ono-ae-248 and Disease-Models--Animal

We previously demonstrated that the prostaglandin E(2) (PGE(2))-EP3 pathway negatively regulates allergic reactions in a murine allergic asthma model.. We investigated whether the PGE(2)-EP3 pathway also regulates the development of murine experimental allergic conjunctivitis (EAC).. The expression of EP3 was examined by means of RT-PCR and immunohistochemistry in wild-type mice, as well as by means of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside staining in mice deficient in EP3 (Ptger3(-/-) mice) carrying the beta-galactosidase gene at the EP3 gene locus. EAC was induced by immunization of mice with short ragweed pollen (RW), followed by challenge with eye drops of RW, and eosinophil infiltration and eotaxin-1 mRNA expression in the conjunctiva were examined. Mice were also treated with a topical application of an EP3-selective agonist during the elicitation phase. Quantitative RT-PCR was used to detect expression of COXs and prostaglandin E synthases, and ELISA was used to measure PGE(2) production in the eyelid.. EP3 was constitutively expressed in conjunctival epithelium on the ocular surface. Ptger3(-/-) mice demonstrated significantly increased eosinophil infiltration in conjunctiva after RW challenge compared with wild-type mice. Consistently, significantly higher expression of eotaxin-1 mRNA was observed in Ptger3(-/-) mice. Conversely, treatment of wild-type mice with an EP3-selective agonist resulted in a significant decrease in eosinophil infiltration, which was blunted in Ptger3(-/-) mice. Expression of COX-2 and prostaglandin E synthases was upregulated and PGE(2) content was increased in the eyelids after RW challenge.. These data suggest that PGE(2) acts on EP3 in conjunctival epithelium and downregulates the progression of EAC.

Topics: Ambrosia; Animals; beta-Galactosidase; Chemokine CCL11; Conjunctiva; Conjunctivitis, Allergic; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Eosinophils; Epithelium; Glyceraldehyde-3-Phosphate Dehydrogenases; Intramolecular Oxidoreductases; Mice; Mice, Inbred BALB C; Mice, Knockout; Pollen; Prostaglandin-E Synthases; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP3 Subtype; Up-Regulation

Prostaglandin (PG) E(2) exerts a variety of actions through 4 G protein-coupled receptors designated as EP(1), EP(2), EP(3), and EP(4). We have reported that PGE(2) acts on EP(3) in airway epithelial cells and exerts anti-inflammatory actions in ovalbumin-induced murine allergic asthma. Although EP(3) is also expressed in skin and PGE(2) is produced abundantly during skin allergic inflammation, the role of PGE(2)-EP(3) signaling in skin allergic inflammation remains unknown.. We sought to investigate whether PGE(2)-EP(3) signaling exerts anti-inflammatory actions in skin allergic inflammation.. We used a murine contact hypersensitivity (CHS) model and examined the role of EP(3) by using an EP(3)-selective agonist, ONO-AE-248 (AE248), and EP(3)-deficient mice. The inflammation was evaluated by the thickness and histology of the hapten-challenged ear. Inflammation-associated changes in gene expression and effects of AE248 were examined by means of microarray analysis of the skin. Localization of EP(3) was examined by staining for beta-galactosidase knocked in at the EP(3) locus in EP(3)-deficient mice. EP(3) action was also examined in cultured keratinocytes.. Administration of AE248 during the elicitation phase significantly suppressed CHS compared with that seen in vehicle-treated mice. Microarray analysis revealed that administration of AE248 inhibited the gene expression of neutrophil-recruiting chemokines, including CXCL1, at the elicitation site. X-gal staining in EP(3)-deficient mice revealed EP(3) expression in keratinocytes, which was further confirmed by anti-EP(3) antibody in wild-type mice. In cultured keratinocytes AE248 suppressed CXCL1 production induced by TNF-alpha.. PGE(2)-EP(3) signaling inhibits keratinocytes activation and exerts anti-inflammatory actions in murine CHS.

Topics: Animals; Chemokine CXCL1; Dermatitis, Contact; Dinitrofluorobenzene; Dinoprostone; Disease Models, Animal; Female; Gene Expression; Humans; Keratinocytes; Mice; Mice, Inbred C57BL; Oligonucleotide Array Sequence Analysis; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP3 Subtype; Signal Transduction; Skin; Tumor Necrosis Factor-alpha

