title: Slingshot isoform-specific regulation of cofilin-mediated vascular smooth muscle cell migration and neointima formation.
abstract: OBJECTIVE
  We hypothesized that cofilin activation by members of the slingshot (SSH) phosphatase family is a key mechanism regulating vascular smooth muscle cell (VSMC) migration and neoinitima formation following vascular injury.
  
  
  RESULTS
  Scratch wound and modified Boyden chamber assays were used to assess VSMC migration following downregulation of the expression of cofilin and each SSH phosphatase isoform (SSH1, SSH2, and SSH3) by small interfering RNA (siRNA), respectively. Cofilin siRNA greatly attenuated the ability of VSMC migration into the "wound," and platelet-derived growth factor (PDGF)-induced migration was virtually eliminated versus a 3.5-fold increase in nontreated VSMCs, establishing a critical role for cofilin in VSMC migration. Cofilin activation (dephosphorylation) was increased in PDGF-stimulated VSMCs. Thus, we assessed the role of the SSH family of phosphatases on cofilin activation and VSMC migration. Treatment with either SSH1 or SSH2 siRNA attenuated cofilin activation, whereas SSH3 siRNA had no effect. Only SSH1 siRNA significantly reduced wound healing and PDGF-induced VSMC migration. Both SSH1 expression (4.7-fold) and cofilin expression (3.9-fold) were increased in balloon injured versus noninjured carotid arteries, and expression was prevalent in the neointima.
  
  
  CONCLUSIONS
  These studies demonstrate that the regulation of VSMC migration by cofilin is SSH1 dependent and that this mechanism potentially contributes to neointima formation following vascular injury in vivo.
authors.affiliation: Department of Physiology, University of South Alabama, Mobile, AL, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Torres
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Drake
authors.forename: Viktoriya
authors.initials: V
authors.lastname: Solodushko
authors.forename: Rashmi
authors.initials: R
authors.lastname: Jadhav
authors.forename: Erika
authors.initials: E
authors.lastname: Smith
authors.forename: Petra
authors.initials: P
authors.lastname: Rocic
authors.forename: David S
authors.initials: DS
authors.lastname: Weber
mesh_terms: D051339:Actin Depolymerizing Factors / Q000502:physiology*; D000818:Animals; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D008297:Male; D008840:Microfilament Proteins / Q000187:drug effects / Q000502:physiology*; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D058426:Neointima / Q000503:physiopathology*; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D020033:Protein Isoforms; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology
chemical_list: D051339:Actin Depolymerizing Factors; D008840:Microfilament Proteins; D010982:Platelet-Derived Growth Factor; D020033:Protein Isoforms; D034741:RNA, Small Interfering; C529152:SSH1 protein, rat; C529153:SSH2 protein, rat; C569440:SSH3 protein, rat; D010744:Phosphoric Monoester Hydrolases