Effects of lipoprotein lipase and statins on cholesterol uptake into heart and skeletal muscle

J Lipid Res. 2007 Mar;48(3):646-55. doi: 10.1194/jlr.M600301-JLR200. Epub 2006 Dec 22.

Abstract

Regulation of cholesterol metabolism in cultured cells and in the liver is dependent on actions of the LDL receptor. However, nonhepatic tissues have multiple pathways of cholesterol uptake. One possible pathway is mediated by LPL, an enzyme that primarily hydrolyzes plasma triglyceride into fatty acids. In this study, LDL uptake and tissue cholesterol levels in heart and skeletal muscle of wild-type and transgenic mice with alterations in LPL expression were assessed. Overexpression of a myocyte-anchored form of LPL in heart muscle led to increased uptake of LDL and greater heart cholesterol levels. Loss of LDL receptors did not alter LDL uptake into heart or skeletal muscle. To induce LDL receptors, mice were treated with simvastatin. Statin treatment increased LDL receptor expression and LDL uptake by liver and skeletal muscle but not heart muscle. Plasma creatinine phosphokinase as well as muscle mitochondria, cholesterol, and lipid droplet levels were increased in statin-treated mice overexpressing LPL in skeletal muscle. Thus, pathways affecting cholesterol balance in heart and skeletal muscle differ.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Northern
  • Cholesterol / metabolism*
  • Cholesterol / pharmacokinetics
  • Cholesterol, LDL / metabolism
  • Cholesterol, LDL / pharmacokinetics
  • Creatine Kinase / metabolism
  • Gene Expression Regulation / drug effects
  • Heart / drug effects
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Lipid Metabolism / drug effects
  • Lipoprotein Lipase / genetics
  • Lipoprotein Lipase / metabolism*
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Microscopy, Electron, Transmission
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / ultrastructure
  • Myocardium / metabolism*
  • Myocardium / ultrastructure
  • Receptors, Lipoprotein / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Simvastatin / pharmacology

Substances

  • Cholesterol, LDL
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Receptors, Lipoprotein
  • Cholesterol
  • Simvastatin
  • Creatine Kinase
  • Lipoprotein Lipase