title: Inhibition of endothelial progenitor cell glycogen synthase kinase-3beta results in attenuated neointima formation and enhanced re-endothelialization after arterial injury.
abstract: OBJECTIVE
  Endothelial progenitor cells (EPCs) are circulating pluripotent vascular cells capable of enhancing re-endothelialization and diminishing neointima formation following arterial injury. Glycogen synthase kinase (GSK)-3beta is a protein kinase that has been implicated in the regulation of progenitor cell biology. We hypothesized that EPC abundance and function could be enhanced with the use of an inhibitor of GSK-3beta (GSKi), thereby resulting in improved arterial repair.
  
  
  RESULTS
  Human EPCs were expanded ex vivo, treated with a specific GSKi, and then assessed for both yield and functional characteristics by in vitro assays for adherence, apoptosis, and survival. In vivo functionality of treated human EPCs was assessed in immune-tolerant mice subjected to femoral artery wire injury. Re-endothelialization was assessed at 72 h and neointima formation at 7 and 14 days following injury. GSKi treatment resulted in an improvement in the yield of EPCs and a reduction in apoptosis in cells derived from both healthy controls and patients with coronary artery disease. Treatment also increased vascular endothelial growth factor secretion, up-regulated expression of mRNA for the alpha-4 integrin subunit, and improved adhesion, an effect which could be abrogated with an alpha-4 integrin blocking antibody. EPCs without or with ex vivo GSKi treatment enhanced re-endothelialization 72 h following injury as well as reduced neointima formation at 7 days (e.g. endothelial coverage: 7.2 +/- 1.7% vs. 70.7 +/- 5.8% vs. 87.2 +/- 4.1%; intima to media ratios: 1.05 +/- 0.19 vs. 0.39 +/- 0.08 vs. 0.14 +/- 0.02; P < 0.05 for all comparisons), an effect that was persistent at 14 days.
  
  
  CONCLUSIONS
  GSKi improves the functional profile of EPCs and is associated with improved re-endothelialization and reduced neointima formation following injury.
authors.affiliation: University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Hibbert
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Ma
authors.forename: Ali
authors.initials: A
authors.lastname: Pourdjabbar
authors.forename: Erik
authors.initials: E
authors.lastname: Holm
authors.forename: Katey
authors.initials: K
authors.lastname: Rayner
authors.forename: Yong-Xiang
authors.initials: YX
authors.lastname: Chen
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Sun
authors.forename: Lionel
authors.initials: L
authors.lastname: Filion
authors.forename: Edward R
authors.initials: ER
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001158:Arteries / Q000293:injuries* / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006706:Homeostasis; D006801:Humans; D039441:Integrin alpha4 / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D023421:Models, Animal; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology* / Q000517:prevention & control*; D013844:Thiazoles / Q000494:pharmacology; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology*; D014508:Urea / Q000031:analogs & derivatives / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D013844:Thiazoles; D042461:Vascular Endothelial Growth Factor A; D039441:Integrin alpha4; C479831:N-(4-methoxybenzyl)-N'-(5-nitro-1,3-thiazol-2-yl)urea; D014508:Urea; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3