Abstract P408: Mesenchymal Stem Cell-derived Angptl4 Improves Endothelial Permeability And Resolution Of Inflammation In Atherosclerosis

Abstract

Objective: Given the fundamental contribution of inflammation to atherosclerosis, we studied the effect of ANGPTL4 in regulating vascular lesions during atherosclerosis. Methods and Results: We analyzed plasma levels of ANGPTL4 and found that acute myocardial infarction (AMI) patients with higher levels of ANGPTL4 had fewer vascular events than did patients with lower ANGPTL4 levels ( p <0.05). Moreover, in AMI patients with heart failure (HF) at admission, the recurrence of HF was lower in patients with a higher level of ANGPTL4. We then investigated the therapeutic application of ANGPTL4 in an atherosclerosis model. Apoe-/- mice fed a high-fat diet were injected with PBS or ANGPTL4 protein (2 μg per mouse, i.p. ) three times per week for 7 weeks. En face staining and mRNA analysis showed that plaque size, necrotic core area, lipid accumulation, and inflammatory molecules were greatly reduced in the ANGPTL4 group. Aortic permeability, measured by leakage of Evans blue dye, was significantly decreased in the ANGPTL4 group. The induction of pro-inflammatory mediators was significantly inhibited in endothelial cells, vascular smooth muscle cells, and macrophages by ANGPTL4 treatment. Endothelial Krüppel-like factor 2 (KLF2) and VE-cadherin were restored to contribute to maintenance of vascular integrity by ANGPTL4 treatment. Elevated levels of circulating leptin, interleukin-6, and interleukin-1β were profoundly reduced. Most importantly, the fibrous cap was significant thicker in the ANGPTL4 group than in the PBS group. Conclusions: ANGPTL4 treatment attenuated atherogenesis, which suggests that targeting vascular stability and inflammation may serve as a novel therapeutic strategy to prevent and treat atherosclerosis. More importantly, ANGPTL4 treatment inhibits necrotic core formation in lesions, leading to the formation of more stable plaques as evidenced by increased fibrous cap thickness.