自噬与外泌体

在真核生物中,细胞可以通过自噬(autophagy)和外泌体(exosome)的分泌两种方式来对外界刺激做出应答从而维持细胞内稳态。自噬是溶酶体依赖性细胞组分降解的过程,其能被氧化应激、饥饿或蛋白质聚集等因素诱导发生。除了自噬途径,细胞还可以通过分泌外泌体来调节细胞的生命活动,新的研究表明自噬与外泌体发生有同样的分子机理。本文综述了自噬与外泌体发生的过程以及两者之间的联系。     

自噬与外泌体在急性肺损伤中的研究进展

急性肺损伤(ALI)是一种常见的临床疾病,在全世界范围内引起严重的健康问题,但其发病机理尚不清楚。自噬(autophagy)是当前生物医学研究热点之一,涉及了多种病理生理过程。近期研究表明,自噬与包含ALI在内的多种肺部疾病的发病进展有关。外泌体(exsome)是由多种活细胞分泌的,由脂质双层被膜包围的纳米级结构(30～100 nm)。它通过传递其囊泡内包含的蛋白质,脂质和核酸来调节细胞间通讯和相互作用。外泌体的存在对其供体细胞、受体细胞、以及细胞间结构都有着重要的生理和病理意义。因此,外泌体的功能及特点得到越来越多的关注,成为疾病的诊断和治疗策略发展的新目标。在本篇综述中,我们概括了近年来自噬和外泌体对ALI病理生理的影响,并提出了二者可能的关联假设。     

自噬的分子细胞机制研究进展

自噬是真核细胞中进化上高度保守的、用于降解和回收利用细胞内生物大分子和受损细胞器的过程。自噬的完成依赖于正常的溶酶体功能,与机体的多种生理和病理过程密切相关。自噬研究已成为当前生命科学研究的热点,揭示自噬的发生机制、自噬与疾病发生的关系对预防与治疗多种人类重大疾病具有重要意义。该文旨在概括目前自噬的研究进展,重点介绍细胞自噬的发生机制及其与疾病的关系。     

基于微流控技术的外泌体分离方法的研究进展

外泌体是一种由细胞分泌的,直径一般为30-150 nm的囊泡。外泌体携带有多种蛋白质、mRNA及miRNA等生物标记物,并直接参与细胞间的信息传递、抗原传递、蛋白转运以及RNA转录等重要的生命活动过程,与癌症等多种疾病的发生密切相关,因此在疾病的发生机制探索和相关疾病的检测中具有重大的应用价值。然而,外泌体通常以游离的形式存在于体液中,对外泌体的分离和纯化是实现基于外泌体的疾病发生机制及疾病检测应用研究的基础。近年来,研究人员利用外泌体的生物物理和生物化学性质研发了多种分离和纯化外泌体的方法技术,主要有超速离心法、聚合物沉淀法、免疫分离法以及基于微流控的分离法等。综述了近年来外泌体分离和纯化方法的研究进展,简要论述了传统的外泌体分离方法,重点介绍了基于微流控技术的外泌体分离方法,并比较了这些方法的分离机制、优缺点以及应用前景。通过对近年来外泌体分离和纯化方法的研究现状进行归纳和比较,旨为相关研究人员开展外泌体研究工作提供参考,从而进一步推进外泌体在疾病检测及其他生物医学应用的研究进展。     

外泌体在肝纤维化中的作用

外泌体(exosomes)是一种能被大多数细胞分泌的微小膜泡,是具有脂质双层膜结构的细胞外囊泡。现认为外泌体是细胞外囊泡(extracellular vesicles, EVs)的一种亚群。研究表明,外泌体是细胞间信息传递的一种载体。肝脏既可以分泌外泌体,同时也是其他组织细胞产生的外泌体的作用靶点,且肝内与肝外来源的外泌体与肝纤维化的形成、发生、发展均有密切联系。本文主要就外泌体在肝纤维化相关疾病中的作用及外泌体与肝纤维化指标之间的关系进行综述。     

综述: 胞外囊泡表面糖缀合物研究进展

胞外囊泡(extracellular vesicles,EVs)是一类由细胞分泌到胞外的能够被受体细胞摄取的膜性囊泡小体,直径在20～ 1 000 nm．近年来,越来越多的研究者发现胞外囊泡在疾病诊断、预后评估以及药物递送等方面具有重要的生物学作用．胞外囊泡可以直接参与细胞间信息的传递以及物质的运输,其携带的核酸(mRNA,microRNA和lncRNA)和蛋白质可以影响受体细胞的生理状态．大量研究表明,胞外囊泡是被糖基化修饰的,胞外囊泡表面覆盖了大量的聚糖以及糖结合蛋白,而已知聚糖类物质在调控细胞黏附、细胞-细胞之间的信息传递、细胞和细胞外基质相互作用、免疫调节和肿瘤转移等方面发挥重要的作用．本文综述了近年来细胞外囊泡表面糖缀合物修饰的前沿研究,以期更好地理解聚糖在胞外囊泡的合成、释放以及运输过程及其生物学功能中的作用．     

干细胞外泌体在衰老和衰老相关疾病中的作用

随着人口老龄化加剧,衰老及其衰老相关疾病已成为影响生活质量的关键问题。近年来,研究发现干细胞具有抑制炎症、调节免疫反应、预防细胞凋亡、替换和促进受损部位修复等功能。但证据表明,干细胞治疗的效果主要来自干细胞分泌的外泌体。外泌体是由内吞膜衍生而来的纳米级囊泡,包含脂质、蛋白质、核酸和代谢产物等活性物质,是细胞与细胞间通讯的主要参与者。外泌体可以将生物活性物质转移至靶细胞,从而引起靶细胞的表型改变,进而调节器官的修复和再生。表型改变包括防止受体细胞凋亡、诱导靶细胞增殖、刺激免疫调节反应、减小靶细胞氧化应激以及增强氧供应。本文简述了外泌体的生物发生、分泌以及信号传导过程,并重点讨论了在基础研究和临床应用中,不同干细胞来源的外泌体对皮肤衰老和衰老相关疾病(例如心血管疾病、骨关节炎、骨质疏松、阿尔兹海默症)的影响。尽管干细胞外泌体的临床应用仍然存在问题,但它从基础研究到临床应用的前景仍然值得探索,这对于延缓衰老和治疗衰老相关疾病具有重要意义。     

自噬体膜的来源

细胞自噬是指细胞通过自噬-溶酶体(autolysosome)降解变性蛋白聚集物和受损细胞器的过程. 自噬对于细胞内环境的稳态、物质的平衡、胚胎发育以及疾病的发生发挥重要作用. 在电镜下观察,自噬体膜是一个双层脂质膜结构. 细胞中因缺乏除了自噬相关蛋白9 (autophagy-related protein 9,ATG9)以外的自噬体膜相关蛋白,故难以确定自噬体膜的来源. 自噬体膜的来源也因此成为目前自噬研究领域的热点问题. 关于自噬体膜的来源,学术界存在两种观点：一种认为自噬体膜是细胞在自噬体组装位点(pre-autophagosomal structure, PAS)重新合成的;另一种观点则认为自噬体膜来源于细胞已有的某些细胞器(如内质网、高尔基体、内吞体、质膜和线粒体). 该文综述了近年有关自噬体膜来源于细胞已有的某些细胞器的研究进展,旨在为相关领域的研究提供参考.     

外泌体miRNA的生物学功能及其在肺纤维化疾病中的调控作用

外泌体是一种微型纳米级细胞外囊泡,由于能够直接参与细胞间信息的传递和物质的运输,被认为是细胞间通讯、免疫调节、疾病诊断和预后循环生物学标志物的重要载体,其携带的核酸和蛋白质等内含物能够影响受体细胞的生理状态.作为一种内源性非编码微小RNA,microRNA (miRNA)对疾病诊断和治疗有着重要的研究价值,有大量证据表明该类分子对肺部疾病的发病进程起着控制调节作用.本文聚焦于近年来细胞外泌体来源miRNA的生物学特性和功能领域,综述了近年来生物医学研究中的热点分子外泌体miRNA在肺部疾病尤其是肺纤维化中调控功能和机制的研究,因此不仅能为肺纤维化疾病的诊断提供新的标志物分子,并且还能够为肺纤维化的外泌体干预治疗建议新的干预策略.     

