Statin induction of liver fatty acid-binding protein (L-FABP) gene expression is peroxisome proliferator-activated receptor-alpha-dependent

J Biol Chem. 2004 Oct 29;279(44):45512-8. doi: 10.1074/jbc.M407461200. Epub 2004 Aug 27.

Abstract

Statins are drugs widely used in humans to treat hypercholesterolemia. Statins act by inhibiting cholesterol synthesis resulting in the activation of the transcription factor sterol-responsive element-binding protein-2 that controls the expression of genes involved in cholesterol homeostasis. Statin therapy also decreases plasma triglyceride and non-esterified fatty acid levels, but the mechanism behind this effect remains more elusive. Liver fatty acid-binding protein (L-FABP) plays a role in the influx of long-chain fatty acids into hepatocytes. Here we show that L-FABP is a target for statins. In rat hepatocytes, simvastatin treatment induced L-FABP mRNA levels in a dose-dependent manner. Moreover, L-FABP promoter activity was induced by statin treatment. Progressive 5'-deletion analysis revealed that the peroxisome proliferator-activated receptor (PPAR)-responsive element located at position -67/-55 was responsible for the statin-mediated transactivation of the rat L-FABP promoter. Moreover, treatment with simvastatin and the PPARalpha agonist Wy14,649 resulted in a synergistic induction of L-FABP expression (mRNA and protein) in rat Fao hepatoma cells. This effect was also observed in vivo in wild-type mice but not in PPARalpha-null animals demonstrating the direct implication of PPARalpha in L-FABP regulation by statin treatment. Statin treatment resulted in a rise in PPARalpha mRNA levels both in vitro and in vivo and activated the mouse PPARalpha promoter in a reporter assay. Altogether, these data demonstrate that L-FABP expression is up-regulated by statins through a mechanism involving PPARalpha. Moreover, PPARalpha might be a statin target gene. These effects might contribute to the triglyceride/non-esterified fatty acid-lowering properties of statins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Caco-2 Cells
  • Carrier Proteins / genetics*
  • Fatty Acid-Binding Proteins
  • Gene Expression Regulation / drug effects*
  • Hepatocytes / metabolism
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Mice
  • Molecular Sequence Data
  • PPAR alpha / genetics
  • PPAR alpha / physiology*
  • Promoter Regions, Genetic
  • Pyrimidines / pharmacology
  • RNA, Messenger / analysis
  • Rats
  • Simvastatin / pharmacology*

Substances

  • Carrier Proteins
  • FABP1 protein, human
  • Fabp1 protein, mouse
  • Fabp1 protein, rat
  • Fatty Acid-Binding Proteins
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • PPAR alpha
  • Pyrimidines
  • RNA, Messenger
  • pirinixic acid
  • Simvastatin