Chi W, Meng F, Li Y, Wang Q, Wang G, Han S, Wang P, Li J
Department of Anesthesiology, Weifang Medical University, Weifang City 261053, Shangdong Province, PR China.
Department of Anesthesiology, Shandong University Affiliated Jinan City Central Hospital, Jinan 250013, PR China.
Neuroscience. 2014 Sep 26;277:111-22. doi: 10.1016/j.neuroscience.2014.06.062. Epub 2014 Jul 5.
MicroRNAs (miRNAs) have emerged as a major regulator in neurological diseases, and understanding their molecular mechanism in modulating cerebral ischemic injury may provide potential therapeutic targets for ischemic stroke. However, as one of 19 differentially expressed miRNAs in mouse brain with middle cerebral artery occlusion (MCAO), the role of miR-134 in ischemic injury is not well understood. In this study, the miR-134 expression level was manipulated both in oxygen-glucose deprivation (OGD)-treated N2A neuroblastoma cells in vitro and mouse brain with MCAO-induced ischemic stroke in vivo, and its possible targets of heat shock protein A5 (HSPA5) and HSPA12B were determined by bioinformatics analysis and dual luciferase assay. The results showed that overexpression of miR-134 exacerbated cell death and apoptosis both in vitro and in vivo. Conversely, downregulating miR-134 levels reduced cell death and apoptosis. Furthermore, non-expression of miR-134 enhanced HSPA12B protein levels in OGD-treated N2A cells as well as in the ischemic region. It could attenuate brain infarction size and neural cell damage, and improve neurological outcomes in mice with ischemic stroke, whereas upregulation of miR-134 had the opposite effect. In addition, HSPA12B was validated to be a target of miR-134 and its short interfering RNAs (siRNAs) could block miR-134 inhibitor-induced neuroprotection in OGD-treated N2A cells. In conclusion, downregulation of miR-134 could induce neuroprotection against ischemic injury in vitro and in vivo by negatively upregulating HSPA12B protein expression.
微小RNA（miRNA）已成为神经疾病的主要调节因子，了解其调节脑缺血损伤的分子机制可能为缺血性中风提供潜在的治疗靶点。然而，作为大脑中动脉闭塞（MCAO）小鼠脑内19种差异表达的miRNA之一，miR-134在缺血损伤中的作用尚未完全明确。在本研究中，我们在体外氧糖剥夺（OGD）处理的N2A神经母细胞瘤细胞和体内MCAO诱导的缺血性中风小鼠脑中操纵miR-134的表达水平，并通过生物信息学分析和双荧光素酶测定确定其可能的靶标热休克蛋白A5（HSPA5）和HSPA12B。结果表明，miR-134的过表达在体外和体内均加剧了细胞死亡和凋亡。相反，下调miR-134水平可减少细胞死亡和凋亡。此外，miR-134的不表达增强了OGD处理的N2A细胞以及缺血区域中HSPA12B蛋白的水平。它可以减轻脑梗死面积和神经细胞损伤，并改善缺血性中风小鼠的神经功能结局，而miR-134的上调则具有相反的作用。此外，HSPA12B被验证为miR-134的靶标，其小干扰RNA（siRNA）可阻断miR-134抑制剂在OGD处理的N2A细胞中诱导的神经保护作用。总之，下调miR-134可通过负向上调HSPA12B蛋白表达在体外和体内诱导对缺血损伤的神经保护作用。