外泌体提取及保存技术研究进展

外泌体是多种活细胞经过"内吞-融合-外排"等一系列过程主动向胞外分泌的纳米级双层膜结构小囊泡,广泛存在于血液和尿液等生物体液中.因其携带着多种蛋白质、核酸和脂质等生物活性分子,所以外泌体不仅在细胞间物质交换和信息传递中发挥重要作用,而且对疾病诊断、预后预测和治疗管理等均具有提示意义.外泌体的高效提取、分离和完整保存是研...     

Exosomes in atherosclerosis: Convergence on macrophages

As the primary cells of atherosclerotic plaques, macrophages play a central role in the occurrence and progression of atherosclerosis (AS). In recent years, macrophages have received extensive attention as therapeutic targets. Exosomes, as natural nanoparticles, have high biocompatibility and strong targeting ability and have been widely studied as imaging agents and drug carriers. Studies on the relationship between atherosclerotic macrophages and exosomes have been focused on for the past few years. Nevertheless, no complex review has been undertaken in this area. In this review, we summarize in detail the role of macrophages in atherosclerosis, especially their plasticity and phenotypic and distributional heterogeneity. Based on the high correlation between macrophages and the pathological process of atherosclerosis, as well as the targeting of exosomes, we further review the clinical application of targeting macrophage-associated exosomes. We focus on the role of macrophage-associated exosomes in the phenotypic transformation of cells in atherosclerosis, providing a new idea for the clinical application of targeting macrophage-associated exosomes. Finally, we specifically summarize and prospect the diagnosis of macrophage-associated exosomes, such as imaging agent delivery, biomarkers and therapeutic strategies.     

Exosome separation using microfluidic systems: size‐based,immunoaffinity‐based and dynamic methodologies

Exosomes, nanovesicles secreted by most types of cells, exist in virtually all bodily fluids. Their rich nucleic acid and protein content make them potentially valuable biomarkers for noninvasive molecular diagnostics. They also show promise, after further development, to serve as a drug delivery system. Unfortunately, existing exosome separation technologies, such as ultracentrifugation and methods incorporating magnetic beads, are time‐consuming, laborious and separate only exosomes of low purity. Thus, a more effective separation method is highly desirable. Microfluidic platforms are ideal tools for exosome separation, since they enable fast, cost‐efficient, portable and precise processing of nanoparticles and small volumes of liquid samples. Recently, several microfluidic‐based exosome separation technologies have been studied. In this article, the advantages of the most recent technologies, as well as their limitations, challenges and potential uses in novel microfluidic exosome separation and collection applications is reviewed. This review outlines the uses of new powerful microfluidic exosome detection tools for biologists and clinicians, as well as exosome separation tools for microfluidic engineers. Current challenges of exosome separation methodologies are also described, in order to highlight areas for future research and development.     

脂肪组织外泌体与机体其他组织互作研究进展 *

脂肪作为机体内最大的分泌器官,可以通过释放激素,细胞因子等调节其他的组织器官.近年来研究发现,脂肪组织可以释放外泌体并通过体液循环传递信号至其他组织器官,调节其靶器官的生理功能,且针对不同的靶器官,外泌体会产生不同的作用效果.机体的稳态是各组织间相互作用的结果,外泌体的发现,为脂肪组织与其他组织互作提供了稳定的物质基础,但是,脂肪外泌体的作用依旧存在着许多未知效果.从脂肪组织外泌体的发现,鉴定,以及脂肪外泌体与肝脏,肌肉和其他组织器官的相互作用等方面进行综述,为脂肪外泌体的研究提供理论依据,以便更好地探索生命的奥秘.     

Emerging Significance and Therapeutic Potential of Extracellular vesicles

Extracellular vesicles (EVs), are membrane-bound vesicles that have many advantages over traditional nanocarriers for drug and gene delivery. Evidence from recent studies indicate that EVs have therapeutic capability with chemical or biological modification. Tumor-derived exosomes (TEXs) were used as a new type of antigens or tumor vaccines in anti-tumor immunotherapy. With superior characteristics, modified EVs were applied to loaded and delivered synthetic drugs, silencing RNA, and microRNA for treatment. Different surface functionalization strategies have been proposed to improve the therapeutic functions of EVs. Appropriately modified EVs for disease intervention provide new avenues for effective clinical treatment strategies. Therefore, this review aimed at elucidating the therapeutic functions of EVs to generate new ideas for treatment and to unlock their hidden potential in translational medicine.     

