The roles of salusins in atherosclerosis and related cardiovascular diseases

Human salusin-alpha and -beta are related peptides of 28 and 20 amino acids, respectively, produced from the same precursor, prosalusin. Salusin-beta exerts more potent mitogenic effects on human vascular smooth muscle cells (VSMCs) and fibroblasts than salusin-alpha. Human macrophage foam cell formation is significantly stimulated by salusin-beta, but suppressed by salusin-alpha. Chronic salusin-beta infusion into apolipoprotein E knockout mice enhances atherosclerotic lesions, paralleling increases in foam cell formation and upregulation of scavenger receptors and of acyl-CoA:cholesterol acyltransferase-1 (ACAT1) in macrophages. In contrast, chronic salusin-alpha infusion reduces atherosclerotic lesions accompanied by significant suppression of foam cell formation owing to ACAT1 downregulation. Salusin-beta is expressed in proliferative neointimal lesions of porcine coronary arteries after stenting. Salusin-alpha and -beta immunoreactivity has been detected in human coronary atherosclerotic plaques, with dominance of salusin-beta in macrophage foam cells, VSMCs, and fibroblasts. Serum salusin-alpha levels are markedly decreased in patients with angiographically proven coronary artery disease compared with patients with mild hypertension and healthy volunteers. Furthermore, among patients with acute coronary syndrome, serum salusin-alpha levels are decreased in accordance with the severity of coronary atherosclerotic lesions. These findings suggest that salusin-beta may contribute to the pathogenesis of atherosclerosis. Decreased levels of salusin-alpha in circulating blood and vascular tissue are closely linked with human atherosclerosis. Therefore, salusin-alpha could be a candidate biomarker for atherosclerosis and may be therapeutically useful for prevention of atherosclerotic cardiovascular diseases. J Am Soc Hypertens 2011;5(5):359-365. (C) 2011 American Society of Hypertension. All rights reserved.