Critical role of exosomes in sperm–egg fusion and virus-induced cell–cell fusion

In mammals, two integral membrane proteins, sperm IZUMO1 and egg CD9, regulate sperm–egg fusion, and their roles are critical, but yet unclear. Recent studies, however, indicate interesting connections between the sperm–egg fusion and virus-induced cell–cell fusion. First, CD9-containing exosome-like vesicles, which are released from wild-type eggs, can induce the fusion between sperm and CD9-deficient egg, even though CD9-deficient eggs are highly refractory to the fusion with sperm. This finding provides strong evidence for the involvement of CD9-containing, fusion-facilitating vesicles in the sperm–egg fusion. Secondly, there are similarities between the generation of retroviruses in the host cells and the formation of small cellular vesicles, termed exosomes, in mammalian cells. The exosomes are involved in intercellular communication through transfer of proteins and ribonucleic acids (RNAs) including mRNAs and microRNAs. These collective studies provide an insight into the molecular mechanism of membrane fusion events.     

成纤维细胞系3T3细胞来源exosome对小鼠乳腺癌细胞增殖能力的影响

目的 观察小鼠成纤维细胞系3T3来源的外泌小体（exosome）对小鼠乳腺癌细胞4T1增殖能力的影响,并探索其中可能的机制。方法 PureExo Exosome提取试剂盒提取3T3细胞上清液中的exosome,按照不同浓度及时间作用于4T1细胞,CCK8法检测4T1细胞的增殖能力,BrdU/PI双掺入法测定细胞DNA合成及细胞周期;免疫印迹法（Western blot）及荧光定量实时PCR（qPCR）检测人表皮生长因子受体2（epidermal growth factor receptor-2, EGFR2,也称HER2）及下游PI3K/AKT信号转导通路相关蛋白的变化。利用HER2单克隆抗体靶向药物赫赛汀（Herceptin）,观察exosome是否影响4T1细胞对于Herceptin敏感度。结果 exosome处理组OD450吸光度值显著高于对照组（P<0.05）,细胞增殖及细胞周期进程加快。Western blot及qPCR实验提示随着exosome浓度的增加,HER2表达逐渐升高, AKT磷酸化水平增加。而同时给予exosome可明显增加4T1细胞对Herceptin的敏感度。结论 小鼠成纤维细胞系3T3来源exosome可促进小鼠乳腺癌细胞4T1增殖及周期进程,并且可能通过HER2激活其下游PI3K/AKT信号通路发挥上述作用。     

Tumor-derived exosomes: Nanovesicles made by cancer cells to promote cancer metastasis

Nanomedicine usually refers to nanoparticles that deliver the functional drugs and siRNAs to treat cancer. Recent research has suggested that cancer cells can also make nanoparticles that also deliver functional molecules in promoting cancer metastasis, which is the leading cause of various cancer mortalities. This nanoparticle is called tumor-derived vesicles, or better-known as tumor-derived exosomes (TEXs). TEXs are nanoscale membrane vesicles (30–140 nm) that are released continuously by various types of cancer cells and contain tumor-derived functional biomolecules, including lipids, proteins, and genetic molecules. These endogenous TEXs can interact with host immune cells and epithelial cells locally and systemically. More importantly, they can reprogram the recipient cells in favor of promoting metastasis through facilitating tumor cell local invasion, intravasation, immune evasion, extravasation, and survival and growth in distant organs. Growing evidence suggests that TEXs play a key role in cancer metastasis. Here, we will review the most recent findings of how cancer cells harness TEXs to promote cancer metastasis through modulating vascular permeability, suppressing systemic immune surveillance, and creating metastatic niches. We will also summarize recent research in targeting TEXs to treat cancer metastasis.     

星形胶质细胞外泌体对缺氧缺血神经元的保护作用

目的 探索星形胶质细胞外泌体对缺氧缺血神经元的影响。方法 体外培养大鼠星形胶质细胞,通过差速离心法获取细胞上清液中的外泌体。采用透射电镜、Nanosight和Western blot鉴定外泌体;采用BCA法检测外泌体蛋白浓度。体外培养大鼠神经元,分为对照组、外泌体组、氧糖剥夺（OGD）组和OGD+外泌体组（n=3）。OGD组和OGD+外泌体组给予无糖培养基和缺氧处理;外泌体组和OGD+外泌体组分别给予终浓度为22 μg/mL的外泌体处理,对照组和OGD组给予等体积PBS处理。采用ELISA法检测神经元乳酸脱氢酶（LDH）水平;TUNEL法检测神经元凋亡指数。结果 外泌体鉴定结果显示差速离心法提取的外泌体符合外泌体特点;与对照组和外泌体组相比,OGD组LDH值和凋亡指数显著增加（P < 0.05）;与OGD组相比,OGD+外泌体组LDH值和凋亡指数均显著降低（P < 0.05）。结论 星形胶质细胞来源的外泌体对神经元缺氧缺血损伤有保护作用。     

