lncRNA NONMMUT010710/miR-27-3p/PPARγ信号通路参与术后认知功能障碍的机制研究

It was demonstrated that the agonist of PPARγ prevented POCD. And PPARγ plays a role to regulate those pathphysiological procedures which were involved in POCD, such as accumulation of Aβ, inflammation, neuronal apoptosis and oxidative stress. Our previous study demonstrated that lncRNA NONMMUT010710 and PPARγ maybe the targets of miR-27-3p. Our PCR and Western-blot results also showed the downregulation of NONMMUT010710 and PPARγ, as well as the upregulation of miR-27-3p. Based on these data, we assume that downregulation of NONMMUT010710 caused by surgery and anesthetics would upregulate miR-27-3p, and then cause the downregulation of PPARγ, ultimately lead to POCD through above pathphysiological procedures. In order to identify our hypothesis, we would carry out experiments both in vitro and in vivo, employ the overexpression/knockout vector, take techniques as cell culture, PCR, Western-blot, apoptosis detection, etc.

有研究表明PPARγ激动剂可以预防POCD的发生，而且PPARγ与Aβ蛋白沉积、中枢炎性反应、神经元凋亡以及过度氧化应激反应等POCD相关的病理生理过程有关。我们前期芯片分析发现lncRNA NONMUT010710和PPARγ可能是miR-27-3p的靶基因，两者之间可能存在竞争性抑制关系。进一步实验证实在POCD小鼠海马组织中，NONMMUT010710与PPARγ表达均下降，miR-27-3p表达增加。因此我们推测围术期因素使NONMMUT010710下调，其对miR-27-3p的竞争性抑制作用减弱，从而使miR-27-3p的靶基因PPARγ含量减少，进而通过促进上述病理生理过程参与POCD的发生。我们将在动物和细胞水平，应用过表达或敲减载体，通过细胞培养、免疫印迹、凋亡检测等技术，以NONMMUT010710/miR-27-3p/PPARγ为核心，深入研究POCD的病理机制。

术后认知功能是一种术后神经系统并发症，老年患者常见。在本项目中，我们研究了非编码RNA NONMMUT055714通过调控miR-7684-5p在POCD发生发展中的作用。在POCD小鼠模型中，向小鼠海马区转染NONMMUT055714过表达慢病毒,使用Morris水迷宫评估认知功能。在原代海马神经元中诱导NONMUTT055714和miR-7684-5p沉默，观察其对细胞生物学过程的影响。通过生物信息学分析和双荧光素酶报告实验探讨NONMMUT055714、miR-7684-5p和SORLA之间的关系。通过细胞和动物实验验证NONMMUT055714在POCD中的保护作用需要miR-7684-5p参与。结果发现NONMMUT055714在POCD小鼠模型中表达下降，在体内过表达NONMMUT055714对POCD小鼠模型的认知功能损害有保护作用。我们发现miR-7684-5p是一种与NONMMUT055714相关的miRNA，且为SORLA的上游调控因子。NONMMUT055714的下调导致SORLA的减少、Aβ和p-tau表达的增加、炎症生物标志物的增加、氧化应激标志物的增加以及体外神经元凋亡的增加。NONMMUT055714下调的作用可通过沉默miR-7684-5p而逆转。综上所述，我们的研究结果表明，NONMMUT055714以ceRNA方式调节miR-7684-5p和SORLA的功能，在POCD中起到神经保护作用。因此，我们提出NONMMUT055714可为未来临床POCD预测和防治的新靶点。