Wang Yangyang, Li Siyu, Liang Xiao, Fan Jianing, Li Shijie, Zhou Fanlin, Li Xiaoju, Lai Mengmeng, Feng Dianmao, Li Yu
School of Medicine, Chongqing University, Chongqing, 400030, P. R. China.
Chongqing Traditional Chinese Medicine Hospital, No.6, Panxi Seven Branch Road, Jiangbei District, Chongqing, 400011, P. R. China.
Alzheimers Res Ther. 2025 Jun 9;17(1):132. doi: 10.1186/s13195-025-01771-1.
Dysregulation retrograde axonal transport in neurons results in autophagosome accumulation, enhancing amyloid β (Aβ) production and accelerating Alzheimer’s disease (AD) progression. Ras-associated GTP-binding protein 7 (Rab7) is pivotal in autophagosome maturation and their fusion with lysosomes, as well as in bidirectional axonal transport through interactions with partner proteins. Recent studies suggest that adapter-associated protein complex 2 subunit α1 (AP2A1) modulates retrograde axonal autophagosomes transport, regulates autophagy, and influences AD progression. However, the interplay between AP2A1 and Rab7, along with the molecular mechanisms underlying their impact on neuronal autophagy in AD, remains poorly understood.
We employed N2a/APPswe cells, primary hippocampal neurons exposed to Aβ oligomers, and APP/PS1 transgenic mice as AD models. To assess the impact of AP2A1 on Rab7 activity and autophagy, we conducted Rab7 pulldown activation assay, transmission electron microscopy (TEM), western blot and immunofluorescence (IF) staining were performed. The interaction between AP2A1 and Rab7 was examined by co-immunoprecipitation (Co-IP), IF staining and molecular docking. Live-cell imaging was utilized to monitor autophagosome axonal transport in primary hippocampal neurons. Aβ levels were quantified through immunohistochemistry and ELISA. Behavioral alterations in mice were evaluated using the Morris water maze, open field test, object recognition test and Y-maze.
We observed reduced levels of AP2A1 and Rab7-GTP, accompanied by autophagosome accumulation, in AD models. Overexpression of AP2A1 restored autophagic flux in these cells. AP2A1 was found to bind and activate Rab7, facilitating the recruitment of retrograde axonal transport proteins DIC1 and RILP. Additionally, AP2A1 overexpression enhanced retrograde axonal autophagosome transport, reinstated autophagic flux, provided neuroprotection, and improved behavioral deficits in AD model mice through Rab7 activation.
Our findings demonstrate that AP2A1 activates Rab7 to restore autophagic function and mitigate AD progression, providing novel therapeutic perspectives for autophagy-targeted interventions in AD.
The online version contains supplementary material available at 10.1186/s13195-025-01771-1.
神经元中逆行轴突运输失调会导致自噬体积累，增强淀粉样β（Aβ）生成并加速阿尔茨海默病（AD）进展。Ras相关GTP结合蛋白7（Rab7）在自噬体成熟及其与溶酶体融合过程中起关键作用，同时也通过与伴侣蛋白相互作用参与双向轴突运输。最近的研究表明，衔接蛋白相关蛋白复合体2亚基α1（AP2A1）调节逆行轴突自噬体运输，调控自噬，并影响AD进展。然而，AP2A1与Rab7之间的相互作用以及它们影响AD中神经元自噬的分子机制仍知之甚少。
我们使用N2a/APPswe细胞、暴露于Aβ寡聚体的原代海马神经元以及APP/PS1转基因小鼠作为AD模型。为了评估AP2A1对Rab7活性和自噬的影响，我们进行了Rab7下拉激活试验、透射电子显微镜（TEM）检查，并进行了蛋白质免疫印迹和免疫荧光（IF）染色。通过免疫共沉淀（Co-IP）、IF染色和分子对接研究AP2A1与Rab7之间的相互作用。利用活细胞成像监测原代海马神经元中自噬体的轴突运输。通过免疫组织化学和酶联免疫吸附测定（ELISA）对Aβ水平进行定量。使用莫里斯水迷宫、旷场试验、物体识别试验和Y迷宫评估小鼠的行为改变。
我们在AD模型中观察到AP2A1和Rab7-GTP水平降低，同时伴有自噬体积累。AP2A1过表达恢复了这些细胞中的自噬流。发现AP2A1与Rab7结合并激活Rab7，促进逆行轴突运输蛋白DIC1和RILP的募集。此外，AP2A1过表达增强了逆行轴突自噬体运输，恢复了自噬流，提供了神经保护，并通过激活Rab7改善了AD模型小鼠的行为缺陷。
我们的研究结果表明，AP2A1激活Rab7以恢复自噬功能并减轻AD进展，为AD中以自噬为靶点的干预提供了新的治疗视角。
在线版本包含可在10.1186/s13195-025-01771-1获取的补充材料。
