Activation of NAD(P)H:Quinone Oxidoreductase 1 Prevents Arterial Restenosis by Suppressing Vascular Smooth Muscle Cell Proliferation

Abstract

—Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are important pathogenic mechanisms in atherosclerosis and restenosis after vascular injury. In this study, we investigated the effects of -lapachone ( L) (3,4-Dihydro-2,2-dimethyl-2H-naphtho[1,2-b]pyran-5,6-dione), which is a potent antitumor agent that stimulates NAD(P)H:quinone oxidoreductase (NQO)1 activity, on neointimal formation in animals given vascular injury and on the proliferation of VSMCs cultured in vitro. L significantly reduced the neointimal formation induced by balloon injury. L also dose-dependently inhibited the FCS- or platelet-derived growth factor–induced proliferation of VSMCs by inhibiting G1/S phase transition. L increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase 1 in rat and human VSMCs. Chemical inhibitors of AMPK or dominant-negative AMPK blocked the L-induced suppression of cell proliferation and the G1 cell cycle arrest, in vitro and in vivo. The activation of AMPK in VSMCs by L is mediated by LKB1 in the presence of NQO1. Taken together, these results show that L inhibits VSMCs proliferation via the NQO1 and LKB1-dependent activation of AMPK. These observations provide the molecular basis that pharmacological stimulation of NQO1 activity is a new therapy for the treatment of vascular restenosis and/or atherosclerosis which are caused by proliferation of VSMCs. (Circ Res. 2009; 104:842-850.) Key Words: vascular smooth muscle cell -lapachone AMPK NQO1 restenosis