Abstract

The VEGF (vascular endothelial growth factor) family and its receptors are essential regulators of angiogenesis and vascular permeability. Currently, the VEGF family consists of VEGF-A, PlGF (placenta growth factor), VEGF-B, VEGF-C, VEGF-D, VEGF-E and snake venom VEGF. VEGF-A has at least nine subtypes due to the alternative splicing of a single gene. Although the VEGF165 isoform plays a central role in vascular development, recent studies have demonstrated that each VEGF isoform plays distinct roles in vascular patterning and arterial development. VEGF-A binds to and activates two tyrosine kinase receptors, VEGFR (VEGF receptor)-1 and VEGFR-2. VEGFR-2 mediates most of the endothelial growth and survival signals, but VEGFR-1-mediated signalling plays important roles in pathological conditions such as cancer, ischaemia and inflammation. In solid tumours, VEGF-A and its receptor are involved in carcinogenesis, invasion and distant metastasis as well as tumour angiogenesis. VEGF-A also has a neuroprotective effect on hypoxic motor neurons, and is a modifier of ALS (amyotrophic lateral sclerosis). Recent progress in the molecular and biological understanding of the VEGF/VEGFR system provides us with novel and promising therapeutic strategies and target proteins for overcoming a variety of diseases.