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

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. •The protective role of macrophage autophagy in atherosclerosis has been reported.•Beclin 1 is an essential autophagy protein.•The localization of Beclin 1 in human carotid/cerebral artery plaques was demonstrated.•Beclin 1 localized to the cytoplasm of macrophages located near necrotic cores.•Colocalization of Beclin 1 with 14–3-3 eta and HMGB1 was demonstrated.•Beclin 1 may be regulated by the 14–3-3 protein and HMGB1 in macrophages.