巨噬细胞来源外泌体介导心肌梗塞后心脏重塑的作用研究

目的:研究活化的巨噬细胞来源外泌体在心肌梗塞后心脏重塑中的作用。方法:采用超高速离心分离提取溶血磷脂酸作用下巨噬细胞来源的外泌体,将其与心脏成纤维细胞共同孵育48小时,利用Edu细胞增殖实验、Transwell实验及免疫荧光等方法检测溶血磷脂酸刺激(LPS)下巨噬细胞来源外泌体对心脏成纤维细胞的增殖、迁移以及分化的影响。选取正常C57雄性小鼠32只,根据其是否结扎左侧冠状动脉前降支及是否进行心脏原位外泌体注射,将实验小鼠随机分为:正常组,假手术组,心梗+空白外泌体组及心梗组+LPS刺激外泌体组。手术完成4周后行心脏超声、Masson染色以检测各组实验小鼠心功能状态及心脏纤维化程度。结果:在细胞实验中,LPS刺激的巨噬细胞来源外泌体可以显著增加心脏成纤维细胞的增殖、迁移以及分化能力;在动物实验中,相对于正常组、假手术组及心梗+空白-外泌体组,心梗+LPS-外泌体组小鼠的左心室射血分数及短轴收缩率显著下降,左心室舒张末及收缩末内径显著增加。Masson染色检测提示心肌梗塞+LPS-外泌体组小鼠心脏纤维化程度显著高于其余三组。结论:活化的巨噬细胞来源的外泌体可以显著加速心梗后心脏重塑的进程。     

TLRs信号通路激活的MSCs外泌体对巨噬细胞极化的影响

目的探讨Toll样受体（TLR）3和4信号通路激活的间充质干细胞外泌体（MSCs-Exo）对巨噬细胞极化的影响。 方法差速贴壁法体外培养大鼠骨髓源MSCs,用外泌体提取试剂盒分别提取MSCs、TLR3信号通路激活的MSCs、TLR4信号通路激活的MSCs培养上清中的外泌体。用含10%FBS、10%L929条件培养基的RPMI-1640培养得M0型巨噬细胞,实验分6组：对照组及MSCs-Exo、TLR3信号通路激活的MSCs-Exo、TLR4信号通路激活的MSCs-Exo、LPS、IL-4+IL-13分别与M0型巨噬细胞共培养,48 h后收集各组巨噬细胞光镜下观察形态,流式和qPCR检测免疫表型（CD206、Arg-1、TNF-α、iNOS）及炎症因子（CCL22、IL-1β、IL-6、IL-10）表达的改变。组间比较采用单因素方差分析及独立t检验进行统计学分析。 结果MSCs鉴定符合间充质干细胞特性,MSCs-Exo为双层膜囊泡结构,直径在40 ~ 200 nm之间,表达外泌体标志性蛋白CD9、HSP70;光镜下观察各组巨噬细胞形态,加MSCs-Exo及TLR3和TLR4信号通路激活的MSCs-Exo刺激的巨噬细胞呈长梭形,伪足较多;流式检测发现,加MSCs-Exo及TLR3和TLR4信号通路激活的MSCs-Exo刺激的巨噬细胞均高表达CD206（107.2±6.87、102.4±9.83、112.0±9.24 vs 56.0±7.38,F?=?47.234,P均< 0.001）、Arg-1（135.2±6.87、130.2±7.59、203.4±9.07 vs 117.8±9.12,F =109.827,P =?0.009、0.048、0.000）;低表达TNF-α（27.0±5.65、24.6±5.02、25.6±4.15 vs 36.6±7.09,F = 4.882,P = 0.046、0.015、0.017）,而MSCs-Exo刺激的巨噬细胞低表达iNOS（240.2 ± 8.43 vs 308.8±9.88,P < 0.001）;TLR3和TLR4信号通路激活的MSCs-Exo刺激的巨噬细胞iNOS表达差异无统计学意义（P > 0.05）。qPCR检测发现,加MSCs-Exo及TLR3和TLR4信号通路激活的MSCs-Exo刺激的巨噬细胞均高表达CCL22（2.277±0.744、1.570±0.209、1.642±0.443 vs 1.000±0.111,F = 23.654,P = 0.015、0.003、0.031）、IL-10（1.233±0.136、2.426±0.343、1.390±0.155 vs 1.000±0.130,F?= 103.251,P = 0.048、0.000、0.008）,低表达IL-1β（0.383±0.035、0.640±0.143、0.242±0.073 vs 1.000±0.082,F = 12.315,P = 0.000、0.005、0.000）、IL-6（0.386±0.066、0.655±0.046、0.533±0.090 vs 1.000±0.204,F = 30.140,P = 0.001、0.006、0.016）。 结论TLR3和TLR4信号通路激活的MSCs-Exo均能促使巨噬细胞向M2型极化。     

