Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
Date (from‐to) : 2012/04 -2014/03
Author : ZOU KUN; KOMANO Hiroto
The longer and neurotoxic species of amyloid beta-protein (Abeta), Abeta42 and Abeta43, contribute to Abeta accumulation in Alzheimer's disease (AD) pathogenesis and are considered to be the primary cause of the disease. In contrast, Abeta40, inhibits amyloid deposition and may have neuroprotective effects. Herein, we provide evidence that Abeta43 deposition appears earlier than Abeta42 and Abeta40 deposition in the brain of mutant amyloid precursor protein transgenic (APPtg) mice, suggesting that Abeta43 is the earliest depositing Abeta species. In addition, we found increased Abeta43 levels and Abeta43/Abeta42 ratio in the serum of AD patients, which may be used as diagnostic blood biomarkers for AD. We further identified the brain Abeta43-to-Abeta42-converting enzyme as ACE2. Notably, the combination of ACE2 and ACE could convert Abeta43 to Abeta40. Thus, maintaining brain ACE2 and ACE activities may be important for preventing brain amyloid neurotoxicity and deposition in AD.