猕猴模型探讨脑老化过程中DNA甲基化和去甲基化的表观遗传调控作用

Brain ageing has been associated with alterations in multiple epigenetic systems including DNA methylation patterns. DNA 5-Hydroxymethylcytosin (5hmC), a new epigenetic hallmark which was discovered recently, is becoming a hot topic in many biological processes. However, the 5hmC-mediated epigenetic underpinnings of brain aging remain poorly understood, particularly in humans and closely related non-human primates. We present preliminary data showing that the levels of 5hmC were abundant in Rhesus monkey brain during postnatal development and maturation. Nevertheless, a significant reduction of 5hmC was found in cortex and hippocampus during ageing. These results indicate that the involvement of 5hmC in the process of brain aging and points out common and particular signatures that might aid in differential diagnosis as biomarkers and in the discovery of novel therapeutic targets. The core hypothesis of this application is that dynamic changes in 5hmC-mediated epigenetic regulation play a important role in driving the process of brain aging. We will explore this hypothesis through two ways. Our first aim is to map the patterns of dynamic changes in 5hmC and 5mC in rhesus monkey brain during aging. The second part of our strategy will be to explore whether change in 5hmC-mediated epigenetic regulation is a key factor for driving brain aging. We will pursue the mechanism of reduction of 5hmC as well as its role in driving brain aging. We will focus on exploring whether loss of 5hmC is a key factor in driving brain aging. We will further explore the mechanism of 5hmC-mediated epigenetic regulation in driving brain ageing. We will also examine whether the manipulation of TET family enzymes have effects on brain ageing. The goal of these studies is to identify if 5hmC-mediated epigenetic regulation links to brain ageing and how change in 5hmC-mediated epigenetic regulation to drive brain ageing.

脑老化过程与表观遗传调控系统密切相关。DNA甲基化和去甲基化是机体重要的表观调控系统之一，直接参与到许多生命过程。本研究试图探讨与阐明DNA甲基化和去甲基化的变化是否参与了脑老化的过程，特别是DNA去甲基化中间产物5hmC介导的表观遗传调控对脑老化的影响和作用。我们计划通过猕猴为研究模型，应用分子及细胞生物学手段，以及现代分子遗传学及DNA深度测序等技术，来探讨和阐明发生在脑老化过程中DNA甲基化和去甲基化变化特征。重点阐明5hmC特异性变化的原因和机理，同时利用CRISPR/Cas9技术结合病毒介导的靶基因或特异性shRNAs来实现对TETs酶蛋白活性进行人为操控，然后来观察5hmC介导的表观调控对脑老化过程的影响；在此基础上，筛选和确定能够特异性调控TET家族蛋白酶功能的天然活性物质，进一步发现延缓或改善脑老化进程的天然药物。

脑老化过程与表观遗传调控系统密切相关,其中就包括DNA甲基化和去甲基化修饰系统。DNA甲基化和去甲基化是机体重要的表观调控系统之一，直接参与到许多生命过程。本研究我们利用猕猴为研究对象，利用MeDIP_seq和hMeDIP_seq等生物信息学方法，完成对大脑衰老过程中的DNA甲基化/去甲基化的变化特征描述；在此基础上，应用分子及神经生物学技术，确定了发生在脑老化过程中DNA甲基化/去甲基化的原因和调控作用，同时，利用CRISPR/Cas9技术结合病毒介导的靶基因或特异性shRNAs来实现对TETs酶蛋白活性的操控，然后确定5hmC 水平变化对脑老化过程的影响。另外，利用云南丰富的动植物资源，筛选能够特异性调控TET家族蛋白酶功能的天然活性物质。我们的研究为深入理解DNA甲基化/去甲基化在大脑衰老中的变化特征及调控作用提供了可靠的实验依据，为下一步发现延缓或改善脑老化进程的天然药物奠定基础。