Expression level of vascular endothelial growth factor in hippocampus is associated with cognitive impairment in patients with Alzheimer's disease

Although the enhanced expression of vascular endothelial growth factor (VEGF) in the brains of patients with Alzheimer's disease (AD) has been reported, the functional significance of VEGF level in the progression of AD is still unclear. We examined the VEGF expression in the hippocampus of patients with AD at different stages of progression by Western blot analysis, and found that the VEGF189 isoform (VEGF₁₈₉) was barely detectable in normal hippocampus, but significantly increased at the early stage of patients with AD. VEGF₁₈₉ was decreased with advancing stages of AD. Immunostaining shows that VEGF was significantly increased in the cells in the CA1, CA3, and dentate gyrus regions of hippocampus and layers III and V of entorhinal cortex of patients with AD, compared with normal brain. Confocal images show that VEGF was predominantly expressed in neurons and astrocytes in the hippocampus and entorhinal cortex of patients with AD. Our data suggest that VEGF level is associated with progressive loss of cognitive function in patients with AD.