Fig. 2: IMD_1-53 promoted atherosclerotic plaque stability at the aortic root of ApoE^−/− mice.

Eight-week-old male ApoE^−/− were fed a standard chow diet (con) or a high-fat diet (HFD) for 16 weeks. After 10 weeks of HFD feeding, ApoE^−/− mice received either PBS or intermedin_1-53 (IMD_1-53) during the left 6 weeks of high-fat diet feeding. A, B Necrotic core area at the aortic root was measured. Representative H&E-stained sections (A) from each group are displayed next to the quantification data (B). Black arrows indicate the necrotic core. Scale bars, 200 μm. C, D Collagen area at the aortic root was measured. Representative picrosirius red-stained sections (C) from each group are displayed next to the quantification data (D). Scale bars, 200 μm. n = 9–11. Data are mean ± SD. ^*P < 0.05, ^**P < 0.01^; one-way ANOVA. E–H Representative images of CD68 (E) and α-SMA (F) immunohistochemical staining and quantitative analysis of macrophage (G) and vascular smooth muscle cell (VSMC) (H) contents at the aortic root of mice from each group. Black arrows indicate cells stained positively for CD68 or α-SMA. Scale bars, 200 μm. I Quantitative analysis of plaque vulnerability index at the aortic root of mice from each group. n = 6. Data are mean ± SD. ^**P < 0.01 compared with con, ^#P < 0.05, ^##P < 0.01 compared with HF group; one-way ANOVA.