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

Objective: To investigate the expression and significance of protease activated receptor 2 (PAR2) in ovarian epithelial carcinoma. Methods: PAR2 mRNA expression levels in 410 cases of epithelial ovarian carcinoma and 88 cases of human normal ovary were analyzed from cancer Genome Atlas (TCGA) database and tissue genotypic expression database (GTEx). Immunohistochemical (IHC) staining of PAR2 protein was performed in 149 patients with ovarian cancer who underwent primary surgical treatment at Cancer Hospital of Chinese Academy of Medical Sciences. Then the relationship between mRNA/protein expression of PAR2 and clinicopathological features and prognosis was analyzed. Gene functions and related signaling pathways involved in PAR2 were studied by enrichment analysis. Results: The mRNA expression of PAR2 in epithelial ovarian carcinoma was significantly higher than that in normal ovarian tissue (3.05±0.72 vs. 0.33±0.16, P=0.004). There were 77 cases showing positive and 19 showing strong positive of PAR2 IHC staining among the 149 patients, accounting for 64.4% in total. PAR2 mRNA/protein expression was closely correlated with tumor reduction effect and initial therapeutic effect (P<0.05). Survival analysis showed that the progression free survival time (P=0.033) and overall survival time (P=0.011) in the group with high PAR2 mRNA expression was significantly lower than that in the low PAR2 mRNA group. Multivariate analysis showed tumor reduction effect, initial therapeutic effect were independent prognostic factors on both progression-free survival and overall survival (P<0.05). The progression-free survival (P=0.016) and overall survival (P=0.038) of the PAR2 protein high expression group was significantly lower than that of the low group. Multivariate analysis showed PAR2 expression, initial treatment effect and chemotherapy resistance were independent prognostic factors on both progression-free survival and overall survival (P<0.05). Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), PAR2 target genes were mainly enriched in function related to intercellular connection, accounting for 40%. Gene enrichment analysis (GSEA) showed that the Wnt/β-catenin signaling pathway (P=0.023), the MAPK signaling pathway (P=0.029) and glycolysis related pathway (P=0.018) were enriched in ovarian cancer patients with high PAR2 mRNA expression. Conclusions: PAR2 expression is closely related to tumor reduction effect, initial treatment effect and survival of ovarian cancer patients. PAR2 may be involved in Wnt/β-catenin signaling pathway and intercellular connection promoting ovarian cancer invasion and metastasis.
Female ; Humans ; Carcinoma, Ovarian Epithelial ; Receptor, PAR-2 ; Ovarian Neoplasms/pathology* ; Prognosis ; RNA, Messenger/metabolism*

Animals ; Cardiovascular Diseases ; etiology ; metabolism ; Humans ; Inflammation ; metabolism ; Periodontitis ; complications ; metabolism ; microbiology ; Platelet Aggregation ; physiology ; Porphyromonas gingivalis ; pathogenicity ; RNA, Messenger ; metabolism ; Receptor, PAR-1 ; metabolism ; Receptor, PAR-2 ; genetics ; metabolism ; Receptors, Proteinase-Activated ; metabolism ; Receptors, Thrombin ; metabolism

OBJECTIVETo explore the quantity of mast cells and the role of protease activated receptor-2 (PAR-2) in experimental rat liver fibrosis.

METHODSRats were sacrificed at 0, 2, 4, 8, and 12 weeks after subcutaneous injection of CCl(4). Mast cells were displayed by toluidine blue stain. The content of liver hydroxyproline was measured by the method of base hydrolyzate. The mRNA expression and the protein expression of PAR-2 in livers were detected by RT-PCR and immunohistochemistry at each time point.

RESULTSIn normal rat livers there were a few mast cells (2.5+/-1.0) distributed along the hepatic portal areas. In the cirrhosis model group the number of mast cells in the livers increased degree by degree (2 weeks vs 4 weeks vs 8 weeks, 9.1+/-0.5 vs 15.7+/-3.0 vs 32.0+/-3.3; P less than 0.05), and they were distributed densely around the hepatic portal areas and the central veins. The content of liver hydroxyproline increased progressively from 0 to 12 weeks. In normal livers PAR-2 mRNA was hardly detected, at 2 weeks there was some expression of PAR-2 mRNA (PAR-2/beta-actin 0.15+/-0.01, P less than 0.05), at 4 weeks its expression increased (PAR-2/beta-actin 0.35+/-0.02, P less than 0.05) and it maintained a higher level (PAR-2/beta-actin 0.80+/-0.02, P less than 0.05) since then. The changing trend of the protein expression of PAR-2 was the same as that of PAR-2 mRNA expression.

CONCLUSIONSPAR-2 mRNA expression and the protein expression of PAR-2 were consistent with the increase of the mast cells, and the content of liver hydroxyproline may play an important role in mediating liver fibrosis.

