Pitavastatin inhibits lysophosphatidic acid-induced proliferation and monocyte chemoattractant protein-1 expression in aortic smooth muscle cells by suppressing Rac-1-mediated reactive oxygen species generation

Vascul Pharmacol. 2007 Apr;46(4):286-92. doi: 10.1016/j.vph.2006.11.002. Epub 2006 Nov 14.

Abstract

Lysophosphatidic acid (LPA), a product generated during oxidative modification of low-density lipoprotein (LDL) and a major lipid extracted from human atherosclerotic plaques, has been shown to elicit smooth muscle cell (SMC) proliferation and inflammation, thereby being involved in atherogenesis. Recently, statins, an inhibitor of 3-hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase, have been reported to reduce the risk of cardiovascular events and slows the progression of atherosclerosis, at least partly, via pleiotropic effects. However, the effect of statin on the LPA-signaling in SMCs remains to be elucidated. In this study, we investigated whether and how pitavastatin could inhibit the LPA-induced proliferation and monocyte chemoattractant protein-1 (MCP-1) expression in cultured human aortic SMCs. LPA dose-dependently increased intracellular reactive oxygen species (ROS) generation in SMCs, which was blocked by diphenylene iodonium (DPI), an inhibitor of NADPH oxidase or pitavastatin. The anti-oxidative property of pitavastatin was prevented by simultaneous treatment of geranylgeranyl pyrophosphate. Furthermore, overexpression of dominant negative Rac-1 mutant was found to inhibit the LPA-induced ROS generation in SMCs. LPA induced Rac-1 activation in SMCs, which was suppressed by pitavastatin or LPA receptor antagonist. Pitavastatin, DPI, and an anti-oxidant N-acetylcysteine inhibited the LPA-induced proliferation and MCP-1 gene expression in SMCs. These results suggest that pitavastatin could block the LPA-induced proliferation and MCP-1 expression in SMCs by suppressing Rac-1-mediated NADPH oxidase-dependent ROS generation. Our present study provides a novel beneficial aspect of pitavastatin; pitavastatin may act as a blocker of the LPA-signaling in SMCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / pharmacology*
  • Aorta / drug effects
  • Aorta / metabolism
  • Cell Proliferation / drug effects*
  • Cells, Cultured
  • Chemokine CCL2 / metabolism
  • Dose-Response Relationship, Drug
  • Gene Expression / drug effects
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Lysophospholipids / pharmacology*
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / metabolism
  • Myocytes, Smooth Muscle / drug effects*
  • Myocytes, Smooth Muscle / metabolism
  • NADPH Oxidases / metabolism
  • Quinolines / pharmacology*
  • RNA, Messenger / metabolism
  • Reactive Oxygen Species / metabolism*
  • Receptors, Lysophosphatidic Acid / drug effects
  • Signal Transduction / drug effects*
  • Transfection
  • rac1 GTP-Binding Protein / metabolism

Substances

  • Antioxidants
  • CCL2 protein, human
  • Chemokine CCL2
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Lysophospholipids
  • Quinolines
  • RAC1 protein, human
  • RNA, Messenger
  • Reactive Oxygen Species
  • Receptors, Lysophosphatidic Acid
  • NADPH Oxidases
  • rac1 GTP-Binding Protein
  • pitavastatin
  • lysophosphatidic acid