外泌体介导消化道恶性肿瘤中的免疫异常

外泌体是一种由磷脂双分子层包裹的细胞外囊泡,对免疫系统起重要调控作用.外泌体上的MHC-Ⅰ、MHC-Ⅱ类分子、肿瘤相关抗原等可刺激免疫系统,而其免疫抑制性蛋白可通过诱导免疫抑制性细胞群产生、减少免疫细胞数、减弱免疫细胞杀伤效应等途径抑制免疫系统.外泌体在肿瘤微环境中发挥免疫抑制作用,即外泌体可介导结直肠癌、胃癌、肝癌、...     

结直肠癌细胞来源外泌体对CD8^+T细胞的免疫调节

背景:关于人结直肠癌细胞来源外泌体对于免疫细胞功能影响的报道较少。目的:探讨人结直肠癌细胞系Lovo来源外泌体对人CD8+T细胞的免疫调节作用。方法:收集Lovo细胞来源外泌体检测其表面特异性标志,BCA检测总蛋白量。将Lovo细胞来源外泌体与人外周血淋巴细胞共培养96 h,通过流式细胞术检测CD8^+T细胞的增殖情况、CD8^+T细胞表面活化标志CD38、HLA-DR的表达以及细胞因子γ-干扰素和白细胞介素2的分泌水平。结果与结论:①提取的外泌体表达CD9、CD63;②Lovo细胞来源外泌体抑制CD8^+T细胞表面CD38和HLA-DR的表达并抑制CD8+T细胞的增殖,同时降低CD8^+T细胞分泌γ-干扰素水平;③结果表明Lovo细胞来源外泌体可抑制人CD8+T细胞的活化及功能。     

结直肠癌细胞来源的外泌体miR-34a对M2型巨噬细胞极化的影响北大核心CSCD

目的:探究结直肠癌来源的外泌体对巨噬细胞极化的影响及其作用机制。方法:建立THP-1来源的M2型巨噬细胞体外诱导分化模型,利用流式细胞染色实验检测细胞分化效率;通过与结直肠癌细胞共培养、结直肠癌细胞外泌体干预M2型巨噬细胞分化,利用实时荧光定量PCR实验检测ARG1、IL-10和NLRP3 mRNA的表达水平。结果:体外诱导分化的M2型THP-1巨噬细胞CD163阳性细胞比例显著升高;与对照组相比,与结直肠癌细胞HCT8和HCT116共培养的M2型巨噬细胞ARG1、IL-10表达水平显著升高,NLRP3表达水平下降。与转染阴性对照microRNA(miR-NC)组相比,转染miR-34a inhibitor的HCT8和HCT116共培养或外泌体刺激下,M2型巨噬细胞ARG1、IL-10表达水平下降,NLRP3表达水平升高;与miR-NC组相比,转染miR-34a inhibitor的THP-1细胞ARG1、IL-10表达水平显著下降,NLRP3表达水平显著升高。结论:结直肠癌细胞来源的外泌体miR-34a可以抑制巨噬细胞NLRP3的表达,促进巨噬细胞M2型极化。     

巨噬细胞J774A.1外泌体促进结直肠癌细胞系MC38和CT26的增殖和迁移

目的探讨巨噬细胞J774A.1分泌的外泌体对小鼠结直肠癌细胞系MC38和CT26增殖和迁移的影响及作用机制。方法应用流式细胞术对J774A.1细胞进行表型鉴定;应用透射电镜、纳米颗粒跟踪分析(NTA)和Western blot分别检测J774A.1细胞外泌体的形态特征、大小和表面标志物;荧光显微镜下观察MC38和CT26细胞对外泌体的摄取情况;应用CCK8法检测外泌体对MC38和CT26细胞增殖作用的影响;细胞划痕实验检测MC38和CT26细胞的迁移能力;Western blot检测增殖相关通路的磷酸化蛋白p-MEK1/2和p-ERK1/2的表达变化。结果 J774A.1细胞为表达细胞表面标志分子CD68和CD206的M2型巨噬细胞。J774A.1细胞的外泌体均能被结直肠癌细胞MC38和CT26摄取,而且能够促进它们增殖(P0.05)、迁移及MEK-ERK信号通路激活。结论巨噬细胞J774A.1的外泌体能够促进结直肠癌细胞系MC38和CT26的增殖及迁移,这可能与MEK-ERK信号通路的磷酸化增加有关。     

