title: Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization.
abstract: Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner.
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Srinivasa Raju
authors: SR
authors: Datla
authors: Department of Chemical and Biomolecular Engineering and.
authors: Daniel J
authors: DJ
authors: McGrail
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Sasa
authors: S
authors: Vukelic
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Lauren P
authors: LP
authors: Huff
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Alicia N
authors: AN
authors: Lyle
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Lily
authors: L
authors: Pounkova
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Minyoung
authors: M
authors: Lee
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Bonnie
authors: B
authors: Seidel-Rogol
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Mazen K
authors: MK
authors: Khalil
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Lula L
authors: LL
authors: Hilenski
authors: Department of Internal Medicine, Division of Pulmonary and Critical Care, University of Texas Southwestern Medical Center, Dallas, Texas.
authors: Lance S
authors: LS
authors: Terada
authors: Department of Chemical and Biomolecular Engineering and The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia;
authors: Michelle R
authors: MR
authors: Dawson
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta;
authors: Bernard
authors: B
authors: Lassègue
authors: Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta; kgriend@emory.edu.
authors: Kathy K
authors: KK
authors: Griendling
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion; D002465:Cell Movement; D016764:Cell Polarity; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D051381:Rats; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D010982:Platelet-Derived Growth Factor; C000593573:Poldip2 protein, rat; D006861:Hydrogen Peroxide; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498911:Nox4 protein, rat; D051416:Focal Adhesion Protein-Tyrosine Kinases; D020742:rhoA GTP-Binding Protein
keywords: NADPH oxidase 4; cytoskeleton; focal adhesions; polymerase-δ-interacting protein 2; reactive oxygen species; traction forces; vascular smooth muscle cells