小鼠胰岛微血管内皮细胞外泌体的提取和鉴定方法

目的：建立小鼠胰岛微血管内皮细胞来源的外泌体的提取和鉴定方法,为糖尿病胰岛微血管内皮受损的发病机制研究及重建胰岛微循环完整性的应用提供必要材料。方法选取小鼠胰岛微血管内皮细胞株（MS-1）细胞作为研究对象,取其培养上清液,经多步离心结合蔗糖／D2O垫超速离心方法获取提取物,然后采用透射电镜和Western blotting 法对提取物进行形态和蛋白成分分析,以确定其是否为外泌体。结果提取物呈形态均一的类圆形囊泡,有完整双层膜包绕,内部含有低电子密度物质。囊泡大小约为40～100 nm,可散在分布,也可聚集成团,提取物均阳性表达CD63、CD9和TSG101分子。结论经过形态和蛋白成分分析证实所提取到的物质正是MS-1细胞来源的外泌体,便于后续临床和基础研究工作的开展。     

间充质干细胞外泌体在骨关节炎治疗修复中的研究进展

骨关节炎(OA)是种以关节软骨退变为特征的疾病,其缺乏干预性药物,对于晚期OA患者往往通过关节置换术以维持生活质量。外泌体(exosomes)是一种由不同细胞分泌的细胞外囊泡,可以传递DNA、微小RNA(microRNA,miRNA)、mRNA、蛋白质等多种信息,并以此通过多种方式进行细胞间信号传递和功能调节。间充质干...     

外泌体在甲状腺癌诊治中的研究进展

甲状腺癌(Thyroid Carcinoma,TC)是世界上发病率增长最快的癌症之一,寻找新型高特异性、高灵敏度、无创的早期诊断和术后监测标记物成为当下研究热点。外泌体是细胞间信息物质交流的重要载体,由于其高稳定性、低细胞毒性、低免疫原性和高膜通透性等特征,使其具有成为无创、新型的疾病诊断和治疗手段的潜能。近年来,外泌体在甲状腺癌非侵入性疾病诊断、监测、给药、治疗和预后评估等领域取得了实质性突破。论文综述了TC来源的外泌体在肿瘤中发生和发展、诊断监测以及治疗中的应用前景。     

PI3K/Akt和MAPK/ERK信号通路在胃癌细胞来源的Exosome促进同源肿瘤细胞增殖中的作用

目的:研究胃癌细胞来源的Exosome对同源肿瘤细胞增殖的影响,初步探讨PI3K/Akt和MAPK/ERK信号转导通路在此过程中的作用.方法:采用离心超滤和蔗糖密度梯度离心的方法从胃癌MGC803细胞的上清液中分离出胃癌细胞来源的Exosome.应用透射电子显微镜观察Exosome的形态,MTT检测细胞活力,Weste...     

动脉粥样硬化人群中血液外泌体的蛋白质谱分析

目的预测血液中外泌体在动脉粥样硬化中的作用及机制。方法招募56个受试对象,分成两个比较组:健康人群与动脉粥样硬化人群、高血压人群与高血压合并动脉粥样硬化人群。用试剂盒提取受试者血液中外泌体,利用蛋白质谱分析技术检测外泌体中蛋白表达,将蛋白表达谱的结果进行基因功能(GO)分析。结果GO分析显示,在生物学过程中,两个比较组中都出现显著差异的有5个条目,分别是"固有免疫反应的正向调节"、"免疫反应激活信号转导"、"固有免疫反应激活"、"固有免疫反应激活信号转导"和"固有免疫反应激活细胞表面受体信号通路";在分子功能类别中,两个比较组中有2个条目是重复出现的,分别是"抗原结合"和"酶结合";在两个组别比较中都出现差异蛋白有3个,分别是蛋白酶亚基α6(PSMA6)、蛋白酶亚基α7(PSMA7)和膜联蛋白A2。结论固有免疫系统可能在动脉粥样硬化疾病发病中起重要作用。PSMA6、PSMA7和膜联蛋白A2有可能成为动脉粥样硬化疾病防治的新的靶蛋白。