Activation of activator protein 2 alpha by aspirin alleviates atherosclerotic plaque growth and instability in vivo

AIMS: Aspirin has been used for the secondary prevention and treatment of cardiovascular disease for several decades. We investigated the roles of transcriptional factor activator protein 2α (AP-2α) in the beneficial effects of aspirin in the growth and vulnerability of atherosclerotic plaque. METHODS AND RESULTS: In mice deficient of apolipoprotein E (Apoe(-/-)), aspirin (20, 50 mg/kg/day) suppressed the progression of atherosclerosis in aortic roots and increased the plaque stability in carotid atherosclerotic plaques induced by collar-placement. In vivo lentivirus-mediated RNA interference of AP-2α reversed the inhibitory effects of aspirin on atherosclerosis in Apoe(-/-) mice. Mechanically, aspirin increased AP-2α phosphorylation and its activity, upregulated IkBα mRNA and protein levels, and reduced oxidative stress in cultured vascular smooth muscle cells. Furthermore, deficiency of AP-2α completely abolished aspirin-induced upregulation of IkBα levels and inhibition of oxidative stress in Apoe(-/-) mice. Clinically, conventional doses of aspirin increased AP-2α phosphorylation and IkBα protein expression in humans subjects. CONCLUSION: Aspirin activates AP-2α to upregulate IkBα gene expression, resulting in attenuations of plaque development and instability in atherosclerosis.