Essential autophagic protein Beclin 1 localizes to atherosclerotic lesions of human carotid and major intracranial arteries

Abstract

Macrophage autophagy has been shown to exert a protective role in atherosclerosis. Beclin 1 is an essential autophagic protein, and the Beclin-1-interacting complex promotes the formation of autophagosomes. However, the localization of Beclin 1 in human atherosclerotic lesions has not been clarified to date. We hence investigated the immunolocalization of Beclin 1 in atherosclerotic lesions of human carotid and major intracranial arteries. Furthermore, we investigated the colocalization of Beclin 1 with the 14–3-3 eta isoform and high mobility group box 1 (HMGB1). Beclin 1 was observed in the cytoplasm of many foamy macrophages located near to or in the periphery of lipid-rich necrotic cores. Beclin 1 colocalized with the 14–3-3 eta isoform in carotid plaques, and also colocalized with HMGB1 in carotid plaques. This is the first demonstration of Beclin 1 immunolocalization in human carotid and main cerebral artery plaques. We believe that our results will contribute towards understanding the role of autophagy in atherosclerosis and towards the prevention of stroke.