Abstract 567: Atg16l1 Expression in Carotid Atherosclerotic Plaques Is Associated With Plaque Vulnerability

Objective: Autophagy has emerged as a cell survival mechanism critical for cellular homeostasis, which may play a protective role in atherosclerosis. ATG16L1, a protein essential for early stages of autophagy, has been implicated in the pathogenesis of inflammatory diseases such as Crohn’s disease. However, it is unknown whether ATG16L1 is involved in atherosclerosis. Our aim was to analyze ATG16L1 expression in carotid atherosclerotic plaques in relation to markers of plaque vulnerability. Approach and results: Histological analysis of 143 endarterectomized human carotid atherosclerotic plaques revealed that ATG16L1 was expressed in areas surrounding the necrotic core and the shoulder regions. Double immunofluorescence labelling for ATG16L1 and cell type markers CD68, α-actin-smooth muscle cell, CD31 or tryptase revealed that ATG16L1 was abundantly expressed in phagocytic cells, endothelial cells, as well as mast cells in human advanced carotid plaques. ATG16L1 immunogold labelling was predominantly obse...