A polarized localization of amino acid/carnitine transporter B^0,+ (ATB^0,+) in the blood-brain barrier

Magdalena Czeredys (1) , Caroline Mysiorek (2) , Natalia Kulikova (1) , Lukasz Samluk (1) , Vincent Berezowski (2) , Roméo Cecchelli (2) , Katarzyna A. Nalecz (1)

1 Nencki Institute of Experimental Biology
2 LBHE - Laboratoire de Physiopathologie de la Barrière Hémato-Encéphalique

Brain capillary endothelial cells control the uptake and efflux from the brain of many hydrophilic compounds due to highly specialized transporters often localized in a polarized way. Localization of Na⁺- and Cl^--dependent amino acid and carnitine transporter B^0,+ (ATB^0,+) was studied in a co-culture of bovine brain capillary endothelial cells (BBCEC) grown on filters above astrocytes (an in vitro blood-brain barrier model). Immunoblotting and three-dimensional immunocytochemistry analysis with anti- B^0,+antibodies demonstrated the presence of this transporter and its prevalent co-localization with P-glycoprotein i.e. at the apical side. The sensitivity of leucine uptake through the apical membrane to 2-aminobicyclo-[2.2.1]-heptane-2-carboxylic acid (BCH), D-serine as well as sodium and chloride replacement confirm the functioning of ATB^0,+ and suggests an important physiological role of ATB^0,+ in controlling the delivery of amino acids and carnitine to the brain.

Mots clés: ATB<SUP>0; +</SUP>; Blood-brain barrier; Leucine; Carnitine; Astrocytes

Domaines: Biochimie, Biologie Moléculaire

Magdalena Czeredys, Caroline Mysiorek, Natalia Kulikova, Lukasz Samluk, Vincent Berezowski, et al.. A polarized localization of amino acid/carnitine transporter B^0,+ (ATB^0,+) in the blood-brain barrier. Biochemical and Biophysical Research Communications, 2008, 376 (2), p. 267-270. ⟨hal-00543646⟩