脐带间充质干细胞分泌的外泌体对骨性关节炎模型大鼠的镇痛作用

目的:观察脐带间充质干细胞分泌的外泌体对骨性关节炎模型大鼠疼痛行为、软骨修复及背根神经节(DRG)中转录激活因子3(ATF-3)及生长相关蛋白43(GAP-43)表达的影响,并探讨外泌体治疗关节炎疼痛的可能机制。方法:采用随机数字表法将54只雄性SD大鼠分为假手术组、模型组和外泌体组,每组18只,除假手术组外,其余2组...     

REVIEW ARTICLE: The Role of Placental Exosomes in Reproduction

Citation Mincheva‐Nilsson L, Baranov V. The Role of Placental Exosomes in Reproduction. Am J Reprod Immunol 2010 Cell communication comprises cell–cell contact, soluble mediators and intercellular nanotubes. There is, however, another cell–cell communication by released membrane‐bound microvesicles that convey cell–cell contact ‘by proxy’ transporting signals/packages of information from donor to recipient cells locally and/or at a distance. The nanosized exosomes comprise a specialized type of microvesicles generated within multivesicular bodies (MVB) and released upon MVB fusion with the plasma membrane. Exosomes are produced by a variety of immune, epithelial and tumor cells. Upon contact, exosomes transfer molecules that can render new properties and/or reprogram their recipient cells. Recently, it was discovered that the syncytiotrophoblast constitutively and throughout the pregnancy secretes exosomes. The placenta‐derived exosomes are immunosuppressive and carry proteins and RNA molecules that in a redundant way influence a number of mechanisms and promote the fetal allograft survival. In this review, we summarize the current knowledge on the nature of placenta‐derived exosomes and discuss their role in pregnancy.     

间充质干细胞外泌体在创伤修复再生中作用的研究进展

间充质干细胞（MSCs）外泌体能够通过旁分泌作用,发挥类似干细胞的促进组织器官修复再生的功能,避免了直接移植MSCs的风险,如致瘤、伦理、免疫排斥反应等。MSCs外泌体参与细胞通讯,维持微环境的稳态,促进细胞的增殖、迁移及细胞外基质的修复再生,且能够在不同物种之间传递,却不会引起明显的免疫反应,在组织器官的修复与再生方...     

间充质干细胞来源的外泌体在子痫前期中的实验研究进展

子痫前期是妊娠期常见并发症,严重威胁母婴健康,目前临床上尚无有效治疗方法。间充质干细胞来源的外泌体（mesenchymal stem cell-derived exosomes,MSC-exos）是纳米级别微粒子,携带有蛋白质、脂质和核酸等生物活性物质,是细胞间通讯的媒介。MSC-exos可参与免疫调节、促进细胞增殖与...     

B cell activation regulates exosomal HLA production

Exosomes are nanovesicles produced constitutively and inducibly by several types of cells. They are generated as intraluminal vesicles of multivesicular bodies and express MHC and several endosomal/lysosomal proteins. In spite of their potential role in cellular immunity, the regulatory mechanisms of exosome production are largely unknown. In this study, we have established a novel ELISA system to quantify exosomal HLA using a combination of anti-HLA class I and anti-HLA-DR mAb. We found that exosomal HLA production of B cells was enhanced by contact with CD4(+) T cells. Neutralizing anti-CD154 (CD40L) mAb inhibited this effect, and a soluble CD40L significantly increased production of exosomal HLA in B cells. In addition, B cell stimulation via BCR and TLR9 enhanced their production while IL-4 stimulation alone failed to do so. Strikingly, an inhibitor of the classical NF-kappaB pathway drastically inhibited exosomal HLA production in stimulated B cells, indicating that the classical NF-kappaB pathway is critical for exosomal HLA production in B cells. Together, these findings suggest a pivotal role of B cell activation in exosomal HLA production in vivo.     

