Figure 3.

Major Plaque Features Associated With the Inferred Physical Plaque Age

Young plaques have (A) more apoptotic cells (TUNEL, log2 % apoptotic cells) and (B) larger cores (log2 % of plaque area) than old (cutoff: 8.7 years; ∗P < 0.05). (C) To compare the physical age between plaque regions, plaques were dissected into the cap, core, and interface region between the cap or core toward the media, and the age of each region was determined by ¹⁴C-dating. Neutral lipids (Oil Red O) are shown in red. Scale bars: 500 μm. (D) The cap region is physically the youngest. Lines and bars represent the median and interquartile range. Kruskal-Wallis and Mann-Whiney U tests were used (N = 52). ∗∗P < 0.01; ∗∗∗P < 0.001. (E) Representative immunofluorescent images of TUNEL (red), CD68 (green), DAPI (blue), and alpha-actin (green). TUNEL⁺alpha-actin⁺ cells in the cap and TUNEL⁺CD68⁺ in the core region are shown. Scale bars: 1 mm (left, alpha-actin) and 10 μm (immunofluorescent). TUNEL = terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling.