VEGF-A stimulates podosome-mediated collagen-IV proteolysis in microvascular endothelial cells

J Cell Sci. 2016 Jul 1;129(13):2586-98. doi: 10.1242/jcs.186585. Epub 2016 May 26.


Podosomes are dynamic cell-matrix contact structures that combine several key abilities, including adhesion, matrix degradation and mechanosensing. These actin-based cytoskeletal structures have been mostly studied in monocytic cells, but much less is known about those formed in other lineages. In this study, we characterise podosomes in capillary-derived microvascular endothelial cells. We identify two types of podosomes: constitutive podosomes that form in the absence of specific stimulation and induced podosomes that arise in response to the angiogenic factor VEGF-A. Constitutive and VEGF-A-induced podosomes share similar components but exhibit marked differences in terms of gelatinolytic activity. We also show that the extracellular matrix proteins laminin and collagen-IV are key determinants of the VEGF-A response, but neither collagen-I nor fibronectin are conducive for podosome induction. Moreover, only collagen-IV elicits the formation of proteolytically active podosomes through a mechanism involving increased Src phosphorylation, p190RhoGAP-B (also known as ARHGAP5) relocalisation and MT1-MMP (also known as MMP14) cell surface exposure at podosome sites. We hypothesise that by promoting podosome formation, VEGF-A enables endothelial cells to overcome the basement membrane barrier to allow sprouting outwards from the existing vasculature.

Keywords: Basement membrane; Collagen-IV; Endothelial cells; Podosomes; VEGF-A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Collagen Type IV / biosynthesis
  • Collagen Type IV / genetics*
  • Cytoskeleton / genetics
  • Cytoskeleton / metabolism
  • Endothelial Cells / metabolism
  • GTPase-Activating Proteins / biosynthesis
  • GTPase-Activating Proteins / genetics*
  • Gene Expression Regulation
  • Humans
  • Matrix Metalloproteinase 14 / biosynthesis
  • Matrix Metalloproteinase 14 / genetics*
  • Phosphorylation
  • Podosomes / genetics
  • Podosomes / metabolism*
  • Proteolysis
  • Vascular Endothelial Growth Factor A / administration & dosage
  • Vascular Endothelial Growth Factor A / metabolism*


  • ARHGAP5 protein, human
  • Actins
  • Collagen Type IV
  • GTPase-Activating Proteins
  • Vascular Endothelial Growth Factor A
  • MMP14 protein, human
  • Matrix Metalloproteinase 14