Abstract
Lipopolysaccharide (LPS) produces prostaglandins (PGs) concomitant to eliciting macrophage migration. We evaluated the role of PGs in initiating the migration of macrophages, especially focusing on PGD2 and PGE2. In RAW264.7 macrophages, cyclooxygenase (COX)-2 inhibitor, CAY10404 [3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole], completely inhibited LPS-mediated migration at 4 h (early phase) but only partially inhibited the migration at 8 h (late phase), suggesting the presence of PG-dependent and -independent pathways. In the early phase, LPS up-regulated mRNA expressions of COX-2, hematopoietic PGD synthase (H-PGDS), and microsomal-PGE synthase 1, increasing PGD2 and PGE2 substantially. The chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes (CRTH2) agonist, DK-PGD2 (13–14-dihydro-15-keto-PGD2), and the EP4 agonist, ONO-AE1-329 (16-{3-methoxymethyl}phenyl-ω-tetranor-3,7-dithia-prostaglandin E1), but not selective agonists of D prostanoid receptor, E prostanoid receptor (EP) 2, or EP3, stimulated random migration (chemokinesis). In peritoneal macrophages from CRTH2-deficient and H-PGDS-deficient mice, LPS-mediated migration was significantly inhibited at either early or late phases of the migration. The H-PGDS inhibitor, HQL-79 [4-(diphenylmethoxy)-1-[3-(1H-tetrazol-5-yl)propyl-piperidine]], partially inhibited the migration of the RAW264.7 macrophage in both phases. These results suggest the importance of the PGD2/CRTH2 pathway in LPS-mediated migration of macrophages. In the late phase of migration, LPS up-regulated monocyte chemoattractant protein (MCP)-1 mRNA. The CC chemokine receptor (CCR2) antagonist, RS102895 [1′-[2-[4-(trifluoromethyl)phenyl]ethyl]-spiro[4H-3,1-benzoxazine-4,4′-piperidin]-2(1H)-one], inhibited LPS-mediated migration in the late phase without affecting the early phase. ONO-AE1-329, but not DK-PGD2, up-regulated MCP-1 mRNA. Taken together, LPS stimulation of chemokinesis or chemotaxis, or both, occurs in macrophages via PGD2 and PGE2 in tandem arrangement; i.e., 1) LPS stimulates prostaglandin signaling, initiating early migration through the PGD2/CRTH2 and PGE2/EP4 signaling pathways; and 2) LPS leads induction of MCP-1, which contributes to later phase migration of the macrophages through the PGE2/EP4 pathway.
Footnotes
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This study was supported by the Japanese Ministry of Education (Grants-in-Aid for Scientific Research 18380173 and 19658109 to M.H., 16208029 to H.O., and 19688014 to T.M.) and by the Yakult Bioscience Foundation.
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.108.137992.
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ABBREVIATIONS: PG, prostaglandin LPS, lipopolysaccharide; TLR, Toll-like receptor; MCP, monocyte chemoattractant protein; COX, cyclooxygenase; CCR, CC chemokine receptor; RS102895, 1′-[2-[4-(trifluoromethyl)phenyl]ethyl]-spiro[4H-3,1-benzoxazine-4,4′-piperidin]-2(1H)-one; H-PGDS, hematopoietic PGD synthase; L-PGDS, lipokalin PGD synthase; DP, D prostanoid receptor; CRTH2, chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes; mPGES-1, microsomal PGE synthase-1; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; RT, reverse transcriptase; PCR, polymerase chain reaction; qRT, quantitative reverse transcriptase; Ct, threshold cycle; CAY10404, 3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole; BW245C, (4S)-(3-[(3R,S)-3-cyclohexyl-3-hydroxypropyl]-2,5-dioxo)-4-imidazolidineheptanoic acid; DK-PGD2, 13–14-dihydro-15-keto-PGD2; HQL-79, 4-(diphenylmethoxy)-1-[3-(1H-tetrazol-5-yl)propylpiperidine]; ONO-DI-004, 17S-2,5-ethano-6-oxo-17,20-dimethyl prostaglandin E1; ONO-AE1-259, 11,15-O-dimethyl prostaglandin E2; ONO-AE-248, 16S-9-deoxy-9β-chloro-15-deoxy-16-hyfroxy-17,17-trimethylene-19,20-didehydro prostaglandin F2; ONO-AE1-329, 16-{3-methoxymethyl}-phenyl-ω-tetranor-3,7-dithia-prostaglandin E1; PPAR, peroxisome proliferator-activated receptor.
- Received February 13, 2008.
- Accepted May 19, 2008.
- The American Society for Pharmacology and Experimental Therapeutics
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