BACKGROUND/AIMS: There have been no reports on the effect of chronic psychological stress on colonic immune cells or the regional differences. We aimed to investigate the effect of chronic psychological stress on the number of mast cells and protease-activated receptor (PAR)-2-positive cells in the rat colonic mucosa. METHODS: Six-week-old and 14-week-old Ws/Ws rats, which lack mast cells after 10 weeks, were used as control and mast cell-deficient groups, respectively. The rats were divided into stress and sham-treated groups. Rats in the stressed group were exposed to water avoidance stress (WAS, 1 hour/day) for 13 days. Fecal pellet output and the number of mast cells and PAR-2-positive cells in colonic mucosa were compared between the WAS and sham groups. RESULTS: In 6-week-old rats, the WAS group showed a significantly higher number of mast cells compared to the sham group. In 14-week-old rats, mast cells were nearly absent in the colonic mucosa. WAS significantly increased PAR-2-positive cells in 14-week-old rats, but not in 6-week-old rats. Indirect estimation of PAR-2-positive mast cells in 6-week-old rats suggested that the majority of increased mast cells following WAS did not express PAR-2. WAS increased mast cells and PAR-2-positive cells mainly in the proximal colon. Fecal pellet output was continuously higher in the WAS group than in the sham group, and the difference was significant for both 6-week-old and 14-week-old rats. CONCLUSIONS: Chronic psychological stress increased the number of mast cells and PAR-2-positive cells in rat colonic mucosa, and these increases were more prominent in the proximal colon.
Animals ; Cell Count* ; Colon* ; Mast Cells* ; Mucous Membrane ; Rats* ; Receptor, PAR-2 ; Stress, Psychological

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*

The cockroach represents one of the most common sources of indoor allergens worldwide, and 40%-60% of patients with asthma in urban and inner-city areas possess IgE antibodies to cockroach allergens. In Korean homes, four cockroach species have been found, of which the most commonly encountered is the German cockroach. The pathogenic mechanism underlying the association between cockroach allergens and allergic diseases has not been fully elucidated. Allergenicity is associated with the cockroach allergens themselves, enzymatic protease activity, and ligands for pattern recognition receptors. Although allergen-specific adaptive immune responses orchestrate the cockroach allergic response, recent data suggest that the innate immune system is also a critical contributor to pathogenesis. We review the current evidence for the demographics of cockroach exposure and sensitization, characteristics of cockroach allergens, and inflammatory responses to cockroach allergens initiated through protease-dependent pathways.
Allergens ; Antibodies ; Asthma ; Blattellidae ; Cockroaches ; Demography ; Humans ; Hypersensitivity ; Immune System ; Immunoglobulin E ; Ligands ; Receptor, PAR-2 ; Receptors, Pattern Recognition

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

BACKGROUND: Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. OBJECTIVE: To evaluate the basic physiological role of PAR-2 in skin. METHODS: We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. RESULTS: Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. CONCLUSION: Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands.
Blotting, Western ; Bony Callus ; Calcium ; Carcinoma, Squamous Cell ; Cell Line ; Epidermis* ; Homeostasis ; Humans ; Inflammation ; Keratinocytes ; Melanosomes ; Pain Perception ; Receptor, PAR-2 ; Skin ; Sweat Glands* ; Sweat* ; Syringoma

BACKGROUND: Protease-activated receptor 2 (PAR2) belongs to a family of G protein- coupled receptors activated by proteolytic cleavage. Trypsin-like serine proteases interact with PAR2 expressed by a variety of tissues and immune cells. The aim of our study was to investigate whether PAR2 stimulation can lead to the activation of human macrophages. METHODS: PAR2-mediated proliferation of human macrophage cell line THP-1 was measured with MTT assay. We also examined the extracellular regulated kinase (ERK) phosphorylation and cytokine production induced by trypsin and PAR2-agonist using western blot and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: Treatment of trypsin or PAR2-activating peptide increased cell proliferation in a dose-dependent manner, and induced the activation of ERK1/2 in THP-1 cells. In addition, trypsin-induced cell proliferation was inhibited by pretreatment of an ERK inhibitor (PD98059) or trypsin inhibitor (SBTI). Moreover, PAR2 activation by trypsin increased the secretion of TNF-alpha in THP-1 cells. CONCLUSION: There results suggest that PAR2 activation by trypsin-like serine proteases can induce cell proliferation through the activation of ERK in human macrophage and that PAR2 may play a crucial role in the cell proliferation and cytokine secretion induced by trypsin-like serine proteases.
Blotting, Western ; Cell Line* ; Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Humans* ; Macrophages* ; Phosphorylation ; Phosphotransferases ; Receptor, PAR-2* ; Serine Proteases ; Trypsin ; Tumor Necrosis Factor-alpha