Animals ; Hydroxyproline ; metabolism ; Liver ; metabolism ; Liver Cirrhosis, Experimental ; metabolism ; Male ; Mast Cells ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-2 ; metabolism

OBJECTIVETo investigate the effect of protease-activated receptor 2 (PAR-2) on rat apoptotic cardiomyocytes underwent ischemia reperfusion (I/R) injury.

METHODSHealthy male Sprague-Dawley rats were randomly divided into five groups (n = 8 each): sham-operation group, I/R (ligating the left coronary artery for 30 minutes and followed by 120 minutes reperfusion) group and three SLIGRL-NH2 groups treated with intravenous PAR-2 agonist SLIGRL-NH2 at different doses (0.5, 1, 3 mg/kg) 5 minutes before reperfusion. Apoptic cardiomyocytes was detected by TUNEL staining and by DNA ladder on agarose gel electrophoresis. Bax and Bcl-2 expression in myocardium was analyzed by immunohistochemical technique. The mRNA expression of PAR-2 was determined by Real-time quantitative polymerase chain reaction (RT-PCR).

RESULTS(1) The apoptosis index and the expression of Bcl-2 and Bax were significantly increased in IR group and SLIGRL-NH2 groups than those in sham group (P < 0.05-0.01). (2) Compared with I/R group, the apoptosis index and the expression of Bax were significantly reduced while the expression of Bcl-2 and PAR-2 mRNA were significantly upregulated by SLIGRL-NH2 in a dose-dependent manner. (3) DNA Agarose gel electrophoresis demonstrated that DNA ladder existed in I/R and 0.5 mg/kg SLIGRL-NH2 group, but not in 1, 3 mg/kg SLIGRL-NH2 groups.

CONCLUSIONSPAR-2 agonist SLIGRL-NH2 could reduce myocardial apoptosis by upregulating the Bcl-2 and PAR-2 mRNA level and downregulating Bax expression in a dose-dependent manner in this rat I/R model.

Animals ; Apoptosis ; drug effects ; Male ; Myocytes, Cardiac ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-2 ; agonists ; metabolism ; Reperfusion Injury ; metabolism ; pathology ; bcl-2-Associated X Protein ; metabolism

No abstract available.
Animals ; Colon/*metabolism ; Constipation/*physiopathology ; Diarrhea/*physiopathology ; Female ; Ganglia, Spinal/*cytology ; Humans ; Irritable Bowel Syndrome/*physiopathology ; Male ; Nociceptors/*physiology ; Receptor, PAR-2/*physiology

PURPOSE: Recent findings of increased cathelicidin protein and its proteolytic fragments in rosacea suggest a pathogenic role for cathelicidin in this disease. The relationship between cathelicidin and protease-activated receptor 2 (PAR-2) is therefore of interest, as PAR-2, expressed principally in keratinocytes, regulates pro-inflammatory cytokine expression in the skin. The purpose of this study was to determine the relationship between expression of PAR-2 and cathelicidin in rosacea and to test the effect of direct PAR-2 activation on cathelicidin expression in keratinocytes. MATERIALS AND METHODS: Samples from 40 patients with clinicopathologic diagnosis of rosacea and facial skin tissue samples from 20 patients with no specific findings or milium without inflammation were retrieved. Intensities of immunohistochemical staining for PAR-2 and cathelicidin were compared between normal and rosacea-affected skin tissues. Additionally, correlations between PAR-2 and cathelicidin staining intensities within rosacea patients were analyzed. In cultured keratinocytes, changes in PAR-2, cathelicidin, and vascular endothelial growth factor (VEGF) mRNA and protein were analyzed after treatment with PAR-2 activating peptide (AP). RESULTS: Cathelicidin expression was significantly higher in rosacea skin tissues than in normal tissues (p<0.001), while PAR-2 expression was not significantly higher in rosacea tissues than in normal skin tissues. A positive correlation between PAR-2 and cathelicidin within rosacea samples was observed (R=0.330, p=0.037). After treatment of PAR-2 AP, both mRNA and protein levels for PAR-2, cathelicidin, and VEGF significantly increased in cultured keratinocytes, compared with PAR-2 control peptide treatment. CONCLUSION: PAR-2 may participate in the pathogenesis of rosacea through activation of cathelicidin LL-37, a mediator of innate immune responses in the skin.
Adult ; Aged ; Antimicrobial Cationic Peptides/*metabolism ; Cytokines/metabolism ; Female ; Humans ; Immunity, Innate ; Inflammation/metabolism ; Keratinocytes/*metabolism ; Male ; Middle Aged ; Receptor, PAR-2/*metabolism ; Rosacea/*pathology ; Skin/pathology ; Vascular Endothelial Growth Factor A/*metabolism

OBJECTIVETo observe the dynamic change in expression of protease-activated receptor 2 (PAR2) during onset and progression of liver fibrosis by using a rat model.

