RT Journal Article SR Electronic T1 Arachidonic acid directly activates the human DP2 receptor JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP MOLPHARM-AR-2024-000884 DO 10.1124/molpharm.124.000884 A1 Kurz, Michael A1 Ulrich, Michaela A1 Kirchhofer, Sina B A1 Bittner, Alwina A1 Daude, Michael A1 Diederich, Wibke E A1 Pauk, Kim A1 Garn, Holger A1 Bünemann, Moritz YR 2024 UL http://molpharm.aspetjournals.org/content/early/2024/09/16/molpharm.124.000884.abstract AB Aberrant type 2 inflammatory responses are the underlying cause of the pathophysiology of allergic asthma, allergic rhinitis and other atopic diseases with an alarming prevalence in relevant parts of the western world. A bulk of evidence points out the important role of the DP2 receptor in this inflammation processes. A screening of different polyunsaturated fatty acids (PUFAs) at a fluorescence resonance energy transfer (FRET)-based DP2 receptor conformation sensor expressed in HEK cells revealed an agonistic effect of the prostaglandin (PG) D2 precursor arachidonic acid (AA) on DP2 receptor activity of about 80% of the effect induced by PGD2. In a combination of experiments at the conformation sensor and using a BRET-based G protein activation sensor expressed together with DP2 receptor-wt in HEK cells, we found that arachidonic acid act as a direct activator of the DP2 receptor but not DP1 receptor, in a concentration range considered physiologically relevant. Pharmacological inhibition of cyclooxygenases and lipoxygenases as well as cytochrome P450 did not lead to a diminished arachidonic acid response on the DP2 receptor, confirming a direct action of arachidonic acid on the receptor. Significance Statement We identified the prostaglandin precursor arachidonic acid to directly activate the DP2 receptor, a G protein-coupled receptor that is known to play an important role in type 2 inflammation.