FIGURE 2.

Schematic outline of the Sprouting process. Angiogenesis is a complex process involving: (A) a basement membrane alteration produced by MMP, which expose growth factors receptors, characterized by a dilated mother vessel projecting ECs into the connective tissue; (B) tip cell specification and filopodia extension determined by growth factors amount-dependent arising from the growing capillary bud; (C) ECs migrate in parallel establishing a lumen and sealed by integral endothelial junctions and pericyte recruitment; (D) stalk cells display vacuole exocytosis for lumen constitution; (E) polarized ECs continuously deposit the basement membrane, and the proliferating pericytes migrate through the basement membrane of the capillary sprout, resulting in the entire constitution of the new vessel wall; (F) complete BM reconstitution and the restoration of blood flow.