|
||
J. Cell Biol.,
Volume 140, Number 5, March 9, 1998 1255-1263
v
3 Requirement for Sustained Mitogen-activated
Protein Kinase Activity during Angiogenesis
Departments of Immunology and Vascular Biology, The Scripps Research Institute, La Jolla, California 92037
Angiogenesis depends on growth factors and
vascular cell adhesion events. Integrins and growth factors are capable of activating the ras/MAP kinase pathway in vitro, yet how these signals influence endothelial
cells during angiogenesis is unknown. Upon initiation of angiogenesis with basic fibroblast growth factor
(bFGF) on the chick chorioallantoic membrane
(CAM), endothelial cell mitogen-activated protein
(MAP) kinase (ERK) activity was detected as early as 5 min yet was sustained for at least 20 h. The initial wave
of ERK activity (5-120 min) was refractory to integrin
antagonists, whereas the sustained activity (4-20 h) depended on integrin
v
3, but not
1 integrins. Inhibition of MAP kinase kinase (MEK) during this sustained
v
3-dependent ERK signal blocked the
formation of new blood vessels while not influencing
preexisting blood vessels on the CAM. Inhibition of
MEK also blocked growth factor induced migration but
not adhesion of endothelial cells in vitro. Therefore, angiogenesis depends on sustained ERK activity regulated by the ligation state of both a growth factor receptor and integrin
v
3.
This article has been cited by other articles:
|
|