Chi Shun-Tzu, Wei Pei-Cih, Chiu Ya-Jen, Lin Te-Hsien, Lin Chih-Hsin, Chen Chiung-Mei, Yao Ching-Fa, Lin Wenwei, Lee-Chen Guey-Jen, Chang Kuo-Hsuan
School of Life Science, National Taiwan Normal University, Taipei, Taiwan.
Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
J Neurochem. 2025 Jan;169(1):e16300. doi: 10.1111/jnc.16300.
Misfolding and accumulation of amyloid-β (Aβ) in the brains of patients with Alzheimer's disease (AD) lead to neuronal loss through various mechanisms, including the downregulation of eukaryotic elongation factor 2 (EEF2) protein synthesis signaling. This study investigated the neuroprotective effects of indole and coumarin derivatives on Aβ folding and EEF2 signaling using SH-SY5Y cells expressing Aβ-green fluorescent protein (GFP) folding reporter. Among the tested compounds, two indole (NC009-1, -6) and two coumarin (LM-021, -036) derivatives effectively reduced Aβ misfolding and associated reactive oxygen species (ROS) production. Additionally, these compounds decreased acetylcholinesterase and caspase-3/-6 activities while promoting neurite outgrowth. NC009-1 increased active phosphorylation of extracellular-signal regulated kinase (ERK) (T202/Y204), leading to an increase in inactive eukaryotic elongation factor 2 kinase (EEF2K) phosphorylation (S366). LM-021 decreased the active phosphorylation of AMP-activated protein kinase (AMPK) (T172) and EEF2K (S398), while LM-036 exhibited dual effects, increasing inactive phosphorylation and decreasing active phosphorylation of EEF2K. These changes in EEF2K phosphorylation led to decreased EEF2K activity and a subsequent reduction in inactive phosphorylation of EEF2 (T56). This cascade further promoted the phosphorylation of transcription factor cAMP-response-element binding protein (CREB) (S133) and the expression of brain-derived neurotrophic factor (BDNF), and reduced BCL-2 associated X-protein (BAX)/B-cell lymphoma 2 (BCL2) ratio. Knockdown of EEF2 abolished the effects of NC009-1, LM-021, and LM-036 on CREB phosphorylation, BDNF expression, caspase-3 activity, and neurite outgrowth. These findings demonstrate that NC009-1, LM-021, and LM-036 exert their neuroprotective effects through modulation of EEF2K signaling, highlighting their potentials as therapeutic candidates for AD.
阿尔茨海默病（AD）患者大脑中β-淀粉样蛋白（Aβ）的错误折叠和积累通过多种机制导致神经元丢失，包括真核生物延伸因子2（EEF2）蛋白合成信号的下调。本研究使用表达Aβ-绿色荧光蛋白（GFP）折叠报告基因的SH-SY5Y细胞，研究了吲哚和香豆素衍生物对Aβ折叠和EEF2信号传导的神经保护作用。在测试的化合物中，两种吲哚（NC009-1、-6）和两种香豆素（LM-021、-036）衍生物有效减少了Aβ的错误折叠和相关活性氧（ROS）的产生。此外，这些化合物降低了乙酰胆碱酯酶和半胱天冬酶-3/-6的活性，同时促进了神经突的生长。NC009-1增加了细胞外信号调节激酶（ERK）（T202/Y204）的活性磷酸化，导致非活性真核生物延伸因子2激酶（EEF2K）磷酸化（S366）增加。LM-021降低了AMP活化蛋白激酶（AMPK）（T172）和EEF2K（S398）的活性磷酸化，而LM-036表现出双重作用，增加了EEF2K的非活性磷酸化并降低了其活性磷酸化。EEF2K磷酸化的这些变化导致EEF2K活性降低，随后EEF2（T56）的非活性磷酸化减少。这一级联反应进一步促进了转录因子环磷腺苷反应元件结合蛋白（CREB）（S133）的磷酸化和脑源性神经营养因子（BDNF）的表达，并降低了BCL-2相关X蛋白（BAX）/B细胞淋巴瘤2（BCL2）的比率。敲低EEF2消除了NC009-1、LM-021和LM-036对CREB磷酸化、BDNF表达、半胱天冬酶-3活性和神经突生长的影响。这些发现表明，NC009-1、LM-021和LM-036通过调节EEF2K信号传导发挥神经保护作用，突出了它们作为AD治疗候选药物的潜力。
