标题：Scavenger receptor class B type I is solely responsible for the selective uptake of cholesteryl esters from HDL by the liver and the adrenals in mice
出版社：American Society for Biochemistry and Molecular Biology
摘要：Scavenger receptor class B type I (SR-BI) has been identified as a functional HDL binding protein that can mediate the selective uptake of cholesteryl ester (CE) from HDL. To quantify the in vivo role of SR-BI in the process of selective uptake, HDL was labeled with cholesteryl ether ([3H] CEt-HDL) and 125I-tyramine cellobiose ([125I]TC-HDL) and injected into SR-BI knockout (KO) and wild-type (WT) mice. In SR-BI KO mice, the clearance of HDL-CE from the blood circulation was greatly diminished (0.043 ± 0.004 pools/h for SR-BI KO mice vs. 0.106 ± 0.004 pools/h for WT mice), while liver and adrenal uptake were greatly reduced. Utilization of double-labeled HDL ([3H]CEt and [125I]TC) indicated the total absence in vivo of the selective decay and liver uptake of CE from HDL in SR-BI KO mice. Parenchymal cells isolated from SR-BI KO mice showed similar association values for [3H]CEt and [125I]TC in contrast to WT cells, indicating that in parenchymal liver cells SR-BI is the only molecule exerting selective CE uptake from HDL. Thus, in vivo and in vitro, SR-BI is the sole molecule mediating the selective uptake of CE from HDL by the liver and the adrenals, making it the unique target to modulate reverse cholesterol transport.