巨噬细胞外泌体在增殖性糖尿病视网膜病变中的研究进展

糖尿病视网膜病变(diabetic retinopathy, DR)是糖尿病患者最常见的微血管系统并发症之一，是视力丧失的主要原因。增殖性糖尿病视网膜病变(proliferative diabetic retinopathy, PDR)是DR的终末期表现，其主要的病理生理学特征是视网膜新生血管形成(retinal neovascularization, RNV)。但PDR现有治疗方式存在局限性。外泌体作为细胞间沟通交流的重要使者，其携带的非编码RNA和生物活性蛋白质等重要信号分子，通过影响血管内皮细胞的增殖和迁移，在RNV中发挥关键作用。巨噬细胞是一种多功能调节细胞，越来越多的研究表明巨噬细胞外泌体在调控新生血管形成中起重要作用。该文就巨噬细胞外泌体在增殖性糖尿病视网膜病变形成中的作用与机制研究进展进行综述。     

工程化外泌体介导巨噬细胞清除肿瘤外泌体*

目的:通过膜表面修饰改造技术构建工程化外泌体(engineered exosomes,enExos),并以此介导巨噬细胞特异性清除膜表面富含表皮生长因子受体(epidermal growth factor receptor,EGFR)的肿瘤外泌体。方法:利用表面展示技术获得膜表面展示趋化因子(chemokine 8,CXCL8)的外泌体,同时在其磷脂双分子层上修饰EGFR核酸适配体制备工程化外泌体;纳米颗粒跟踪和纳米粒度电位分析enExos的尺寸、电位;CCK-8试剂盒检测细胞活力;透射电子显微镜观察enExos与高表达EGFR的肿瘤外泌体的特异性结合;荧光成像技术及流式细胞术分析探究enExos靶向趋化巨噬细胞吞噬高表达EGFR的肿瘤外泌体。结果:成功构建膜表面展示EGFR与CXCL8的工程化外泌体,enExos可以特异性识别并捕获高表达EGFR的肿瘤外泌体,同时利用其趋化因子CXCL8特异性靶向巨噬细胞膜表面趋化因子受体CXCR1/CXCR2,刺激巨噬细胞对肿瘤外泌体的捕获及清除。结论:工程化外泌体促进了特定肿瘤外泌体的清除,为后续深入研究工程化外泌体抑制癌症转移的作用奠定基础,并期望为癌症转移治疗提供新的研究方向。     

间充质干细胞来源外泌体促心肌梗死血管新生及其机制研究进展

血管新生(angiogenesis)是机体内一个复杂的生理学和病理学过程,是治疗缺血性疾病的重要措施。大量实验研究已表明间充质干细胞(mesenchymal stem cells, MSCs)等干细胞移植可促进心肌梗死后血管新生,近期研究证实这一作用可能主要通过分泌外泌体形式介导。外泌体(exosome)通过传递与血管新生相关微RNA(microRNA, mi RNA)或蛋白质等生物活性物质,调控靶器官中与血管新生相关通路的基因表达,提高内皮细胞在缺血缺氧环境下的存活、迁移、成管能力,促进心肌梗死区域血管新生。通过基因修饰手段增强外泌体介导的心脏修复作用,以及将外泌体与生物活性肽结合形成工程外泌体来靶向缺血心肌治疗,是目前外泌体在心血管领域的热点研究方向。本文结合近年外泌体研究的相关文献,就MSCs来源外泌体促进心肌梗死血管新生的具体机制及现状研究作一综述。     

膀胱癌细胞来源外泌体的提取与鉴定

目的:提取并鉴定膀胱癌5637细胞来源外泌体。方法:收集膀胱癌5637细胞培养上清液,采用多步骤离心法提取膀胱癌5637细胞外泌体。透射电子显微镜观察外泌体形态及颗粒直径。Bradford法定量外泌体蛋白含量。蛋白质免疫印迹鉴定外泌体标志蛋白。结果:20 m L 5637细胞培养基可收集约50-80μg外泌体。膀胱癌5637细胞来源外泌体呈典型的茶杯样形态,外泌体颗粒直径大约在30-150 nm。膀胱癌5637细胞外泌体提取物中可检测到标志蛋白CD63、TSG101、Hsp70和Hsp90表达。结论:多步骤离心法可以用于提取膀胱癌5637细胞外泌体,为后续开展膀胱癌5637细胞外泌体作用与机制的研究奠定了基础。     

脂肪间充质干细胞来源外泌体的功能

外泌体是细胞外膜质纳米囊泡,将蛋白质、核酸(DNA和RNA)转运到靶细胞中,介导局部和系统的细胞间通信,从而改变受体细胞的行为.这些小泡在许多生物功能中发挥重要作用,如脂肪合成、免疫调节、神经再生和肿瘤调节等.脂肪间充质干细胞目前被认为是细胞治疗和再生医学领域中一种功能丰富的工具,可产生和分泌多种外泌体,继承细胞的多种...     

不同体液来源外泌体分离鉴定方法评估

外泌体是细胞分泌的磷脂双分子层胞外囊泡,作为载体在细胞间发挥着物质传递和信息交流的功能.外泌体存在于多种不同体液中,在疾病诊断和药物载体方面具有良好的应用前景.由于外泌体纳米级别的大小和异质性,以及体液复杂的组成,使得体液来源外泌体的分离尤为困难.目前,体液来源外泌体分离有6种常用方法:超速离心法、沉淀法、分子筛色谱层...     

间充质干细胞来源的外泌体的特性及其在疾病治疗中的作用

外泌体(exosomes)是细胞主动向外环境中分泌的纳米囊泡结构,通常直径在100纳米以下。外泌体是来源细胞与靶细胞之间的物质交换和信息交流的新型载体,可以携带效应分子直接被周围细胞摄取或经血液循环至全身,在正常的生理过程或疾病的发生发展中发挥精细的调控作用。作为一种旁分泌介质,间充质干细胞(mesenchymal stem cell, MSC）来源的外泌体(MSC-exosomes)能够起到与干细胞相似的生理作用。MSC-exosomes所携带的生物活性蛋白质、脂质及DNA、mRNA和非编码RNA等生物活性物质,可能是MSC发挥治疗作用的重要机制之一。本文针对外泌体的生物学来源和近年来MSC-exosomes的标志物与特异性内容物在产生释放、提取鉴定和生物学功能等方面的研究,以及未来的应用前景进行综述,有利于研究者们在该领域开展更深入的研究。     

Exosomes Derived from Human Primary and Metastatic Colorectal Cancer Cells Contribute to Functional Heterogeneity of Activated Fibroblasts by Reprogramming Their Proteome

Cancer‐associated fibroblasts (CAFs) are a heterogeneous population of activated fibroblasts that constitute a dominant cellular component of the tumor microenvironment (TME) performing distinct functions. Here, the role of tumor‐derived exosomes (Exos) in activating quiescent fibroblasts into distinct functional subtypes is investigated. Proteomic profiling and functional dissection reveal that early‐ (SW480) and late‐stage (SW620) colorectal cancer (CRC) cell‐derived Exos both activated normal quiescent fibroblasts (α‐SMA^?, CAV⁺, FAP⁺, VIM⁺) into CAF‐like fibroblasts (α‐SMA⁺, CAV^?, FAP⁺, VIM⁺). Fibroblasts activated by early‐stage cancer‐exosomes (SW480‐Exos) are highly pro‐proliferative and pro‐angiogenic and display elevated expression of pro‐angiogenic (IL8, RAB10, NDRG1) and pro‐proliferative (SA1008, FFPS) proteins. In contrast, fibroblasts activated by late‐stage cancer‐exosomes (SW620‐Exos) display a striking ability to invade through extracellular matrix through upregulation of pro‐invasive regulators of membrane protrusion (PDLIM1, MYO1B) and matrix‐remodeling proteins (MMP11, EMMPRIN, ADAM10). Conserved features of Exos‐mediated fibroblast activation include enhanced ECM secretion (COL1A1, Tenascin‐C/X), oncogenic transformation, and metabolic reprogramming (downregulation of CAV‐1, upregulation of glycogen metabolism (GAA), amino acid biosynthesis (SHMT2, IDH2) and membrane transporters of glucose (GLUT1), lactate (MCT4), and amino acids (SLC1A5/3A5)). This study highlights the role of primary and metastatic CRC tumor‐derived Exos in generating phenotypically and functionally distinct subsets of CAFs that may facilitate tumor progression.     

