α-Tocopherol transfer protein does not regulate the cellular uptake and intracellular distribution of α- and γ-tocopherols and -tocotrienols in cultured liver cells.

ABSTRACT: Liver cells express a cytosolic α-tocopherol transfer protein (αTTP) with high binding affinity for α-tocopherol (αT) and much lower affinities for the non-αT congeners. The role of αTTP in the intracellular distribution of the different vitamin E forms is currently unknown. We therefore investigated the intracellular localization of αT, γ-tocopherol (γT), α-tocotrienol (αT3), and γ-tocotrienol (γT3) in cultured hepatic cells with and without stable expression of αTTP. We first determined cellular uptake of the four congeners and found the methylation of the chromanol ring and saturation of the sidechain to be important factors, with tocotrienols being taken up more efficiently than tocopherols and the γ-congeners more than the α-congeners, irrespective of the expression of αTTP. This, how

SUBMITTER: Irias-Mata A 

PROVIDER: S-EPMC6082990 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature