The vascular endothelial growth factor (VEGF) family of cell signaling proteins is responsible for a range of processes in the development and maintenance of adult tissues. Members of the VEGF family include placental growth factor (PGF), VEGF-A, VEGF-B, VEGF-C, and VEGF-D. Products are available to detect VEGF-A, VEGF-C, and VEGFR-3/FLT4, the receptor that binds VEGF-C and VEG-F-D.
Human VEGF-A is a 38-kDa homodimeric protein that consists of two 165 amino acid polypeptide chains. VEGF-A promotes embryonic development of the circulatory system (vasculogenesis) and new blood vessel formation from existing vasculature (angiogenesis). It also regulates vascular permeability, endothelial cell growth, cell migration, and apoptosis. VEGF-A is expressed in many tumor samples; VEGF-mediated vascularization enables tumors to grow rapidly. Mutations in VEGF-A are associated with proliferative and nonproliferative diabetic retinopathy. Alternate names for VEGF-A include VEGF, vascular permeability factor (VPF), and MVCD1.
VEGF-C undergoes complex post-translational processing, generating multiple isoforms that bind to and activate VEGFR-2 and VEGFR-3 receptors. Only the fully processed form can bind the VEGFR-2 receptor. VEGF-C regulates vascular permeability as well as endothelial cell growth and migration. It may also control angiogenesis of the venous and lymphatic vascular systems during embryogenesis, and it may maintain the differentiated lymphatic endothelium in adults. Alternate names for VEGF-C include vascular endothelial growth factor-related protein (VRP), FLT4 ligand DHM, and Flt4 ligand (Flt4-L).
Vascular endothelial growth factor receptor 3 (VEGFR-3), encoded by the human FLT4 gene, is a cell-surface tyrosine kinase receptor that binds VEGF-C and VEGF-D. It is involved in adult lymphangiogenesis and maintenance of the lymphatic endothelium. Activation of VEGFR-3/FLT4 results in upregulation of VEGF-C expression, creating a positive feedback loop. VEGFR-3/FLT4 activates several downstream signaling pathways through the action of MAPK1/ERK2, MAPK3/ERK1, MAPK8, c-Jun, and AKT1. Mutations in the FLT4 gene are associated with hereditary lymphedema type IA. Alternate names for VEGFR-3 include fms-related tyrosine kinase 4, PCL, LMPH1A, and FLT41.
ELISAs for VEGF Detection
The VEGF assay kits are solid-phase sandwich ELISAs using two antibodies that are highly specific to human VEGF, VEGF-C, or VEGFR-3/Flt-4 proteins, mouse VEGF protein, or rat VEGF protein; the capture antibody is precoated on the ELISA plate, and the detection antibody is HRP-conjugated. These kits can be used to measure soluble human, mouse, or rat VEGF proteins in EDTA plasma, heparin plasma, or cell culture supernatants.
Antibodies for VEGF Detection
VEGF antibody products are affinity-purified VEGF IgG antibodies that recognize human or rat VEGF-A or VEGF-C protein. These antibodies were raised in rabbit or mouse using a synthetic peptide or recombinant protein and can be used to detect VEGF-A or VEGF-C protein by Western blot (WB) or immunohistochemistry (IHC).