Expression of proteasome β5 subunit in human atherosclerotic plaque

Abstract

To evaluate the expression of proteasome β5 subunit in human atherosclerotic plaque. The specimens of carotid endarterectomy were collected from 16 carotid stenosis patients. For the case group, they were divided into 2 groups: plaque (group A) and areas adjacent to plaque (group B). And carotid endarterium was obtained from 6 patients undergoing aortic replacement surgery. Relatively normal arterial intima (subclavian artery & innominate artery) was selected as the control group (group C). Content of proteasome β5 subunit was evaluated by hematoxylin & eosin (HE) staining, immunohistochemistry and Western blot. (1) In patients with diabetes, hyperlipidemia and probable smoking, proteasome β5 subunit was enhanced in all groups; (2) Proteasome β5 subunit was demonstrated in both cytoplasm and nucleus of vascular smooth muscle cells, but mainly confined to cytoplasm; (3)The positive expression rate of β5 was 9/16 in group A, 11/16 in group B and 6/6 in group C. There was significant divergence in the expression of β5 in different sample sub-groups: group A (atherosclerotic plaque) < group B (areas adjacent to plaque) < group C (control group). The expression of β5 decrease markedly in human atherosclerotic plaques.