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ABCG1 is involved in vitamin E efflux
- Olivier, Maryline, Bott, Romain, Frisdal, Eric, Nowicki, Marion, Plengpanich, Wanee, Desmarchelier, Charles, Roi, Stéphanie, Quinn, Carmel M., Gelissen, Ingrid, Jessup, Wendy, Van Eck, Miranda, Guérin, Maryse, Le Goff, Wilfried, Reboul, Emmanuelle
- BBA - Molecular and Cell Biology of Lipids 2014 v.1841 pp. 1741-1751
- cholesterol, gamma-tocopherol, hepatocytes, humans, lipoproteins, liver, macrophages, mice, physiological transport, rats, tissues, transporters
- Vitamin E membrane transport has been shown to involve the cholesterol transporters SR-BI, ABCA1 and NPC1L1. Our aim was to investigate the possible participation of another cholesterol transporter in cellular vitamin E efflux: ABCG1. In Abcg1-deficient mice, vitamin E concentration was reduced in plasma lipoproteins whereas most tissues displayed a higher vitamin E content compared to wild-type mice. α- and γ-tocopherol efflux was increased in CHO cells overexpressing human ABCG1 compared to control cells. Conversely, α- and γ-tocopherol efflux was decreased in ABCG1-knockdown human cells (Hep3B hepatocytes and THP-1 macrophages). Interestingly, α- and γ-tocopherol significantly downregulated ABCG1 and ABCA1 expression levels in Hep3B and THP-1, an effect confirmed in vivo in rats given vitamin E for 5days. This was likely due to reduced LXR activation by oxysterols, as Hep3B cells and rat liver treated with vitamin E displayed a significantly reduced content in oxysterols compared to their respective controls. Overall, the present study reveals for the first time that ABCG1 is involved in cellular vitamin E efflux.