PMID- 10103054
OWN - NLM
STAT- MEDLINE
DCOM- 19990519
LR  - 20190620
IS  - 0014-2956 (Print)
IS  - 0014-2956 (Linking)
VI  - 261
IP  - 1
DP  - 1999 Apr
TI  - Uptake and fate of class B scavenger receptor ligands in HepG2 cells.
PG  - 227-35
AB  - Class B scavenger receptors (SR-Bs) interact with native, acetylated and oxidized
      low-density lipoprotein (LDL, AcLDL and OxLDL), high-density lipoprotein (HDL3)
      and maleylated BSA (M-BSA). The aim of this study was to analyze the catabolism
      of CD36- and LIMPII-analogous-1 (CLA-1), the human orthologue for the scavenger
      receptor class B type I (SR-BI), and CD36 ligands in HepG2 (human hepatoma)
      cells. Saturation binding experiments revealed moderate-affinity binding sites
      for all the SR-B ligands tested with dissociation constants ranging from 20 to 30
      microg.mL-1. Competition binding studies at 4 degrees C showed that HDL and
      modified and native LDL share common binding site(s), as OxLDL competed for the
      binding of 125I-LDL and 125I-HDL3 and vice versa, and that only M-BSA and LDL may
      have distinct binding sites. Degradation/association ratios for SR-B ligands show
      that LDL is very efficiently degraded, while M-BSA and HDL3 are poorly degraded. 
      The modified LDL degradation/association ratio is equivalent to 60% of the LDL
      degradation ratio, but is three times higher than that of HDL3. All lipoproteins 
      were good cholesteryl ester (CE) donors to HepG2 cells, as a 3.6-4.7-fold
      CE-selective uptake ([3H]CE association/125I-protein association) was measured.
      M-BSA efficiently competed for the CE-selective uptake of LDL-, OxLDL-, AcLDL-
      and HDL3-CE. All other lipoproteins tested were also good competitors with some
      minor variations. Hydrolysis of [3H]CE-lipoproteins in the presence of
      chloroquine demonstrated that modified and native LDL-CE were mainly hydrolyzed
      in lysosomes, whereas HDL3-CE was hydrolyzed in both lysosomal and extralysosomal
      compartments. Inhibition of the selective uptake of CE from HDL and native
      modified LDL by SR-B ligands clearly suggests that CLA-1 and/or CD36 are involved
      at least partially in this process in HepG2 cells.
FAU - Rhainds, D
AU  - Rhainds D
AD  - Departement des Sciences Biologiques, Universite du Quebec a Montreal, Canada.
FAU - Falstrault, L
AU  - Falstrault L
FAU - Tremblay, C
AU  - Tremblay C
FAU - Brissette, L
AU  - Brissette L
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Eur J Biochem
JT  - European journal of biochemistry
JID - 0107600
RN  - 0 (CD36 Antigens)
RN  - 0 (Cholesterol Esters)
RN  - 0 (Iodine Radioisotopes)
RN  - 0 (Ligands)
RN  - 0 (Lipoproteins)
RN  - 0 (Membrane Proteins)
RN  - 0 (Receptors, Immunologic)
RN  - 0 (Receptors, Lipoprotein)
RN  - 0 (Receptors, Scavenger)
RN  - 0 (SCARB1 protein, human)
RN  - 0 (Scarb1 protein, mouse)
RN  - 0 (Scavenger Receptors, Class B)
RN  - 10028-17-8 (Tritium)
SB  - IM
MH  - Binding, Competitive
MH  - Biological Transport, Active
MH  - CD36 Antigens/*metabolism
MH  - Cell Line
MH  - Cholesterol Esters/metabolism
MH  - Humans
MH  - Iodine Radioisotopes
MH  - Kinetics
MH  - Ligands
MH  - Lipoproteins/metabolism
MH  - Lysosomes/metabolism
MH  - *Membrane Proteins
MH  - *Receptors, Immunologic
MH  - Receptors, Lipoprotein/*metabolism
MH  - Receptors, Scavenger
MH  - Scavenger Receptors, Class B
MH  - Tritium
EDAT- 1999/04/02 00:00
MHDA- 1999/04/02 00:01
CRDT- 1999/04/02 00:00
PHST- 1999/04/02 00:00 [pubmed]
PHST- 1999/04/02 00:01 [medline]
PHST- 1999/04/02 00:00 [entrez]
AID - 10.1046/j.1432-1327.1999.00264.x [doi]
PST - ppublish
SO  - Eur J Biochem. 1999 Apr;261(1):227-35. doi: 10.1046/j.1432-1327.1999.00264.x.