Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China.
Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong.
Metab Brain Dis. 2024 Oct;39(7):1335-1351. doi: 10.1007/s11011-024-01395-8. Epub 2024 Aug 1.
Alzheimer's disease (AD) is characterized by cognitive decline stemming from the accumulation of beta-amyloid (Aβ) plaques and the propagation of tau pathology through synapses. Exosomes, crucial mediators in neuronal development, maintenance, and intercellular communication, have gained attention in AD research. Yet, the molecular mechanisms involving exosomal miRNAs in AD remain elusive. In this study, we treated APPswe/PSEN1dE9 transgenic (APP/PS1) mice, a model for AD, with either vehicle (ADNS) or fasudil (ADF), while C57BL/6 (control) mice received vehicle (WT). Cognitive function was evaluated using the Y-maze test, and AD pathology was confirmed through immunostaining and western blot analysis of Aβ plaques and phosphorylated tau. Exosomal RNAs were extracted, sequenced, and analyzed from each mouse group. Our findings revealed that fasudil treatment improved cognitive function in AD mice, as evidenced by increased spontaneous alternation in the Y-maze test and reduced Aβ plaque load and phosphorylated tau protein expression in the hippocampus. Analysis of exosomal miRNAs identified three miRNAs (mmu-let-7i-5p, mmu-miR-19a-3p, mmu-miR-451a) common to both ADNS vs ADF and WT vs ADNS groups. Utilizing miRTarBase software, we predicted and analyzed target genes associated with these miRNAs. Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of miRNA target genes indicated that mmu-miR-19a-3p and mmu-miR-451a are implicated in signal transduction, immune response, cellular communication, and nervous system pathways. Specifically, mmu-miR-19a-3p targeted genes involved in the sphingolipid signaling pathway, such as Pten and Tnf, while mmu-miR-451a targeted Nsmaf, Gnai3, and Akt3. Moreover, mmu-miR-451a targeted Myc in signaling pathways regulating the pluripotency of stem cells. In conclusion, fasudil treatment enhanced cognitive function by modulating exosomal MicroRNAs, particularly mmu-miR-451a and mmu-miR-19a-3p. These miRNAs hold promise as potential biomarkers and therapeutic targets for novel AD treatments.
阿尔茨海默病（AD）的特征是认知能力下降，源于β-淀粉样蛋白（Aβ）斑块的积累和 tau 病理学通过突触的传播。外泌体是神经元发育、维持和细胞间通讯的重要介质，在 AD 研究中受到关注。然而，涉及 AD 中外泌体 miRNA 的分子机制仍不清楚。在这项研究中，我们用载体（ADNS）或法舒地尔（ADF）处理 APPswe/PSEN1dE9 转基因（APP/PS1）小鼠，一种 AD 模型，而 C57BL/6（对照）小鼠则接受载体（WT）。通过 Y 迷宫测试评估认知功能，并通过免疫染色和 Aβ斑块和磷酸化 tau 蛋白的 western blot 分析确认 AD 病理学。从每个小鼠组中提取、测序和分析外泌体 RNA。我们的研究结果表明，法舒地尔治疗改善了 AD 小鼠的认知功能，表现在 Y 迷宫测试中自发交替增加，以及海马中 Aβ斑块负荷和磷酸化 tau 蛋白表达减少。对外泌体 miRNA 的分析发现了三种 miRNA（mmu-let-7i-5p、mmu-miR-19a-3p、mmu-miR-451a）在 ADNS 与 ADF 以及 WT 与 ADNS 两组中均存在。利用 miRTarBase 软件，我们预测并分析了与这些 miRNA 相关的靶基因。miRNA 靶基因的基因本体（GO）注释和京都基因与基因组百科全书（KEGG）途径分析表明，mmu-miR-19a-3p 和 mmu-miR-451a 参与信号转导、免疫反应、细胞通讯和神经系统途径。具体而言，mmu-miR-19a-3p 靶向参与鞘脂信号通路的基因，如 Pten 和 Tnf，而 mmu-miR-451a 靶向 Nsmaf、Gnai3 和 Akt3。此外，mmu-miR-451a 靶向调节干细胞多能性的信号通路中的 Myc。总之，法舒地尔通过调节外泌体 MicroRNAs，特别是 mmu-miR-451a 和 mmu-miR-19a-3p，增强了认知功能。这些 miRNA 有望成为新型 AD 治疗的潜在生物标志物和治疗靶点。