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a lethal pulmonary fibrotic disease. In general, the exaggerated activation of the coagulation cascade has been observed during initiation or maintenance of the fibrotic disease. In our recent study, immunohistochemical expression of protease-activated receptor-2 (PAR-2), which plays a key role in coagulation cascade, was observed in surgical specimen of IPF patients, and associated with poor clinical outcome. The aim of this study was to evaluate the overexpression of PAR-2 in inflammatory cells from peripheral blood and bronchoalveolar lavage fluid in IPF patients. METHODS: From May 2011 to March 2012, IPF patients and controls were enrolled in Seoul National University Hospital. Peripheral blood and bronchoalveolar lavage fluid were collected for analysis of PAR-2 expression. Flow cytometry and reverse transcription polymerase chain reaction were used for PAR-2 receptor and mRNA assessment. RESULTS: Twelve IPF patients and 14 controls were included in this study. Among them, flow cytometry analysis was conducted from 26 peripheral blood (patient group, 11; control group, 13) and 7 bronchoalveolar lavage fluid (patient group, 5; control group, 2). The expression of PAR-2 receptor was not different between patient and control groups (p=0.074). Among all 24 population, PAR-2 mRNA assessment was performed in 19 persons (patient group, 10; control group, 9). The mRNA expression of PAR-2 was not significant different (p=0.633). CONCLUSION: In IPF patients, PAR-2 receptor and mRNA expression were not different from control group.
Bronchoalveolar Lavage ; Bronchoalveolar Lavage Fluid ; Flow Cytometry ; Humans ; Idiopathic Pulmonary Fibrosis ; Polymerase Chain Reaction ; Receptor, PAR-2 ; Reverse Transcription ; RNA, Messenger

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

Atopic dermatitis (AD) results from gene and environment interactions that lead to a range of immunological abnormalities and breakdown of the skin barrier. Protease-activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is expressed in suprabasal layers of the epidermis. PAR2 is activated by both trypsin and a specific agonist peptide, SLIGKV-NH₂ and is involved in both epidermal permeability barrier homeostasis and epithelial inflammation. In this study, we investigated the effect of lobaric acid on inflammation, keratinocyte differentiation, and recovery of the skin barrier in hairless mice. Lobaric acid blocked trypsin-induced and SLIGKV-NH₂-induced PAR2 activation resulting in decreased mobilization of intracellular Ca²⁺ in HaCaT keratinocytes. Lobaric acid reduced expression of interleukin-8 induced by SLIGKV-NH₂ and thymus and activation regulated chemokine (TARC) induced by tumor necrosis factor-a (TNF-α) and IFN-γ in HaCaT keratinocytes. Lobaric acid also blocked SLIGKV-NH₂-induced activation of ERK, which is a downstream signal of PAR2 in normal human keratinocytes (NHEKs). Treatment with SLIGKV-NH₂ downregulated expression of involucrin, a differentiation marker protein in HaCaT keratinocytes, and upregulated expression of involucrin, transglutamase1 and filaggrin in NHEKs. However, lobaric acid antagonized the effect of SLIGKV-NH₂ in HaCaT keratinocytes and NHEKs. Topical application of lobaric acid accelerated barrier recovery kinetics in a SKH-1 hairless mouse model. These results suggested that lobaric acid is a PAR2 antagonist and could be a possible therapeutic agent for atopic dermatitis.
Animals ; Chemokine CCL17 ; Dermatitis, Atopic ; Epidermis ; GTP-Binding Proteins ; Homeostasis ; Humans ; Inflammation ; Interleukin-8 ; Keratinocytes ; Kinetics ; Mice ; Mice, Hairless ; Necrosis ; Permeability ; Receptor, PAR-2 ; Skin* ; Trypsin