Down-regulation of miRNA-30a alleviates cerebral ischemic injury through enhancing beclin 1-mediated autophagy.
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 of beclin 1 mRNA to negatively regulate Beclin 1-protein level via promoting beclin 1 messenger 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.
Department of Neurobiology, Beijing Institute for Brain Disorders, Capital Medical University, #10 You An Men Wai Xi Tou Tiao, Beijing, 100069, People's Republic of China.
Peng
P
Wang
Jia
J
Liang
Yun
Y
Li
Jiefei
J
Li
Xuan
X
Yang
Xinxin
X
Zhang
Song
S
Han
Shujuan
S
Li
Junfa
J
Li
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis*; D001343:Autophagy / Q000502:physiology*; D000071186:Beclin-1; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D015536:Down-Regulation / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism*
D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; C115010:Becn1 protein, mouse; D035683:MicroRNAs; C534715:Mirn30d microRNA, mouse