间充质干细胞释放的细胞外囊泡包裹的miR-132上调通过抑制Smad2/c-jun途径对Acvr2b的抑制作用减轻缺血性神经元损伤
Upregulation of Extracellular Vesicles-Encapsulated miR-132 Released From Mesenchymal Stem Cells Attenuates Ischemic Neuronal Injury by Inhibiting Smad2/c-jun Pathway Acvr2b Suppression.
作者信息
Feng Bin, Meng Lei, Luan Liming, Fang Zhihao, Zhao Peng, Zhao Guangyu
机构信息
Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
出版信息
Front Cell Dev Biol. 2021 Mar 8;8:568304. doi: 10.3389/fcell.2020.568304. eCollection 2020.
Ischemic cerebrovascular disease is a significant and common public health issue worldwide. The emerging roles of mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) in ischemic neuronal injury continue to be investigated. The current study aimed to investigate the role of EV-derived miR-132 from MSCs in ischemic neuronal injury. EVs were initially isolated from bone MSCs (BMSCs) and subsequently evaluated. A middle cerebral artery occlusion (MCAO) mouse model was constructed with the neurological function evaluated through a series of neurological scores, a pole test, and a foot fault test. Histopathological changes, neuron viability, and apoptosis, as well as cerebral infarction, were detected by hematoxylin and eosin (HE) staining and 2,3,5-triphenyltetrazolium hydrochloride (TTC) staining. The targeting relationship between microRNA (miR)-132 and Activin receptor type IIB (Acvr2b) was further confirmed based on dual-luciferase reporter gene assay results. Loss- and gain-of-function assays were conducted to elucidate the role of miR-132, EV-derived miR-132, Acvr2b, and Smad2 in oxygen-glucose deprivation (OGD)-treated neurons, and in mice models. Neuronal cell viability and apoptosis were evaluated via Cell Counting kit-8 (CCK-8) and flow cytometry. Our results indicated that Acvr2b was highly expressed, while miR-132 was poorly expressed in the MCAO mice and OGD-treated neurons. Acvr2b silencing or upregulation of miR-132 led to an elevation in neuronal activity, decreased neuronal apoptosis, reduced expression of Bax, and cleaved-caspase 3, as well as increased Bcl-2 expression. Acvr2b expression was targeted and inhibited by miR-132. EV-derived Acvr2b promoted activation of phosphorylated-Smad2 (p-Smad2)/c-jun signaling pathway, ultimately inducing neuronal injury. Our study provides evidence demonstrating that the overexpression of c-jun inhibits the protective role of MSCs-derived EV-miR-132 in neuronal injury. Upregulation of EV-derived miR-132 released from MSCs attenuates ischemic neuronal injury by inhibiting Smad2/c-jun pathways the suppression of Acvr2b.
缺血性脑血管疾病是全球范围内一个重大且常见的公共卫生问题。间充质干细胞(MSCs)衍生的细胞外囊泡(EVs)在缺血性神经元损伤中的新作用仍在不断研究中。当前研究旨在探讨MSCs来源的EV-miR-132在缺血性神经元损伤中的作用。首先从骨髓间充质干细胞(BMSCs)中分离出EVs,随后进行评估。构建大脑中动脉闭塞(MCAO)小鼠模型,并通过一系列神经学评分、杆试验和足部错误试验评估神经功能。通过苏木精-伊红(HE)染色和2,3,5-三苯基氯化四氮唑(TTC)染色检测组织病理学变化、神经元活力和凋亡以及脑梗死情况。基于双荧光素酶报告基因检测结果进一步证实了微小RNA(miR)-132与激活素受体IIB型(Acvr2b)之间的靶向关系。进行功能缺失和功能获得试验,以阐明miR-132、EV来源的miR-132、Acvr2b和Smad2在氧糖剥夺(OGD)处理的神经元以及小鼠模型中的作用。通过细胞计数试剂盒-8(CCK-8)和流式细胞术评估神经元细胞活力和凋亡。我们的结果表明,在MCAO小鼠和OGD处理的神经元中,Acvr2b高表达,而miR-132低表达。Acvr2b沉默或miR-132上调导致神经元活性升高、神经元凋亡减少、Bax表达降低、裂解的半胱天冬酶-3减少以及Bcl-2表达增加。Acvr2b的表达受到miR-132的靶向抑制。EV来源的Acvr2b促进磷酸化Smad2(p-Smad2)/c-jun信号通路的激活,最终诱导神经元损伤。我们的研究提供了证据表明,c-jun的过表达抑制了MSCs来源的EV-miR-132在神经元损伤中的保护作用。上调MSCs释放的EV来源的miR-132通过抑制Smad2/c-jun途径(抑制Acvr2b)减轻缺血性神经元损伤。