Modulation of activin A-induced differentiation in vitro by vascular endothelial growth factor in Xenopus presumptive ectodermal cells.
We have previously demonstrated that activin A at low concentrations induced ventral mesoderm including blood-like cells from Xenopus animal caps and that beating heart could be also induced from animal caps treated with 100 ng/ml activin A, suggesting that activin A might be involved in cardiac vasculogenesis. A vascular endothelial growth factor (VEGF) is a powerful mitogen for endothelial cells and is an inducer and regulator of angiogenesis. However, VEGF function in Xenopus development is not clearly identified. In this study, we determined the effect of VEGF on activin A-induced differentiation of animal cap. The VEGF induced duct-like structure composed of Flk-1-positive cells together with the induction of nonvascular tissues, such as neural tissues. This histological result was coincident with our reverse transcriptase-polymerase chain reaction analysis that VEGF together with activin A promoted the expression of Xenopus N-CAM and Xenopus brachyury. This study suggests that VEGF has additional biological activities besides angiogenesis, and arises a different function that VEGF induces stroma cell migration or recruitment that are required for blood vessel formation. This differentiation system will aid in the understanding of angiogenesis during early development.
Yoshida
Shiro
S
Department of Obstetrics and Gynecology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.
Furue
Miho
M
Nagamine
Kentaro
K
Abe
Takanori
T
Fukui
Yasuto
Y
Myoishi
Yasufumi
Y
Fujii
Tomoyuki
T
Okamoto
Tetsuji
T
Taketani
Yuji
Y
Asashima
Makoto
M
D028341:Activins / Q000494:pharmacology*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D004475:Ectoderm / Q000166:cytology* / Q000187:drug effects; D004625:Embryo, Nonmammalian; D005260:Female; D028322:Inhibin-beta Subunits / Q000494:pharmacology*; D008297:Male; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects; D008954:Models, Biological; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology
D042461:Vascular Endothelial Growth Factor A; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits