microRNA与新生鼠缺氧缺血脑损伤的细胞自噬调控

Neonatal hypoxic-ischemic encephalopathy (HIE) is a severe disease that can cause high mortality and disability in newborns. Therefore, it is very important to explore the mechanisms underlying HIE and the repairing mechanisms after hypoxic-ischemic injury. Autophagy has been documented as a key factor to regulate neural injury induced by hypoxia-ischemia in neonatal rats. We have previously demonstrated that several autophagy-related genes, such as LC3, Beclin1, Atg10, and Atg16L, were up-regulated significantly, using microRNA chip to screen the differential expression of genes in brain tissues of hypoxic-ischemic and sham control neonatal rats. Based on the bio-informatic study, we found that microRNAs targeting autophagy-related genes overlap with the microRNAs identified by microRNA chip screen in our perliminary studies. Therefore, we hypothesize that the effect of specific microRNAs plays a key role in the mechanisms of pathologic changes and self-repair by regulating autophagy after hypoxic-ischemic brain damage. In this project, we will try to study the key microRNAs that target autophagy-related genes and elucidate the signaling pathways regulating the expression of autophagy-related microRNAs. Due to the stable and high tissue compatibility characteristics of microRNAs, we will also try to explore the feasibility of using microRNAs to inhibit hypoxic-ischemic brain damage using a neonatal rat model to mimic newborns with HIE in clinic. This work will provide a new method to treat and prevent HIE.

新生儿缺氧缺血性脑病（HIE）是引起新生儿死亡和儿童致残的重大难治性疾病，探索HIE损伤与修复机制意义重大。研究表明，自噬是参与缺氧缺血(HI)后神经损伤的重要因素。前期工作中，我们用表达谱芯片筛查新生鼠HI脑组织基因差异表达，发现自噬相关基因LC3、Beclin1、Atg10及Atg16L明显上调。经生物信息学分析发现，靶向调控这些自噬基因的微小RNA（microRNA）与芯片筛查发现新生鼠HI脑组织差异表达的microRNA有重叠。因此，推测特异性 microRNA的表达是调控HI后自噬的重要机制。本课题将研究与新生鼠HI脑损伤相关调控自噬的关键microRNA分子，探明调节这些microRNA表达的信号通路。同时，将利用microRNA分子具有高稳定性和组织相容性的特点，通过体内外实验，探索microRNA分子抑制新生鼠HI脑损伤的新方法，为临床治疗新生儿HIE提供新思路。

新生儿缺氧缺血性脑病（HIE）是引起新生儿死亡和儿童致残的重大难治性疾病，探索HIE损伤与修复机制意义重大。有研究表明，自噬是参与缺氧缺血(HI)后神经损伤的重要因素。我们用表达谱芯片筛查新生鼠HI脑组织基因差异表达，发现自噬相关基因LC3、Beclin1、Atg10及Atg16L明显上调。经生物信息学分析发现，靶向调控这些自噬基因的微小RNA（microRNA）与芯片筛查发现新生鼠HI脑组织差异表达的microRNA有重叠。因此，推测特异性 microRNA的表达是调控HI后自噬的重要机制。为了验证该推测，本项目的研究中，在体外培养神经元缺氧缺血及新生大鼠缺氧缺血脑损伤模型中，应用生物信息学和分子生物学等技术，筛选鉴定得到微小RNA miR-30d-5p，证实其可通过靶向调控自噬蛋白Beclin 1而调控缺氧缺血诱导的神经元自噬。miR-30d-5p 拮抗剂经脑室内注射，可促进缺氧缺血诱导的神经元自噬，减少神经元凋亡，减轻脑损伤。进一步的拓展研究中，探讨了骨髓间充质干细胞对缺氧缺血神经元的保护作用，并阐明了骨髓间充质干细胞对缺氧缺血脑损伤过程中自噬的调控机制，验证了BMSCs引起的自噬是由BMSCs分泌BDNF所启动的。发表基金资助论文72篇，其中SCI 46篇（IF>5共14篇），中文核心26篇。申请专利2项。获得部省级以上科技进步奖2项。举办新生儿重大疾病国际研讨会2次。研究成果在国际学术会议交流11次，国内学术会议29次。培养研究生25名。