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

PURPOSE: Protease-activated receptor 2 (PAR2) reportedly triggers the immune response in allergic asthma. We aimed to investigate the mechanism on allergic inflammation mediated by PAR2. METHODS: Human lung epithelial cells (A549 cells) were used for in vitro, and the German cockroach extract (GCE)-induced mouse model was developed for in vivo studies. RESULTS: In A549 cells, the levels of reactive oxygen species (ROS) and thymic stromal lymphopoietin (TSLP) were significantly increased by GCE treatment, but were suppressed by PAR2-antagonist (PAR2-ant) or N-acetylcysteine (NAC) treatment. Claudin-1 was degraded by GCE, and was restored by PAR2-ant or NAC in the cells. In the mouse model, the clinical appearance including bronchial hyperresponsiveness, bronchoalveolar lavage fluid analysis and total immunoglobulin E were significantly suppressed by PAR2-ant or NAC. Moreover, TSLP levels in the lung were suppressed by the same treatments in the lung. Claudin-1 was also degraded by GCE, and was restored by PAR2-ant or NAC. CONCLUSIONS: ROS generation and epidermal tight junction degradation are triggered by protease, followed by the induction of TSLP in allergic asthma. Our findings could suggest that PAR2-ant or anti-oxidants could be considered for allergic diseases as preventive alternatives.
Acetylcysteine ; Animals ; Asthma ; Blattellidae ; Bronchoalveolar Lavage Fluid ; Claudin-1 ; Epithelial Cells ; Humans ; Immunoglobulin E ; Immunoglobulins ; In Vitro Techniques ; Inflammation ; Lung ; Mice ; Oxygen ; Reactive Oxygen Species ; Receptor, PAR-2 ; Receptors, Proteinase-Activated ; Tight Junctions

BACKGROUND/AIMS: Previous studies have revealed that mast cells (MCs) may activate the protease-activated receptors and release of neuropeptides involved in the pathogenesis of irritable bowel syndrome (IBS). The levels of protease-activated receptor 2 (PAR-2) and tryptase can contribute to understanding the pathogenesis of IBS. METHODS: Colonoscopic biopsies were performed of 38 subjects (20 with IBS-diarrhea [IBS-D], eight with IBS-constipation [IBS-C], and 10 healthy volunteers). The mRNA and protein levels of tryptase and PAR-2 were assessed by real-time PCR and Western blot. The levels of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene-related peptide (CGRP) were measured by immunohistochemistry, and MCs were counted by toluidine blue staining. RESULTS: Significant increases in the mRNA expression of tryptase (p<0.05, IBS-D, IBS-C vs control) and PAR-2 (p<0.05, IBS-D, IBS-C vs control) and in the tryptase protein level (p<0.05, IBS-D, IBS-C vs control) were detected in IBS. Elevations of MCs, CGRP, VIP and SP (p<0.05, IBS-D vs control) were observed for IBS-D only. CONCLUSIONS: Tryptase levels may upregulate the function of PAR-2, resulting in the release of neuropeptide and they were correlated with clinical symptoms associated with IBS.
Biopsy ; Blotting, Western ; Calcitonin Gene-Related Peptide ; Immunohistochemistry ; Inflammation ; Irritable Bowel Syndrome* ; Mast Cells ; Neuropeptides ; Real-Time Polymerase Chain Reaction ; Receptor, PAR-2* ; Receptors, Proteinase-Activated ; RNA, Messenger ; Substance P ; Tolonium Chloride ; Tryptases* ; Vasoactive Intestinal Peptide

Platelet activation has a major role in hemostasis and thrombosis. Various agonists including adenosine diphosphate (ADP) and thrombin interact with G protein-coupled receptors (GPCRs) which transduce signals through various G proteins. Recent studies have elucidated the role of GPCRs and their corresponding G proteins in the regulation of events involved in platelet activation. However, agonist-induced platelet activation in companion animals has not been elucidated. This study was designed to characterize the platelet response to various agonists in dog platelets. We found that 2-methylthio-ADP-induced dog platelet aggregation was blocked in the presence of either P2Y₁ receptor antagonist MRS2179 or P2Y₁₂ receptor antagonist AR-C69931MX, suggesting that co-activation of both the P2Y₁ and P2Y₁₂ receptors is required for ADP-induced platelet aggregation. Thrombin-induced dog platelet aggregation was inhibited in the presence of either AR-C69931MX or the PKC inhibitor GF109203X, suggesting that thrombin requires secreted ADP to induce platelet aggregation in dog platelets. In addition, thrombin-mediated Akt phosphorylation was inhibited in the presence of GF109203X or AR-C69931MX, indicating that thrombin causes Gi stimulation through the P2Y₁₂ receptor by secreted ADP in dog platelets. Unlike human and murine platelets, protease-activated receptor 4 (PAR4)-activating peptide AYPGKF failed to cause dog platelet aggregation. Moreover, PAR1-activating peptide SFLLRN or co-stimulation of SFLLRN and AYPGKF failed to induce dog platelet aggregation. We conclude that ADP induces platelet aggregation through the P2Y₁ and P2Y₁₂ receptors in dogs. Unlike human and murine platelets, selective activation of the PAR4 receptor may be insufficient to cause platelet aggregation in dog platelets.
Adenosine Diphosphate ; Animals ; Blood Platelets ; Dogs ; GTP-Binding Proteins ; Hemostasis ; Humans ; Pets ; Phosphorylation ; Platelet Activation ; Platelet Aggregation ; Receptors, Proteinase-Activated ; Thrombin ; Thrombosis