外泌体在缺血性脑卒中的研究进展

正1外泌体概述外泌体是直径在30~100 nm的胞外囊泡,通过细胞被释放到细胞外液中~([1])。它们存在于生物体液中,诸如血液和脑脊液。外泌体携带有DNA、RNA、蛋白质和脂质等。由于外泌体的微泡结构为其内在的小分子提供了一个安全稳定的环境,同时这些信号小分子利用循环系统在胞间信号交换发挥重要作用,这让外泌体表现出一个成熟、稳定的信号传输系统~([2])。研究发现,外泌体中的m RNA和micro RNA     

血清替代培养法使血清外泌体干扰最小化

外泌体是细胞之间及细胞和细胞外基质之间信号交流的途径之一。近年来,对外泌体的研究呈现显著增长的态势。在体外细胞培养系统中,为保证细胞正常的生理状态,血清是培养液中必须添加的成分。随之而来的问题是,由于血清中含有大量外泌体,其数量数倍于研究中需要进行针对性研究的特定外泌体,从而对特定外泌体的定量和分析造成了干扰。为了去除培养液血清中的外泌体,很多研究者采用差速离心法、密度梯度离心法等进行处理。该研究通过流式细胞分析对外泌体定量后发现,加入2%血清的培养液在进行差速离心处理后,外泌体数量减少了30.6%;而加入5%的血清培养液,外泌体数量下降了32.4%。由此可见,差速离心处理对不同浓度血清的培养液结果类似,只能去除约30%的血清外泌体,留下约70%的血清外泌体,仍然会对实验数据造成干扰。因此,在人脐静脉内皮细胞体外培养系统中,该研究探索了一种新型血清替代培养法,即以无生物成分的血清替代物XerumFree替代培养液中的大部分血清,经过对一系列配比进行探索发现,当XerumFree与胎牛血清FBS体积比为15:1时,细胞既可以正常生长,又可以分泌外泌体,而背景中外泌体干扰程度降低到2%,从而较好地解决了外源性外泌体形成的背景干扰问题,为体外研究外泌体提供了明确的参考方案。     

外泌体在特应性皮炎中作用的研究进展

外泌体是含有核酸、蛋白质、脂质、细胞因子、转录因子受体等生物活性分子的细胞外囊泡, 几乎所有的细胞都可以分泌外泌体。外泌体在免疫应答、神经元之间的信号传导、生殖和发育等多方面发挥重要作用。近年来, 关于外泌体在特应性皮炎(atopic dermatitis, AD)、银屑病、玫瑰痤疮等非感染性炎症性皮肤病方面的研究也取得了一定的进展。文章就外泌体在AD病情进展、诊断和临床治疗领域的研究结果进行综述, 以期为AD临床诊断和治疗提供依据。     

预处理来源外泌体在细胞增殖分化及凋亡中的作用

背景：预处理来源外泌体的生物学功能及特性目前已有大量研究且在部分疾病治疗中得到验证并取得良好的效果,提示其在组织再生及临床应用领域可能具有更广阔的前景。目的：该综述主要阐述预处理来源外泌体的供体细胞预处理方式以及预处理因素对外泌体功能作用的影响,归纳预处理来源外泌体对细胞增殖、分化及凋亡等作用的影响和临床应用现状。方法：检索PubMed、Web of Science、中国知网和万方数据库的相关文献,英文检索词为“pretreatment,cell factor,hypoxia,ischemia”等,并以“外泌体、小细胞外囊泡、预处理”等为中文检索词,最终纳入75篇文献进行综述。结果与结论：(1)细胞来源外泌体虽然生物兼容性好、免疫原性低,但存在产量低和靶向性弱等缺点,其生物学性能高度依赖于细胞的状态、种类及培养环境等,预处理细胞及其微环境可影响所获外泌体的内容物与含量。(2)常见的外泌体预处理方式有细胞因子、缺氧/低氧、药物和物理干预等,不同细胞或不同预处理方式获得的外泌体可能具有不同的生物学特性。(3)与未预处理外泌体相比,预处理来源外泌体可调控细胞增殖与凋亡、成骨分化及血管形成等功...     

