Neurovascular dysfunction and vascular amyloid accumulation as early events in Alzheimer's disease Academic Article in Scopus uri icon

abstract

  • © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Alzheimer's disease (AD) is clinically characterized by a progressive loss of cognitive functions and short-term memory. AD patients present two distinctive neuropathological lesions: neuritic plaques and neurofibrillary tangles (NFTs), constituted of beta-amyloid peptide (Aß) and phosphorylated and truncated tau proteins. Aß deposits around cerebral blood vessels (cerebral amyloid angiopathy, CAA) is a major contributor to vascular dysfunction in AD. Vascular amyloid deposits could be early events in AD due to dysfunction in the neurovascular unit (NVU) and the blood¿brain barrier (BBB), deterioration of the gliovascular unit, and/or decrease of cerebral blood flow (CBF). These pathological events can lead to decreased Aß clearance, facilitate a neuroinflammatory environment as well as synaptic dysfunction and, finally, lead to neurodegeneration. Here, we review the histopathological AD hallmarks and discuss the two-hit vascular hypothesis of AD, emphasizing the role of neurovascular dysfunction as an early factor that favors vascular Aß aggregation and neurodegeneration. Addtionally, we emphasize that pericyte degeneration is a key and early element in AD that can trigger amyloid vascular accumulation and NVU/BBB dysfunction. Further research is required to better understand the early pathophysiological mechanisms associated with NVU alteration and CAA to generate early biomarkers and timely treatments for AD.

publication date

  • January 1, 2022