PKCε activation promotes FGF-2 exocytosis and induces endothelial cell proliferation and sprouting

J Mol Cell Cardiol. 2013 Oct;63:107-17. doi: 10.1016/j.yjmcc.2013.07.006. Epub 2013 Jul 20.

Abstract

Protein kinase C epsilon (PKCε) activation controls fibroblast growth factor-2 (FGF-2) angiogenic signaling. Here, we examined the effect of activating PKCε on FGF-2 dependent vascular growth and endothelial activation. ψεRACK, a selective PKCε agonist induces pro-angiogenic responses in endothelial cells, including formation of capillary like structures and cell growth. These effects are mediated by FGF-2 export to the cell membrane, as documented by biotinylation and immunofluorescence, and FGF-2/FGFR1 signaling activation, as attested by ERK1/2-STAT-3 phosphorylation and de novo FGF-2 synthesis. Similarly, vascular endothelial growth factor (VEGF) activates PKCε in endothelial cells, and promotes FGF-2 export and FGF-2/FGFR1 signaling activation. ψεRACK fails to elicit responses in FGF-2(-/-) endothelial cells, and in cells pretreated with methylamine (MeNH2), an exocytosis inhibitor, indicating that both intracellular FGF-2 and its export toward the membrane are required for the ψεRACK activity. In vivo ψεRACK does not induce angiogenesis in the rabbit cornea. However, ψεRACK promotes VEGF angiogenic responses, an effect sustained by endothelial FGF-2 release and synthesis, since anti-FGF-2 antibody strongly attenuates VEGF responses. The results demonstrate that PKCε stimulation promotes angiogenesis and modulates VEGF activity, by inducing FGF-2 release and autocrine signaling.

Keywords: Angiogenesis; Endothelial cells; Exocytosis; Fibroblast growth factor-2; Protein kinase C ε; Vascular endothelial growth factor.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Cell Membrane / metabolism
  • Cell Proliferation / drug effects
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Enzyme Activation
  • Exocytosis / physiology*
  • Fibroblast Growth Factor 2 / genetics
  • Fibroblast Growth Factor 2 / metabolism*
  • Fibroblast Growth Factor 2 / pharmacology
  • Gene Expression Regulation / drug effects
  • Male
  • Mice
  • Neovascularization, Physiologic / drug effects
  • Oligopeptides / pharmacology
  • Protein Kinase C-epsilon / metabolism*
  • Protein Transport
  • Rabbits
  • Vascular Endothelial Growth Factor A / metabolism
  • Vascular Endothelial Growth Factor A / pharmacology

Substances

  • His-Asp-Ala-Pro-Ile-Gly-Tyr-Asp
  • Oligopeptides
  • Vascular Endothelial Growth Factor A
  • Fibroblast Growth Factor 2
  • Protein Kinase C-epsilon