外泌体在肿瘤转移前微环境形成中的作用

肿瘤的转移前微环境（pre-metastatic niche，PMN）特指原发肿瘤灶为肿瘤细胞远处播散和定植准备的微环境，此微环境的六个特征包括炎症、免疫抑制、血管生成/血管通透性、亲器官性、重编程和淋巴管生成。PMN形成的关键成分包括肿瘤源性分泌因子、细胞外囊泡（含外泌体）、骨髓源性细胞、免疫抑制细胞和宿主基质细胞等，其中，外泌体作为细胞间重要的信使，在肿瘤PMN的形成中具有重要作用。本综述就外泌体在肿瘤PMN形成中的作用进行探讨。     

妊娠期糖尿病中胎盘外泌体对滋养细胞增殖、细胞周期及凋亡的影响*

目的：探讨妊娠期糖尿病（GDM）中胎盘外泌体对滋养细胞增殖、细胞周期及细胞凋亡的影响。方法： 选取2018 年3 月至2019 年4 月间重庆市第七人民医院50 例诊断为GDM患者（GDM组），另选取50 例正常孕产 妇作为对照组。分离纯化GDM组和对照组孕产妇外周血血浆中的胎盘外泌体，通过透射电镜观察外泌体的形 态，纳米粒径分析检测外泌体的直径，免疫印迹检测外泌体标志性蛋白CD63、TSG101 及胎盘标志性分子胎盘 碱性磷酸酶（PLAP）的表达。PKH67染色后荧光共聚焦显微镜观察体外培养滋养细胞系对外泌体的摄取情况； 应用MTT实验检测外泌体对滋养细胞增殖能力的影响，流式细胞术检测外泌体对滋养细胞周期的影响，Annexin V-FITC/PI 双染色结合流式细胞术检测外泌体对滋养细胞凋亡的影响。结果：成功从外周血中分离获得了胎盘外 泌体，形态呈典型的杯状或双凹状，直径为40 ～ 120 nm，CD63、TSG101、PLAP 表达呈阳性；与对照组相比， GDM组胎盘外泌体以浓度依赖性促进滋养细胞的增殖、细胞周期进展，并抑制滋养细胞的凋亡。结论：GDM中 胎盘外泌体可能通过促进滋养细胞的增殖、细胞周期进展，抑制滋养细胞凋亡等参与GDM的发生和发展。     

Mesenchymal stem cell-derived exosomes attenuate phosgene-induced acute lung injury in rats

Objective: We have previously found that mesenchymal stem cell (MSC) therapy can ameliorate phosgene-induced acute lung injury (ALI). Moreover, exosomes can be used as a cell-free alternative therapy. In the present study, we aimed to assess the effect of MSC-derived exosomes on phosgene-induced ALI.

Methods: MSC-derived exosomes were isolated from MSCs through ultracentrifugation. Sprague-Dawley (SD) rats were exposed to phosgene at 8.33?g/m³ for 5?min. MSC-derived exosomes were intratracheally administered and rats were sacrificed at the time points of 6, 24 and 48?h.

Results: Compared with the phosgene group, MSC-derived exosomes reversed respiratory function alterations, showing increased levels of TV, PIF, PEF and EF50 as well as decreased levels of RI and EEP. Furthermore, MSC-derived exosomes improved pathological alterations and reduced wet-to-dry ratio and total protein content in BALF. MSC-derived exosomes reduced the levels of TNF-α, IL-1β and IL-6 and increased the IL-10 level in BALF and plasma. MSC-derived exosomes suppressed the MMP-9 level and increased the SP-C level.

Conclusions: MSC-derived exosomes exerted beneficial effects on phosgene-induced ALI via modulating inflammation, inhibiting MMP-9 synthesis and elevating SP-C level.     

Exosomes play roles in sequential processes of tumor metastasis

Overwhelming evidence demonstrates that exosomes, a series of biologically functional small vesicles of endocytic origin carrying a variety of active constituents, especially tumor-derived exosomes, contribute to tumor progression and metastasis. This review focuses on the specific multifaceted roles of exosomes in affecting sequenced four crucial processes of metastasis, through which cancer cells spread from primary to secondary organs and finally form macroscopic metastatic lesions. First, exosomes modulate the primary tumor sites to assist cancer growth and dissemination. In this part, five main biological events are reviewed, including the transfer of oncogenic constituents, the recruitment and activation of fibroblasts, the induction of angiogenesis, immunosuppression and epithelial-mesenchymal transition (EMT) promotion. In Step 2, we list two recently disclosed mechanisms during the organ-specific homing process: the exosomal integrin model and exosomal epidermal growth factor receptor (EGFR)/miR-26/hepatocyte growth factor (HGF) model. Subsequently, Step 3 focuses on the interactions between exosomes and pre-metastatic niche, in which we highlight the specific functions of exosomes in angiogenesis, lymphangiogenesis, immune modulation and metabolic, epigenetic and stromal reprogramming of pre-metastatic niche. Finally, we summarize the mechanisms of exosomes in helping the metastatic circulating tumor cells escape from immunologic surveillance, survive in the blood circulation and proliferate in host organs.     

