Adipocyte fatty acid binding protein acts as a suppressor of autophagy contributing to foam cell formation

Abstract

Background and objectives: Growing bodies of evidence demonstrate that adipocyte fatty acid binding protein (A-FABP) mediates the pathogenesis of atherosclerosis through its direct impacts on macrophages. Loss-of-function study was conducted by utilizing peritoneal macrophages derived from A-FABP knockout (KO) mice, to investigate the role of A-FABP in autophagy and macrophage foam cell formation.

Key findings: 1. No morphological changes between the peritoneal macrophages derived from A-FABP knockout (KO) or their wild-type (WT) littermates. 2. Foam cell formation was successfully induced by the treatment of acetylated low-density lipoproteins (LDL) in peritoneal macrophages derived from A-FABP WT and KO mice. 3. LDL treatment induces autophagy in peritoneal macrophages from both A-FABP WT and KO mice. 4. The extent of LDL-induced autophagy is reduced in peritoneal macrophages of WT mice and is accompanied by increased lipid droplet accumulation when compared with A-FABP KO mice.

Conclusions: A-FABP is a suppressor of autophagy and contributes to the attenuation of cholesterol efflux, subsequently resulting in enhancement of lipid droplets accumulation in peritoneal macrophages. A-FABP mediates the formation of macrophage foam cell via the suppression of autophagy. The results suggest that A-FABP is a potential therapeutic target to suspend the progression of atherosclerosis and remit the atherosclerotic lesion.