title: Inhibition of glycogen synthase kinase 3β promotes tight junction stability in brain endothelial cells by half-life extension of occludin and claudin-5.
abstract: 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 3β (GSK3β) inhibition has on primary human brain endothelial cells. Here we show that GSK3β 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 GSK3β. Inhibition of GSK3β 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 GSK3β 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 β-catenin with ZO-1 as a function of GSK3β inhibition. Collectively, our findings suggest the possibility of using GSK3β inhibitors as a means to extend the half-life of key tight junction proteins to promote re-sealing of the BBB during neuroinflammation.
authors: Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America. servio@temple.edu
authors: Servio H
authors: SH
authors: Ramirez
authors: Shongshan
authors: S
authors: Fan
authors: Holly
authors: H
authors: Dykstra
authors: Slava
authors: S
authors: Rom
authors: Aaron
authors: A
authors: Mercer
authors: Nancy L
authors: NL
authors: Reichenbach
authors: Larisa
authors: L
authors: Gofman
authors: Yuri
authors: Y
authors: Persidsky
mesh_terms: D001552:Benzazepines / Q000494:pharmacology; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D062507:Claudin-5 / Q000378:metabolism*; D017097:Electric Impedance; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D018021:Lithium Chloride / Q000494:pharmacology; D062793:Occludin / Q000378:metabolism*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D001552:Benzazepines; D062507:Claudin-5; D004791:Enzyme Inhibitors; D007211:Indoles; D062793:Occludin; D062826:Zonula Occludens-1 Protein; C119620:kenpaullone; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; D018021:Lithium Chloride