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。     

外泌体微RNA治疗骨关节炎研究进展

骨关节炎是骨科常见的顽固性疾病之一,因其高发病率、高致残率,给患者和社会带来沉重的负担。随着组织工程领域的飞速发展,外泌体治疗骨关节炎的潜力已得到证实。其中,外泌体特异性微RNA（miRNA）可抑制软骨降解和滑膜炎症、促进软骨下骨重塑,从而缓解甚至逆转骨关节炎的病理改变。本文对外泌体miRNA治疗对骨关节炎患者软骨、滑膜、软骨细胞外基质及软骨下骨的影响进行综述,以期为临床上应用外泌体miRNA治疗骨关节炎提供参考。     

尿源干细胞及其外泌体治疗肾脏病的作用北大核心

背景:尿源干细胞为尿液中存在的间充质干细胞,具备自我增殖与多向分化的潜能,由于其本身存在于泌尿系统,并且很可能来源于肾脏组织,相较于其他间充质干细胞存在先天的优势,因此尿源干细胞及其外泌体可能具备对于肾脏病的特殊干预作用。目的:综述尿源干细胞及其外泌体的生物学特性,以及二者在肾脏病领域的应用进展,以期为临床肾脏疾病的治疗提供新思路。方法:以“urine-derived stem cell*,urine-derived stromal cell*,urine-derived mesenchymal stem cell*,urine-derived mesenchymal stromal cell*,urine-derived progenitor cell*,kidney diseases,acute kidney injury,diabetic nephropathies,kidney failure,chronic,tissue engineering,organoids”为检索词检索PubMed数据库,以“尿源干细胞,急性肾损伤,慢性肾病,糖尿病肾病,组织工程,类器官”为检索词检索CNKI数据库,发表时间限定为2000年1月至2021年10月。检索后严格按照纳入和排除标准进行人为筛选,最终纳入31篇文献进行综述。结果与结论:①尿源干细胞作为泌尿系统来源的间充质干细胞,具备间充质干细胞共有的特性。此外,其在肾脏病领域是一种有效的干预措施和适宜的种子细胞来源;②尿源干细胞及其外泌体在急性肾损伤动物及细胞模型上,可以显著缓解肾功能损害和组织学损伤,抑制炎症、细胞凋亡和氧化应激;在慢性肾脏病(包括糖尿病肾病)方面,尿源干细胞及其外泌体可以延缓肾功能进展及组织学改变,抑制炎症细胞浸润及纤维化,发挥对足细胞的保护作用;此外,其在肾脏组织工程与再生医学领域的应用也同样具有广阔的前景;③虽然尿源干细胞及其外泌体在肾脏病领域的研究尚处于初始阶段,但已体现出较大的潜力和价值,在未来有望成为临床肾脏病治疗的有效手段之一。     

Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection

BackgroundDeveloping a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells’ proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection.MethodsUsing 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets.ResultsAn exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature’s negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell–mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature’s negative predictive value was 90.6% and its positive predictive value was 77.8%.ConclusionsOur findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.     

Pivoting Novel Exosome-Based Technologies for the Detection of SARS-CoV-2

The National Institutes of Health (NIH) launched the Rapid Acceleration of Diagnostics (RADx) initiative to meet the needs for COVID-19 diagnostic and surveillance testing, and to speed its innovation in the development, commercialization, and implementation of new technologies and approaches. The RADx Radical (RADx-Rad) initiative is one component of the NIH RADx program which focuses on the development of new or non-traditional applications of existing approaches, to enhance their usability, accessibility, and/or accuracy for the detection of SARS-CoV-2. Exosomes are a subpopulation of extracellular vesicles (EVs) 30–140 nm in size, that are critical in cell-to-cell communication. The SARS-CoV-2 virus has similar physical and molecular properties as exosomes. Therefore, the novel tools and technologies that are currently in development for the isolation and detection of exosomes, may prove to be invaluable in screening for SARS-CoV-2 viral infection. Here, we describe how novel exosome-based technologies are being pivoted for the detection of SARS-CoV-2 and/or the diagnosis of COVID-19. Considerations for these technologies as they move toward clinical validation and commercially viable diagnostics is discussed along with their future potential. Ultimately, the technologies in development under the NIH RADx-Rad exosome-based non-traditional technologies toward multi-parametric and integrated approaches for SARS-CoV-2 program represent a significant advancement in diagnostic technology, and, due to a broad focus on the biophysical and biochemical properties of nanoparticles, the technologies have the potential to be further pivoted as tools for future infectious agents.     

唾液外泌体与口腔疾病相关研究进展

唾液外泌体是指存在于唾液中的直径在30～150 nm的细胞外囊泡。随着近年来技术手段的发展,大量研究揭示唾液外泌体在多种口腔疾病的发生发展中发挥重要作用,如唾液外泌体CD9及CD81通过调控细胞粘附及运动促进肿瘤细胞转移、唾液外泌体miR-24-3p通过作用于PER1促进肿瘤细胞增殖、唾液外泌体程序性细胞死亡配体-1(programmed cell death-ligand 1,PD-L1)mRNA抑制炎症组织的破坏等,具有作为诊断口腔癌、牙周炎等口腔疾病的生物标志物的潜能。因此,唾液外泌体可作为口腔疾病潜在的预后和诊断标志物。唾液外泌体除与口腔疾病,如口腔癌、牙周炎、口腔扁平苔藓、干燥综合征等有关外,还同远处部位肿瘤如胰腺癌、肺癌等及系统性疾病如帕金森综合征、炎症性肠病等密切相关;深入研究唾液外泌体对口腔、全身系统性疾病的诊断与治疗作用,开发唾液外泌体作为疾病诊断的生物标志物的潜力具有重要意义。     

尿外泌体在膀胱尿路上皮细胞癌中的表达及临床意义

目的:探讨尿外泌体(exosome)在膀胱尿路上皮细胞癌中的表达情况及其临床意义。方法:采用超速离心法提取30例膀胱尿路上皮细胞癌患者和15例健康人群的尿外泌体。利用投射电镜观察形态,BCA法进行蛋白定量,Western blot检测尿外泌体表面分子CD9。结果:健康人群尿外泌体水平[(125.99±47.71)μg/μL]与膀胱尿路上皮细胞癌患者尿外泌体表达水平[(259.74±57.47)μg/μL]差异有统计学意义。根据肿瘤的浸润程度,非肌层浸润性膀胱癌患者尿外泌体水平与肌层浸润性膀胱癌患者尿外泌体水平差异有统计学意义。而肌层浸润性膀胱癌各期患者尿外泌体水平差异无统计学意义。结论:尿外泌体检测可能为膀胱癌的早期诊断提供一种可行的方案。     

外泌体及其在干细胞中的研究进展

外泌体是在细胞间交流中起重要作用的小分泌囊泡,可由多种类型的细胞分泌,在细胞间起着质膜交换及转运蛋白质、mRNA、microRNA和细胞器等生命活性物质的作用.外泌体可通过改变基因调控网络或表观遗传重组来调控正常的生理过程.最近的研究发现,干细胞分泌的外泌体可以有效转运mRNA、microRNA和蛋白质,在调控组织再生方面发挥重要作用.该文对外泌体的生成及其在干细胞中的研究进展进行综述.     

Exosomes Derived from Glioma Cells under Hypoxia Promote Angiogenesis through Up-regulated Exosomal Connexin 43

Glioblastoma multiform (GBM) is a highly aggressive primary brain tumor. Exosomes derived from glioma cells under a hypoxic microenvironment play an important role in tumor biology including metastasis, angiogenesis and chemoresistance. However, the underlying mechanisms remain to be elucidated. In this study, we aimed to explore the role of connexin 43 on exosomal uptake and angiogenesis in glioma under hypoxia. U251 cells were exposed to 3% oxygen to achieve hypoxia, and the expression levels of HIF-1α and Cx43, involved in the colony formation and proliferation of cells were assessed. Exosomes were isolated by differential velocity centrifugation from U251 cells under normoxia and hypoxia (Nor-Exos and Hypo-Exos), respectively. Immunofluorescence staining, along with assays for CCK-8, tube formation and wound healing along with a transwell assay were conducted to profile exosomal uptake, proliferation, tube formation, migration and invasion of HUVECs, respectively. Our results revealed that Hypoxia significantly up-regulated the expression of HIF-1α in U251 cells as well as promoting proliferation and colony number. Hypoxia also increased the level of Cx43 in U251 cells and in the exosomes secreted. The uptake of Dio-stained Hypo-Exos by HUVECs was greater than that of Nor-Exos, and inhibition of Cx43 by ^37,43gap27 or lenti-Cx43-shRNA efficiently prevented the uptake of Hypo-Exos by recipient endothelial cells. In addition, the proliferation and total loops of HUVECs were remarkably increased at 24 h, 48 h, and 10 h after Hypo-Exos, respectively. Notably, ^37,43gap27, a specific Cx-mimetic peptide blocker of Cx37 and Cx43, efficiently alleviated Hypo-Exos-induced proliferation and tube formation by HUVECs. Finally, ^37,43gap27 also significantly attenuated Hypo-Exos-induced migration and invasion of HUVECs. These findings demonstrate that exosomal Cx43 contributes to glioma angiogenesis mediated by Hypo-Exos, and suggests that exosomal Cx43 might serve as a potential therapeutic target for glioblastoma.