title: Downregulation of N-cadherin in the neointima stimulates migration of smooth muscle cells by RhoA deactivation.
abstract: OBJECTIVE
  The aim of the study was to analyze whether cadherin- and Rho-family GTPases-mediated dynamic rearrangement of cell-cell adhesion play an important role during human arterial smooth muscle cell (haSMC) migration.
  
  
  METHODS
  Expression patterns of N-cadherin and beta-catenin were analyzed in a domestic pig restenosis model after 14, 28, and 90 days as well as in quiescent and migratory haSMCs in vitro. N-cadherin expression was upregulated by transient sense; downregulation was induced by antisense transfection. For functional inhibition, antibody GC-4 was used. Cell migration was quantified using Boyden chamber assays. Regulation of RhoA GTPase was tested by assessment of RhoA activity.
  
  
  RESULTS
  In vivo analysis of N-cadherin expression in a porcine restenosis model revealed downregulation in the neointima after 14 days. After 28 days, N-cadherin expression was slightly restored, while after 90 days, no difference between medial and neointimal expression was detectable. beta-Catenin levels remained unchanged during the whole period. According to the in vivo situation, N-cadherin was significantly downregulated in migratory haSMCs compared to quiescent cells in vitro. After N-cadherin overexpression, haSMC migration was reduced by 87% (P<0.001). By contrast, inhibition of N-cadherin in quiescent haSMCs by GC-4 increased the migratory potential by 87% (P<0.01). In haSMCs overexpressing N-cadherin, a significant upregulation of RhoA activity was demonstrated, while RhoA activity was blocked by GC-4.
  
  
  CONCLUSIONS
  These results indicate that the regulation of haSMC attachment by N-cadherins is essential for haSMC migration. Modification of N-cadherin expression and activity induces RhoA signaling with relevance for the reorganization of the actin cytoskeleton.
authors.affiliation: Medical Clinic I, University Hospital Aachen, Pauwelsstr 30, 52074 Aachen, Germany. ruediger.blindt@post.rwth-aachen.de
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Blindt
authors.forename: Anja-Katrin
authors.initials: AK
authors.lastname: Bosserhoff
authors.forename: Julia
authors.initials: J
authors.lastname: Dammers
authors.forename: Nicole
authors.initials: N
authors.lastname: Krott
authors.forename: Lütfü
authors.initials: L
authors.lastname: Demircan
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
authors.forename: Peter
authors.initials: P
authors.lastname: Hanrath
authors.forename: Christian
authors.initials: C
authors.lastname: Weber
authors.forename: Felix
authors.initials: F
authors.lastname: Vogt
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015820:Cadherins / Q000032:analysis* / Q000235:genetics; D002465:Cell Movement; D023903:Coronary Restenosis / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D023421:Models, Animal; D009130:Muscle, Smooth / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic; D016376:Oligonucleotides, Antisense / Q000235:genetics; D013552:Swine; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection / Q000379:methods; D017539:Tunica Intima / Q000378:metabolism*; D051176:beta Catenin; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D016376:Oligonucleotides, Antisense; D015534:Trans-Activators; D051176:beta Catenin; D020742:rhoA GTP-Binding Protein