Erythropoietin Rescues Memory Impairment in a Rat Model of Chronic Cerebral Hypoperfusion via the EPO-R/JAK2/STAT5/PI3K/Akt/GSK-3β Pathway.

Vascular dementia is the second most common cause of dementia in older people and is characterized by the sudden onset of impairments in thinking skills and behavior, which generally occur following a stroke. Unfortunately, effective therapy for vascular dementia remains inadequate. Erythropoietin (EPO) is a glycoprotein hormone that controls erythropoiesis, or red blood cell production. Recently, a prominent role for EPO has been defined in the nervous system, and there is growing interest in the potential therapeutic use of EPO for neuroprotection. However, whether it is protective from memory impairments and the underlying mechanisms of vascular dementia (VD) remains unknown. In the current study, we reported that supplements with exogenous erythropoietin (EPO) for 4 weeks could restore impaired memory in 2-vessel occlusion (2VO) rats, a well-established vascular dementia animal model. EPO also rescued impairments in dendritic spines and cholinergic dysfunctions in the hippocampus. Moreover, EPO suppressed the overactivation of GSK-3β in the hippocampus by stimulating the JAK2/STAT5/PI3K/Akt signal pathway. Furthermore, we found that genetic knockdown of the EPO receptor (EPO-R) by shRNA blocks the neuroprotection conferred by EPO on memory in VD. We hypothesized that EPO treatment is able to rescue the memory impairments in VD by stimulating the EPO-R/JAK2/STAT5/PI3K/Akt/GSK-3β pathway and suggest the potential usage of EPO in the therapy for VD.