Blood–brain barrier (BBB) dysfunction is a key hallmark in the pathology of many neuroinflammatory disorders. Extracellular vesicles (EVs) are lipid membrane-enclosed carriers of molecular cargo that are involved in cell-to-cell communication. Circulating endothelial EVs are increased in the plasma of patients with neurological disorders, and immune cell-derived EVs are known to modulate cerebrovascular functions. However, little is known about whether brain endothelial cell (BEC)-derived EVs themselves contribute to BBB dysfunction. Human cerebral microvascular cells (hCMEC/D3) were treated with TNFα and IFNy, and the EVs were isolated and characterised. The effect of EVs on BBB transendothelial resistance (TEER) and leukocyte adhesion in hCMEC/D3 cells was measured by electric substrate cell-substrate impedance sensing and the flow-based T-cell adhesion assay. EV-induced molecular changes in recipient hCMEC/D3 cells were analysed by RT-qPCR and Western blotting. A stimulation of naïve hCMEC/D3 cells with small EVs (sEVs) reduced the TEER and increased the shear-resistant T-cell adhesion. The levels of microRNA-155, VCAM1 and ICAM1 were increased in sEV-treated hCMEC/D3 cells. Blocking the expression of VCAM1, but not of ICAM1, prevented sEV-mediated T-cell adhesion to brain endothelia. These results suggest that sEVs derived from inflamed BECs promote cerebrovascular dysfunction. These findings may provide new insights into the mechanisms involving neuroinflammatory disorders.

中文翻译：

---

内皮衍生的细胞外囊泡在炎症中诱导脑血管功能障碍

血脑屏障 (BBB) 功能障碍是许多神经炎症性疾病病理学的关键标志。细胞外囊泡 (EV) 是脂质膜包裹的分子货物载体，参与细胞间通讯。神经系统疾病患者血浆中循环内皮 EV 增加，已知免疫细胞衍生的 EV 可调节脑血管功能。然而，关于脑内皮细胞 (BEC) 衍生的 EV 本身是否会导致 BBB 功能障碍，我们知之甚少。用TNFα和IFNγ处理人脑微血管细胞（hCMEC/D3），分离和表征EV。EVs 对 hCMEC/D3 细胞中 BBB 跨内皮电阻 (TEER) 和白细胞粘附的影响通过电基质细胞-基质阻抗传感和基于流动的 T 细胞粘附测定来测量。通过 RT-qPCR 和蛋白质印迹分析了受体 hCMEC/D3 细胞中 EV 诱导的分子变化。用小 EV (sEV) 刺激幼稚 hCMEC/D3 细胞会降低 TEER 并增加抗剪切 T 细胞粘附。的水平microRNA-155、 VCAM1 和 ICAM1 在 sEV 处理的 hCMEC/D3 细胞中增加。阻断 VCAM1 的表达，而不是 ICAM1 的表达，阻止了 sEV 介导的 T 细胞与脑内皮细胞的粘附。这些结果表明，源自发炎 BEC 的 sEV 会促进脑血管功能障碍。这些发现可能为涉及神经炎症性疾病的机制提供新的见解。