METHODSA cholestatic liver fibrosis model was established in Sprague-Dawley rats (aged 8-9 weeks, body weight 350 - 400 g) by bile duct ligation surgery. Rats receiving a sham operation and unoperated rats served as the negative and normal control groups, respectively. At baseline (pre-surgery) and post-surgery weeks 2, 4, 6, and 8, five rats from each group were sacrificed for whole liver resection. The protein and mRNA expressions of PAR2 and collagen I/III were detected by western blotting and RT-PCR, respectively. Between-group differences were assessed by analysis of variance testing.

RESULTSAt post-surgery week 2, the liver fibrosis group showed higher expression of PAR2 mRNA and protein than either control group. The expression levels of PAR2 continued to rise over time in the liver fibrosis group (peaking at week 8), and were significantly higher than those detected in the control groups (weeks 4-6: P less than 0.05; week 8, P less than 0.05). A similar trend was observed for the expression of collagen I/III.

CONCLUSIONDynamic expression of PAR2 observed in a cholestatic liver fibrosis rat model may indicate a role for this factor in the formation of liver fibrosis.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Disease Models, Animal ; Liver ; metabolism ; pathology ; Liver Cirrhosis, Biliary ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-2 ; metabolism

Proteases in the skin are essential to epidermal permeability barrier homeostasis. In addition to their direct proteolytic effects, certain proteases signal to cells by activating protease-activated receptors (PARs), the G-protein-coupled receptors. The expression of functional PAR-2 on human skin and its role in inflammation, pruritus, and skin barrier homeostasis have been demonstrated. Atopic dermatitis (AD) is a multifactorial inflammatory skin disease characterized by genetic barrier defects and allergic inflammation, which is sustained by gene-environmental interactions. Recent studies have revealed aberrant expression and activation of serine proteases and PAR-2 in the lesional skin of AD patients. The imbalance between proteases and protease inhibitors associated with genetic defects in the protease/protease inhibitor encoding genes, increase in skin surface pH, and exposure to proteolytically active allergens contribute to this aberrant protease/PAR-2 signaling in AD. The increased protease activity in AD leads to abnormal desquamation, degradation of lipid-processing enzymes and antimicrobial peptides, and activation of primary cytokines, thereby leading to permeability barrier dysfunction, inflammation, and defects in the antimicrobial barrier. Moreover, up-regulated proteases stimulate PAR-2 in lesional skin of AD and lead to the production of cytokines and chemokines involved in inflammation and immune responses, itching sensation, and sustained epidermal barrier perturbation with easier allergen penetration. In addition, PAR-2 is an important sensor for exogenous danger molecules, such as exogenous proteases from various allergens, and plays an important role in AD pathogenesis. Together, these findings suggest that protease activity or PAR-2 may be a future target for therapeutic intervention for the treatment of AD.
Anti-Infective Agents/pharmacology ; Dermatitis, Atopic/*enzymology ; Endopeptidases/metabolism ; Homeostasis ; Humans ; Hydrogen-Ion Concentration ; Inflammation ; Models, Biological ; Models, Genetic ; Peptide Hydrolases/*metabolism ; Receptor, PAR-2/*metabolism ; Serine Proteases/metabolism ; Signal Transduction ; Skin/enzymology/pathology ; Treatment Outcome

This study was performed in order to assess whether acute stress can increase mast cell and enterochromaffin (EC) cell numbers, and proteinase-activated receptor-2 (PAR2) expression in the rat colon. In addition, we aimed to investigate the involvement of corticotrophin-releasing factor in these stress-related alterations. Eighteen adult rats were divided into 3 experimental groups: 1) a saline-pretreated non-stressed group, 2) a saline-pretreated stressed group, and 3) an astressin-pretreated stressed group. The numbers of mast cells, EC cells, and PAR2-positive cells were counted in 6 high power fields. In proximal colonic segments, mast cell numbers of stressed rats tended to be higher than those of non-stressed rats, and their PAR2-positive cell numbers were significantly higher than those of non-stressed rats. In distal colonic segments, mast cell numbers and PAR2-positive cell numbers of stressed rats were significantly higher than those of non-stressed rats. Mast cell and PAR2-positive cell numbers of astressin-pretreated stressed rats were significantly lower than those of saline-pretreated stressed rats. EC cell numbers did not differ among the three experimental groups. Acute stress in rats increases mast cell numbers and mucosal PAR2 expression in the colon. These stress-related alterations seem to be mediated by release of corticotrophin-releasing factor.
Animals ; Colon/*metabolism ; Corticotropin-Releasing Hormone/antagonists & inhibitors/metabolism/pharmacology/*physiology ; Enterochromaffin Cells/cytology ; Male ; Mast Cells/*cytology/immunology/metabolism ; Peptide Fragments/pharmacology ; Rats ; Rats, Wistar ; Receptor, PAR-2/*metabolism ; Restraint, Physical ; *Stress, Physiological