Molecular mechanism of angiogenesis

Angiogenesis is one of the chief events both in development and postnatal pathological conditions. Recent extensive studies revealed the key signaling and transcriptional regulators of sprouting angiogenesis. Sprouting angiogenesis is a multistep process composed of endothelial loosening, endothelial cell migration, stalk elongation, anastomosis, and stabilization. Although the initial process of sprouting is triggered by soluble proangiogenic factors such as VEGF and FGF, the rather complicated subsequent step recruits many signaling and adhesion molecules which are pivotal players in autonomous and conditional specification in development. There is a marked similarity at the molecular level between embryogenic and postnatal angiogenesis. By its physiological constraint, endothelium differentiation is closely linked with blood cell specification. Many transcription factors with a major role in hematopoietic stem cell generation are also involved in angiogenesis