Structural determinants of arylacetic acid nonsteroidal anti-inflammatory drugs necessary for binding and activation of the prostaglandin D2 receptor CRTH2.

Article Details

Citation

Hata AN, Lybrand TP, Marnett LJ, Breyer RM

Structural determinants of arylacetic acid nonsteroidal anti-inflammatory drugs necessary for binding and activation of the prostaglandin D2 receptor CRTH2.

Mol Pharmacol. 2005 Mar;67(3):640-7. Epub 2004 Nov 24.

PubMed ID
15563582 [ View in PubMed
]
Abstract

The chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) receptor, a G protein-coupled receptor that mediates chemotaxis of inflammatory cells in response to prostaglandin D2 (PGD2), is hypothesized to play a role in Th2-mediated allergic disease. In addition to PGD2, CRTH2 can be activated by indomethacin, a nonselective cyclooxygenase inhibitor and widely used nonsteroidal anti-inflammatory drug (NSAID). To evaluate the structural features that confer CRTH2 binding selectivity, structure-activity relationship analysis of arylacetic acid class NSAIDs as CRTH2 receptor ligands was performed. Indomethacin, sulindac sulfide, and zomepirac displaced [3H]PGD2 binding at the mouse CRTH2 receptor (mCRTH2) with comparable affinity (Ki = 1.5 +/- 0.1, 2.5 +/- 0.4, and 3.3 +/- 0.3 microM, respectively). The indomethacin metabolite 5'-O-desmethyl indomethacin (5'-DMI) possessed binding affinity similar to indomethacin; however, elimination of the 2-methyl substituent on the indole ring resulted in a 10-fold decrease in binding affinity. No binding was detected for indole acetic acid and indole derivatives such as tryptophan, serotonin, and 5-hydroxy indole acetic acid, demonstrating the importance of the N-acyl moiety of indomethacin. Neutral derivatives of indomethacin also failed to bind to mCRTH2, suggesting that the negatively charged carboxylate moiety participates in a key ligand-receptor interaction. Despite similar binding affinities, NSAID-type mCRTH2 ligands exhibited variable potencies as mCRTH2 agonists. Sulindac sulfide and 5'-DMI inhibited intracellular cyclic AMP ([cAMP]i) generation and stimulated cell migration comparable with indomethacin. In contrast, zomepirac did not inhibit [cAMP]i generation or stimulate cell migration but weakly antagonized the effects of indomethacin on [cAMP]i. Together, these results reveal structural features of arylacetic acid NSAIDs that may be exploited for the development of selective CRTH2 ligands.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
IndomethacinProstaglandin D2 receptor 2ProteinHumans
Unknown
Other/unknown
Details
SulindacProstaglandin D2 receptor 2ProteinHumans
Unknown
Antagonist
Details
ZomepiracProstaglandin D2 receptor 2ProteinHumans
Unknown
Not AvailableDetails