Triglyceride-rich lipoprotein metabolism in unique VLDL receptor, LDL receptor, and LRP triple-deficient mice

J Lipid Res. 2005 Jun;46(6):1097-102. doi: 10.1194/jlr.C500007-JLR200. Epub 2005 Mar 16.

Abstract

The very low density lipoprotein receptor (VLDLR), low density lipoprotein receptor (LDLR), and low density lipoprotein receptor-related protein (LRP) are the three main apolipoprotein E-recognizing endocytic receptors involved in the clearance of triglyceride (TG)-rich lipoproteins from plasma. Whereas LDLR deficiency in mice results in the accumulation of plasma LDL-sized lipoproteins, VLDLR or LRP deficiency alone only minimally affects plasma lipoproteins. To investigate the combined effect of the absence of these receptors on TG-rich lipoprotein levels, we have generated unique VLDLR, LDLR, and LRP triple-deficient mice. Compared with wild-type mice, these mice markedly accumulated plasma lipids and lipases. These mice did not show aggravated hyperlipidemia compared with LDLR and LRP double-deficient mice, but plasma TG was increased after high-fat diet feeding. In addition, these mice showed a severely decreased postprandial TG clearance typical of VLDLR-deficient (VLDLR-/-) mice. Collectively, although VLDLR deficiency in LRP- and LDLR-/- mice does not aggravate hyperlipidemia, these triple-deficient mice represent a unique model of markedly delayed TG clearance on a hyperlipidemic background.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Cholesterol / metabolism
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / physiology
  • Genotype
  • Hyperlipidemias / pathology
  • Leucine-Responsive Regulatory Protein
  • Lipid Metabolism
  • Lipoproteins / metabolism*
  • Mice
  • Mice, Transgenic
  • Polymerase Chain Reaction
  • Receptors, LDL / genetics*
  • Receptors, LDL / physiology
  • Time Factors
  • Transcription Factors / genetics*
  • Transcription Factors / physiology
  • Triglycerides / chemistry*
  • Triglycerides / metabolism

Substances

  • DNA-Binding Proteins
  • Lipoproteins
  • Receptors, LDL
  • Transcription Factors
  • Triglycerides
  • VLDL receptor
  • Leucine-Responsive Regulatory Protein
  • Cholesterol