Cooperative and redundant roles of VEGFR-2 and VEGFR-3 signaling in adult lymphangiogenesis

FASEB J. 2007 Apr;21(4):1003-12. doi: 10.1096/fj.06-6656com. Epub 2007 Jan 8.

Abstract

Activation of vascular endothelial growth factor (VEGF) receptor-3 (VEGFR-3) by VEGF-C initiates lymphangiogenesis by promoting lymphatic proliferation and migration. However, it is unclear whether VEGFR-3 signaling is required beyond these initial stages, namely during the organization of new lymphatic endothelial cells (LECs) into functional capillaries. Furthermore, the role of VEGFR-2, which is also expressed on LECs and binds VEGF-C, is unclear. We addressed these questions by selectively neutralizing VEGFR-3 and/or VEGFR-2 for various time periods in an adult model of lymphangiogenesis in regenerating skin. While blocking either VEGFR-2 or VEGFR-3 with specific antagonist mAbs (DC101 and mF4-31C1, respectively) prior to lymphatic migration prevented lymphangiogenesis, blocking VEGFR-3 subsequent to migration did not affect organization into functional capillaries, and VEGFR-2 blocking had only a small hindrance on organization. These findings were confirmed in vitro using human LECs and anti-human antagonist mAbs (IMC-1121a and hF4-3C5): both VEGFR-2 and -3 signaling were required for migration and proliferation, but tubulogenesis in 3D cultures was unaffected by VEGFR-3 blocking and partially hindered by VEGFR-2 blocking. Furthermore, both in vitro and in vivo, while VEGFR-3 blocking had no effect on LEC organization, coneutralization of VEGFR-2, and VEGFR-3 completely prevented lymphatic organization. Our findings demonstrate that cooperative signaling of VEGFR-2 and -3 is necessary for lymphatic migration and proliferation, but VEGFR-3 is redundant with VEGFR-2 for LEC organization into functional capillaries.

Publication types

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

MeSH terms

  • Animals
  • Cell Movement
  • Cell Proliferation
  • Female
  • Humans
  • Lymph Nodes / pathology
  • Lymphatic System
  • Mice
  • Mice, Inbred BALB C
  • Signal Transduction*
  • Skin / metabolism
  • Vascular Endothelial Growth Factor C / metabolism
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism
  • Vascular Endothelial Growth Factor Receptor-2 / physiology*
  • Vascular Endothelial Growth Factor Receptor-3 / metabolism
  • Vascular Endothelial Growth Factor Receptor-3 / physiology*
  • Wound Healing

Substances

  • Vascular Endothelial Growth Factor C
  • Vascular Endothelial Growth Factor Receptor-2
  • Vascular Endothelial Growth Factor Receptor-3