Porcine VEGFR1 / Flt1 / Vascuoar Endothelial Growth Factor Receptor 1 ELISA Kit

• Microplate reader with 450 nm wavelength filter
• Multichannel Pipette, Pipette, microcentrifuge tubes and disposable pipette tips
• Incubator
• Deionized or distilled water
• Absorbent paper
• Buffer resevoir

When carrying out an ELISA assay it is important to prepare your samples in order to achieve the best possible results. Below we have a list of procedures for the preparation of samples for different sample types.

Vascular endothelial Growth Factor Receptor-1 (VEGFR-1), also known as Fms Related Receptor Tyrosine Kinase 1 (FLT-1), is a protein-coding gene that codes for a member of the Vascular Endothelial Growth Factor receptor (VEGFR) family. Several transcript variants, that encode different isoforms, have been identified for this gene. In Humans, cells that express VEGFR1 include most vascular endothelial cells and peripheral blood monocytes. Tissues where VEGFR1 expression is observed includes lung, placenta, liver, kidney, heart and brain tissues. Specific isoforms can be found in corneal epithelial cells and vascular smooth muscle cells (VSMC).

The VEGFR family of proteins are tyrosine kinase receptors (RTKs). The structure of VEGFR1 contains an extracellular ligand-binding region with seven immunoglobulin (Ig) domains, a transmembrane segment and a cytoplasmic tyrosine kinase (TK) domain. Different isoforms have been identified, including both full-length transmembrane receptor isoforms and shortened, soluble isoforms. The latter forms are associated with the onset of pre-eclampsia

The VEGFR1 protein acts as a cell surface receptor for VEGF-A, VEGF-B and placental growth factor (PGF). The protein pays an essential role in embryonic vasculature development, angiogenesis regulation, cell migration and survival, chemotaxis and macrophage function and tumour cell invasion. I

Both VEGFR1 and 2 have high binding affinities to VEGF-A. However, VEGFR1 differs from VEGFR2/KDR in its protein kinase activity, which is very low compared to the latter. Thus, VEGFR1 is thought to function as a negative regulator of VEGFA signaling by limiting the amount of free VEGFA and preventing its binding to KDR. The protein also modulates KDR signalling by forming heterodimers.

VEGFR1 plays a critical role in angiogenesis. Its interactions with VEGF-A, VEGF-B and PGF initiate signalling pathways such as the MAPK1/ERK2, MAPK3/ERK1 and the MAP kinase signaling pathway, as well as of the AKT1 signaling pathway. However, it is important to note that VEGFR1 exerts both positive and negative regulatory effects on angiogenesis, exhibiting a multifaceted role in vascular development and homeostasis.

While it has been noted to play an essential role as a negative regulator of embryonic angiogenesis by inhibiting excessive proliferation of endothelial cells, they are also noted to promote endothelial cell proliferation, survival and angiogenesis in adulthood.

Its function in promoting cell proliferation seems to be cell-type specific. Promotes PGF-mediated proliferation of endothelial cells, proliferation of some types of cancer cells, but does not promote proliferation of normal fibroblasts (in vitro).The soluble form of VEGFR1, sFlt-1, acts as a decoy receptor that binds and sequesters VEGF ligands,thereby limiting their interaction with membrane-bound VEGFRs.This regulatory mechanism allows VEGFR1 to modulate angiogenesis in a context-dependent manner.

Delving into the intricate mechanisms governing VEGFR1 signaling and its interplay with other VEGF receptors becomes crucial in providing a foundation for developing targeted therapeutic strategies aimed at manipulating angiogenesis in various pathological conditions.

VEGFR inhibitors are a class of cancer drugs that can inhibit angiogenesis by inhibiting the VEGF pathway. Both small molecules as well as monoclonal antibodies have been developed as VEGFR-1 inhibitors. VEGFR1 inhibitors may exhibit varying degrees of selectivity and may also affect other receptors, such as VEGFR2 and VEGFR3. Some examples are Axitinib (Inlyta), Pazopanib (Votrient) and Cediranib (Recentin).