LncRNA MALAT1 silencing protects against cerebral ischemia-reperfusion injury through miR-145 to regulate AQP4
LncRNA MALAT1 silencing protects against cerebral ischemia-reperfusion injury through miR-145 to regulate AQP4
复制标题
LncRNA MALAT1沉默通过miR-145调节AQP4防止脑缺血再灌注损伤
DOI：
10.1186/s12929-020-00635-0
复制
发表时间：
2020-03-06
影响因子：
11
通讯作者：
Chen, Wei
中科院分区：
文献类型：
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作者：
Wang, Hongwei;Zheng, Xiaoxiao;Chen, Wei
背景
本研究旨在验证长非编码RNA(LncRNA)MALAT1是否参与脑缺血再灌注损伤，并探讨MALAT1调控水通道蛋白4(AQP4)的机制。
方法
本研究在体内外建立了葡萄糖剥夺(OGD)/复氧(RX)星形胶质细胞模型和大脑中动脉阻塞(MCAO)/再灌注小鼠模型。分别用细胞计数试剂盒-8法、流式细胞仪、三苯基四氮唑(TTC)染色和Western blotting检测细胞存活率、细胞凋亡率、脑梗塞体积和AQP4的丰度。
结果
我们发现，在MCAO/再灌注模型和OGD/RX模型中，MALAT1的表达均显著上调。MALAT1基因敲除可增加MA-C细胞的存活率，减少细胞凋亡率，而AQP4 siRNA与针对MALAT1的siRNA联合不能增强这一作用。进一步的实验表明，MALAT1通过miR-145正向调控AQP4的表达。MALAT1 siRNA不能减轻miR-145抑制剂作用后损伤的加剧。然而，miR-145抑制剂逆转了MALAT1的保护作用，表明MALAT1沉默通过miR-145对脑缺血再灌注损伤具有保护作用。TTC染色显示，sh-MALAT1治疗组小鼠全脑梗死区明显缩小。
结论
综上所述，本研究证实MALAT1通过竞争性结合miR-145影响AQP4的表达，从而促进脑缺血再灌注损伤，提示MALAT1可能成为治疗缺血性卒中的新靶点。
Background
The present study aimed to verify whether long noncoding RNA (lncRNA) MALAT1 is involved in brain tissue damage induced by ischemia-reperfusion injury, and to explore the mechanism by which MALAT1 regulates aquaporin 4 (AQP4).
Methods
In this study, we established glucose deprivation (OGD)/reoxygenation (RX) astrocyte cell model and middle cerebral artery occlusion (MCAO)/reperfusion mouse model in vitro and in vivo. Then cell counting kit-8 assay, flow cytometry analysis, Triphenyltetrazolium chloride (TTC) staining, and western blotting were used to determine cell viability, cell apoptosis, cerebral infarction volume, and the abundance of AQP4, respectively.
Results
We found that the level of MALAT1 was significantly upregulated in both the MCAO/reperfusion model and OGD/RX model. Knockdown of MALAT1 increased cell viability and reduced cell apoptosis in MA-C cells, while an AQP4 siRNA combined with a siRNA targeting MALAT1 could not enhance this effect. Further experiments showed that MALAT1 positively regulated AQP4 expression via miR-145. The MALAT1 siRNA did not alleviate the exacerbation of damage after miR-145 inhibitor action. However, an miR-145 inhibitor reversed the protection effects of MALAT1, indicating that MALAT1 silencing protects against cerebral ischemia-reperfusion injury through miR-145. TTC staining showed that the infracted area of whole brain was significantly attenuated in treated with sh-MALAT1 group in vivo.
Conclusion
Taken together, our study confirmed that MALAT1 promotes cerebral ischemia-reperfusion injury by affecting AQP4 expression through competitively binding miR-145, indicating that MALAT1 might be a new therapeutic target for treatment cerebral ischemic stroke.