For aortic sinus analysis, hearts were fixed in 4% formalin, dehydrated, embedded with paraffin, and sliced into 5-μm-thick sections from the aortic region towards the apex of the heart. H&E staining (Servicebio) was then performed. For plaque analysis, fibrous caps and necrotic cores were examined using Masson’s trichrome staining (Servicebio). To measure fibrous cap thickness, at least three measurements of the thinnest fibrous cap within one atherosclerotic plaque were taken and averaged, as described previously.14 (link) The necrotic core area was analyzed by measuring the total acellular area in atherosclerotic plaque, as described previously.14 (link) F4/80 staining was performed to determine the macrophage content in the atherosclerotic plaque. Sections were stained with anti-F4/80 antibody (1:500, rat anti-mouse monoclonal antibody) followed by incubation with goat anti-rabbit (1:300) antibody. Slides were mounted with mounting medium containing DAPI (Servicebio). Images were analyzed in the area of atherosclerotic lesions using a confocal fluorescence microscope (Olympus, Tokyo, Japan) and Image-Pro Plus software (Media Cybernatics).