Scavenger receptor class B, type I on non-malignant and malignant human epithelial cells mediates cholesteryl ester-uptake from high density lipoproteins

Int J Biochem Cell Biol. 2003 Apr;35(4):441-54. doi: 10.1016/s1357-2725(02)00272-8.

Abstract

Hepatoma cell lines serve as a suitable model to study hepatic clearance of lipoprotein-associated cholesteryl esters (CEs). The present study aimed at investigating holoparticle-association of and selective CE-uptake from human high density lipoprotein subclass 3 (HDL3) by non-malignant adult (Chang-liver) and non-malignant fetal (WRL-68) epithelial cell lines as well as a hepatocellular carcinoma (HUH-7) cell line. Binding properties of 125I-HDL3 at 4 and 37 degrees C were similar for all three cell lines while degradation rates were highest for Chang-liver cells. Calculating the selective uptake of HDL3-associated CEs as the difference between [3H]CE- and 125I-HDL3 cell-association revealed that the selective lipid uptake and holoparticle-association was similar in Chang-liver while in WRL-68 and HUH-7 cells pronounced capacity for lipid tracer uptake in excess of holoparticle uptake was measured. Using RT-PCR, Northern and Western blot analysis, as well as immunocytochemical technique pronounced expression of scavenger receptor class B, type I (SR-BI) but not SR-BII (a splice variant of SR-BI less efficient for selective CE-uptake than SR-BI) could be identified in HUH-7 and WRL-68 cells. A polyclonal antiserum raised against SR-BI significantly decreased cell-association of [3H]CE-HDL3 in HUH-7 and WRL-68. The present findings suggest that the capacity for selective cholesteryl ester-uptake from high density lipoprotein by malignant and normal epithelial cells from the liver depends on expression of the scavenger receptor class B, type I.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD36 Antigens / metabolism*
  • CHO Cells
  • Carcinoma, Hepatocellular / metabolism
  • Cholesterol Esters / metabolism*
  • Cricetinae
  • Epithelial Cells / metabolism
  • Hepatocytes / metabolism*
  • Humans
  • Lipoproteins, HDL / metabolism*
  • Liver Neoplasms / metabolism
  • Lysosomal Membrane Proteins
  • Membrane Proteins*
  • Receptors, Lipoprotein*
  • Receptors, Scavenger
  • Scavenger Receptors, Class B
  • Sialoglycoproteins*
  • Tumor Cells, Cultured

Substances

  • CD36 Antigens
  • Cholesterol Esters
  • Lipoproteins, HDL
  • Lysosomal Membrane Proteins
  • Membrane Proteins
  • Receptors, Lipoprotein
  • Receptors, Scavenger
  • SCARB2 protein, human
  • Scarb1 protein, mouse
  • Scavenger Receptors, Class B
  • Sialoglycoproteins