外泌体作为靶向治疗载体的研究进展

外泌体是来源于细胞内膜的纳米级的囊泡，包含有核酸、蛋白和脂质等生命物质，作为一种细胞间交流的机制，在生命活动中发挥着重要作用。相对于脂质体载体，外泌体更稳定，生物相容性好，免疫原性低，而且可以渗透生物屏障，例如血脑屏障、胎盘屏障等。重点介绍外泌体载体靶向性的基础、外泌体载体装载负荷的方法及外泌体载体目前的应用进展和前景。     

肝细胞癌患者血清外泌体mRNA表达谱及临床意义分析

背景与目的:外泌体是包含了复杂RNA和蛋白质的小膜泡,其中肿瘤细胞分泌的外泌体中的mRNA携带了大量肿瘤细胞遗传信息,因此对外泌体中特异性mRNA的分析,有望找到肿瘤诊断的新型分子标志物和治疗靶点。本研究通过高通量筛选与生物信息学方法探讨肝细胞癌(HCC)患者血清外泌体mRNA的表达特征及其潜在功能。方法:采集3例HCC患者及3例正常人的静脉血,用外泌体提取试剂盒提取血清外泌体,用Magen试剂盒提取外泌体RNA,对血清外泌体mRNA进行纯化、行反转录形成cDNA、PCR扩增、测序,最后将对所得数据质量进行评价后与参考数据进行比对,分析得到差异表达外泌体mRNA,并采用GO和KEGG通路富集分析对差异基因进行功能与通路注释。结果:与正常人比较,HCC患者有397个外泌体mRNA表达上调,192个外泌体mRNA表达下调;其中,NRGN、PF4、RGS18等17个基因表达明显上调,CXCL8、MORF4L2、SYCP1等14个基因显明显下调。GO富集分析显示,表达上调的外泌体mRNA的靶基因与蛋白质结合、蛋白质异二聚化活性、免疫系统过程的调节、胞外囊泡、细胞外细胞器、应激反应等有关,表达下调的外泌体mRNA的靶基因与嗅觉受体活性、细胞因子活性、CXCR趋化因子受体结合、中间丝、中间丝状细胞骨架等有关;KEGG通路分析显示,在上调的外泌体mRNA中,30条通路被显著富集,在下调的外泌体mRNA中9条通路被显著富集,其中,在上调的外泌体mRNA中,血小板激活、Rap 1信号通路、吞噬体、病毒致癌、肌动蛋白细胞骨架的调节与抗原处理和呈递等是最丰富和最有意义的通路;在下调的外泌体mRNA中,基础转录因子和细胞因子-细胞因子受体相互作用分别是最丰富和最有意义的通路。结论:HCC患者与正常人的血清外泌体mRNA表达特征存在较大差异,其与HCC发生、发展、转移可能密切相关,这为寻找新的诊断标志物及治疗靶点提供了依据。     

纳米颗粒和外泌体靶向载药系统诊治动脉粥样硬化的机遇与挑战

动脉粥样硬化是一种慢性炎症性疾病,粥样斑块慢性聚集并沉积于大中型动脉内膜,导致严重的狭窄和血运障碍,引发组织器官缺血缺氧。纳米药物相对于传统药物在动脉粥样硬化治疗中因其具有独特的优势而广泛受到关注。本文重点综述几种纳米靶向颗粒（系统）和外泌体靶向载药系统在抗动脉粥样硬化研究中的应用,简述代表性纳米材料的合成过程,对其靶向性进行分析,并概述纳米药物的益处和内在挑战。尽管面临着一些需要解决和完善的挑战,但是纳米颗粒和外泌体靶向载药治疗的前景广阔,并有望将其推广应用于临床实践中。     

M1型巨噬细胞源外泌体增强卵泡膜细胞的活力

目的:探讨M1型巨噬细胞源外泌体对卵泡膜细胞活力的影响及其作用机制。方法:采用脂多糖(LPS)处理Raw264.7小鼠巨噬细胞,构建M1型巨噬细胞模型及巨噬细胞-卵泡膜细胞共培养体系。超速离心法分离巨噬细胞分泌的外泌体;通过电镜、Western blot和纳米流式检测仪鉴定外泌体。体外分离培养小鼠卵泡膜细胞,与PKH67荧光标记的外泌体共孵育,观察卵泡膜细胞摄取外泌体的情况。CCK-8法检测细胞活力,流式细胞术分析细胞周期分布,q PCR及Western blot检测细胞周期蛋白依赖性激酶抑制因子1B(CDKN1B)的表达。结果:在巨噬细胞-卵泡膜细胞共培养体系中,LPS诱导的M1型巨噬细胞通过外泌体增强卵泡膜细胞活力。电镜、Western blot及纳米流式检测结果显示,巨噬细胞源外泌体被成功分离。PKH67标记的外泌体与卵泡膜细胞共孵育实验证实卵泡膜细胞能摄取大量巨噬细胞源外泌体。这些外泌体可增强卵泡膜细胞的活力,使卵泡膜细胞G0/G1期比例下降,S期比例升高,且卵泡膜细胞CDKN1B的m RNA及蛋白相对表达量均明显低于对照组。结论:卵泡膜细胞能摄取巨噬细胞分泌的外泌体。M1型巨噬细胞源外泌体通过抑制CDKN1B的表达而增强卵泡膜细胞的活力。     

