erythropoietin

erythropoietin
Name	Erythropoietin
HGNCid	3415
OMIM	133170
RefSeq	NM_000799
UniProt	P01588
Band	22

erythropoietin. It is a glycoprotein hormone primarily synthesized by the kidney in response to cellular hypoxia. Its principal function is to stimulate the production of red blood cells in the bone marrow, a process known as erythropoiesis. This hormone is critical for maintaining oxygen homeostasis in the circulatory system.

Structure and function

The molecular structure is characterized by a compact globular domain stabilized by two disulfide bonds. It acts by binding to the erythropoietin receptor on the surface of erythroid progenitor cells in the bone marrow. This binding triggers the JAK-STAT signaling pathway, promoting cell survival, proliferation, and differentiation into mature red blood cells. The activity is essential for adapting to conditions such as high altitude or blood loss.

Biosynthesis and regulation

Production occurs predominantly in peritubular interstitial cells of the renal cortex, with a minor contribution from the liver, especially during fetal development. The primary stimulus for its secretion is hypoxia, detected by hypoxia-inducible factors within renal cells. Factors like cobalt chloride and estrogen can also stimulate production, while hyperoxia or a high red blood cell count provides negative feedback. The gene responsible is located on chromosome 7.

Medical uses

Recombinant forms, such as epoetin alfa and darbepoetin alfa, are used therapeutically. Major applications include treating anemia associated with chronic kidney disease and chemotherapy for cancer. It is also used to reduce the need for allogeneic blood transfusion in elective surgery and to treat anemia in patients with myelodysplastic syndrome. Administration is typically via subcutaneous injection or intravenous infusion.

Adverse effects and safety

Significant risks include an increased incidence of thrombotic events, such as myocardial infarction and stroke, particularly when hemoglobin levels rise too rapidly. There is also an associated risk of pure red cell aplasia due to neutralizing antibody formation. Use in patients with active malignancy has been linked to potential tumor progression. Safety is monitored through regular complete blood count testing.

History and discovery

The existence of a humoral factor regulating red blood cell production was first postulated in the early 20th century. The hormone was definitively isolated and purified in 1977 by researchers including Eugene Goldwasser at the University of Chicago. The gene was successfully cloned in 1985, enabling the production of recombinant protein by Amgen. This development was pivotal for the biotechnology industry.

Research and other applications

Investigations explore its role beyond erythropoiesis, including potential effects on neuroprotection and cardioprotection following events like stroke or myocardial infarction. Studies also examine its use in improving athletic performance, a practice prohibited by the World Anti-Doping Agency. Research continues into novel erythropoiesis-stimulating agents and its function in the central nervous system.

Category:Peptide hormones Category:Hematology Category:Glycoproteins