DNA动态甲基化介导的基因组不稳定性在术后中枢神经系统功能障碍中的作用

Genetic instability may play an important role in the process of aging associated neurodegeneration, and likely interacts with neurotoxins including Aβ. And dynamic DNA methylation participates the modulation of both DNA damage and repair process. The previous studies conducted by the applicant show that anesthetics could induce DNA damage in prefrontal cortex and hippocampus, regions of central nervous system (CNS), while both surgery and anesthetics induce Aβ generation and deposition, and synaptic dysfunction. Our preliminary data also indicate there is a relationship between perioperative factors, DNA methylation and related DNA damage. We, therefore, hypothesize that dynamic DNA methylation mediated genetic instability may be a major contributor on the process of postoperative CNS dysfunction. So the current project is designed to investigate surgery and anesthetics induced dynamic DNA methylation and genetic instability, and to determine the mediational mechanism of dynamic DNA methylation on genetic instability such as DNA damage induction, NHEJ repair pathway, p53 and other molecular entities. Furthermore, the interventions for mitigating DNA methylation and associated DNA damage are employed to investigate the effects of dynamic DNA methylation mediated genetic instability on postoperative CNS neurotoxicity and dysfunction. The outcome of the proposed project will further our understanding the role of epigenetics and genomics on the process of postoperative CNS dysfunction, and to provide valid therapeutic targets.

基因组不稳定性在衰老、神经退行性疾病中扮演了重要角色，与Aβ生成等神经毒性反应存在相互作用，而DNA甲基化的动态变化则参与了DNA损伤-修复的调控。申请人前期研究显示，麻醉因素可导致中枢前额叶和海马区的DNA损伤，且手术麻醉因素均可导致Aβ生成和神经突触功能障碍，再结合项目预实验提示的围术期因素、DNA甲基化及DNA损伤的关系，推测DNA动态甲基化介导的基因组不稳定性是术后中枢功能障碍发病的重要环节。故本项目拟观察手术麻醉因素所致的中枢DNA甲基化水平变化和基因组不稳定性，并从DNA损伤诱导、NHEJ修复通路和p53等角度研究DNA动态甲基化对基因组不稳定性的介导机制。在此基础上，从DNA甲基化和DNA损伤层面进行干预，研究DNA动态甲基化介导的基因组不稳定性在术后中枢神经毒性反应和功能障碍中的作用。研究结果将揭示表观遗传学-基因组学机制在术后中枢神经系统功能障碍发病中的作用和治疗靶点。

基因组不稳定性在衰老、神经退行性疾病中扮演了重要角色，与Aβ生成等神经毒性反应存在相互作用，而DNA甲基化的动态变化则参与了DNA损伤-修复的调控。申请人前期研究显示，麻醉因素可导致中枢前额叶和海马区的DNA损伤，手术麻醉因素均可导致Aβ生成和神经突触功能障碍。本项目按照计划执行，研究了围术期因素作用下的记忆基因甲基化水平的动态变化；探索了围术期因素作用下的基因组稳定性以及DNA损伤的发生情况和关键机制，并进行了干预研究；研究了手术和麻醉因素作用下大脑海马组织的全转录组情况，从基因表达的层面揭示包括甲基化修饰在内的功能变化；同时，项目研究了围术期因素作用下，多种非编码RNA在基因损伤等多种神经毒性反应过程中的作用和关联机制。此部分工作以基因组损伤研究为基础，进一步拓展到全基因组和转录组研究，为后续单细胞水平的研究工作奠定了基础。此外，结果所揭示的表观遗传学-基因组学机制在术后中枢神经系统功能障碍发病中的作用有助于潜在的治疗靶点的发现。