Review: Eicosanoids in preterm labor and delivery: Potential roles of exosomes in eicosanoid functions

Preterm delivery is a major obstetric health problem contributing to poor neonatal outcome including low birth weight, respiratory distress syndrome, gastrointestinal, immunologic, central nervous system, hearing, and vision problems. Worldwide, approximately 15 million babies are born prematurely each year. The critical question which remains is how to identify women destined to deliver preterm from those who will achieve a term delivery. Prostaglandins, in all mammals, are important in the parturient process. Increased intrauterine prostaglandin production is associated with labor and in fact prostaglandin E₂ (PGE₂) or analogs are widely used clinically for cervical ripening and labor induction. Measurements of circulating eicosanoids have been problematic because of the rapid and major clearance by the lungs and then kidneys resulting in very low concentrations in plasma. Moreover, since eicosanoids are produced by all mammalian tissues, the sources of the measured eicosanoids are unknown. Our understanding of how cells communicate has undergone a paradigm shift with the recognition of the role of exosomes in intercellular signaling. Recent publications have identified enzymes and products of arachidonic acid metabolism (eicosanoids) within exosomes. This review will explore the potential roles of exosomes in eicosanoid functions that are critical in preterm labor and delivery.     

Review: Embryo- and endometrium-derived exosomes and their potential role in assisted reproductive treatments–liquid biopsies for endometrial receptivity

Multiple pregnancies resulting from the transfer of more than one embryo pose a significant threat to offspring born through Assisted Reproductive Treatments (ART). Transferring one embryo at a time would eliminate this risk. However, current approaches of identifying the highest quality embryo to transfer are either unreliable (e.g. morphology assessment) or highly invasive and potentially detrimental to embryos (e.g. PGD). Approaches for non-invasive embryo selection would be a major advancement that would increase efficiency and reduce both the costs and the risks associated with ART. Exosomes are a particular subtype of extracellular vesicles (EVs) that are secreted from a wide range of cells, including placental and endometrium cells. Exosomes are very stable vesicles that contain a broad spectrum of molecules, including proteins, mRNAs and miRNAs. Very little is known about this form of cell-to-cell communication in the context of ovarian follicular biology and implantation, but emerging data suggest that exosomes secreted by the blastocyst could influence gene expression and receptivity of endometrial cells thereby controlling its own implantation. Here we review emerging findings regarding exosomal signalling in reproductive biology and the prospects for mapping blastocyst-derived exosomal profiles as a means for supporting single embryo transfer policies.     

肿瘤微环境中外泌体在肿瘤发生发展中作用及机制

外泌体(exosomes)是直径在30~100 nm,内含RNA、脂质和蛋白质的纳米级囊泡,来源于细胞内溶酶体微粒内陷形成的多囊泡体,与细胞膜融合后释放到胞外,是肿瘤微环境中细胞间通讯和遗传物质的重要载体。肿瘤在发生、发展过程中可通过外泌体与肿瘤微环境中的免疫细胞、内皮细胞和肿瘤相关成纤维细胞之间相互作用从而促进肿瘤的进展,其携带蛋白质、脂质和核酸等内容物释放到细胞外随着体液运输改变肿瘤微环境、促进肿瘤细胞增殖、加快血管形成及促进癌症发展;肿瘤微环境是由肿瘤细胞、巨噬细胞、成纤维细胞及细胞外基质等共同构成的局部稳态环境,在癌症的发生、复发、转移和化疗耐药等过程中发挥重要的作用。本综述着重讨论外泌体的生物学特性及对肿瘤微环境的影响,为研究及诊断治疗肿瘤提供新的思路。     

外泌体的生物学特征及其作为靶向药物载体在恶性肿 瘤的应用

肿瘤治疗过程中会出现很多严重的不良反应，如何将药物特异性导向癌细胞就成为了肿瘤治疗中亟需解决的问 题。外泌体是由细胞分泌的、纳米级别的、双层脂质的盘状囊泡结构。正常细胞与肿瘤细胞均可分泌外泌体，供体细胞分泌的 外泌体携带着蛋白质、脂质和核糖核酸（包括microRNA和lncRNA），可直接被同组织内其周围的受体细胞所吸收；同时外泌体 几乎存在于唾液、血液、尿液、脑脊髓液等所有体液中，通过体液运输被不同组织内受体细胞所吸收，为受体细胞的生长提供必 要的营养物质。肿瘤细胞中往往可对外释放出高于正常组织的外泌体，在肿瘤发展过程中外泌体对肿瘤的生长、转移和血管 生成起到重要的作用；同时癌细胞所分泌的外泌体中有着可用来区别与其他细胞外泌体不同的特征性分子，可作为肿瘤临床 诊断的分子标志物，也可作为肿瘤分级、精准治疗及预后评估的重要依据。鉴于此，本文收集国外内相关研究资料，对外泌体 的生物学特征进行总结，并综述了其在临床肿瘤诊断、治疗中的作用及应用潜力，并对外泌体进一步的发展方向进行展望，以 期能为外泌体在临床肿瘤精准治疗中的应用提供理论支持。