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.     

Melatonin-stimulated exosomes enhance the regenerative potential of chronic kidney disease-derived mesenchymal stem/stromal cells via cellular prion proteins

Chronic kidney disease (CKD) is caused by dysfunctional kidneys, which result in complications like cardiovascular diseases. Chronic kidney disease-induced pathophysiological conditions decrease efficacy of autologous mesenchymal stem/stromal cell (MSC)-based therapy by reducing MSC functionality. To enhance therapeutic potential in patients with CKD, we isolated exosomes derived from melatonin-treated healthy MSCs (MT exosomes) and assessed the biological functions of MT exosome–treated MSCs isolated from patients with CKD (CKD-MSCs). Treatment with melatonin increased the expression of cellular prion protein (PrP^C) in exosomes isolated from MSCs through the upregulation of miR-4516. Treatment with MT exosomes protected mitochondrial function, cellular senescence, and proliferative potential of CKD-MSCs. MT exosomes significantly increased the level of angiogenesis-associated proteins in CKD-MSCs. In a murine hindlimb ischemia model with CKD, MT exosome–treated CKD-MSCs improved functional recovery and vessel repair. These findings elucidate the regenerative potential of MT exosome–treated CKD-MSCs via the miR-4516-PrP^C signaling axis. This study suggests that the treatment of CKD-MSCs with MT exosomes might be a powerful strategy for developing autologous MSC-based therapeutics for patients with CKD. Furthermore, miR-4516 and PrP^C could be key molecules for enhancing the regenerative potential of MSCs in ischemic diseases.     

Exosomes play roles in sequential processes of tumor metastasis

Overwhelming evidence demonstrates that exosomes, a series of biologically functional small vesicles of endocytic origin carrying a variety of active constituents, especially tumor-derived exosomes, contribute to tumor progression and metastasis. This review focuses on the specific multifaceted roles of exosomes in affecting sequenced four crucial processes of metastasis, through which cancer cells spread from primary to secondary organs and finally form macroscopic metastatic lesions. First, exosomes modulate the primary tumor sites to assist cancer growth and dissemination. In this part, five main biological events are reviewed, including the transfer of oncogenic constituents, the recruitment and activation of fibroblasts, the induction of angiogenesis, immunosuppression and epithelial-mesenchymal transition (EMT) promotion. In Step 2, we list two recently disclosed mechanisms during the organ-specific homing process: the exosomal integrin model and exosomal epidermal growth factor receptor (EGFR)/miR-26/hepatocyte growth factor (HGF) model. Subsequently, Step 3 focuses on the interactions between exosomes and pre-metastatic niche, in which we highlight the specific functions of exosomes in angiogenesis, lymphangiogenesis, immune modulation and metabolic, epigenetic and stromal reprogramming of pre-metastatic niche. Finally, we summarize the mechanisms of exosomes in helping the metastatic circulating tumor cells escape from immunologic surveillance, survive in the blood circulation and proliferate in host organs.     

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??Exosomes refer to 40??100 nm extracellular vesicles secreted from various types of cells that contain cell's lipid??proteins and nucleic acids??which can be accessed to recipient cell by plasma membrane fusion??surface receptor-mediated uptake??and cell internalization??affecting the function and activity of the recipient cell. The RNA and miRNA contained in exosomes can be transferred with the exosomes to the recipient cells??and are translated in the recipient cells??which is a new carrier of genetic exchange. The research of exosomes in oral field focuses on exosome-mediated cell communication and modulating immunocompetence. In this paper??the exosomes derived from salivary origin??oral cancer sources and periodontal pathogens were reviewed to summarize the research progress in exosomes of the oral area.     

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??Objective    To study the influence of exosome secreted by the human bone marrow mesenchymal stem cells ??hBMMSCs?? on proliferation and differentiation of periodontal ligament stem cells ??hPDLSCs????and to provide experimental basis and evidence of the mechanism of hBMMSCs in promoting periodontal tissue regeneration. Methods    hPDLSCs were cultured by enzyme digestion method and hBMMSCs were cultured by centrifugation method?? and the immunophenotype was identified by flow cytometry. Supernatant of hBMMSCs in P3 was collected?? exosome was extracted by kit and observed by SEM??and CD63 level was tested by WB. The experiment group was treated by exosome of hBMMSCs and control group was treated by DD water. hPDLSCs proliferation was tested by MTT and colony unite forming was tested in 7 days. After osteogenetic induction?? ALP and Alizarin Red staining were performed and quantitative analysis was carried. Meanwhile osteogenesis-related gene expression was tested by qPCR. Results    hPDLSCs positively expressed CD29?? CD44?? CD90?? CD146 and Stro-1?? hBMMSCs positively expressed CD29?? CD44?? CD90 and CD106??both negatively expressed CD14?? CD34 and CD45. Exosome secreted by hBMMSCs were small ball-shaped under SEM and expressed CD63 strongly by WB. The proliferation and colony unite forming of experimental group was significantly higher than control group ??P < 0.05??. The quantitative expression of ALP and alizarin red staining after osteogenetic induction were significantly stronger than the control group ??P < 0.05??. The osteogenetic gene expression??including Runx2?? OCN?? ALP?? BSP and Col - ?? was significantly higher than that of control group by qPCR ??P < 0.05??. Conclusion    The exosome secreted by hBMMSCs can promote??proliferation and osteogenesis of hPDLSCs in vitro.     

Metabolomic Identification of Exosome-Derived Biomarkers for Schizophrenia: A Large Multicenter Study

Exosomes have been suggested as promising targets for the diagnosis and treatment of neurological diseases, including schizophrenia (SCZ), but the potential role of exosome-derived metabolites in these diseases was rarely studied. Using ultra-performance liquid chromatography-tandem mass spectrometry, we performed the first metabolomic study of serum-derived exosomes from patients with SCZ. Our sample comprised 385 patients and 332 healthy controls recruited from 3 clinical centers and 4 independent cohorts. We identified 25 perturbed metabolites in patients that can be used to classify samples from patients and control participants with 95.7% accuracy (95% CI: 92.6%–98.9%) in the training samples (78 patients and 66 controls). These metabolites also showed good to excellent performance in differentiating between patients and controls in the 3 test sets of participants, with accuracies 91.0% (95% CI: 85.7%–96.3%; 107 patients and 62 controls), 82.7% (95% CI: 77.6%–87.9%; 104 patients and 142 controls), and 99.0% (95% CI: 97.7%–100%; 96 patients and 62 controls), respectively. Bioinformatic analysis suggested that these metabolites were enriched in pathways implicated in SCZ, such as glycerophospholipid metabolism. Taken together, our findings support a role for exosomal metabolite dysregulation in the pathophysiology of SCZ and indicate a strong potential for exosome-derived metabolites to inform the diagnosis of SCZ.