Department of Bioengineering, College of Engineering, Hanyang University, 222 Wangsimni-ro, Seondong-gu, Seoul 04763, Korea.
Nanoscale. 2021 Sep 7;13(33):14166-14178. doi: 10.1039/d0nr07516g. Epub 2021 Aug 11.
Ischemic stroke is caused by a reduction in blood flow to the brain due to narrowed cerebral arteries. Thrombolytic agents have been used to induce reperfusion of occluded cerebral arteries. However, brain damage continues to progress after reperfusion and induces ischemia-reperfusion (I/R) injury. The receptor for advanced glycation end-products (RAGE) is overexpressed in hypoxic cells of the ischemic brain. In this study, an exosome linked to RAGE-binding-peptide (RBP-Exo) was developed as a hypoxia-specific carrier for nose-to-brain delivery of anti-microRNA oligonucleotide (AMO). The RBP-Exos were less than 50 nm in size and had negative surface charge. In vitro studies showed that RBP-Exos delivered AMO181a to Neuro2A cells more efficiently than unmodified exosomes (Unmod-Exos). In addition, RAGE was downregulated by RBP-Exos, suggesting that the RBP moiety of the RBP-Exos reduced the RAGE-mediated signal pathway. MicroRNA-181a (miR-181a) is one of the upregulated miRNAs in the ischemic brain and its downregulation can reduce the damage to the ischemic brain. Cholesterol-modified AMO181a (AMO181a-chol) was loaded onto the RBP-Exo by hydrophobic interaction. The AMO181a-chol-loaded RBP-Exo (RBP-Exo/AMO181a-chol) was administered intranasally to a rat middle cerebral artery occlusion (MCAO) model. MiR-181a was knocked down and Bcl-2 was upregulated by intranasal delivery of RBP-Exo/AMO181a-chol. In addition, tumor necrosis factor-α (TNF-α) expression and apoptosis were reduced by RBP-Exo/AMO181a-chol. As a result, RBP-Exo/AMO181a-chol significantly suppressed infarct size compared with the controls. In conclusion, RBP-Exo was a hypoxia-specific carrier for nose-to-brain delivery of AMO181a-chol in an ischemic stroke model. Furthermore, the combined effects of RBP and AMO181a-chol exerted neuroprotective effects in the ischemic brain.
缺血性中风是由于大脑动脉狭窄导致血流减少引起的。溶栓剂已被用于诱导闭塞的脑动脉再灌注。然而，再灌注后脑损伤仍在继续发展，并引起缺血再灌注（I/R）损伤。在缺血性大脑的缺氧细胞中，晚期糖基化终产物（RAGE）受体过度表达。在这项研究中，开发了一种与 RAGE 结合肽（RBP-Exo）连接的外泌体，作为一种缺氧特异性载体，用于将抗 microRNA 寡核苷酸（AMO）递送到鼻内脑。RBP-Exo 的大小小于 50nm，具有负表面电荷。体外研究表明，与未修饰的外泌体（Unmod-Exos）相比，RBP-Exo 更有效地将 AMO181a 递送到 Neuro2A 细胞中。此外，RAGE 被 RBP-Exo 下调，这表明 RBP-Exo 的 RBP 部分减少了 RAGE 介导的信号通路。microRNA-181a（miR-181a）是缺血性大脑中上调的 microRNA 之一，其下调可以减少对缺血性大脑的损伤。胆固醇修饰的 AMO181a（AMO181a-chol）通过疏水相互作用加载到 RBP-Exo 上。AMO181a-chol 加载的 RBP-Exo（RBP-Exo/AMO181a-chol）通过鼻内给药递送到大鼠大脑中动脉闭塞（MCAO）模型。通过鼻内递送 RBP-Exo/AMO181a-chol，miR-181a 被敲低，Bcl-2 被上调。此外，RBP-Exo/AMO181a-chol 降低了肿瘤坏死因子-α（TNF-α）的表达和细胞凋亡。结果，与对照组相比，RBP-Exo/AMO181a-chol 显著抑制了梗死面积。总之，RBP-Exo 是一种缺氧特异性载体，用于在缺血性中风模型中鼻内递送 AMO181a-chol。此外，RBP 和 AMO181a-chol 的联合作用在缺血性大脑中发挥了神经保护作用。
