miR-132-3p 前体增强间充质基质细胞衍生的外泌体改善脑缺血损伤的作用。
miR-132-3p priming enhances the effects of mesenchymal stromal cell-derived exosomes on ameliorating brain ischemic injury.
机构信息
Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China.
Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China.
出版信息
Stem Cell Res Ther. 2020 Jun 29;11(1):260. doi: 10.1186/s13287-020-01761-0.
BACKGROUNDS/AIMS: Mesenchymal stromal cell-derived exosomes (MSC-EXs) could exert protective effects on recipient cells by transferring the contained microRNAs (miRs), and miR-132-3p is one of angiogenic miRs. However, whether the combination of MSC-EXs and miR-132-3p has better effects in ischemic cerebrovascular disease remains unknown.
METHODS
Mouse MSCs transfected with scrambler control or miR-132-3p mimics were used to generate MSC-EXs and miR-132-3p-overexpressed MSC-EXs (MSC-EXs). The effects of EXs on hypoxia/reoxygenation (H/R)-injured ECs in ROS generation, apoptosis, and barrier function were analyzed. The levels of RASA1, Ras, phosphorylations of PI3K, Akt and endothelial nitric oxide synthesis (eNOS), and tight junction proteins (Claudin-5 and ZO-1) were measured. Ras and PI3K inhibitors were used for pathway analysis. In transient middle cerebral artery occlusion (tMCAO) mouse model, the effects of MSC-EXs on the cerebral vascular ROS production and apoptosis, cerebral vascular density (cMVD), Evans blue extravasation, brain water content, neurological deficit score (NDS), and infarct volume were determined.
RESULTS
MSC-EXs could deliver their carried miR-132-3p into target ECs, which functionally downregulated the target protein RASA1, while upregulated the expression of Ras and the downstream PI3K phosphorylation. Compared to MSC-EXs, MSC-EXs were more effective in decreasing ROS production, apoptosis, and tight junction disruption in H/R-injured ECs. These effects were associated with increased levels of phosphorylated Akt and eNOS, which could be abolished by PI3K inhibitor (LY294002) or Ras inhibitor (NSC 23766). In the tMCAO mouse model, the infusion of MSC-EXs was more effective than MSC-EXs in reducing cerebral vascular ROS production, BBB dysfunction, and brain injury.
CONCLUSION
Our results suggest that miR-132-3p promotes the beneficial effects of MSC-EXs on brain ischemic injury through protecting cerebral EC functions.
背景/目的：间充质基质细胞衍生的外泌体（MSC-EXs）可以通过转移其中包含的 microRNAs（miRs）对受体细胞发挥保护作用，miR-132-3p 是一种血管生成 miR 之一。然而，MSC-EXs 和 miR-132-3p 的联合应用是否对缺血性脑血管病有更好的效果尚不清楚。
方法
使用转染 scramble 对照或 miR-132-3p 模拟物的小鼠间充质基质细胞生成 MSC-EXs 和 miR-132-3p 过表达 MSC-EXs（MSC-EXs）。分析 EXs 对缺氧/复氧（H/R）损伤的 EC 中 ROS 生成、凋亡和屏障功能的影响。测量 RASA1、Ras、PI3K、Akt 和内皮型一氧化氮合酶（eNOS）的磷酸化水平以及紧密连接蛋白（Claudin-5 和 ZO-1）的水平。使用 Ras 和 PI3K 抑制剂进行通路分析。在短暂性大脑中动脉闭塞（tMCAO）小鼠模型中，检测 MSC-EXs 对脑血管 ROS 生成和凋亡、脑血管密度（cMVD）、伊文思蓝外渗、脑水含量、神经功能缺损评分（NDS）和梗死体积的影响。
结果
MSC-EXs 可以将其携带的 miR-132-3p 递送至靶 EC，从而功能性地下调靶蛋白 RASA1，同时上调 Ras 和下游 PI3K 磷酸化水平。与 MSC-EXs 相比，MSC-EXs 更有效地减少 H/R 损伤的 EC 中 ROS 生成、凋亡和紧密连接破坏。这些作用与磷酸化 Akt 和 eNOS 水平的增加有关，而 PI3K 抑制剂（LY294002）或 Ras 抑制剂（NSC 23766）可消除这些作用。在 tMCAO 小鼠模型中，与 MSC-EXs 相比，MSC-EXs 的输注更有效地减少脑血管 ROS 生成、BBB 功能障碍和脑损伤。
结论
我们的结果表明，miR-132-3p 通过保护脑 EC 功能促进 MSC-EXs 对脑缺血损伤的有益作用。
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