%0 Journal Article
%T Inhibition of Glycogen Synthase Kinase 3¦Â Promotes Tight Junction Stability in Brain Endothelial Cells by Half-Life Extension of Occludin and Claudin-5
%A Servio H. Ramirez
%A Shongshan Fan
%A Holly Dykstra
%A Slava Rom
%A Aaron Mercer
%A Nancy L. Reichenbach
%A Larisa Gofman
%A Yuri Persidsky
%J PLOS ONE
%D 2013
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0055972
%X Neuroinflammatory conditions often involve dysfunction of the Blood-Brain Barrier (BBB). Therefore, identifying molecular targets that can maintain barrier fidelity is of clinical importance. We have previously reported on the anti-inflammatory effects that glycogen synthase kinase 3¦Â (GSK3¦Â) inhibition has on primary human brain endothelial cells. Here we show that GSK3¦Â inhibitors also promote barrier tightness by affecting tight junction (TJ) protein stability. Transendothelial electrical resistance (TEER) was used to evaluate barrier integrity with both pharmacological inhibitors and mutants of GSK3¦Â. Inhibition of GSK3¦Â produced a gradual and sustained increase in TEER (as much as 22% over baseline). Analysis of subcellular membrane fractions revealed an increase in the amount of essential tight junction proteins, occludin and claudin-5, but not claudin-3. This phenomenon was attributed to a decrease in TJ protein turnover and not transcriptional regulation. Using a novel cell-based assay, inactivation of GSK3¦Â significantly increased the half-life of occludin and claudin-5 by 32% and 43%, respectively. A correlation was also established between the enhanced association of ¦Â-catenin with ZO-1 as a function of GSK3¦Â inhibition. Collectively, our findings suggest the possibility of using GSK3¦Â inhibitors as a means to extend the half-life of key tight junction proteins to promote re-sealing of the BBB during neuroinflammation.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0055972