Metformin Facilitates Intracellular Amyloid β Degradation by Increasing Insulin-degrading Enzyme Expression in M146L Cell Line
10.13471/j.cnki.j.sun.yat-sen.univ（med.sci）.2022.0402
- VernacularTitle:二甲双胍通过增强M146L细胞IDE表达促进胞内Aβ降解
- Author:
Ting XIE
1
;
Cai-li XU
1
;
Jiao-ling TANG
1
;
Kai-hua GUO
1
Author Information
1. Department of Anatomy and Physiology， Zhongshan School of Medicine， Sun Yat-Sen University， Guangzhou 510080， China
- Publication Type:Journal Article
- Keywords:
metformin;
insulin-degrading enzyme;
amyloid β;
Alzheimer’s disease;
M146L cell line
- From:
Journal of Sun Yat-sen University(Medical Sciences)
2022;43(4):522-529
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo explore the effects of metformin （Met） on amyloid-β （Aβ） in AD cell model M146L and the underlying mechanism. MethodsMTT assay was performed to determine the optimal concentration of Met. Western blotting was performed to measure the protein levels of Aβ42， amyloid precursor protein （APP） ， β-site APP-cleaving enzyme （BACE）and proteolytic enzymes including insulin-degrading enzyme （IDE）， neprilysin （NEP）， and light chain 3 Ⅱ/Ⅰ （LC3 Ⅱ/Ⅰ）； Immunofluorescence was performed to visualize how Aβ42 peptides and IDE were affected by Met. Western blotting was performed to test levels of IDE and Aβ42 after treatment of Met and Bacitracin （Bac）， a special inhibitor of IDE. ResultsIn this study， we showed that the levels of Aβ42 were down-regulated by the Met treatment （P<0.05）. No effect was observed on the expression of APP and BACE， both of which are related to the production of Aβ， after Met treatment in M146L cells （P＞0.05）. Furthermore， levels of proteolytic enzymes including IDE， NEP， and LC3Ⅱ/Ⅰ levels were markedly decreased in the M146L cells compared to the CHO cells （P<0.05） ， and only the level of IDE was reversed after the Met treatment for 24 h （P<0.05）. Importantly， Met-mediated Aβ42 degradation in M146L cells was completely blocked by the Bac （P<0.05）. ConclusionsThis study clarifies the ameliorating effect of Met on the abnormal accumulation of Aβ42 in M146L cells， and that the underlying mechanism is mediated by the increased expression of IDE in the Aβ degradation pathway， providing an experimental basis for the T2DM drug metformin as a potential therapeutic target for AD.
