title: Comparative reactivity of remnant-like lipoprotein particles (RLP) and low-density lipoprotein (LDL) to LDL receptor and VLDL receptor: effect of a high-dose statin on VLDL receptor expression.
abstract: BACKGROUND
  Comparison of the reactivity of remnant-like lipoprotein particles (RLP) and LDL particles to LDL receptor and VLDL receptor has not been investigated.
  
  
  METHODS
  LDL receptor- or VLDL receptor-transfected ldlA-7, HepG2 and L6 cells were used. Human LDL and rabbit β-VLDL were isolated by ultracentrifugation. Human RLP was isolated using an immunoaffinity mixed gel. The effect of statin on lipoprotein receptors was examined.
  
  
  RESULTS
  Both LDL receptor and VLDL receptor recognized RLP. In LDL receptor transfectants, RLP, β-VLDL and LDL all bound to LDL receptor. Cold RLP competed efficiently with DiI-β-VLDL; however, cold LDL competed weakly. In VLDL receptor transfectants, RLP and β-VLDL bound to VLDL receptor, but not LDL. RLP bound to VLDL receptor with higher affinity than β-VLDL because of higher apolipoprotein E in RLP. LDL receptor expression was induced in HepG2 by the low concentration of statin while VLDL receptor expression was induced in L6 myoblasts at higher concentration.
  
  
  CONCLUSIONS
  RLP are bound to hepatic LDL receptor more efficiently than LDL, which may explain the mechanism by which statins prevent cardiovascular risk by primarily reducing plasma RLP rather than by reducing LDL. Additionally, a high-dose of statins also may reduce plasma RLP through muscular VLDL receptor.
authors.affiliation: Third Department of Internal Medicine, University of Fukui, Faculty of Medical Science, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Imagawa
authors.forename: Sadao
authors.initials: S
authors.lastname: Takahashi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Zenimaru
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kimura
authors.forename: Jinya
authors.initials: J
authors.lastname: Suzuki
authors.forename: Isamu
authors.initials: I
authors.lastname: Miyamori
authors.forename: Tadao
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hattori
authors.forename: Tokuo T
authors.initials: TT
authors.lastname: Yamamoto
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Nakano
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Nakajima
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008074:Lipoproteins / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D032446:Myoblasts / Q000187:drug effects / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D011973:Receptors, LDL / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity; D015533:Transcriptional Activation / Q000187:drug effects; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D011804:Quinolines; D011973:Receptors, LDL; D014280:Triglycerides; C036053:VLDL receptor; C112017:remnant-like particle cholesterol; D002784:Cholesterol; D005947:Glucose; C108475:pitavastatin