| First Author | Ji Y | Year | 1999 |
| Journal | J Biol Chem | Volume | 274 |
| Issue | 47 | Pages | 33398-402 |
| PubMed ID | 10559220 | Mgi Jnum | J:115122 |
| Mgi Id | MGI:3690692 | Doi | 10.1074/jbc.274.47.33398 |
| Citation | Ji Y, et al. (1999) Hepatic scavenger receptor BI promotes rapid clearance of high density lipoprotein free cholesterol and its transport into bile. J Biol Chem 274(47):33398-402 |
| abstractText | The clearance of free cholesterol from plasma lipoproteins by tissues is of major quantitative importance, but it is not known whether this is passive or receptor-mediated. Based on our finding that scavenger receptor BI (SR-BI) promotes free cholesterol (FC) exchange between high density lipoprotein (HDL) and cells, we tested whether SR-BI would effect FC movement in vivo using [(14)C]FC- and [(3)H]cholesteryl ester (CE)-labeled HDL in mice with increased (SR-BI transgenic (Tg)) or decreased (SR-BI attenuated (att)) hepatic SR-BI expression. The initial clearance of HDL FC was increased in SR-BI Tg mice by 72% and decreased in SR-BI att mice by 53%, but was unchanged in apoA-I knockout mice compared with wild-type mice. Transfer of FC to non-HDL and esterification of FC were minor and could not explain differences. The hepatic uptake of FC was increased in SR-BI Tg mice by 34% and decreased in SR-BI att mice by 22%. CE clearance and uptake gave similar results, but with much slower rates. The uptake of HDL FC and CE by SR-BI Tg primary hepatocytes was increased by 2.2- and 2.6-fold (1-h incubation), respectively, compared with control hepatocytes. In SR-BI Tg mice, the initial biliary secretion of [(14)C]FC was markedly increased, whereas increased [(3)H]FC appeared after a slight delay. Thus, in the mouse, a major portion of the clearance of HDL FC from plasma is mediated by SR-BI. |
