Activation of diacylglycerol kinase alpha is required for VEGF-induced angiogenic signaling in vitro

Oncogene. 2004 Jun 17;23(28):4828-38. doi: 10.1038/sj.onc.1207633.

Abstract

Vascular endothelial growth factor-A (VEGF-A) promotes angiogenesis by stimulating migration, proliferation and organization of endothelium, through the activation of signaling pathways involving Src tyrosine kinase. As we had previously shown that Src-mediated activation of diacylglycerol kinase-alpha (Dgk-alpha) is required for hepatocytes growth factor-stimulated cell migration, we asked whether Dgk-alpha is involved in the transduction of angiogenic signaling. In PAE-KDR cells, an endothelial-derived cell line expressing VEGFR-2, VEGF-A165, stimulates the enzymatic activity of Dgk-alpha: activation is inhibited by R59949, an isoform-specific Dgk inhibitor, and is dependent on Src tyrosine kinase, with which Dgk-alpha forms a complex. Conversely in HUVEC, VEGF-A165-induced activation of Dgk is only partially sensitive to R59949, suggesting that also other isoforms may be activated, albeit still dependent on Src tyrosine kinase. Specific inhibition of Dgk-alpha, obtained in both cells by R59949 and in PAE-KDR by expression of Dgk-alpha dominant-negative mutant, impairs VEGF-A165-dependent chemotaxis, proliferation and in vitro angiogenesis. In addition, in HUVEC, specific downregulation of Dgk-alpha by siRNA impairs in vitro angiogenesis on matrigel, further suggesting the requirement for Dgk-alpha in angiogenic signaling in HUVEC. Thus, we propose that activation of Dgk-alpha generates a signal essential for both proliferative and migratory response to VEGF-A165, suggesting that it may constitute a novel pharmacological target for angiogenesis control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta
  • Cell Division / drug effects
  • Cells, Cultured
  • Chemotaxis / drug effects
  • Diacylglycerol Kinase / genetics
  • Diacylglycerol Kinase / metabolism*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / enzymology*
  • Enzyme Activation
  • Genetic Vectors
  • Humans
  • Neovascularization, Physiologic / drug effects*
  • RNA Interference
  • RNA, Small Interfering / genetics
  • Recombinant Proteins / metabolism
  • Retroviridae
  • Swine
  • Transfection
  • Vascular Endothelial Growth Factor A / pharmacology*

Substances

  • RNA, Small Interfering
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor A
  • Diacylglycerol Kinase