In vivo imaging of mucosal CD4+ T cells using single photon emission computed tomography in a murine model of colitis

Immune responses that occur in the context of human infectious and inflammatory diseases are usually studied by sampling cells from peripheral blood, from biopsies, or by end-point harvests at necropsy. These approaches are likely to yield information that is incomplete and/or non-representative. Here, we report the development and validation of a non-invasive method to localize and to quantitate the disposition of specific subpopulations of cells in vivo. In a murine model of dextran sulfate sodium (DSS)-induced colitis, CD4+ T cells were visualized in the colon by single photon emission computed tomography (SPECT-CT) after injection of monoclonal, non-depleting, indium-111 (111In) labeled anti-CD4+ antibodies. The SPECT-CT colon uptake ratio (CUR) was found to correlate (p<0.01) with the number of total CD4+ T cells and with standard measures of pathology (colon length, cell counts, and histopathologic evidence of apoptosis, edema, and cellular infiltrates) as assessed by direct examination of diseased colon. Each of these parameters, including the SPECT-CT signal uptake, increased as a function of DSS dose (p<0.05). We conclude that CT-SPECT imaging using an 111In-labeled anti-CD4+ antibody is reflective of traditional parameters of pathology in this experimental model of murine colitis. This approach should be readily applicable to the imaging of discrete cell subpopulations in non-human primates and in humans, thus augmenting our understanding of infectious diseases and inflammation in vivo.     

Plasma-derived MHC class II+ exosomes from tumor-bearing mice suppress tumor antigen-specific immune responses

Tumor-specific immunosuppression is frequently observed in tumor-bearing hosts. Exosomes are nano-sized, endosomal-derived membrane vesicles secreted by most tumor and hematopoietic cells and have been shown to actively participate in immune regulation. We previously demonstrated that antigen-specific immunosuppressive exosomes could be isolated from the blood plasma of antigen-immunized mice. Here, we demonstrate that plasma-derived exosomes isolated from mice bearing OVA-expressing tumors were able to suppress OVA-specific immune responses in a mouse delayed-type hypersensitivity model. Enrichment of tumor-derived exosomes in the plasma of mice bearing subcutaneous melanoma was not detected using an exosome-tagging approach. Instead, depletion of MHC class II(+) vesicles from plasma-derived exosomes or using plasma-derived exosomes isolated from MHC class II-deficient mice resulted in significant abrogation of the suppressive effect. These results demonstrate that circulating host-derived, MHC class II(+) exosomes in tumor-bearing hosts are able to suppress the immune response specific to tumor antigens.     

细胞外囊泡在头颈部肿瘤中的研究进展

肿瘤的增殖和转移能力是由肿瘤微环境(TME)中细胞间的“相互对话”介导的。细胞外囊泡(EVs)是细胞主动分泌、可以介导细胞间通信的一种囊泡状小体,几乎来自所有类型的细胞,是癌细胞及其微环境之间的关键信号介质,在实现TME细胞间物质转运和信息传递方面发挥着重要作用。肿瘤细胞来源的EVs可以通过激活多种信号通路改变靶细胞生理状态,影响肿瘤微环境等方式参与肿瘤细胞的增殖与迁移。EVs在头颈部肿瘤(HNCs)中的分子机制和临床应用尚处于早期阶段,有待进一步研究。以头颈肿瘤的TME为研究重心,阐明EVs复杂的信号网络参与介导肿瘤增殖、侵袭转移、血管生成和肿瘤耐药的相关机制。     

Exosome-cargoed microRNAs: Potential therapeutic molecules for diabetic wound healing

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Altered level of plasma exosomes in patients with Gaucher disease

Mutations in the glucocerebrosidase gene (GBA) cause Gaucher disease (GD), the lysosomal storage disorder (LSD), and are the most common genetic risk factor of Parkinson's disease (PD). Lysosome functionality plays a critical role for secretion of extracellular vesicles (EVs) and their content. Here we compared EVs from the blood plasma of 8 GD patients and 8 controls in terms of amounts, size distribution, and composition of their protein cargo. EVs were isolated via sequential centrifugation and characterized by сryo-electron microscopy (cryo-EM), nanoparticle tracking analysis (NTA), and dynamic light scattering (DLS). The presence of exosomal markers HSP70 and tetrasponins were analyzed by Western blot and flow cytometry. Protein profiling was performed by mass-spectrometry (shotgun analysis).Here, for the first time we reported an increased size and altered morphology in exosomes derived from blood plasma of GD patients. An increased size of plasma exosomes from GD patients compared to controls was demonstrated by cryo-EM and DLS (р<0.0001, p < 0.001, respectively) and confirmed by mode size detected by NTA (p < 0.02). Cryo-EM demonstrated an increased number of double and multilayer vesicles in plasma EVs from GD patients. We found that the EVs were enriched with the surface exosomal markers (CD9, СD63, CD81) and an exosome-associated protein HSP70 in case of the patients with the disease. Proteomic profiling of exosomal proteins did not reveal any proteins associated with PD pathogenesis. Thus, we showed that lysosomal dysfunction in GD patients lead to a striking alteration of plasma exosomes in size and morphology.