Exogenous Aβ 1-42 monomers improve synaptic and cognitive function in Alzheimer's disease model mice

• Published in: Neuropharmacology 2022-05, Vol.209, p.109002
• Main Authors: Duan, Yanhong, Lv, Junyan, Zhang, Zhonghui, Chen, Zhenzhen, Wu, Hao, Chen, Jinnan, Chen, Zhidong, Yang, Jiarun, Wang, Dasheng, Liu, Yamei, Chen, Fuxue, Tian, Yang, Cao, Xiaohua
• Format: Article
• Language: English
• Subjects: Alzheimer Disease - pathology; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Cognition; Disease Models, Animal; Mice; Mice, Transgenic; Peptide Fragments; Plaque, Amyloid - pathology; Presenilin-1 - genetics
• ISSN: 1873-7064

Growing evidence has suggested the poor correlation between brain amyloid plaque and Alzheimer's disease (AD). Presenilin1 (PS1) and presenilin2 (PS2) conditional double knockout (cDKO) mice exhibited the reduced 42-amino acid amyloid-β peptide (Aβ ) level and AD-like symptoms, indicating a different pathological mechanism from the amyloid cascade hypothesis for AD. Here we found that exogenous synthetic Aβ monomers could improve the impaired memory not only in cDKO mice without Aβ deposition but also in the APP/PS1/Tau triple transgenic 3 × Tg-AD mice with Aβ deposition, which were mediated by α7-nAChR. Our findings demonstrate for the first time that reduced soluble Aβ level is the main cause of cognitive dysfunction in cDKO mice, and support the opinions that low soluble Aβ level due to Aβ deposition may also cause cognitive deficits in 3 × Tg-AD mice. Therefore, "loss-of-function" of Aβ should be avoided when designing therapies aimed at reducing Aβ burden in AD.