Scavenger receptor class B, type I (SR-BI) is the major route for the delivery of high density lipoprotein cholesterol to the steroidogenic pathway in cultured mouse adrenocortical cells.
The class B, type I scavenger receptor, SR-BI, binds high density lipoprotein (HDL) and mediates the selective uptake of HDL cholesteryl ester (CE) by cultured transfected cells. The high levels of SR-BI expression in steroidogenic cells in vivo and its regulation by tropic hormones provides support for the hypothesis that SR-BI is a physiologically relevant HDL receptor that supplies substrate cholesterol for steroid hormone synthesis. This hypothesis was tested by determining the ability of antibody directed against murine (m) SR-BI to inhibit the selective uptake of HDL CE in Y1-BS1 adrenocortical cells. Anti-mSR-BI IgG inhibited HDL CE-selective uptake by 70% and cell association of HDL particles by 50% in a dose-dependent manner. The secretion of [3H]steroids derived from HDL containing [3H]CE was inhibited by 78% by anti-mSR-BI IgG. These results establish mSR-BI as the major route for the selective uptake of HDL CE and the delivery of HDL cholesterol to the steroidogenic pathway in cultured mouse adrenal cells.
Temel
R E
RE
Department of Pharmacological Sciences, University Medical Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.
Trigatti
B
B
DeMattos
R B
RB
Azhar
S
S
Krieger
M
M
Williams
D L
DL
D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001693:Biological Transport, Active; D018955:CD36 Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D002788:Cholesterol Esters / Q000378:metabolism; D008076:Cholesterol, HDL / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D007074:Immunoglobulin G / Q000494:pharmacology; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008954:Models, Biological; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D013256:Steroids / Q000096:biosynthesis*
D018955:CD36 Antigens; D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D017931:DNA Primers; C059714:HDL cholesteryl ester; D007074:Immunoglobulin G; D008075:Lipoproteins, HDL; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D013256:Steroids