Apelin Signaling Pathway
There are many substances that relax blood vessels in the body, such as NO,
prostacyclin, vasoactive intestinal peptide, etc. Recently, another vasodilator
substance, Apelin, has been discovered. In 1993, Carroll et al. discovered a protein
similar in structure to angiotensin II type 1 receptor, named angiotensin type 1
receptor-associated protein, also known as APJ, which belongs to the G-protein
coupled family. In 1998, Tatemoto et al. extracted the APJ endogenous ligand named
Apelin from bovine gastric secretion, which is a new adipocytokine and forms an
Apelin/APJ system with APJ. Apelin is homologous to angiotensin II (AngII) and is a
new member of the renin-angiotensin system (RAS). Apelin has many biological
effects such as lowering blood pressure, regulating heart and blood vessel
contraction, insulin secretion, pituitary hormone release, and humoral balance.
The Apelin/APJ system together with AngII-AT1 antagonism maintains blood pressure
homeostasis, and the imbalance between the two may be an important factor in the
development of hypertension. Recently, studies have found that Apelin may be
associated with heart diseases such as heart failure, coronary heart disease, atrial
fibrillation, and as a new adipokine, Apelin is expressed in obesity with insulin
resistance, regulation of fatty insulin axis and obesity-related diseases (such as
hypertension, type 2 diabetes, etc.). In addition, Apelin can also inhibit the release of
vasopressin, which has a diuretic effect, and has a certain relationship with kidney
disease.
Apelin family
Carroll et al. found that Apelin mRNA was expressed in the mammary gland, lung,
cardiovascular, brain, kidney, testis, ovary and skeletal muscle of rats, and expressed
in the breast and lung, vascular endothelium, adipose tissue and gastric parietal cells.
In humans, Apelin is mainly expressed in vascular endothelial cells of heart, kidney
and lung, and is less expressed in cardiomyocytes, lung, kidney, adrenal secretory
cells, vascular smooth muscle cells, adipose tissue, and nerve cells. The human apelin
gene is located on chromosome Xq25-26 and consists of three exons and two introns.
https://www.creative-diagnostics.com/apelin-signaling-pathway.htm