外泌体circRPPH1促进结直肠癌增殖和转移北大核心CSCD

目的:探讨外泌体circRPPH1在结直肠癌(CRC)细胞中的生物学功能及潜在作用机制。方法:对GEO数据库GSE126094进行分析,筛选并验证CRC组织差异表达circRNA。SW620和SW480细胞转染circRPPH1 shRNA(sh-circRPPH1)后,MTT、流式细胞术和Transwell实验观察细胞增殖活性、细胞周期、迁移和侵袭能力变化。将转染Oe-circRPPH1质粒和sh-circRPPH1的SW620和SW480细胞(供体细胞)分别与未经处理的SW620和SW480细胞(受体细胞)共培养,qRT-PCR检测供体细胞、细胞外泌体及受体细胞circRPPH1表达。在线生物信息学数据和双荧光素酶报告基因实验预测并验证circRPPH1的靶miRNA及其下游靶基因。结果:circRPPH1在CRC肿瘤组织和癌细胞中高表达;敲除circRPPH1可抑制SW620和SW480细胞增殖、阻滞细胞周期、抑制细胞迁移和侵袭。SW620和SW480细胞可通过外泌体将circRPPH1传递给周围癌细胞。生物信息学和荧光素酶报告基因实验显示,circRPPH1在CRC细胞中起miR-330-5p海绵作用,miR-330-5p在CRC肿瘤组织和癌细胞中均呈低表达;NRAS是miR-330-5p的下游靶基因,在CRC肿瘤组织和癌细胞中均呈高表达。结论:circRPPH1在CRC细胞增殖和转移过程中发挥重要作用,并可能通过海绵miRNA发挥调控作用,提示外泌体circRPPH1在CRC中起致癌作用,可能是CRC的潜在生物标志物。     

CD4+CD25+ Treg 细胞分泌外泌体在疾病中作用的研究进展

调节性T 细胞为T 细胞的一类控制体内自身免疫反应性的T 细胞亚群,在维持机体的免疫耐受以及调控免 疫应答中起重要作用。外泌体是细胞分泌的异质性纳米级胞外囊泡。现在研究认为外泌体在细胞间通讯中发挥重要作用, 外泌体可将其细胞内的多种RNA、DNA 片段、脂质和蛋白质等物质转送到不同的受体细胞,从而改变受体细胞的生物学活性。 多项研究证据表明Treg 细胞可分泌外泌体发挥免疫调节作用,并参与感染免疫、器官移植、超敏反应、自身免疫病以及肿瘤的 发生与发展。本文对Treg 细胞来源外泌体的组成成分、形成途径以及其免疫调节作用等进行综述。     

Exosomes – Structure,Biogenesis and Biological Role in Non‐Small‐Cell Lung Cancer

Many different cells produce and release membraneous microvesicles (MV) or exosomes into their microenvironment. Exosomes represent a specific subtype of secreted derived vesicles which are defined as homogenous vesicles of 30–100 nm lined by a lipid bilayer, which contain a specific set of proteins, lipids, and nucleic acids. There are clear evidences that they serve as important biological signals messengers and carriers in physiological as well as in pathological processes. Those derived from tumours (tumour‐derived exosomes, TD‐exosomes) function as protumourigenic factors that can mediate intercellular communication in the tumour microenvironment and also contribute to cancer progression. The main functions of exosomes in the cancer microenvironment include the following: promotion of primary cancer growth, stimulation of angiogenesis, activation of stromal fibroblasts, sculpting the cancer ECM, generation of a premetastatic niche and suppression of host immune response. Exosomes have recently emerged as potentially promising diagnostic and prognostic biomarkers in cancer and other diseases. This article is a summary of information about the structure and origin of exosomes and also indicates the importance of exosomes and microRNAs in lung cancer. The role of exosomes in NSCLC is little known, and its explanation requires thorough research.     