Irritable bowel syndrome (IBS) is the most common disorder referred to gastroenterologists and is characterized by altered bowel habits, abdominal pain, and bloating. Visceral hypersensitivity (VH) is a multifactorial process that may occur within the peripheral or central nervous systems and plays a principal role in the etiology of IBS symptoms. The pharmacological studies on selective drugs based on targeting specific ligands can provide novel therapies for modulation of persistent visceral hyperalgesia. The current paper reviews the cellular and molecular mechanisms underlying therapeutic targeting for providing future drugs to protect or treat visceroperception and pain sensitization in IBS patients. There are a wide range of mediators and receptors participating in visceral pain perception amongst which substances targeting afferent receptors are attractive sources of novel drugs. Novel therapeutic targets for the management of VH include compounds which alter gut-brain pathways and local neuroimmune pathways. Molecular mediators and receptors participating in pain perception and visceroperception include histamine-1 receptors, serotonin (5-hydrodytryptamine) receptors, transient receptor potential vanilloid type I, tachykinins ligands, opioid receptors, voltage-gated channels, tyrosine receptor kinase receptors, protease-activated receptors, adrenergic system ligands, cannabinoid receptors, sex hormones, and glutamate receptors which are discussed in the current review. Moreover, several plant-derived natural compounds with potential to alleviate VH in IBS have been highlighted. VH has an important role in the pathology and severity of complications in IBS. Therefore, managing VH can remarkably modulate the symptoms of IBS. More preclinical and clinical investigations are needed to provide efficacious and targeted medicines for the management of VH.
Abdominal Pain ; Central Nervous System ; Gonadal Steroid Hormones ; Humans ; Hyperalgesia ; Hypersensitivity* ; Irritable Bowel Syndrome* ; Ligands ; Pain Perception ; Pathology ; Phosphotransferases ; Receptors, Adrenergic ; Receptors, Cannabinoid ; Receptors, Glutamate ; Receptors, Opioid ; Receptors, Proteinase-Activated ; Receptors, Serotonin ; Tachykinins ; Tyrosine ; Visceral Pain

BACKGROUND AND OBJECTIVES: The nasal epithelium is the first barrier encountered by airborne allergens and an active participant in airway inflammation. Fungi have been increasingly recognized as important pathogens in sinusitis and consists of several allergenic proteins. We hypothesized that fungi induce the release of inflammatory mediators, and tried to find out the mechanism of epithelial cell activation. SUBJECTS AND METHOD: The epithelial cells of nasal polyp were obtained from patients and stimulated with Alternaria, Aspergillus, and Cladosporium. Interleukin-8 (IL-8), granulocyte-macrophage colony stimulating factor (GM-CSF), regulated on activation and normal T expressed and secreted (RANTES) were measured to determine the activation of epithelial cells. Nasal epithelial cell activation was inhibited with serine and cystein protease inhibitors. Reverse transcriptase-polymerase chain reaction (RT-PCR) test for protease-activated receptors (PARs) mRNA expression in nasal epithelial cells were performed. RESULTS: Fungi enhanced the production of chemical mediators from nasal epithelial cells. Serine protease inhibitors inhibited the activation of nasal epithelial cells. When nasal epithelial cells were activated, PAR2 and PAR3 mRNAs were more strongly expressed than non-activated cells. CONCLUSION: Serine proteases in fungi interact with nasal epithelial cells and enhance the production of inflammatory cytokines. PARs might play a role in the process of epithelial cell activation.
Allergens ; Alternaria ; Aspergillus ; Cladosporium ; Colony-Stimulating Factors ; Cytokines ; Epithelial Cells* ; Fungi* ; Humans ; Inflammation ; Interleukin-8 ; Nasal Mucosa ; Nasal Polyps ; Protease Inhibitors ; Receptors, Proteinase-Activated ; RNA, Messenger ; Serine ; Serine Proteases ; Serine Proteinase Inhibitors ; Sinusitis