Prostaglandin (PG) E2 is a potential anti-inflammatory mediator that attenuates airway inflammation. To elucidate the functions of the PGE2 receptors (EP1, EP2, EP3, and EP4) in allergic inflammation, we examined the in vivo effects of EP agonists on mucus hypersecretion and eosinophil infiltration in rat nasal epithelium.. We induced hypertrophic and metaplastic changes in goblet cells in nasal epithelium of ovalbumin-sensitized rats by intranasal challenge with ovalbumin. The effects of subcutaneous injections of EP agonists on mucus production and eosinophil infiltration were examined.. The EP4 agonist (1 to 100 microg/kg) dose-dependently inhibited ovalbumin-induced mucus production. The EP2 and EP3 agonists (100 microg/kg) also significantly inhibited mucus production. The EP3 agonist inhibited antigen-induced eosinophil infiltration, whereas the EP1 agonist showed no effect. This suppression of mucus production by the EP4 agonist was only effective when the EP4 agonist was given in the effector phase; administration in the induction phase resulted in no effect.. These results indicate that PGE2 acts as an anti-inflammatory mediator via the EP receptors of airways in allergic inflammation. Selective EP agonists may provide a new therapeutic strategy for airway mucus hypersecretion.

Topics: Alprostadil; Animals; Dinoprostone; Disease Models, Animal; Hypertrophy; Male; Metaplasia; Methyl Ethers; Mucus; Nasal Mucosa; Neutrophil Infiltration; Rats; Rats, Inbred F344; Receptors, Prostaglandin E; Rhinitis

We examined the in vivo effects of agonists for prostaglandin E2 receptors (EP1, EP2, EP3, and EP4) on mucus hypersecretion. We also examined the in vitro effects of EP agonists on airway epithelial cells.. For the in vivo study, we induced hypertrophic and metaplastic changes of goblet cells in rat nasal epithelium by intranasal lipopolysaccharide (LPS) instillation. For the in vitro study, we used NCI-H292 cells and cultured human nasal epithelial cells.. Subcutaneous injection of the EP4 agonist (1 to 100 microg/kg) dose-dependently inhibited LPS-induced mucus production and neutrophil infiltration. The EP3 agonist (100 microg/kg) also had some inhibitory effects on mucus production, whereas the EP1 and EP2 agonists showed no effect. The LPS-induced mucus secretion was significantly inhibited by the EP3 and EP4 agonists at 10(-6) mol/L in cultured epithelial cells. The LPS-induced interleukin-8 secretion was also inhibited by the EP3 and EP4 agonists.. These results indicate that the EP4 agonist inhibited LPS-induced airway mucus hypersecretion directly or indirectly through the suppression of interleukin-8 secretion and neutrophil infiltration.

Topics: Animals; Carcinoma, Mucoepidermoid; Cell Line, Tumor; Dinoprostone; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Goblet Cells; Lipopolysaccharides; Male; Mucus; Nasal Mucosa; Nose Neoplasms; Rats; Rats, Inbred F344; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP4 Subtype; Respiratory Hypersensitivity; Reverse Transcriptase Polymerase Chain Reaction; RNA, Neoplasm; Secretory Rate

Inflammatory pain is caused by sensitization of peripheral and central nociceptive neurons. Prostaglandins substantially contribute to neuronal sensitization at both sites. Prostaglandin E2 (PGE2) applied to the spinal cord causes neuronal hyperexcitability similar to peripheral inflammation. Because PGE2 can act through EP1-EP4 receptors, we addressed the role of these receptors in the spinal cord on the development of spinal hyperexcitability. Recordings were made from nociceptive dorsal horn neurons with main input from the knee joint, and responses of the neurons to noxious and innocuous stimulation of the knee, ankle, and paw were studied after spinal application of recently developed specific EP1-EP4 receptor agonists. Under normal conditions, spinal application of agonists at EP1, EP2, and EP4 receptors induced spinal hyperexcitability similar to PGE2. Interestingly, the effect of spinal EP receptor activation changed during joint inflammation. When the knee joint had been inflamed 7-11 hr before the recordings, only activation of the EP1 receptor caused additional facilitation, whereas spinal application of EP2 and EP4 receptor agonists had no effect. Additionally, an EP3alpha receptor agonist reduced responses to mechanical stimulation. The latter also attenuated spinal hyperexcitability induced by spinal PGE2. In isolated DRG neurons, the EP3alpha agonist reduced the facilitatory effect of PGE2 on TTX-resistant sodium currents. Thus pronociceptive effects of spinal PGE2 can be limited, particularly under inflammatory conditions, through activation of an inhibitory splice variant of the EP3 receptor. The latter might be an interesting target for controlling spinal hyperexcitability in inflammatory pain states.

Topics: Animals; Arthritis; Carrageenan; Cell Separation; Dinoprostone; Disease Models, Animal; Ganglia, Spinal; Kaolin; Knee Joint; Male; Neurons; Pain; Patch-Clamp Techniques; Physical Stimulation; Protein Isoforms; Rats; Rats, Wistar; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP3 Subtype; Spinal Cord