Qu Xin, Wang Ning, Cheng Weitao, Xue Yueqiao, Chen Wenjin, Qi Meng
Department of Neurosurgery, Xuan Wu Hospital, Capital Medical University, Beijing 100053, P.R. China.
Exp Ther Med. 2019 Nov;18(5):3920-3928. doi: 10.3892/etm.2019.8060. Epub 2019 Sep 27.
The present study aimed to investigate the role of microRNA-146a (miR-146a) in intracerebral hemorrhage (ICH), and to further assess its underlying mechanism. An ICH rat model was established in the current study and 1 h following ICH induction, rats were treated with or without an miR-146a mimic. A total of 3 days following ICH induction, rat neurological score, brain water content and neuronal apoptosis were measured via flow cytometry. Levels of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1β were detected via ELISA and certain biomarkers of oxidative stress, including malondialdehyde, superoxide dismutase and glutathione peroxidase, were also determined in current study. The expression of genes and proteins were detected in current study via reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. MicroRNA.org software and a dual luciferase reporter assay were used to confirm the association between miR-146a and TRAF6. The results of the current study revealed that miR-146a was significantly downregulated in ICH rats, and its overexpression reduced neurological damage and brain edema, as evidenced by decreased neurological scores and brain water content. Results from further analyses demonstrated that the overexpression of miR-146a inhibited neuronal apoptosis, reduced pro-inflammatory cytokine production and prevented oxidative stress in ICH rats. In addition, it was revealed that the upregulation of miR-146a repressed the TRAF6/NF-κB pathway in the brain tissue of ICH rats. TRAF6 was also determined to be a target of miR-146a. In conclusion, these data indicated that miR-146a protects against ICH by inhibiting inflammation and oxidative stress.
本研究旨在探讨微小RNA-146a（miR-146a）在脑出血（ICH）中的作用，并进一步评估其潜在机制。在本研究中建立了ICH大鼠模型，在脑出血诱导后1小时，对大鼠进行有无miR-146a模拟物的处理。在脑出血诱导后总共3天，通过流式细胞术测量大鼠神经功能评分、脑含水量和神经元凋亡。通过酶联免疫吸附测定法检测促炎细胞因子肿瘤坏死因子-α和白细胞介素-1β的水平，并且在本研究中还测定了某些氧化应激生物标志物，包括丙二醛、超氧化物歧化酶和谷胱甘肽过氧化物酶。在本研究中分别通过逆转录定量聚合酶链反应和蛋白质印迹法检测基因和蛋白质的表达。使用MicroRNA.org软件和双荧光素酶报告基因测定法来确认miR-146a与肿瘤坏死因子受体相关因子6（TRAF6）之间的关联。本研究结果显示，miR-146a在ICH大鼠中显著下调，其过表达减少了神经损伤和脑水肿，神经功能评分降低和脑含水量减少证明了这一点。进一步分析的结果表明，miR-146a的过表达抑制了ICH大鼠的神经元凋亡，减少了促炎细胞因子的产生并防止了氧化应激。此外，结果显示miR-146a的上调抑制了ICH大鼠脑组织中的TRAF6/核因子κB（NF-κB）通路。还确定TRAF6是miR-146a的一个靶点。总之，这些数据表明miR-146a通过抑制炎症和氧化应激来预防ICH。