Exosomes/microvesicles: mediators of cancer-associated immunosuppressive microenvironments

Cancer cells, both in vivo and in vitro, have been demonstrated to release membranous structures, defined as microvesicles or exosomes, consisting of an array of macromolecules derived from the originating cells, including proteins, lipids, and nucleic acids. While only recently have the roles of these vesicular components in intercellular communication become elucidated, significant evidence has demonstrated that tumor exosomes can exert a broad array of detrimental effects on the immune system—ranging from apoptosis of activated cytotoxic T cells to impairment of monocyte differentiation into dendritic cells, to induction of myeloid-suppressive cells and T regulatory cells. Immunosuppressive exosomes of tumor origin can be found within neoplastic lesions and in biologic fluids from cancer patients, implying a potential role of these pathways in in vivo tumor progression and systemic paraneoplastic syndromes. Through the expression of molecules involved in angiogenesis promotion, stromal remodeling, signaling pathway activation through growth factor/receptor transfer, chemoresistance, and genetic intercellular exchange, tumor exosomes could represent a central mediator of the tumor microenvironment. By understanding the nature of these tumor-derived exosomes/microvesicles and their roles in mediating cancer progression and modulating the host immune response will significantly impact therapeutic approaches targeting exosomes.     

High-grade ovarian cancer secreting effective exosomes in tumor angiogenesis

Ovarian cancer, the most lethal gynecological cancer, related closely to tumor stage. High-grade ovarian cancer always results in a late diagnose and high recurrence, which reduce survival within five years. Until recently, curable therapy is still under research and anti-angiogenesis proves a promising way. Tumor-derived exosomes are essential in tumor migration and metastases such as angiogenesis is enhanced by exosomes. In our study, we have made comparison between high-grade and unlikely high-grade serous ovarian cancer cells on exosomal function of endothelial cells proliferation, migration and tube formation. Exosomes derived from high-grade ovarian cancer have a profound impact on angiogenesis with comparison to unlikely high-grade ovarian cancer. Proteomic profiles revealed some potential proteins involved in exosomal function of angiogenesis such as ATF2, MTA1, ROCK1/2 and so on. Therefore, exosomes plays an influential role in angiogenesis in ovarian serous cancer and also function more effectively in high-grade ovarian cancer cells.     

Bladder cancer tissue-derived exosomes suppress ferroptosis of T24 bladder cancer cells by transporting miR-217

It has been reported that miR-217 can inhibit the oncogenic activity and progression of bladder cancer (BCa) cells, but it has not been explored whether miR-217 is involved in the regulation of ferroptosis. In the present study, RNA transfection, real-time PCR, flow cytometry, Western blotting assays, immunofluorescence and ELISA were performed to explore the effects and mechanisms of miR-217 in BCa tissue-derived exosomes. We found that extracellular fluid from bladder cancer tissue promoted the growth and miR-217 expression of T24 cells and inhibited ferroptosis. MiR-217 was confirmed to inhibit ferroptosis in bladder cancer cells by RNA interference and functional assays. By cell membrane fluorescence probe (CM-Dil) labeling, inhibiting exosome secretion by GW4689 and exosome extraction, we determined that BCa tissue-derived exosomes transport miR-217 into T24 cells. Culture of T24 cells with extracellular fluid after RNA interference showed that exosomes carrying miR-217 derived from BCa tissues inhibited ferroptosis of T24 cells. We conclude that bladder cancer tissue-derived exosomes inhibit ferroptosis of T24 bladder cancer cells by transporting miR-217. The results of our study provide a new insight into the progression of bladder cancer.     

