| 67470 |
Q9DBM0 |
ABCG8_MOUSE |
ATP-binding cassette sub-family G member 8 (EC 7.6.2.-) (Sterolin-2) |
DISRUPTION PHENOTYPE |
Mice are born at the expected Mendelian rate. They display decreased cholesterol levels, but strongly increased levels of the food-derived plant sterols campesterol and beta-sitosterol in blood plasma, liver and spleen (PubMed:25378657). Besides, mutant mice may have slightly increased total plasma triglyceride levels. Expression of Abcg5 is not affected. Mutant mice display decreased biliary sterol secretion (PubMed:15040800). Mice deficient for both Abcg5 and Abcg8 appear healthy and are fertile, but display strongly increased levels of the food-derived plant sterols sitosterol and campesterol in liver and blood plasma (PubMed:12444248, PubMed:14657202, PubMed:25378657). When mice are fed chow containing 0.02% cholesterol, cholesterol levels in blood plasma and in liver are considerably lower than in wild-type (PubMed:12444248, PubMed:14657202). In spite of the increased plasma and liver levels of plant sterols, and the decreased cholesterol levels, the total sterol levels in plasma and liver are closely similar in wild-type and mutant mice (PubMed:14657202). When mice are fed chow containing 2% cholesterol, plasma cholesterol levels remain stable in wild-type, but increase 2.4-fold in mutant mice. In the liver of mice kept on chow containing 2% cholesterol, cholesterol levels increase 3-fold for wild-type mice and 18-fold for mutant mice, resulting in much higher cholesterol levels than in wild-type livers (PubMed:12444248). Dietary cholesterol absorption appears normal in mutant mice, but the absorption of dietary cholestanol, campesterol and sitosterol is increased (PubMed:12444248). At the same time, mutant mice have very low cholesterol levels in bile, suggesting that the increased hepatic cholesterol levels are due to impaired cholesterol secretion into bile (PubMed:12444248). Likewise, the levels of the food-derived plant sterols stigmasterol, sitosterol, campesterol and brassicasterol are strongly decreased in bile from mutant mice (PubMed:14657202). In contrast, biliary phospholipid and bile acid levels appear unchanged relative to wild-type (PubMed:12444248). The blood plasma of mice with liver-specific or intestine-specific disruption of Abcg5 and Abcg8 has nearly normal levels of cholesterol, and mildly increased levels of sitosterol and campesterol (PubMed:25378657). Mice with intestine-specific disruption of Abcg5 and Abcg8 have strongly increased levels of sitosterol and campesterol in enterocytes, similar to that observed for mice with complete gene disruption (PubMed:25378657). In addition, they display strongly increased levels of sitosterol and campesterol in bile (PubMed:25378657). Mice with liver-specific disruption of Abcg5 and Abcg8 have slightly increased levels of campesterol and sitosterol in the liver, and normal, low levels of sitosterol and campesterol in bile (PubMed:25378657). Enterocytes and liver from mice with liver-specific or intestine-specific disruption of Abcg5 and Abcg8 have normal cholesterol levels (PubMed:25378657). {ECO:0000269|PubMed:12444248, ECO:0000269|PubMed:14657202, ECO:0000269|PubMed:15040800, ECO:0000269|PubMed:25378657}. |