Cell interactions with collagen matrices in vivo and in vitro depend on phosphatidylinositol 3-kinase and free cytoplasmic calcium

Cell Adhes Commun. 1998 Sep;5(6):461-73. doi: 10.3109/15419069809005604.


We have investigated the role of phosphatidylinositol 3-kinase (PI3-kinase) in cellular interactions with collagenous matrices. Platelet-derived growth factor-BB (PDGF-BB) elicited a mobilization of intracellular Ca2+ in pig aortic endothelial (PAE) cells transfected with wild type PDGF beta-receptor. This response was greatly reduced in PAE cells transfected with PDGF beta-receptors mutated at positions Y740 and Y751 to prevent PI3-kinase binding. The experimental drug 1D-myo-inositol 1,2,6-trisphosphate (alpha-trinositol) induced a rapid increase and subsequent oscillations of the cytoplasmic Ca2+ concentration in cultured fibroblasts. This response was not due to an effect of alpha-trinositol on inositol 1,4,5-trisphosphate (IP3) receptors. alpha-Trinositol did not influence PDGF-BB elicited chemotaxis through collagen-coated membranes of PAE cells transfected with the wild-type PDGF beta-receptor, but restored PDGF-BB elicited chemotaxis of PAE cells transfected with the PI3-kinase binding-site mutated PDGF beta-receptor. Collagen gel contraction has been suggested to serve as a model for cellular control of interstitial fluid pressure (PIF) in dermis. The PI3-kinase inhibitors wortmannin (50 nM) and LY294002 (5 microM) inhibited the stimulation of fibroblast-mediated collagen gel contraction by 0.4 nM PDGF-BB. Injection of wortmannin in rat paw skin induced a lowering of PIF, and this effect was abolished in animals pre-treated with alpha-trinositol. Pretreatment of rats with alpha-trinositol abolished the decrease in PIF induced by injecting monoclonal anti-rat alpha 2 beta 1 integrin IgG in rat paw skin. Taken together our data indicate that cell-collagen interactions in vivo and in vitro depend on PI3-kinase, and that this dependence can be bypassed by a drug eliciting intracellular Ca2+ mobilization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Antibodies, Monoclonal
  • Becaplermin
  • Calcium Signaling* / drug effects
  • Cell Communication*
  • Cells, Cultured
  • Chemotaxis / drug effects
  • Chromones / pharmacology
  • Collagen / metabolism*
  • Endothelium, Vascular
  • Extracellular Matrix / metabolism*
  • Fibroblasts
  • Inositol 1,4,5-Trisphosphate / pharmacology
  • Inositol Phosphates / pharmacology*
  • Integrin beta1 / immunology
  • Integrin beta1 / physiology
  • Morpholines / pharmacology
  • Mutation
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoinositide-3 Kinase Inhibitors
  • Platelet-Derived Growth Factor / pharmacology
  • Pressure
  • Proto-Oncogene Proteins c-sis
  • Rats
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor / genetics
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • Swine
  • Wortmannin


  • Androstadienes
  • Antibodies, Monoclonal
  • Chromones
  • Inositol Phosphates
  • Integrin beta1
  • Morpholines
  • Phosphoinositide-3 Kinase Inhibitors
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins c-sis
  • Becaplermin
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Inositol 1,4,5-Trisphosphate
  • Collagen
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor
  • atrinositol
  • Wortmannin