Molecular pharmacology of the human prostaglandin D2 receptor, CRTH2
N Sawyer, E Cauchon, A Chateauneuf… - British journal of …, 2002 - Wiley Online Library
N Sawyer, E Cauchon, A Chateauneuf, RPG Cruz, DW Nicholson, KM Metters, GP O'Neill…
British journal of pharmacology, 2002•Wiley Online LibraryThe recombinant human prostaglandin D2 (PGD2) receptor, hCRTH2, has been expressed
in HEK293 (EBNA) and characterized with respect to radioligand binding and signal
transduction properties. High and low affinity binding sites for PGD2 were identified in the
CRTH2 receptor population by saturation analysis with respective equilibrium dissociation
constants (KD) of 2.5 and 109 nm. This revealed that the affinity of PGD2 for CRTH2 is eight
times less than its affinity for the DP receptor. Equilibrium competition binding assays …
in HEK293 (EBNA) and characterized with respect to radioligand binding and signal
transduction properties. High and low affinity binding sites for PGD2 were identified in the
CRTH2 receptor population by saturation analysis with respective equilibrium dissociation
constants (KD) of 2.5 and 109 nm. This revealed that the affinity of PGD2 for CRTH2 is eight
times less than its affinity for the DP receptor. Equilibrium competition binding assays …
- The recombinant human prostaglandin D2 (PGD2) receptor, hCRTH2, has been expressed in HEK293(EBNA) and characterized with respect to radioligand binding and signal transduction properties. High and low affinity binding sites for PGD2 were identified in the CRTH2 receptor population by saturation analysis with respective equilibrium dissociation constants (KD) of 2.5 and 109 nM. This revealed that the affinity of PGD2 for CRTH2 is eight times less than its affinity for the DP receptor.
- Equilibrium competition binding assays revealed that of the compounds tested, only PGD2 and several related metabolites bound with high affinity to CRTH2 (Ki values ranging from 2.4 to 34.0 nM) with the following rank order of potency: PGD2>13,14‐dihydro‐15‐keto PGD2>15‐deoxy‐Δ12,14‐PGJ2>PGJ2>Δ12‐PGJ2>15(S)‐15 methyl‐PGD2. This is in sharp contrast with the rank order of potency obtained at DP : PGD2>PGJ2>Δ12‐PGJ2>15‐deoxy‐Δ12,14‐PGJ2 >>>13,14‐dihydro‐15‐keto‐PGD2.
- Functional studies demonstrated that PGD2 activation of recombinant CRTH2 results in decrease of intracellular cAMP in a pertussis toxin‐sensitive manner. Therefore, we showed that CRTH2 can functionally couple to the G‐protein Gαi/o. PGD2 and related metabolites were tested and their rank order of potency followed the results of the membrane binding assay.
- By Northern blot analysis, we showed that, besides haemopoietic cells, CRTH2 is expressed in many other tissues such as brain, heart, thymus, spleen and various tissues of the digestive system. In addition, in situ hybridization studies revealed that CRTH2 mRNA is expressed in human eosinophils. Finally, radioligand binding studies demonstrated that two eosinophilic cell lines, butyric acid‐differentiated HL‐60 and AML 14.3D10, also endogenously express CRTH2.
British Journal of Pharmacology (2002) 137, 1163–1172. doi:10.1038/sj.bjp.0704973
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