A role of CD36 in the perception of an oxidised phospholipid species in mice.

CD36 is a broadly expressed transmembrane protein that engages multiple ligands, including polar lipids. This protein is thought to even contribute to the chemosensory detection of long-chain fatty acids in the oral cavity of rodents. In this study, we assessed whether animals consciously perceive a ligand of CD36, 1-(palmitoyl)-2-(5-keto-6-octanedioyl)phosphatidylcholine (KOdiA-PC), and if so, whether CD36 is involved in sensing the oxidised phospholipid species. We found that mice avoided or hesitated to ingest fluids containing KOdiA-PC, suggesting a conscious perception of the lipid in the animals. We assessed the involvement and role of CD36 in the KOdiA-PC perception by comparing the behavioural responses of wild-type and CD36-deficient mice to the test fluids, and provided evidence that the protein could play a role in sensing a lower level of the lipid. We also found that transection of the olfactory nerve of wild-type mice resulted in an inability to perceive KOdiA-PC, suggesting the significance of olfactory system in the lipid sensing. Our findings, coupled with the recent finding of CD36 expression in the mouse olfactory epithelium, led us to predict that the site of CD36 action in the KOdiA-PC sensing plausibly lies within the nasal cavity of the animal.