Wnt/β-catenin信号通路及骨髓间充质干细胞源性外泌体在温和灸联合骨髓间充质干细胞移植促进大鼠肛门括约肌修复中的作用*

目的 基于前期研究证实温和灸联合骨髓间充质干细胞（bone marrow mesenchymal stem cell,BMSC）移植可协同促进大鼠损伤肛门括约肌结构和功能修复的基础,探索协同修复效果是涉及Wnt/β-catenin通路,及BMSC源性外泌体对C212成肌细胞的影响。方法 将16只SD大鼠随机等分4组,所有大鼠均采用Zutshi大鼠肛门括约肌复合体损伤模型,造模成功后分别采用温和灸30 min、BMSC移植及生理盐水治疗,连续14 d。治疗结束后剥离肛门括约肌后采用q PCR和Western blot检测组间Wnt4、Wnt5a、Wnt5b蛋白表达差异。将BMSC源性外泌体与小鼠成肌细胞C2C12共培养后采用EDU及CCK8检测BMSC外泌体对C2C12细胞增殖作用,探索不同浓度外泌体对BMSC增殖的差异。流式细胞术检测BMSC源性外泌体对C2C12细胞周期的影响。结果 免疫印迹和qPCR分析结果提示温和灸联合BMSC移植可促进Wnt4、Wnt5A、Wnt5B高表达。CCK8结果显示BMSC源性外泌体可促进C2C12细胞的增殖,在浓度为25 μg/mL时疗效最佳。共培养结果显示BMSC源性外泌体可抑制Cleaved Caspase3和BAX表达,并显著上调BCL2表达。结论 温和灸联合BMSC移植可促进Wnt4、Wnt5A、Wnt5B高表达,BMSC源性外泌体可调控成肌细胞C2C12的细胞周期从而促进增殖并抑制凋亡,推测温和灸联合BMSC移植可能通过激活Wnt/β-catenin信号通路促进对大鼠损伤肛门括约肌的修复作用。     

肿瘤来源外泌体调控癌细胞转移机制的研究进展

外泌体在细胞生理、病理过程中发挥重要调控作用,为细胞之间的信号传递搭建了桥梁,而且与癌细胞的远处转移调控密切相关。本文综述了外泌体特征、合成、分泌、成分、功能、生物发生以及肿瘤来源外泌体对肿瘤微环境、肿瘤细胞信号传递以及肿瘤血管生成等各个环节的调控功能及机制,并分析了外泌体在恶性肿瘤转移诊断和治疗方面的潜在价值和应用前景。     

不同碘水平下甲状腺结节患者血清外泌体中miRNA生物学标志物的筛选* "(1., b.流行病学教研室,济南250000;2.,山东成武274200;3.泰安市中心医院a.甲状腺外科, b.检验科,山东泰安271000;4.山东第一医科大学第二附属医院a.甲状腺外科,b.检验医学科,山东泰安271000)

摘要:目的比较不同碘水平下甲状腺结节患者与健康人血清外泌体微小核糖核酸( microRNA, miRNA)表达谱的差异,分析其共同点,为筛选不同碘水平下甲状腺结节早期诊断标志物提供参考依据。方法收集10例不同碘水平下甲状腺结节患者及体检健康者的外周血样本,采用砷饰催化分光光度法测定各组血清碘水平;提取外泌体miRNA,利用高通量测序技术测定血清miRNA的表达水平;预测差异靶基因,并进一步进行CO( Gene ontology)分析和KECG(Kyoto Encyclopedia of Genes andGenomes)分析。结果在不同碘水平的甲状腺结节患者与健康人群中存在6个表达下调的miRNA,分别为 miR-324-5p.miR-6511b-3p, miR-9903 ,miR-550a-3p、miR-50O1-3p、miR-3688-3p。差异表达的外泌体 miRNA可调控MAPK信号通路、PI3K-AKT信号通路、VEGF信号通路及NF-KB信号通路。结论筛选出6个差异表达miRNA,有望作为不同碘水平下甲状腺结节早期诊断的生物学标志物。