Matrix-degrading podosomes in smooth muscle cells

Eur J Cell Biol. 2006 Apr;85(3-4):183-9. doi: 10.1016/j.ejcb.2005.08.001. Epub 2005 Sep 12.


Activation of protein kinase C by phorbol esters triggers the remodelling of the actin cytoskeleton and the formation of podosomes in smooth muscle cells (SMCs). Regional control of actin dynamics at specialised microdomains results in a local reduction in contractile forces. The molecular basis for this local inhibition of contractility includes the clustering of cortactin during podosome formation (which precedes the rapid, local dispersion of myosin, tropomyosin and h1 calponin), and the specific recruitment of 110-kDa actin filament-associated protein (AFAP-110) and 190-kDa Rho-specific GTPase-activating protein (p190RhoGAP) to the microdomains. Podosome formation also correlates with cell polarisation, the induction of cell motility, and local degradation of the extracellular matrix. These findings may provide explanations for the complex mechanisms underlying SMC invasion in the course of the development of atherosclerotic lesions and restenosis, and support the concept that matrix degradation and the concomitant engagement of the molecular machinery initiating actin-based cell motility drive tissue invasion in smooth muscle.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Actin Cytoskeleton / ultrastructure*
  • Animals
  • Cell Differentiation / physiology
  • Extracellular Matrix / metabolism*
  • Focal Adhesions / metabolism
  • Focal Adhesions / ultrastructure
  • Humans
  • Muscle, Smooth, Vascular / metabolism
  • Myocytes, Smooth Muscle / cytology
  • Myocytes, Smooth Muscle / metabolism*
  • Myocytes, Smooth Muscle / ultrastructure*
  • Signal Transduction / physiology
  • Substrate Specificity