Ultra-LEAF™ Purified anti-human VEGFR1 Antibody, VEGFR1, W21039F,BioLegend,652753

The VEGF family includes five members, VEGFA (VEGFA165), VEGFB, VEGFC, VEGFD and placenta growth factor (PLGF). Structurally, these growth factors are homodimers although heterodimers have been described that are composed of VEGFA and PLGF. There are three VEGF receptor tyrosine kinases: VEGFR1 (Flt1), VEGFR2 (Flk1), and VEGFR3 (Flt4). The expression of these receptors is overlapping; nevertheless, a distribution pattern has been reported: VEGFR1 is expressed on monocytes and macrophages, VEGFR2 on vascular endothelial cells, and VEGFR3 on lymphatic endothelial cells. VEGFR1 and VEGFR2 share 43.2% amino acid sequence homology and are structurally similar. VEGFR1 is an angiogenic and anti-angiogenic factor depending on the ligand binding it (PLGF-1 inhibits angiogenesis, whereas VEGF and PLGF2 are pro-angiogenic). Also, VEGFR1 mediates the angiostatic effect of pigment epithelium-derived factor (PEDF). A soluble form of VEGFR1 was initially identified in conditioned culture medium of HUVEC cells and it was found that it binds with high affinity to VEGFA. Soluble VEGFR1 and VEGFR2 act as decoy receptors for VEGFA, regulating the availability of VEGFA of which there are at least four different alternatively spliced soluble proteins. sVEGFR1 expression is upregulated by hypoxic conditions via HIF1-α in cytotrophoblasts. In preeclampsia activated platelets bind to monocytes to produce sVEGFR1. Increased circulating sVEGFR1 has been correlated with reduced free PLGF and reduced free VEGF in the blood compared to normal pregnancies. In addition, sVEGFR1 has been detected in cornea, and it is essential for preserving the avascular ambit of the cornea.