AIBP reduces atherosclerosis by promoting reverse cholesterol transport and ameliorating inflammation in apoE−/− mice

ApoA-1 binding protein (AIBP) is a secreted protein that interacts with apoA-I and accelerates cholesterol efflux from cells. We have recently reported that AIBP promotes apoA-1 binding to ABCA1 in the macrophage cell membrane, partially through 115–123 amino acids. However, the effects of AIBP on the development of atherosclerosis in vivo remain unknown. ApoE−/− mice with established atherosclerotic plaques were infected with rAAV-AIBP or rAAV-AIBP(Δ115-123), respectively. AIBP-treated mice showed reduction of atherosclerotic lesion formation, increase in circulating HDL levels and enhancement of reverse cholesterol transport to the plasma, liver, and feces. AIBP increased ABCA1 protein levels in aorta and peritoneal macrophages. Furthermore, AIBP could diminish atherosclerotic plaque macrophage content and the expression of chemotaxis-related factors. In addition, AIBP prevented macrophage inflammation by inactivating NF-κB and promoted the expression of M2 markers like Mrc-1 and Arg-1. However, lack of 115–123 amino acids of AIBP(Δ115-123) had no such preventive effects on the progression of atherosclerosis. Our observations demonstrate that AIBP inhibits atherosclerosis progression and suggest that it may be an effective target for prevention of atherosclerosis. •AIBP alleviates atherosclerotic plaques in apoE−/− mice.•AIBP increases circulating HDL cholesterol levels and enhances RCT in apoE−/− mice.•AIBP decreases macrophage accumulation, migration and expression of chemotactic factors.•AIBP diminishes inflammation in apoE−/− mice.