Objective: To test the hypothesis that chronic infusion of angiotensin-(1-7) [Ang-(1-7)] may dose-dependently inhibit atherosclerotic lesion formation by targeting vascular smooth muscle cells and a large dose of Ang-(1-7) may stabilize mature plaque by targeting macrophages.
Approach and results: In vivo, the effects of Ang-(1-7) on atherogenesis and plaque stability were observed in ApoE(-/-) mice fed a high-fat diet and chronic angiotensin II infusion. In vitro, the effects of Ang-(1-7) on vascular smooth muscle cells' proliferation and migration, and macrophage inflammatory cytokines were examined. Ang-(1-7) dose-dependently attenuated early atherosclerotic lesions and inhibited vascular smooth muscle cells' proliferation and migration via suppressing extracellular regulated protein kinase/P38 mitogen-activated protein kinase and janus kinase/signal transducers and activators of transcription activities and enhancing smooth muscle 22α and angiotensin II type 2 receptor expression. Ang-(1-7) treatment resulted in high contents of collagen and vascular smooth muscle cells, and low contents of macrophages and lipids in carotid mature plaques. Ang-(1-7) lowered the expression levels of proinflammatory cytokines and activities of matrix metalloproteinases in mature plaques.
Conclusions: Ang-(1-7) treatment inhibits early atherosclerotic lesions and increases plaque stability in ApoE(-/-) mice, thus providing a novel and promising approach to the treatment of atherosclerosis.
Keywords: angiotensin II; angiotensin-(1–7); atherosclerosis; plaque, atherosclerotic.