Table III.

Factors regulating VEGF expression.

Regulator	Mechanisms	References
Ang-1,2,3	Controls growth, maturation and stability of blood vessels; Ang-2, destabilizes.	245
FGFa/b	Promotes EC proliferation and migration; induces vascular branching.	237
PDGF	Recruits perithelial cells, vascular aging.	246
TGF-β	Bidirectional regulation: Low concentrations of TGF-β promote blood vessel formation, high concentrations of TGF-β inhibit EC growth, and promote smooth muscle cell differentiation and basement membrane formation.	247,248
HGF	Promotes EC proliferation, improves VEGF secretion in ECs and induces angiogenesis	249
HIF-1α	Interacts with NICD to increase the response to hypoxia and upregulates DLL4	250
Foxc1/Foxc2	Activates DLL4 expression	251
Angiopoietins/Tie	Increases expression of Ang-2/1	252,253

VEGF, vascular endothelial growth factor; Ang, angiopoietin; FGF, fibroblast growth factor; PDGF, platelet-derived growth factor; TGF-β, transforming growth factor β; HGF, hepatocyte growth factor; HIF-1α, hypoxia-inducible factor 1α; Fox, forkhead box; EC, endothelial cell; NICD, Notch intracellular domain; DLL4, Delta-like ligand 4.