Peripheral Macrophage-derived Exosomes promote repair after Spinal Cord Injury by inducing Local Anti-inflammatory type Microglial Polarization via Increasing Autophagy

Treatment for spinal cord injury (SCI) remains a challenge worldwide, and inflammation is a major cause of secondary injury after SCI. Peripheral macrophages (PMs) have been verified as a key factor that exert anti-inflammatory effects after SCI, but the mechanism is unidentified. As local macrophages, microglia also exert significant effects after SCI, especially polarization. Exosomes show source cell-like biological functions to target cells and have been the subject of much research in recent years. Thus, we hypothesized the PM-derived exosomes (PM-Exos) play an important role in signal transmission with local microglia and can be used therapeutic agents for SCI in a series of in vivo and in vitro studies. For the in vivo experiment, three groups of Sprague-Dawley (SD) rats subjected to spinal cord contusion injury were injected with 200 µg/ml PM-Exos, 20 µg/ml PM-Exos or PBS via the tail vein. Recovery of the rats and of spinal cord function were observed. In vitro, we investigated the potential anti-inflammatory mechanism of PM-Exos and evaluated microglial autophagy, anti-inflammatory type microglia polarization and the upstream signaling pathway. The results showed that spinal cord function and recovery were better in the PM-Exo groups than the control group. In the in vitro study, microglial autophagy levels and the expression of anti-inflammatory type microglia were higher in the experimental groups than the control group. Moreover, the expression of proteins related to the PI3K/AKT/mTOR autophagic signaling pathway was suppressed in the PM-Exo groups. PM-Exos have a beneficial effect in SCI, and activation of microglial autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway, enhancing the polarization of anti-inflammatory type microglia, that may play a major role in the anti-inflammatory process.     

Macrophage Polarization in Inflammatory Diseases

Diversity and plasticity are two hallmarks of macrophages. M1 macrophages (classically activated macrophages) are pro-inflammatory and have a central role in host defense against infection, while M2 macrophages (alternatively activated macrophages) are associated with responses to anti-inflammatory reactions and tissue remodeling, and they represent two terminals of the full spectrum of macrophage activation. Transformation of different phenotypes of macrophages regulates the initiation, development, and cessation of inflammatory diseases. Here we reviewed the characters and functions of macrophage polarization in infection, atherosclerosis, obesity, tumor, asthma, and sepsis, and proposed that targeting macrophage polarization and skewing their phenotype to adapt to the microenvironment might hold great promise for the treatment of inflammatory diseases.     

Exosomes derived from pro‐inflammatory bone marrow‐derived mesenchymal stem cells reduce inflammation and myocardial injury via mediating macrophage polarization

Exosomes are served as substitutes for stem cell therapy, playing important roles in mediating heart repair during myocardial infarction injury. Evidence have indicated that lipopolysaccharide (LPS) pre‐conditioning bone marrow‐derived mesenchymal stem cells (BMSCs) and their secreted exosomes promote macrophage polarization and tissue repair in several inflammation diseases; however, it has not been fully elucidated in myocardial infarction (MI). This study aimed to investigate whether LPS‐primed BMSC‐derived exosomes could mediate inflammation and myocardial injury via macrophage polarization after MI. Here, we found that exosomes derived from BMSCs, in both Exo and L‐Exo groups, increased M2 macrophage polarization and decreased M1 macrophage polarization under LPS stimulation, which strongly depressed LPS‐dependent NF‐κB signalling pathway and partly activated the AKT1/AKT2 signalling pathway. Compared with Exo, L‐Exo had superior therapeutic effects on polarizing M2 macrophage in vitro and attenuated the post‐infarction inflammation and cardiomyocyte apoptosis by mediating macrophage polarization in mice MI model. Consequently, we have confidence in the perspective that low concentration of LPS pre‐conditioning BMSC‐derived exosomes may develop into a promising cell‐free treatment strategy for clinical treatment of MI.     