外泌体在淋巴瘤中的研究进展

摘要：病毒感染和环境污染等使得淋巴瘤的发病率逐年升高,早期诊断和精准治疗具有十分重要的临床意义。外泌体是一种脂质双层膜结构的微小囊泡,介导了细胞间交流和信息交换。近几年许多研究证实外泌体是淋巴瘤的发生、进展和耐药的重要机制。外泌体内核酸和小分子可用于淋巴瘤的早期诊断和预测患者预后。材料学修饰可显著增强外泌体治疗的靶向性和治疗效能。本文总结了外泌体生物学特性、分离和鉴定方法、与肿瘤相关性、及其在淋巴瘤中的研究进展,为淋巴瘤的预警和治疗提供参考。     

Proteomic identification of the contents of small extracellular vesicles from in vivo Plasmodium yoelii infection

Small extracellular vesicles, including exosomes, are formed by the endocytic pathway and contain genetic and protein material which reflect the contents of their cells of origin. These contents have a role in vesicle-mediated information transfer, as well as physiological and pathological functions. Thus, these vesicles are of great interest as therapeutic targets, or as vehicles for immunomodulatory control. In Plasmodium spp. infections, vesicles derived from the parasite or parasite-infected cells have been shown to induce the expression of pro-inflammatory elements, which have been correlated with manifestations of clinical disease. Herein, we characterised the protein cargo of naturally occurring sEVs in the plasma of P. yoelii-infected mice. After in vivo infections, extracellular vesicles in the size range of exosomes were collected by sequential centrifugation/ultracentrifugation followed by isopycnic gradient separation. Analysis of the vesicles was performed by transmission electron microscopy, dynamic light scattering, SDS–PAGE and flow cytometry. LC-MS analysis followed by bioinformatics analysis predicted parasite protein cargo associated with exosomes. Within these small extracellular vesicles, we identified proteins of interest as vaccine candidates, uncharacterized proteins which may be targets of T cell immunoreactivity, and proteins involved in metabolic processes, regulation, homeostasis and immunity. Importantly, the small extracellular vesicles studied in our work were obtained from in vivo infection rather than from the supernatant of in vitro cultures. These findings add to the growing interest in parasite small extracellular vesicles, further our understanding of the interactions between host and parasite, and identify novel proteins which may represent potential targets for vaccination against malaria.     

外泌体在皮肤修复与再生中作用的研究进展

外泌体是直径在30-100 nm左右的囊泡结构。作为一种活细胞分泌的亚细胞成分,外泌体广泛参与细胞之间的交流,并可以作为干细胞的旁分泌因子来发挥生物学效应。研究发现外泌体可以参与皮肤组织修复与再生的各个过程,通过促进皮肤细胞的增殖迁移,促进血管新生,调节免疫反应来促进创伤愈合与皮肤组织再生,为进一步实现无细胞治疗提供了新的实现途径。对于某些慢性创面,例如糖尿病性皮肤溃疡等也有较好的治疗效果。本文就外泌体在皮肤修复与再生中作用的研究进展做一综述。     

Generation of mesenchymal stem-like cells for producing extracellular vesicles

Mesenchymal stem cells (MSCs) are multipotent progenitor cells with therapeutic potential against autoimmune diseases, inflammation, ischemia, and metabolic disorders. Contrary to the previous conceptions, recent studies have revealed that the tissue repair and immunomodulatory functions of MSCs are largely attributed to their secretome, rather than their potential to differentiate into desired cell types. The composition of MSC secretome encompasses cytokines and growth factors, in addition to the cell-derived structures known as extracellular vesicles (EVs). EVs are membrane-enclosed nanoparticles that are capable of delivering biomolecules, and it is now believed that MSC-derived EVs are the major players that induce biological changes in the target tissues. Based on these EVs’ characteristics, the potential of EVs derived from MSC (MSC-EV) in terms of tissue regeneration and immune modulation has grown during the last decade. However, the use of MSCs for producing sufficient amount of EVs has not been satisfactory due to limitations in the cell growth and large variations among the donor cell types. In this regard, pluripotent stem cells (PSCs)-derived MSC-like cells, which can be robustly induced and expanded in vitro, have emerged as more accessible cell source that can overcome current limitations of using MSCs for EV production. In this review, we have highlighted the methods of generating MSC-like cells from PSCs and their therapeutic outcome in preclinical studies. Finally, we have also discussed future requirements for making this cell-free therapy clinically feasible.