Asparagine endopeptidase cleaves apolipoprotein A1 and accelerates pathogenesis of atherosclerosis
Mengmeng Wang, … , Xifei Yang, Keqiang Ye
Mengmeng Wang, … , Xifei Yang, Keqiang Ye
Published May 15, 2025
Citation Information: J Clin Invest. 2025;135(10):e185128. https://doi.org/10.1172/JCI185128.
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Research Article Cardiology Vascular biology

Asparagine endopeptidase cleaves apolipoprotein A1 and accelerates pathogenesis of atherosclerosis

Abstract

Atherosclerosis is a slowly progressing inflammatory disease characterized with cholesterol disorder and intimal plaques. Asparagine endopeptidase (AEP) is an endolysosomal protease that is activated under acidic conditions and is elevated substantially in both plasma and plaques of patients with atherosclerosis. However, how AEP accelerates atherosclerosis development remains incompletely understood, especially from the view of cholesterol metabolism. This project aims to reveal the crucial substrate of AEP during atherosclerosis plaque formation and to lay the foundation for developing novel therapeutic agents for Atherosclerosis. Here, we show that AEP is augmented in the atherosclerosis plaques obtained from patients and proteolytically cuts apolipoprotein A1 (APOA1) and impairs cholesterol efflux and high-density lipoprotein (HDL) formation, facilitating atherosclerosis pathologies. AEP is activated in the liver and aorta of apolipoprotein E–null (APOE-null) mice, and deletion of AEP from APOE–/– mice attenuates atherosclerosis. APOA1, an essential lipoprotein in HDL for cholesterol efflux, is cleaved by AEP at N208 residue in the liver and atherosclerotic macrophages of APOE–/– mice. Blockade of APOA1 cleavage by AEP via N208A mutation or its specific inhibitor, #11a, substantially diminishes atherosclerosis in both APOE–/– and LDLR–/– mice. Hence, our findings support that AEP disrupts cholesterol metabolism and accelerates the development of atherosclerosis.

Authors

Mengmeng Wang, Bowei Li, Shuke Nie, Xin Meng, Guangxing Wang, Menghan Yang, Wenxin Dang, Kangning He, Tucheng Sun, Ping Xu, Xifei Yang, Keqiang Ye

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Figure 6

Blockade of APOA1 cleavage by AEP attenuates atherosclerosis in APOE–/– mice.

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Blockade of APOA1 cleavage by AEP attenuates atherosclerosis in APOE–/– ...
(A–L) APOE–/– mice were injected with AAV-control, AAV-APOA1, or AAV-ApoA 1 N208A virus at 6-week-old and fed with HFD for 12 weeks beginning at 8-weeks old. (A) Representative macroscopic images of aortic arch and aortic root stained with H&E and ORO. Scale bars: 1 mm (top); 25 μm (bottom 2 rows). (B) Quantification of aortic plaque and ORO area in aortic root (n = 9 per group). (C) Representative macrographs of aorta stained with ORO. Scale bar: 1 mm. (D) Quantification of aortic plaque area of whole aorta (n = 6 per group). (E) AEP enzymatic activities of aorta (n = 3 per group). (F) Serum levels of total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL-C) and HDL-C (n = 9 per group). (G) Western blot analysis of C/EBP-β, AEP, APOA1, and APOA1 N208 levels in aorta (n = 3 per group). (H and I) IF staining and quantification of CD68 (green), AEP (white), and APOA1 N208 (red) in aorta. The nuclei were counterstained with DAPI (blue) (n = 9 per group). Scale bars, 20 μm. (J) Western blot analysis of C/EBP-β, AEP, APOA1, and APOA1 N208 levels in liver (n = 3 per group). (K and L) IF staining and quantification of AEP (white) and APOA1 N208 (red) in liver. Nuclei were counterstained with DAPI (blue) (n = 9 per group). Scale bars, 20 μm. All data are presented as the mean ± SEM. 1-way ANOVA with Tukey’s post hoc test (B, D–F, I, and L). *P < 0.05; **P < 0.01; ***P < 0.001.