Neuroprotective actions of erythropoietin and preliminary clinical applications to neurological disorders

Erythropoietin (Epo) is a hypoxic responsive cytokine required for proliferation and differentiation of erythroid cells. It has been shown that Epo and its receptor (EpoR) are expressed in various tissues including the nervous system and that Epo exerts anti-apoptotic action through activating a number of pro-survival signal cascades. There is increasing evidence that Epo protects neurons from glutamate and hypoxic damage and exerts strong neuroprotective and neurorestoractive actions in many experimental models for stroke, brain and spinal cord trauma, chronic neurodegenerative disease, and so on. It is noteworthy that preliminary clinical studies suggest that Epo treatment may provide beneficial effects in patients with several types of neurological conditions including acute stroke. This review will discuss roles of endogenous Epo in the nervous system, clinical applicability of exogenous Epo as a neuroprotective agent, with special references to the results of the clinical trials.