The AMY Antigen Co-Occurs with A{beta} and Follows Its Deposition in the Amyloid Plaques of Alzheimer's Disease and Down Syndrome

摘要

Novel plaque-like "AMY" lesions were recently described in the brains of patients with Alzheimer's disease (AD). Using three Aß antibodies, we now document the co-occurrence of AMY immunoreactivity (IR) with amyloid ß-peptide (Aß) in the large majority of plaques in AD brain. AMY IR was detected in many compacted plaques, whereas its co-localization with early, diffuse Aß deposits was rare. AMY IR overlapped considerably or fully with Aß and, in more severely affected AD brains, decorated the periphery of some plaques. In a temporal series of 29 Down syndrome (DS) brains from patients aged 12 to 73 years, the earliest AMY IR was detected in some plaques at age 15, following the earliest appearance of Aß plaques (age 12 years), and then accrued within a subset of Aß deposits, namely, the more spherical, compacted plaques. Brains from DS patients 29 years and older showed AMY staining in many Aß plaques, as seen in AD. Brains from eight monkeys aged 17 to 34 years and thirty APP transgenic mice aged 8 to 20 months showed Aß IR but no AMY IR. We conclude that AMY IR represents an amyloid-associated antigen that co-deposits in most but not all Aß plaques in AD and DS and that accumulation of the AMY antigen follows Aß deposition in plaques.