CD36 a new cellular target of electrophilic Nitro-Fatty Acids.

VAZQUEZ MAXIMILIANO; GUTIERREZ VICTORIA; ACTIS DATO VIRGINIA; CHIABRANDO, GUSTAVO; BONACCI, GUSTAVO

CHICAGO

Congreso; Socity for Redox Biology and Medicine Congress; 2018

Socity for Redox Biology and Medicine

CD36 is a high affinity receptor that facilitates the binding and uptake of long-chain fatty acids and modified-LDL into the cell. These CD36ligands have also been described to trigger cell signaling with different effects on cell metabolism. Since nitro-fatty acids are electrophilic lipidmediators which exhibit anti-inflammatory and cytoprotective actions in experimental models of atherosclerosis and other inflammatorydiseases, we have hypothesized that nitrolipids may bind and signal through CD36 receptor. Hereby, we demonstrated that Nitro-Oleic Acid(NO2-OA) displays CD36-mediated intracellular signaling via Src/ERK and AMPK pathways. Pharmacological strategies to inhibit bothligands binding to CD36 (SSO) and CD36 downstream signaling pathway for ERK (PD98059) and Src (PP1), allowed us to elucidate thespecificity of the pathway involved. Therefore, to study their interaction, an in vitro assay was developed using recombinant CD36 (rCD36) andbiotinylated-NO2-OA. This reaction, revealed by Western blot, exhibited that NO2-OA interacts with CD36. Competition assays withincreasing molar concentration of OA, GSH and unbiotinylated NO2-OA exposed the reversibility of this interaction. Similar experimentalsettings showed that NO2OA impairs modified-LDL binding to rCD36, which was supplemented with experiments in RAW264.7 macrophagescell line, where pre-incubation with NO2-OA showed a decrease in cholesterol accumulation after modified-LDL treatment. Altogether this datasuggests that NO2-OA acts as a CD36 ligand and triggers its downstream signaling to modulate modified-LDL uptake and fatty acid metabolismin macrophages.