Down-Regulation of miRNA-30a Alleviates Cerebral Ischemic Injury Through Enhancing Beclin 1-Mediated Autophagy
Down-Regulation of miRNA-30a Alleviates Cerebral Ischemic Injury Through Enhancing Beclin 1-Mediated Autophagy
复制标题
miRNA-30a 的下调通过增强 Beclin 1 介导的自噬减轻脑缺血损伤
DOI：
10.1007/s11064-014-1310-6
复制
发表时间：
2014-07-01
影响因子：
4.4
通讯作者：
Li, Junfa
中科院分区：
文献类型：
--
作者：
Wang, Peng;Liang, Jia;Li, Junfa
了解缺血/再灌注引起的神经元死亡和神经功能障碍的分子机制可能为缺血性中风提供治疗靶点。我们之前在大脑中动脉闭塞（MCAO）6小时后的小鼠大脑中鉴定出19种MicroRNA（miRNA）中，上调的miRNA-30a可以负向调节Beclin 1信使RNA（mRNA），导致肿瘤细胞和心肌细胞的自噬活性降低，但其在缺血性中风中的作用尚不清楚。在本研究中，评估了 miRNA-30a 对缺氧葡萄糖剥夺 (OGD) 后 N2A 细胞和培养的皮质神经元以及 MCAO 诱导的缺血性中风的小鼠大脑的缺血性损伤的影响。结果表明，6 h MCAO（未再灌注）后小鼠大脑中 miRNA-30a 表达水平上调，但在 1 h MCAO/24 h 再灌注小鼠的梗塞周围区域以及在 1 h OGD/6-48 h 再氧合后的 N2A 细胞中，miRNA-30a 表达水平显着下调。在 1 小时 OGD/24 小时复氧后，N2A 细胞和培养的皮层神经元中微管相关蛋白 1 轻链 3 (LC3)-II/LC3-I 的转化率和 Beclin 1 蛋白水平均增加。下调的 miRNA-30a 可以通过增强 Beclin 1 介导的自噬来减轻 N2A 细胞和培养皮质神经元中 1 h OGD/24 h 再氧合引起的缺血性损伤，因为 miRNA-30a 识别 beclin 1mRNA 的 3'-非翻译区，通过促进 beclin 1 信使 RNA (mRNA) 降解来负调节 Beclin 1 蛋白水平，并且 Beclin 1 siRNA 消除了 1 小时 OGD/24 小时复氧处理的 N2A 细胞中抗 miR-30a 诱导的神经保护作用。此外，抗 miR-30a 减轻了缺血性中风小鼠的神经细胞损失并改善了行为结果。这些结果表明，miRNA-30a的下调通过增强beclin 1介导的自噬减轻缺血性损伤，为缺血性中风提供潜在的治疗靶点。
The understanding of molecular mechanism underlying ischemia/reperfusion-induced neuronal death and neurological dysfunction may provide therapeutic targets for ischemic stroke. The up-regulated miRNA-30a among our previous identified 19 MicroRNAs (miRNAs) in mouse brain after 6 h middle cerebral artery occlusion (MCAO) could negatively regulate Beclin 1 messenger RNA (mRNA) resulting in decreased autophagic activity in tumor cells and cardiomyocytes, but its role in ischemic stroke is unclear. In this study, the effects of miRNA-30a on ischemic injury in N2A cells and cultured cortical neurons after oxygen glucose deprivation (OGD), and mouse brain with MCAO-induced ischemic stroke were evaluated. The results showed that miRNA-30a expression levels were up regulated in the brain of mice after 6 h MCAO without reperfusion, but significantly down regulated in the peri-infarct region of mice with 1 h MCAO/24 h reperfusion and in N2A cells after 1 h OGD/6–48 h reoxygenation. Both the conversion ratio of microtubule-associated protein 1 light chain 3 (LC3)-II/LC3-I and Beclin 1 protein level increased in N2A cells and cultured cortical neurons following 1 h OGD/24 h reoxygenation. The down-regulated miRNA-30a could attenuate 1 h OGD/24 h reoxygenation-induced ischemic injury in N2A cells and cultured cortical neurons through enhancing Beclin 1-mediated autophagy, as miRNA-30a recognized the 3′-untranslated region ofbeclin 1mRNA to negatively regulate Beclin 1-protein level via promotingbeclin 1messenger RNA (mRNA) degradation, and Beclin 1 siRNA abolished anti-miR-30a-induced neuroprotection in 1 h OGD/24 h reoxygenation treated N2A cells. In addition, anti-miR-30a attenuated the neural cell loss and improved behavioral outcome of mice with ischemic stroke. These results suggested that down-regulation of miRNA-30a alleviates ischemic injury through enhancing beclin 1-mediated autophagy, providing a potential therapeutic target for ischemic stroke.