The expression of scavenger receptor class B, type I (SR-BI) and caveolin-1 in parenchymal and nonparenchymal liver cells.
The liver is the major site of cholesterol synthesis and metabolism, and the only substantive route for eliminating blood cholesterol. Scavenger receptor class B, type I (SR-BI) has been reported to be responsible for mediating the selective uptake of high-density lipoprotein cholesteryl esters (HDL-CE) in liver parenchymal cells (PC). We analysed the expression of SR-BI in isolated rat liver cells, and found the receptor to be highly expressed in liver PC at both the mRNA and protein levels. We also found SR-BI to be expressed in liver endothelial cells (LEC) and Kupffer cells (KC). SR-BI has not previously been reported to be present in LEC. CD36 mRNA was expressed in all three liver cell types. Since caveolin-1 appears to colocalize with SR-BI and CD36 in caveolae of several cell lines, the distribution and expression of caveolin-1 in the liver cells were investigated. Caveolin-1 was not detected in PC but was found in both LEC and KC. This led to the suggestion that caveolin-1 may be more important in the efflux of cholesterol than in the selective uptake of cholesterol in the liver.
Malerød
Lene
L
Division of Molecular Cell Biology, Department of Biology, University of Oslo, P.O. Box 1050 Blindern, 0316 Oslo, Norway.
Juvet
Kristine
K
Gjøen
Tor
T
Berg
Trond
T
D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D007728:Kupffer Cells / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008815:Mice, Inbred Strains; D051381:Rats; D017208:Rats, Wistar; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D014018:Tissue Distribution
C495540:CAV1 protein, human; D018955:CD36 Antigens; C495541:Cav1 protein, mouse; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C495124:SCARB1 protein, human; C454739:Scarb1 protein, mouse; C495125:Scarb1 protein, rat; D051122:Scavenger Receptors, Class B; D008049:Lipase