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Purpose: The study aim was to evaluate the effect of Alzheimer's disease (AD) and inflammatory insult on the function of L-type amino acid transporter 1 (Lat1) at the mouse blood-brain barrier (BBB) as well as Lat1 function and expression in mouse primary astrocytes.Methods: The Lat1 function and expression was determined in wildtype astrocytes with and without lipopolysaccharide (LPS)-induced inflammation and in LPS treated AD APP/PS1 transgenic astrocytes. The function of Lat1 at the BBB was evaluated in wildtype mice with and without LPS-induced neuroinflammation and APP/PS1 transgenic mice by in situ brain perfusion.Results: There were 2.1 and 1.6 -fold decreases in Lat1 mRNA and protein expression in LPS-treated wildtype astrocytes compared to vehicle-treated astrocytes. In contrast, Lat1 mRNA and protein expression were increased by 1.7 and 1.2 -fold (not statistically significant) in the transgenic cells. A similar trend was observed in the cell uptake of [14C]-L-leucine. There were no statistically significant differences in [14C]-L-leucine BBB permeation between the groups.Conclusions: The results showed that neither LPS-induced inflammation or the presence of APP/PS1 mutations alters Lat1 function at the mouse BBB as well as Lat1 protein expression and function in mouse primary astrocytes. [ABSTRACT FROM AUTHOR]

Purpose: The anti-epileptic drug pregabalin crosses the blood-brain barrier (BBB) in spite of its low lipophilicity. This study was performed to determine whether L-type amino acid transporters (LAT1/SLC7A5 and LAT2/SLC7A8) contribute to the uptake of pregabalin.Methods: Pregabalin uptake by LATs-transfected HEK293 cells or hCMEC/D3 cells, an in vitro human BBB model, was measured by LC-MS/MS analysis. Expression of LAT1 mRNA in hCMEC/D3 cells was determined by quantitative RT-PCR analysis.Results: Overexpression of LAT1, but not LAT2, in HEK293 cells significantly increased the cellular uptake of pregabalin, and the LAT1-mediated uptake was saturable with a Km of 0.288 mM. LAT1-mediated amino acid uptake was inhibited specifically and almost completely in the presence of 1 mM pregabalin. The uptake of pregabalin by hCMEC/D3 cells was sodium-independent, saturable (Km = 0.854 mM), and strongly inhibited by large amino acids at 1 mM, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid, a specific system L inhibitor, at 1 mM and by JPH203, a LAT1-selective inhibitor, at 10 μM. Pregabalin uptake in hCMEC/D3 cells was also decreased by 75% by the silencing of LAT1 gene using LAT1 siRNA.Conclusions: Our results indicate that LAT1, but not LAT2, recognizes pregabalin as a substrate. It is suggested that LAT1 mediates pregabalin transport at the BBB. [ABSTRACT FROM AUTHOR]

Purpose: The study aim was to evaluate the effect of Alzheimer's disease (AD) and inflammatory insult on the function of L-type amino acid transporter 1 (Lat1) at the mouse blood-brain barrier (BBB) as well as Lat1 function and expression in mouse primary astrocytes., Methods: The Lat1 function and expression was determined in wildtype astrocytes with and without lipopolysaccharide (LPS)-induced inflammation and in LPS treated AD APP/PS1 transgenic astrocytes. The function of Lat1 at the BBB was evaluated in wildtype mice with and without LPS-induced neuroinflammation and APP/PS1 transgenic mice by in situ brain perfusion., Results: There were 2.1 and 1.6 -fold decreases in Lat1 mRNA and protein expression in LPS-treated wildtype astrocytes compared to vehicle-treated astrocytes. In contrast, Lat1 mRNA and protein expression were increased by 1.7 and 1.2 -fold (not statistically significant) in the transgenic cells. A similar trend was observed in the cell uptake of [ 14 C]-L-leucine. There were no statistically significant differences in [ 14 C]-L-leucine BBB permeation between the groups., Conclusions: The results showed that neither LPS-induced inflammation or the presence of APP/PS1 mutations alters Lat1 function at the mouse BBB as well as Lat1 protein expression and function in mouse primary astrocytes.