomas express the well-known ECFs and the expression of GM-CSF is specific for signet ring carcinoma cells.
Cell Movement/physiology ; Chemotactic Factors, Eosinophil/metabolism* ; Eosinophils/physiology ; Human ; Immunohistochemistry ; Mast Cells/physiology ; Stomach Neoplasms/physiopathology ; Stomach Neoplasms/pathology ; Stomach Neoplasms/metabolism*

In the present work, we have examined the effect of PAF, removal of epithelium, the mechanism of desensitization, and the substances that increases the level of intracellular c-AMP on the differences of mediator release from superfused tracheal strips after passive sensitization with IgG1 versus IgE Ab. In the passive sensitized tracheal tissues, the effect of PAF and the mechanism of desensitization have been examined by PAF antagonist, CV 3988 and DFP, respectively. The epithelium was stripped from one-half of each trachea by mechanical means. Both superfused tracheal tissues were challenged with Ox-Ag. Inhibitors of mediator release were added into a superfused buffer. Hist released was determined by spectrophotofluorometer, and LT by radioimmunoassay. PAF known to mediate the allergic reaction was not released by Ag after both Ab sensitization. Epithelium removal resulted in similar contraction, Hist and LT release after IgG1 Ab activation, but in the IgE Ab activation, epithelium removal resulted in smaller contraction and Hist release. In the L-cysteine and indomethacin pretreatment after two Ab sensitization, epithelium removal decreased the release of Hist and LT. The compound 48/80 pre-challenge and epithelium removal resulted in the increase of Hist release, but in the decrease of LT release after IgG1 or IgE sensitization. The Amount of LT released by Ag after compound 48/80 pre-challenge increased in the absence or presence of epithelium after both Ab sensitization. Mediator release from tissues sensitized with both Abs was not changed by DFP. The responses of inhibitors to prevent the mediator release were more effective on the IgE Ab than on the IgG1 Ab sensitization. These studies suggest that the tracheal epithelium can act to inhibit immune- and non-immune-induced airway responses. Non-immunological responses may in part reflect the role of epithelium as a diffusion barrier and modulator of mediator release. These data also suggest that immunological responses are related to the localization and functional heterogeneity of tissue mast cells.
Animal ; Epithelium/immunology/physiology ; Female ; Guinea Pigs ; *Histamine Release ; *Immunization ; Immunoglobulin E/*immunology ; Immunoglobulin G/*immunology ; Leukotrienes/metabolism ; Mast Cells/immunology ; Support, Non-U.S. Gov't ; Trachea/*immunology/physiology

OBJECTIVETo investigate the role and significance of cardiac mast cells and Toll-like receptor 4 (TLR4) in the development and progression of viral myocarditis (VMC).

METHODSForty-eight Balb/c mice were randomly divided into a control group (n=24) and a model group (n=24). Coxsackievirus B3 was intraperitoneally injected into the model group mice to establish a VMC model. In each group, cardiac tissues were collected from 8 mice at 7, 14 and 28 days after the model was established. The cardiac tissues were stained with hematoxylin and eosin as well as Masson trichrome to observe pathological changes in cardiac tissues. The number and degranulation of cardiac mast cells at each time point were measured and evaluated by toluidine blue staining and transmission electron microscopy. The mRNA and protein expression of TLR4 in cardiac tissues was measured by RT-PCR and immunohistochemistry. In the model group, the correlation between number of cardiac mast cells and mRNA expression of TLR4 at all time points was analyzed.

RESULTSThe model group had significantly higher pathological scores of cardiac tissues than the control group at all time points (P<0.05). The myocardial collagen volume fraction in the model group at 28 days was significantly higher than in the control group at all time points and higher than in the model group at 7 and 14 days (P<0.05). At each time point, the model group had a significantly increased number of mast cells (P<0.05), and significantly increased mRNA and protein expression of TLR4 (P<0.05) compared with the control group. In the model group, the number of cardiac mast cells was positively correlated with the mRNA expression of TLR4 at all time points (R²=0.877, P<0.05).

CONCLUSIONSMice with VMC have significantly increased numbers of cardiac mast cells and expression of TLR4 compared with control mice at all time points, suggesting that mast cells and TLR4 may play important roles in the inflammatory response and fibrosis of VMC.

