FIGURE 5.

Anacardic acid stimulates neutrophils via the S1P4 S1PR. A, docking of anacardic acid to the S1PR (Protein Data Bank code 3V2Y). The sphingolipid mimic present in the crystal structure is highlighted in yellow, and anacardic acid is highlighted in green/white. Anacardic acid binds to the binding pocket with a binding affinity of −10.03 kcal/mol. The aliphatic 15-carbon tail fills the large hydrophobic pocket, and the head group contains conserved hydrogen bonds to S1P1 residues Tyr²⁹, Lys³⁴, and Arg¹²⁰. B, ROS production in response to anacardic acid in the presence of antagonists of the S1P4-selective antagonist CYM50358 or the S1P1/3 antagonist VPC23019 (both 10 μm). C, concentration-response curve showing the effect of CYM50358 on anacardic acid-induced ROS production. The data shown are expressed as mean values ± S.D. and a representative experiment is shown of at least three independent experiments performed in triplicate. Where applicable, the results were analyzed by one-way analysis of variance and post hoc Newman Keuls test. ***, p < 0.001 versus control values.