人嗅黏膜间充质干细胞来源外泌体的分离鉴定及生物学特性研究

外泌体是指释放到细胞外微环境中的直径约50～130 nm的纳米级的膜性囊泡。嗅黏膜间充质干细胞（olfactory mucosa mesenchymal stem cells,OM-MSCs）作为一类新发现的间充质干细胞,在许多疾病中均具有治疗作用,且其内在机制与其旁分泌的外泌体密切相关,但OM-MSCs外泌体的分离、鉴定及生物学特性的研究尚未见报道。本研究采用超速离心法提取OM-MSCs培养液中的外泌体,应用流式细胞术及免疫荧光进行细胞鉴定后,分别用透射电子显微镜、纳米粒径分析及Western印迹对外泌体形态、颗粒大小和表面的特异性分子标志进行分析鉴定。采用CCK8增殖实验,Western印迹和划痕实验,分析其对人脑微血管内皮细胞增殖和迁移的影响。电镜、Western 印迹和纳米粒径分析的结果显示：OM-MSCs来源外泌体形态多为圆形,直径约为40～150 nm;表达外泌体标记物CD63,CD81;CCK-8法检测显示：不同浓度的OM-MSCs源外泌体可提高人脑微血管内皮细胞的增殖活性,且其增殖促进作用具有浓度依赖性（P<0.05）。Western 印迹检测结果显示：相比空白对照组,OM-MSCs源外泌体可显著提高内皮细胞的增殖细胞核抗原蛋白质水平表达（P<0.01）,细胞划痕实验结果显示,OM-MSCs源外泌体可增强内皮细胞的迁移能力,且高于对照组（P<0.01）。本研究表明：通过超速离心法可以分离纯化获得OM-MSCs源外泌体,且该外泌体具有促进人脑微血管内皮细胞迁移和增殖的作用。     

Exosomes Derived from the Human Primary Colorectal Cancer Cell Line SW480 Orchestrate Fibroblast‐Led Cancer Invasion

In localized tumors, basement membrane (BM) prevents invasive outgrowth of tumor cells into surrounding tissues. When carcinomas become invasive, cancer cells either degrade BM or reprogram stromal fibroblasts to breach BM barrier and lead invasion of cancer cells into surrounding tissues in a process called fibroblast‐led invasion. However, tumor‐derived factors orchestrating fibroblast‐led invasion remain poorly understood. Here it is shown that although early‐stage primary colorectal adenocarcinoma (SW480) cells are themselves unable to invade Matrigel matrix, they secrete exosomes that reprogram normal fibroblasts to acquire de novo capacity to invade matrix and lead invasion of SW480 cells. Strikingly, cancer cells follow leading fibroblasts as collective epithelial‐clusters, thereby circumventing need for epithelial to mesenchymal transition, a key event associated with invasion. Moreover, acquisition of pro‐invasive phenotype by fibroblasts treated with SW480‐derived exosomes relied on exosome‐mediated MAPK pathway activation. Mass spectrometry‐based protein profiling reveals that cancer exosomes upregulate fibroblasts proteins implicated in focal adhesion (ITGA2/A6/AV, ITGB1/B4/B5, EGFR, CRK), regulators of actin cytoskeleton (RAC1, ARF1, ARPC3, CYFIP1, NCKAP1, ICAM1, ERM complex), and signalling pathways (MAPK, Rap1, RAC1, Ras) important in pro‐invasive remodeling of extracellular matrix. Blocking tumor exosome‐mediated signaling to fibroblasts therefore represents an attractive therapeutic strategy in restraining tumors by perturbing stroma‐driven invasive outgrowth.