Animals ; Coxsackievirus Infections ; immunology ; Enterovirus B, Human ; Female ; Mast Cells ; physiology ; Mice ; Mice, Inbred BALB C ; Myocarditis ; immunology ; Myocytes, Cardiac ; pathology ; Toll-Like Receptor 4 ; analysis ; genetics ; physiology

Mast cell(MC) takes an important role in trauma and the process of wound healing, and the pathophysiology reaction has a relationship to the time since trauma, which is helpful to determine the post-trauma and postmortem interval, and to distinguish the wound shaped whether before or after death. In this paper, the role of MC and its chemic medium in the process of wound healing, scar shaping, postburns inflammatory response, healing of bone fracture, as well as the signification for forensic medicine and the progress of researching in this field were reviewed.
Burns/physiopathology* ; Forensic Medicine/methods* ; Fractures, Bone/physiopathology* ; Humans ; Inflammation/physiopathology* ; Keloid/physiopathology* ; Mast Cells/physiology* ; Wound Healing/physiology* ; Wounds and Injuries/physiopathology*

Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.
Animals ; Cell Line ; Cytokines ; immunology ; Inflammation Mediators ; immunology ; Mast Cells ; immunology ; microbiology ; Mice ; NF-kappa B ; immunology ; Nod2 Signaling Adaptor Protein ; immunology ; Staphylococcus aureus ; physiology

OBJECTIVETo investigate potential pathophysiological role of cardiac mast cells accumulation and degranulation on the collagen deposition after coronary microembolization (CME).

METHODSCME was induced in miniswine by selective infusion of 15X10(4) microspheres (diameter, 45 mum) into the left anterior descending artery groups (CME group, n=8). Some CME-induced animals were pretreated with the MC stabilizer tranilast (50 mg/kg, twice daily), beginning 2 weeks before CME and thereafter throughout the experimental period (CME +tranilast group, n=8), while some animals received tranilast without CME (tranilast group, n=8). Eight sham-operated animals without CME served as controls. After 30 days, the total number of MC and degranulating MCs and collagen deposition was assessed by histological and electronic microscopy studies.

RESULTSThe numbers of total and degranulating MCs and collagen volume fraction (CVF) at day 30 in CME group were significantly higher than those in controls (P <0.01). Treatment with tranilast significantly reduced the numbers of total and degranulating MCs and CVF at day 30 (all P <0.01). There was a significant positive correlation of the CVF with the number of total MCs (r=0.91, P <0.001) and degranulating MCs (r=0.92, P <0.001) over the CME myocardium.

CONCLUSIONMCs accumulation and degranulating contribute to myocardial fibrosis collagen deposition.

Animals ; Cell Degranulation ; Collagen ; metabolism ; Coronary Vessels ; pathology ; physiopathology ; Embolism ; pathology ; physiopathology ; Mast Cells ; pathology ; physiology ; Myocardium ; metabolism ; pathology ; Swine ; Swine, Miniature

OBJECTIVETo investigate the role of mast cells in the development of renal interstitial fibrosis in children with Henoch-Schonlein purpura nephritis (HSPN) and possible mechanisms.

METHODSParaffin-embedded renal biopsy tissue sections from 20 children with HSPN were examined for the levels of tryptase-beta and transforming growth factor-beta1 (TGF-beta1) by immunohistochemical staining. Mast cells were counted by toluidine blue staining. Masson staining was used to assess the level of renal interstitial fibrosis and renal histopathological scores. Normal renal tissue sections from 5 nephrectomized children for nephroma were used as control group.

RESULTSThe percentages of positive tryptase-beta cellsand mast cells and the TGF-beta1 expression in the HSPN group were significantly higher than those in the control group (P < 0.05). The percentages of positive tryptase-beta cells and mast cells and the TGF-beta1 expression in renal tissue were positively correlated with the glomeruli histopathological score (r =0.940, 0.920, 0.937, respectively; P < 0.05) and were also positively correlated with the histopathological score of renal interstitium (r=0.903, 0.859, 0.948, respectively; P < 0.05). The level of renal interstitial fibrosis was positively correlated with the percentages of positive tryptase-beta cells and mast cells and the expression of TGF-beta1 (r =0.790, 0.766, 0.858, respectively; P < 0.05). There was a positive correlation between the percentages of positive tryptase-beta cells and mast cells (r =0.941, P < 0.05), between the percentage of positive tryptase-beta cells and the TGF-beta1 expression (r =0.897, P < 0.05) and between the percentage of positive mast cells and the TGF-beta1 expression (r=0.942, P < 0.05).

CONCLUSIONSTubulointerstitial mast cell infiltration is associated with the development of renal interstitial fibrosis in children with HSPN. Mast cells together with TGF-beta1 and mast cell-derived tryptase-beta may be involved in the development of the renal interstitial fibrosis in HSPN.

Adolescent ; Child ; Female ; Fibrosis ; Humans ; Kidney ; chemistry ; pathology ; Male ; Mast Cells ; physiology ; Nephritis ; pathology ; Purpura, Schoenlein-Henoch ; metabolism ; pathology ; Transforming Growth Factor beta1 ; analysis ; Tryptases ; analysis