Angiopoietin-related protein 4 precursor:Size: 406 amino acids; 45214 Da
Protein with hypoxia-induced expression in endothelial cells. May act as a regulator of angiogenesis and modulate tumorgenesis. Inhibits proliferation, migration, and tubule formation of endothelial cells and reduces vascular leakage. May exert a protective function on endothelial cells through an endocrine action. It is directly involved in regulating glucose homeostasis, lipid metabolism, and insulin sensitivity. In response to hypoxia, the unprocessed form of the protein accumulates in the subendothelial extracellular matrix (ECM). The matrix-associated and immobilized unprocessed form limits the formation of actin stress fibers and focal contacts in the adhering endothelial cells and inhibits their adhesion. It also decreases motility of endothelial cells and inhibits the sprouting and tube formation. Expressed at high levels in the placenta, heart, liver, muscle, pancreas and lung but expressed poorly in the brain and kidney. Found to be highly expressed in the early stages of collagen-induced arthritis . Serum levels of ANGPTL4 are significantly lower in patients with diabetes type 2 than those in healthy subjects, suggesting that decreased ANGPTL4 could be a causative factor of this disease. Produced in ischemic tissues in conditions such as critical leg ischemia. In tumors, ANGPTL4 could be produced in the hypoxic areas surrounding necrotic regions. High levels could be produced in tumor cells of conventional renal cell carcinoma. This molecule therefore seems to be a marker of conventional renal cell carcinoma.