Osteopontin stimulates vascular smooth muscle cell migration by inducing FAK phosphorylation and ILK dephosphorylation

Biochem Biophys Res Commun. 2007 Apr 27;356(1):13-9. doi: 10.1016/j.bbrc.2007.02.092. Epub 2007 Feb 27.

Abstract

Focal adhesion kinase (FAK) and integrin-linked kinase (ILK) are both involved in integrin-mediated cell migration. However, the molecular mechanism, and the relationship between FAK and ILK activity in signaling transduction for the osteopontin (OPN)-induced migration of vascular smooth muscle cells (VSMCs) remain unclear. Here, we show that treating VSMCs with OPN could result in the dissociation of FAK with ILK by inducing phosphorylation of the former and dephosphorylation of the latter. Furthermore, we demonstrate that FAK phosphorylation induced by OPN is coupled with ILK dephosphorylation. We also provide evidence that ILK acts downstream of FAK in the signaling pathways that mediate OPN-induced VSMC migration. These findings suggest that FAK phosphorylation and ILK dephosphorylation play important roles in VSMC migration induced by OPN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Movement / drug effects*
  • Cells, Cultured
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Immunoprecipitation
  • Male
  • Multivariate Analysis
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / drug effects*
  • Muscle, Smooth, Vascular / metabolism
  • Osteopontin / pharmacology*
  • Phosphorylation / drug effects
  • Protein Binding
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA Interference
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors

Substances

  • Osteopontin
  • integrin-linked kinase
  • Focal Adhesion Protein-Tyrosine Kinases
  • Protein Serine-Threonine Kinases