中文摘要：

外泌体（exosomes）是细胞分泌的纳米级别膜性小泡，在20世纪80年代初就已经被发现，但其在细胞间所起到的信息交流作用，直至最近才开始为人们所认知．应用大规模分析技术使得exosomes中的复杂成分不断被确定，因为其中的脂质、蛋白质和RNA成分在脂质膜的保护下具有充分的生物学活性，可有效发挥对受体细胞的调节作用，引起科学界的极大兴趣，逐渐成为研究热点之一．我们综述了近几年关于exosomes的研究成果，总结了其参与细胞间信息交流的三种主要方式，包括膜表面信号分子的直接作用、膜融合时内容物的胞内调节以及生物活性成分的释放调节．Exosomes的发现使得细胞间的信息交流更加精细和全面，尤其重要的是，它的发现揭示了存在于机体自身的RNA胞间转移途径．我们还进一步综述了exosomes的三种作用方式在神经系统及肿瘤发生发展中的作用，探讨了exosomes在疾病监测、自身免疫性疾病与缺血性疾病治疗中的临床应用价值．在基因治疗领域，由于具有安全有效的靶向运输能力，exosomes将有望成为理想的基因治疗载体．

英文摘要：

Exosomes are nano-sized vesicles ranging from 40 to 100 nm released from various cell types under different functional conditions. They originate from the endosomal system and are secreted by cells upon fusion of multivesicular endosomes with the plasma membrane. Exosomes were initially regarded as clearing mechanisms that discard unwanted proteins and membranes ofreticulocytes during their maturation. However, they are believed to play much wider ranges of roles recently other than clearing, especially information conduction among different cell types. Exosomes deliver bioactive molecules including proteins and RNAs to the target cells by interacting with cell surface receptors or fusing with plasma membrane and release cargo RNAs to target cells, they can also release functionally active molecules in the vicinity of the recipient cells. Recent research focused on their roles in the development and progression of tumors and nervous system diseases, on the other hand, they are also promising biomarkers for clinical diagnostic purpose and ideal therapeutic tools for biodelivery.