Alzheimer's disease (AD) is characterized by a series of interacting pathophysiological cascades, including the aggregation of β-amyloid plaques and the formation of neurofibrillary tangles derived from hyperphosphorylated tau proteins. AD is the cause of approximately 70 % of dementia, an irreversible and untreatable syndrome at its late stage. Hence, more efforts should be devoted to identifying at-risk or preclinical AD populations for early intervention and the improved design of drug trials. The exosome, a nanoscale subtype of extracellular vesicle that serves as a cell-to-cell communication messenger, is an emerging liquid biopsy tool for various diseases including AD. Recently, it has been discovered that brain-derived exosomes can flow through the blood-brain barrier to the peripheral blood, containing important protein and nucleic acid biomarkers that are associated with the pathogenesis and progression of AD. Other reports showed a strong involvement of exosomes in synaptic function, insulin resistance, and neuroinflammation, among others. Here, we summarize those studies and assess the value of exosomes as an emerging tool for the early detection of AD in conjunction with the current clinical diagnosis paradigm.

中文翻译：

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细胞外囊泡作为早期发现阿尔茨海默氏病的新兴工具。

阿尔茨海默氏病（AD）的特征是一系列相互作用的病理生理级联反应，包括β淀粉样蛋白斑块的聚集和源自高磷酸化tau蛋白的神经原纤维缠结的形成。AD是痴呆症的约70％，痴呆症是晚期不可逆和不可治愈的综合征。因此，应该作出更多的努力来识别高风险或临床前的AD人群，以便进行早期干预和改进药物试验的设计。外泌体是细胞外囊泡的纳米级亚型，可作为细胞间的通信信使，是一种针对包括AD在内的各种疾病的新兴液体活检工具。最近，发现脑源性外泌体可以通过血脑屏障流向外周血，含有与AD的发病机制和发展相关的重要蛋白质和核酸生物标记。其他报告显示外泌体强烈参与突触功能，胰岛素抵抗和神经炎症等。在这里，我们总结这些研究，并评估外泌体作为结合当前临床诊断范例对AD进行早期检测的新兴工具的价值。