Retinoids Inhibit the Actions of Angiotensin II on Vascular Smooth Muscle Cells

ABSTRACT—Retinoids are derivatives of vitamin A and powerful inhibitors of cell proliferation and inflammation. Angiotensin II (Ang II) contributes to vascular lesions by promoting cell growth of vascular smooth muscle cells (VSMCs). Therefore, we examined whether retinoids interfere with the proproliferative actions of Ang II in VSMCs via AT1 receptor-dependent or activator protein-1 (AP-1)-dependent mechanisms. VSMCs express retinoid receptor proteins, ie, retinoic acid receptor (RAR) α and retinoid X receptor (RXR) α. Long-term exposure to 1 μmol/L all-trans retinoic acid (RA) dose-dependently inhibited Ang II-induced cell proliferation (P