LncRNA MIAT overexpression reduced neuron apoptosis in a neonatal rat model of hypoxic-ischemic injury through miR-211/GDNF

Objective: To investigate the underlying mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in hypoxic-ischemic (HI)-induced neonatal cerebral palsy. Materials and methods: Neonatal rat model of HI injury was established to detect the motor function. LncRNA MIAT, miR-211, glial cell line-derived neurotrophic factor (GDNF) and caspase-3 expressions were measured by qRT-PCR or western blot. The apoptosis of Neuro2A cells was detected by flow cytometry. RNA immunoprecipitation (RIP) and RNA pull-down assays were performed to confirm the interaction between MIAT and miR-211. Results: Compared with control group, lncRNA MIAT and GDNF were downregulated in striatal tissues of neonatal rats in HI group and oxygen glucose deprivation (OGD)-induced ischemic injury of Neuro2A cells, whereas miR-211 was up-regulated in striatal tissues of HI group and OGD-induced ischemic injury of Neuro2A cells. LncRNA MIAT interacted with miR-211, and lncRNA MIAT overexpression reduced neuron apoptosis through miR-211. Besides, GDNF expression was positively regulated by lncRNA MIAT and negatively regulated by miR-211 in Neuro2A cells. In vivo experiment proved MIAT promoted motor function and relieved HI injury. Conclusion: MIAT overexpression reduced apoptosis of Neuro2A cells through miR-211/GDNF, which relieved HI injury of neonatal rats.

研究目的：探究长链非编码RNA心肌梗死相关转录本（lncRNA MIAT）在缺氧缺血（HI）诱导的新生儿脑瘫中的潜在作用机制。材料与方法：构建缺氧缺血损伤新生大鼠模型，检测其运动功能。采用实时荧光定量聚合酶链反应（qRT-PCR）或蛋白质印迹（western blot）检测lncRNA MIAT、miR-211、胶质细胞源性神经营养因子（GDNF）及半胱氨酸天冬氨酸蛋白酶3（caspase-3）的表达水平。通过流式细胞术检测Neuro2A细胞的凋亡情况。采用RNA免疫沉淀（RIP）与RNA下拉实验验证MIAT与miR-211的相互作用。实验结果：与对照组相比，缺氧缺血组新生大鼠纹状体组织及氧糖剥夺（OGD）诱导的Neuro2A细胞缺血损伤模型中，lncRNA MIAT与GDNF的表达均下调，而miR-211的表达则上调。LncRNA MIAT可与miR-211相互结合，且过表达lncRNA MIAT可通过miR-211减少神经元凋亡。此外，在Neuro2A细胞中，lncRNA MIAT可正向调控GDNF的表达，而miR-211则对GDNF的表达产生负向调控。体内实验证实，MIAT可改善新生大鼠的运动功能并缓解缺氧缺血损伤。结论：过表达MIAT可通过miR-211/GDNF通路减少Neuro2A细胞的凋亡，从而缓解新生大鼠的缺氧缺血损伤。