Neuroprotective function of erythropoietin in the central nervous system

It has been thought that erythropoietin exclusively acts on erythroid precursor cells in vivo. However, we describe that erythropoietin is produced by astrocytes and its receptor is expressed in neurons. Erythropoietin production by astrocytes is dependent on oxygen tension and activated by insulin and insulin-like growth factors. Furthermore, erythropoietin protected the cultured hippocampal and cerebral cortical neurons from glutamate neurotoxicity. These results indicate that, in the central nervous system, erythropoietin acts on neurons in a paracrine fashion, and erythropoietin and its receptor system is independent of that for erythropoiesis.