Evidence of angiogenic vessels in Alzheimer’s disease

Alterations in the blood brain barrier and brain vasculature may be involved in neurodegeneration and neuroinflammation. We sought to determine if vascular remodeling characterized by angiogenic vessels or increased vascular density, occurred in pathologically confirmed Alzheimer’s disease (AD) postmortem human brain tissues. We examined brains of deceased, older catholic clergy from the Religious Order Study, a longitudinal clinical–pathological study of aging and AD. The hippocampus, midfrontal cortex, substantia nigra, globus pallidus and locus ceruleus were examined for integrin αvβ3 immunoreactivity, a marker of angiogenesis, and vascular densities. Activated microglia cell counts were also performed. All areas except the globus pallidus exhibited elevated αvβ3 immunoreactivity in AD cases compared with controls. Only in the hippocampus did the ongoing angiogenesis result in increased vascular density compared with controls. Vascular density was correlated with Aβ load in the hippocampus and αvβ3 reactivity was correlated with neurofibrillary tangles in the midfrontal cortex and in the substantia nigra. These data indicate that ongoing angiogenesis is present in brain regions affected by AD pathology and may be related to tissue injury.