lncRNA AY321332调控新生鼠缺氧缺血脑损伤神经修复的机制

Axonal regeneration plays significant role in neurogenesis, this may decrease neuronal death after brain damage. Axonal regeneration is critical for neural repair after hypoxic-ischemic brain damage (HIBD). Recent researches have demonstrated that long non-coding RNAs (lncRNAs) were involved in the regulation of nerve repair. In previous study, we have found that AY321332 lncRNA expression was correlated with axonal regeneration promoting gene Dpysl3, meanwhile its expression was inversely correlated with apoptosis-related gene Adrb2. In neonatal rat after HIBD, the previous data indicates that AY321332 is associated with regulation of axonal regenetion and neural death. However, the effect of AY321332 on nerve repair and its mechanism has not been reported yet. With these models, we will explore the mechanism of AY321332 in axonal regeneration and neural death, using silence or over-expression of AY321332. We believe that our studies will explore a new neuroprotective pathway and mechanism of lncRNAs in brain damage, and provide new insights in the therapeutic strategies of neonatal hypoxic ischemic encephalopathy.

轴突再生是脑损伤后神经修复的重要环节，不但是神经再生的一种重要形式，还能减少损伤后神经细胞死亡。研究发现中枢神经损伤后多种lncRNA通过参与神经元分化及轴突再生发挥调控神经修复的作用。本课题组在前期研究中通过构建缺氧缺血时鼠神经细胞编码-非编码基因共表达网络，发现lncRNA AY321332与促轴突再生基因Dpysl3表达呈正相关，而与促神经细胞凋亡基因Adrb2表达呈负相关。该结果提示AY321332可能参与调控神经细胞轴突再生以及神经细胞凋亡的关键信号通路，而其具体作用及机制目前尚无研究报道。本课题拟在新生鼠缺氧缺血脑损伤模型及体外神经细胞氧糖剥夺模型中，通过抑制或上调AY321332的表达，观察相应编码基因的表达变化，验证AY321332促进轴突再生及抑制细胞死亡的作用，并进一步研究AY321332发挥上述作用的机制，为临床治疗新生儿缺氧缺血脑病提供新思路。

缺氧缺血脑损伤时神经轴突生长、分化障碍，抑制神经网络形成，是导致神经系统后遗症的重要原因之一。轴突再生是脑损伤后神经修复的重要环节，不但是神经再生的一种重要形式，还能减少损伤后神经细胞死亡。本课题组在构建缺氧缺血鼠神经细胞编码-非编码基因共表达网络时，发现lncRNA AY321332与促轴突再生基因二氢嘧啶酶样3 (Dpysl3 )表达呈正相关，而与促神经细胞凋亡基因肾上腺素能受体β2（Adrb2）表达呈负相关。本课题在新生鼠缺氧缺血脑损伤模型及体外神经细胞氧糖剥夺模型中，通过抑制或增加AY321332的表达，采用RT-PCR和Western blot检测Dpysl3和Adrb2 mRNA和蛋白的表达，采用TUNEL法检测细胞凋亡，采用双盲法进行改良神经功能行为学评分（modified neurological severity score，mNSS）进行行为学检查，采用Morris水迷宫进行神经行为学评价。RT-PCR和Western blot结果证实减少AY321332的表达可下调Dpysl3的表达，上调Adrb2的表达，增加轴突损伤及增加神经元凋亡；增加AY321332的表达可上调Dpysl3的表达，下调Adrb2的表达，减少轴突损伤及减少神经元凋亡。大鼠侧脑室注射Lent-AY3213332增加AY321332表达后，大鼠的神经损伤评分较单纯缺氧缺血组大鼠显著改善，学习记忆能力明显提高。因此，通过干预AY321332的表达，可为临床治疗新生儿缺氧缺血脑病提供新思路。