FLZ inhibited γ-secretase selectively and decreased Aβ mitochondrial production in APP-SH-SY5Y cells

Abstract

Amyloid precursor protein (APP) metabolism is a key factor in the pathogenesis of Alzheimer's disease (AD). Amyloid-beta (Aβ) in mitochondria comes from APP mitochondrial metabolism or from the uptake Aβ from outside of mitochondria. It has been recently proposed that mitochondria are involved in the biochemical pathways through which Aβ causes neuronal dysfunction. The accumulated Aβ in mitochondria decreases the level of cytochrome c oxidase (COX IV) and attenuates the ATP production consequently. FLZ is a synthetic cyclic derivative of squamosamide from Annona glabra. In this study, the effect of FLZ on APP processing in mitochondria was investigated in SH-SY5Y cells over-expressing APP695 (wt/Swe). FLZ treatment attenuated APP processing and decreased Aβ production in mitochondria. The mitochondrial function was increased with the upregulation of COX IV both at protein and activity levels. ATP production was also increased after FLZ treatment. The mechanistic study showed that FLZ inhibited γ-secretase activity by decreasing C-terminal fragment protein level of presenilin, the active center of γ-secretase. The effect of FLZ differs from DAPT (a non-selective γ-secretase inhibitor), suggesting FLZ is a selective γ-secretase inhibitor. FLZ selectively inhibited γ-secretase in the cleavage of recombinant C terminus of APP in vitro, without specifically modulating the processing of recombinant Notch intracellular domain. These results indicate that FLZ decreases Aβ accumulation in mitochondria by selectively inhibiting γ-secretase. We propose that FLZ is a potential anti-AD drug candidate, and its mechanism may be improving mitochondrial function by reducing the Aβ burden in mitochondria.

Centella asiatica Attenuates Amyloid-β-Induced Oxidative Stress and Mitochondrial Dysfunction

“…In both models, we found that Aβ decreased ATP levels. These findings are consistent with other reports of Aβ-treated SH-SY5Y cells [32] as well as cell lines over-expressing APP [10, 33]. CAW treatment prevented this decrease in ATP.…”

Anti-autophagic and anti-apoptotic effects of memantine in a SH-SY5Y cell model of Alzheimer's disease via mammalian target of rapamycin-dependent and -independent pathways

“…The cells were cultured in Dulbecco's modified Eagle's medium (Gibco-BRL, Invitrogen Life Technologies, Carlsbad, CA, USA) supplemented with 10% fetal bovine serum (GE Healthcare Life Sciences, Little Chalfont, UK) and streptomycin/penicillin (100 U/ml) (China National Medicines Corporation, Ltd., Beijing, China) at 37°C in an atmosphere containing 5% CO 2 . The AD cell model was established a previously described ( 25 , 26 ). When the SH-SY5Y cells reached 70% confluence, the cells were transfected with overexpression plasmid pcDNA3.1-APP695, containing a Swedish mutant APP695 gene (Wanleibio, Shenyang, China) using the Lipofectamine ® 2000 reagent (Invitrogen Life Technologies) according to the manufacturer's instructions.…”

Natural Compounds as Therapeutic Agents for Amyloidogenic Diseases

“…Importantly, the squamosamide derivative FLZ showed enhanced antioxidant activity; in APP-SH-SY5Y expressing cells it selectively inhibited "-secretase activity without Scheme 5.3 Anti-amyloidogenic properties of compound FLZ, a squamoside analogue of a constituent from Annona glabrais modulating the Notch pathway (Ye et al 2014). The many positive anti-amyloidogenic studies suggest FLZ may have therapeutic potential for the treatment of AD (illustrated in Scheme 5.3) Kang and Zhang 2012;Pang et al 2009;Li and Liu 2010;Kong et al 2011;Qin et al 2011;Fang and Liu 2008;Bao et al 2012Bao et al , 2013Tai et al 2013) …”