Regulation by adrenocorticotropic hormone of the in vivo expression of scavenger receptor class B type I (SR-BI), a high density lipoprotein receptor, in steroidogenic cells of the murine adrenal gland.
The class B, type I scavenger receptor, SR-BI, binds high density lipoprotein (HDL) and can mediate selective uptake of HDL cholesteryl esters by cultured cells. The high levels of expression of SR-BI in steroidogenic tissues and the importance of selective uptake from HDL as a source of cholesterol for steroidogenesis raised the possibility that SR-BI may participate in cholesterol delivery to steroidogenic tissues in vivo. We have used immunoblotting and immunohistochemical methods to show that SR-BI is specifically expressed in a distinctive pattern on the surfaces of steroid-producing cells in the murine adrenal gland's cortex and that its expression in vivo is induced by adrenocorticotropic hormone and suppressed by glucocorticoids. Thus, expression of SR-BI protein is coordinately regulated with adrenal steroidogenesis. These data provide strong support for the hypothesis that SR-BI is a physiologically relevant HDL receptor that provides substrate cholesterol for steroid hormone synthesis.
Rigotti
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Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. krieger@mit.edu
Edelman
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ER
Seifert
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P
Iqbal
S N
SN
DeMattos
R B
RB
Temel
R E
RE
Krieger
M
M
Williams
D L
DL
D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism*; D002352:Carrier Proteins; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D008075:Lipoproteins, HDL; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D016601:RNA-Binding Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein / Q000378:metabolism*; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B
D018955:CD36 Antigens; D002352:Carrier Proteins; D008075:Lipoproteins, HDL; D008565:Membrane Proteins; D016601:RNA-Binding Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; C031616:high density lipoprotein receptors; C075197:high density lipoprotein binding protein; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone