ABSTRACT

Substantial research has been devoted to discovering the translational potential of extracellular vesicles (EV) as a reliable liquid biopsy in the diagnosis and monitoring of several life-affecting diseases, including chronic inflammatory diseases (CID). So far, the role of EV in the development of CID remains largely unknown due to the lack of specific tools to separate the disease-associated EV subtypes. Therefore, this study aims to fractionate inflammation-associated EV (sub)populations using a two-step separation strategy based on their size combined with a specific inflammatory marker (ICAM-1) and to unravel their proteome signature and functional integrity at the onset of vascular inflammation.

Here, we report that vascular endothelial cells upon inflammation release two heterogeneous size-based populations of EV (EV-10 K and EV-110 K) sharing a cocktail of inflammatory proteins, chemokines, and cytokines (chiefly: ICAM-1, CCL-2, CCL-4, CCL-5, IL-8 and CXCL-10). The co-enrichment of ICAM-1 and classical EV markers within these two size-based populations gave us a promising opportunity to further separate the inflammation-associated EV subpopulations, using an immuno-affinity methodology. Protein profiling of EV subpopulations highlighted that the phenotypic state of inflamed endothelial cells is preferentially mirrored in secreted medium- and large-sized ICAM-1 (+) EV. As functional players, the smaller-sized EV and especially their ICAM-1 (+) EV subpopulation promote the migration of THP-1 monocytes, whereas the large ICAM-1 (+) EV were more potent to induce ICAM-1 expression in recipient endothelial cells. This study provides new insights into the immunomodulatory content of inflammation-associated EV (sub)populations and their functional contributions to the initiation of vascular inflammation (ICAM-1 expression) and monocyte mobilization.

摘要

大量研究致力于发现细胞外囊泡（EV）的翻译潜力，作为诊断和监测多种影响生命的疾病，包括慢性炎症性疾病（CID）的可靠液体活检方法。到目前为止，由于缺乏分离与疾病相关的EV亚型的特定工具，EV在CID发生中的作用仍然未知。因此，本研究旨在通过两步分离策略，根据与特定炎症标记物（ICAM-1）结合的大小，采用两步分离策略对炎症相关的EV（sub）种群进行分级，并在发病初期揭示其蛋白质组特征和功能完整性。血管发炎。

在这里，我们报告说，炎症后血管内皮细胞释放出两种大小不同的EV种群（EV-10 K和EV-110 K），它们共享炎性蛋白，趋化因子和细胞因子（主要是ICAM-1，CCL- 2，CCL-4，CCL-5，IL-8和CXCL-10）。在这两个基于大小的人群中，ICAM-1和经典EV标记物的共同富集为我们提供了一个有前途的机会，可以使用免疫亲和性方法进一步分离与炎症相关的EV亚群。EV亚群的蛋白质谱分析突出显示，发炎的内皮细胞的表型状态优先反映在分泌的中型和大型ICAM-1（+）EV中。作为功​​能参与者，较小的EV，尤其是其ICAM-1（+）EV亚种群可促进THP-1单核细胞的迁移，而较大的ICAM-1（+）EV更能诱导受体内皮细胞中ICAM-1的表达。这项研究提供了新的见解，炎症相关的EV（亚）人群的免疫调节内容及其对血管炎症（ICAM-1表达）的启动和单核细胞动员的功能贡献。