Thrombopoietin

Protein THPO PDB 1v7m

Thrombopoietin (TPO) is a glycoprotein hormone produced primarily by the liver and kidney that regulates the production of platelets by the bone marrow. It is a key regulator of megakaryocytopoiesis, the process by which megakaryocytes develop and produce platelets.

Function

Thrombopoietin plays a crucial role in the regulation of hematopoiesis, specifically in the production and maturation of megakaryocytes, the precursor cells to platelets. TPO binds to the c-Mpl receptor (also known as the thrombopoietin receptor) on the surface of megakaryocytes and their progenitors, stimulating their proliferation and differentiation.

Production

Thrombopoietin is primarily produced in the liver and kidney, with smaller amounts being produced in the bone marrow and spleen. The production of TPO is regulated by the number of circulating platelets; low platelet counts stimulate TPO production, while high platelet counts suppress it.

Clinical Significance

Thrombopoietin levels can be altered in various medical conditions. For example, in thrombocytopenia, a condition characterized by low platelet counts, TPO levels are typically elevated as the body attempts to increase platelet production. Conversely, in conditions such as thrombocythemia, where there is an overproduction of platelets, TPO levels may be reduced.

Recombinant forms of thrombopoietin and TPO receptor agonists are used therapeutically to treat certain conditions associated with low platelet counts, such as idiopathic thrombocytopenic purpura (ITP) and chemotherapy-induced thrombocytopenia.

Related Pages

• Platelet
• Megakaryocyte
• Hematopoiesis
• Thrombocytopenia
• Thrombocythemia
• c-Mpl receptor
• Idiopathic thrombocytopenic purpura
• Chemotherapy

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