CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CD36 a new cellular target of electrophilic nitro-fatty acids.
Autor/es:
VAZQUEZ MM; CHIABRANDO G; ACTIS-DATO V; GUTIERREZ MV; BONACCI G
Lugar:
Chicago
Reunión:
Congreso; 25th Annual Meeting of the Society for Redox Biology and Medicine; 2018
Institución organizadora:
Society for Redox Biology and Medicine (SfRBM)
Resumen:
CD36 is a high affinity receptor that facilitates the binding and uptake of long-chain fatty acids and modified LDL into the cell. These CD36 ligands have also been described to trigger cell signaling with different effects on cell metabolism, migration and viability. Since, nitro-fatty acids are electrophilic lipid mediators which exhibit anti-inflammatory and cytoprotective actions in experimental models of atherosclerosis, cardiac isquemia/reperfusion and other inflammatory diseases, we have hypothesized that nitrolipids may bind and signal through CD36 receptor. In order to this, herein we demonstrated that Nitro-Oleic Acid (NO2-OA) displays CD36-mediated intracellular signaling via Src/ERK and AMPK pathways. Pharmacological strategies to inhibit both ligands binding to CD36 (SSO) and CD36 downstream signaling pathway for ERK (PD98059) and Src (PP1), allowed us to elucidate the specificity of the pathway involved. Therefore, to study their interaction, an in vitro assay was developed using recombinant CD36 (rCD36) and biotinylated-NO2-OA. The products of this reaction exhibited that NO2-OA interacts with CD36 revealed by Western blot using HRP-streptavidin. Competition assays with increasing molar concentration of OA, GSH and unbiotinylated NO2-OA (1:1, 1:10 and 1:100) exposed the reversibility of this interaction. Similar experimental settings showed that NO2OA impairs modified-LDL binding to rCD36, which was supplemented with experiments in RAW264.7 macrophages cell line, where pre-incubation with NO2-OA showed a decrease in cholesterol accumulation after modified-LDL treatment. This result indicates that NO2-OA may bind to the same site as modified-LDL, on the ligand binding domain, and alter its incorporation into the macrophages. Altogether this data suggests that NO2-OA acts as a CD36 ligand and triggers its downstream signaling to modulate fatty acid metabolism in macrophages.