白血病细胞源外泌体的作用研究进展

<正>白血病(leukemia)是一类造血干/祖细胞恶性克隆性疾病。外泌体是活细胞分泌到胞外的一种纳米级的微囊泡,是细胞间对话的信息和物质载体~([1])。外泌体携带亲本细胞来源的蛋白质、核酸(mRNA、microRNA和DNA等)及脂质等生物信息分子,可近距离和/或经体液流动远距离、特异性调控靶细胞的生理和病理活动~([2-3])。靶细胞摄取外泌体的途径主要有网格蛋白介导的内吞途径、小窝蛋白依赖型内     

Analysis of exosome release and its prognostic value in human colorectal cancer

A significant proportion of extracellular nucleic acids in plasma circulate highly protected in tumor‐specific exosomes, but it is unclear how the release of exosomes is modulated in carcinogenesis. We quantified by cytometry exosomes in plasma of 91 colorectal cancer patients to evaluate their potential as a tumor indicator and their repercussions on diagnosis and prognosis. We examined the involvement of TSAP6, a TP53‐regulated gene involved in the regulation of vesicular secretion, in levels of circulating exosomes in plasma of colorectal patients and in HCT116 TP53‐(wild‐type and null) human colorectal cancer cell lines. The fraction of exosomes in cancer patients was statistically higher than in healthy controls (mean rank = 53.93 vs. 24.35). High levels of exosomes in plasma of patients correlated with high levels of carcino‐embryonic antigen (P = 0.029) and with poorly differentiated tumors (P = 0.039) and tended to have shorter overall survival than patients with low levels (P = 0.056). Release of exosomes did not correlate with TSAP6 expression; and regulation of TSAP6 by TP53 was not shown either in tumor samples or in HCT116 cell lines. Although it was not suggested that the TP53/TSAP6 pathway regulates the release of exosomes into the plasma of colorectal cancer patients, the level of circulating exosomes may be used as a tumor indicator, because it correlates with poor prognosis parameters and shorter survival. © 2011 Wiley Periodicals, Inc.     

细胞分泌的囊状小体exosomes的研究进展

有多种细胞都能分泌一种被称为exosomes的小囊泡，这些囊泡由细胞内的内吞小体出泡产生，它包裹着特殊的蛋白质，在信息传递中起着很重要的作用。特别是在免疫系统中，exosomes能够将外来抗原传递给T细胞，并且在免疫调节中发挥作用。exosomes作为一种免疫治疗的新手段，可以应用在肿瘤治疗和免疫耐受等方面。     

Tumor-derived exosomes in the regulation of macrophage polarization

Inflammation Research - This review focuses on exosomes derived from various cancer cells. The review discusses the possibility of differentiating macrophages in alternatively activated...     

Non-compliance is the predominant cause of aspirin resistance in chronic coronary arterial disease patients

Advances in cancer therapy have been substantial in terms of molecular understanding of disease mechanisms, however these advances have not translated into increased survival in the majority of cancer types. One unsolved problem in current cancer therapeutics is the substantial immune suppression seen in patients. Conventionally, investigations in this area have focused on antigen-nonspecific immune suppressive molecules such as cytokines and T cell apoptosis inducing molecules such as Fas ligand. More recently, studies have demonstrated nanovesicle particles termed exosomes are involved not only in stimulation but also inhibition of immunity in physiological conditions. Interestingly, exosomes secreted by cancer cells have been demonstrated to express tumor antigens, as well as immune suppressive molecules such as PD-1L and FasL. Concentrations of exosomes from plasma of cancer patients have been associated with spontaneous T cell apoptosis, which is associated in some situations with shortened survival. In this paper we place the "exosome-immune suppression" concept in perspective of other tumor immune evasion mechanisms. We conclude by discussing a novel therapeutic approach to cancer immune suppression by extracorporeal removal of exosomes using hollow fiber filtration technology