Osteopontin is required for angiotensin II-induced migration of vascular smooth muscle cells.

Migration and proliferation of vascular smooth muscle cells (VSMCs) play a prominent role in the development of atherosclerotic plaques and restenosis lesions. Angiotensin II (Ang-II) is typically associated with excessive proliferation and migration of VSMCs and vascular remodeling. High levels of osteopontin (OPN) mRNA and protein were reported in human atherosclerotic plaque from the aorta, carotid and coronary arteries. However whether OPN plays a role in VSMCs migration induced by Ang-II is unknown. Here we show that, in primary cultured rat VSMCs, Ang-II exhibits chemotactic effect on cultured VSMCs and induces OPN expression dose-dependently. With a lentiviral shRNA specifically targeting OPN and transwell migration assay, we find that blockade of OPN with shRNA inhibits Ang-II-induced MMP9 upregulation and VSMCs migration. Our results demonstrated that OPN is required for Ang-II to induce VSMCs migration and suggested OPN as a potential target in preventing atherosclerotic development.