Bone marrow mesenchymal stem cell-derived exosomes attenuate cerebral ischemia-reperfusion injury-induced neuroinflammation and pyroptosis by modulating microglia M1/M2 phenotypes
Bone marrow mesenchymal stem cell-derived exosomes attenuate cerebral ischemia-reperfusion injury-induced neuroinflammation and pyroptosis by modulating microglia M1/M2 phenotypes
复制标题
骨髓间充质干细胞来源的外泌体通过调节小胶质细胞M1/M2表型减轻脑缺血再灌注损伤诱导的神经炎症和细胞焦亡
DOI：
10.1016/j.expneurol.2021.113700
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发表时间：
2021-04-15
影响因子：
5.3
通讯作者：
Huang, Guozhi
中科院分区：
文献类型：
--
作者：
Liu, Xiaoli;Zhang, Meimei;Huang, Guozhi
背景：NLRP3炎性体介导的细胞焦亡在脑缺血再灌注（I/R）损伤的发病机制中发挥着关键作用。越来越多的证据证实了外泌体通过缓解脑I/R损伤期间炎症反应的功效，但具体机制尚未得到很好的阐明。本研究旨在阐明骨髓间充质干细胞源性外泌体 (BMSC-Exos) 的神经保护作用是否与通过调节小胶质细胞极化来减弱 NLPR3 介导的神经元焦亡有关。 方法：首先对大鼠进行大脑中动脉闭塞 (MCAO)，然后进行再灌注。然后，MCAO后2小时静脉注射BMSC-Exos。使用改良的神经严重程度评分（mNSS）、氯化三苯基四唑（TTC）染色、脑含水量、Morris水迷宫和CatWalk系统来测量神经保护作用。应用Western blotting和免疫荧光染色检测NLRP3炎性体和细胞焦亡。通过实时聚合酶链反应（RT-PCR）和免疫荧光染色测定小胶质细胞极化。为了在体外模拟脑缺血再灌注损伤，将 BV2 和 PC12 细胞暴露于氧-葡萄糖剥夺/复氧条件下。用PBS、BMSC-Exos、IL-4或LPS处理后，将BV2细胞与PC12细胞在Transwell系统中共培养。结果：BMSC-Exos剂量依赖性地减少24小时脑梗死面积和脑含水量，并改善中风后长达5周的神经功能。在体内，NLRP3炎症小体和焦亡相关蛋白主要在神经元上表达并被BMSC-Exos下调。此外，脑缺血再灌注损伤诱导的 M1 极化小胶质细胞可以通过 BMSC-Exos 转变为 M2 表型。在体外，BMSCExos通过调节小胶质细胞极化部分减轻神经元焦亡。结论：BMSC-Exos可以通过调节小胶质细胞极化抑制NLRP3炎性体介导的炎症和焦亡来改善脑缺血再灌注损伤。
Background: Pyroptosis mediated by NLRP3 inflammasome plays a critical role in the pathogenesis of cerebral ischemia-reperfusion (I/R) injury. Mounting evidences have verified the efficacy of exosomes by relieving the inflammatory response during cerebral I/R injury, but the specific mechanism has not been well elucidated. This study aimed to clarify whether the neuroprotective effects of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) are associated with the attenuation of NLPR3-mediated neuron pyroptosis by modulating microglial polarization.Methods: Rats were initially subjected to middle cerebral artery occlusion (MCAO) followed by reperfusion. Then, BMSC-Exos were administered intravenously 2 h after MCAO. The neuroprotective effects were measured using a modified neurological severity score(mNSS), triphenyltetrazolium chloride (TTC) staining, brain water content, Morris water maze,and CatWalk system. Western blotting and immunofluorescence staining were applied to detect NLRP3 inflammasome and pyroptosis. Microglial polarization was determined by real-time polymerase chain reaction (RT-PCR) and immunofluorescence staining. To mimic cerebral I/R injury in vitro, BV2 and PC12 cells were exposed to oxygen-glucose deprivation/reoxygenation. After treatment with PBS, BMSC-Exos, IL-4, or LPS, BV2 cells were co-cultured with PC12 cells in a Transwell system.Results: BMSC-Exos reduced the brain infarct area and brain water content at 24 h dose dependently and improved the neurological function up to 5 weeks after stroke. In vivo, NLRP3 inflammasome- and pyroptosisrelated proteins were mainly expressed on neurons and downregulated by BMSC-Exos. Furthermore, cerebral I/R injury-induced M1-polarized microglia could be shifted toward M2 phenotype by BMSC-Exos. In vitro, BMSCExos alleviated the neuron pyroptosis partially by modulating microglial polarization.Conclusion: BMSC-Exos could ameliorate cerebral I/R injury via suppression of NLRP3 inflammasome-mediated inflammation and pyroptosis by modulating microglial polarization.