BACKGROUND AND OBJECTIVES: Airway epithelial cells contribute to the pathogenesis of air disease by their interaction with inhalant pathogenic extracts. Airborne fungi interact with nasal epithelial cell and enhance the production of inflammatory cytokines. Glucocorticosteroids (GCs) have been used therapeutically for nasal polyps and allergic disease with potent anti-inflammatory effects. The purpose of this study was to investigate the inhibitory effect of GCs on fungi induced nasal epithelial cell activation. MATERIALS AND METHODS: The epithelial cells of nasal polyps were obtained from patients and stimulated with Alternaria. To evaluate the anti-inflammatory effects of GCs, Alternaria was pretreated with GCs (triamcinolone, dexamethasone, and budesonide) and cultured with epithelial cells. Interleukin-8 (IL-8) and granulocyte-macrophage colony stimulating factor (GM-CSF) were measured to determine the activation of epithelial cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) test for protease-activated receptors (PARs) mRNA expression in nasal epithelial cells were performed. RESULTS: Alternaria enhanced the production of IL-8 and GM-CSF from nasal epithelial cells. GCs inhibited the activation of nasal epithelial cells, but the PAR2 and PAR3 mRNA expression were not suppressed by GCs. CONCLUSION: These data suggest that GCs inhibit the production of chemical mediators by Alternaria, but anti-inflammatory effect of GCs are not associated with PARs.
Adrenal Cortex Hormones* ; Alternaria ; Colony-Stimulating Factors ; Cytokines ; Dexamethasone ; Epithelial Cells* ; Fungi ; Granulocyte-Macrophage Colony-Stimulating Factor ; Humans ; Interleukin-8 ; Nasal Polyps* ; Receptors, Proteinase-Activated ; RNA, Messenger

Breast Neoplasms ; metabolism ; pathology ; Cell Polarity ; Epithelial Cells ; metabolism ; pathology ; Epithelial-Mesenchymal Transition ; Eye Proteins ; metabolism ; Female ; Humans ; Membrane Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Receptors, Proteinase-Activated ; metabolism ; Tumor Suppressor Proteins ; metabolism

BACKGROUND/AIMS: Postoperative ileus (POI) is characterized by impaired propulsive function of the gastrointestinal tract after surgery. Although inflammation is considered to be an important pathogenesis of POI, significant data are lacking. We aim to correlate the recovery time of postoperative dysmotility with that of inflammation and mucosal permeability. METHODS: An experimental POI model of guinea pig was used. Contractile activity of the circular muscle of the stomach, jejunum, ileum, and proximal colon was measured through a tissue bath study. Inflammatory cells were counted, and the expression of calprotectin and tryptase were analyzed. The expression of protease-activated receptor 2 (PAR-2), claudin-1, and claudin-2 were analyzed with immunofluorescence. RESULTS: The small bowel and colon showed decreased contractile amplitude in the POI groups compared to control. In contrast to the colon, the contractile amplitude of the small bowel significantly recovered in the POI group at 6 hours after the operation compared to the control group. Inflammation was highly significant in the POI groups compared to the control and sham groups, especially in the colon. Immunofluorescence showed increased PAR-2 expression in the POI groups compared to sham. The decreased claudin-1 expression and increased claudin-2 expression may suggest increased mucosal permeability of the small bowel and colon in the POI groups. CONCLUSIONS: Increased inflammation and mucosal permeability may play an important role in the differential recovery stages in POI. These data may provide further insights into the pathophysiology and potential new therapeutic prospects of POI.
Animals ; Baths ; Claudin-1 ; Claudin-2 ; Colon ; Fluorescent Antibody Technique ; Gastrointestinal Tract ; Guinea Pigs ; Guinea ; Ileum ; Ileus ; Inflammation ; Jejunum ; Leukocyte L1 Antigen Complex ; Permeability ; Receptor, PAR-2 ; Stomach ; Tryptases

BACKGROUNDPrevious studies have indicated that thrombin (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In this study, we explored the effect of TM on the permeability of the blood brain barrier (BBB) and investigated its possible mechanism, aiming at providing a potential target for brain edema therapy after ICHs.

METHODSTM or TM + cathepsin G (CATG) was stereotaxically injected into the right caudate nucleus of Sprague-Dawley rats in vivo. BBB permeability was measured by Evans-Blue extravasation. Brain water content was determined by the dry-wet weight method. Brain microvascular endothelial cells were then cultured in vitro. After TM or TM + CATG was added to the endothelial cell medium, changes in the morphology of cells were dynamically observed by phase-contrast light microscopy, and the expression of matrix metalloproteinase-2 (MMP-2) protein was measured by immunohistochemical method.

RESULTSBBB permeability increased at 6 hours after a TM injection into the ipsilateral caudate nucleus (P < 0.05), peaked between 24 hours (P < 0.01) and 48 hours (P < 0.05) after the injection, and then declined. Brain water content changed in parallel with the changes in BBB permeability. However, at all time points, BBB permeability and brain water content after a TM + CATG injection were not significantly different from the respective parameters in the control group (P > 0.05). TM induced endothelial cell contraction in vitro in a time-dependent manner and enhanced the expression of MMP-2 protein. After incubation with TM + CATG, cell morphology and MMP-2 expression did not change significantly as compared to the control group (P > 0.05).

CONCLUSIONSIncreased BBB permeability may be one of the mechanisms behind TM-induced cerebral edema. TM induces endothelial cell contraction and promotes MMP-2 expression by activating protease activated receptor-1 (PAR-1), possibly leading to the opening of the BBB.

Animals ; Blood-Brain Barrier ; drug effects ; Body Water ; metabolism ; Brain Edema ; etiology ; Cathepsin G ; Cathepsins ; pharmacology ; Cerebral Hemorrhage ; complications ; Matrix Metalloproteinase 2 ; analysis ; Permeability ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-1 ; physiology ; Serine Endopeptidases ; Thrombin ; toxicity