Disrupting DNA G-quadruplex secondary structures to revert premature ageing

衰老的根本原因仍然是生物学的中心谜团之一。最近在几个不同的生物模型中的研究表明，衰老的速度不仅可以被环境和遗传因素改变，而且衰老的时钟也可以逆转，使衰老的细胞和组织恢复年轻的特征。DNA在细胞核中的包装和组织已被证明在整个衰老过程中显著改变，以及一些加速衰老的疾病。小分子配体的治疗可以干扰核组织，逆转患者来源细胞的早衰症状。DNA非规范结构，特别是DNAG-四链结构，在一些加速衰老综合征的DNA包装中也发挥了作用。事实上，特定G-四链解离蛋白的突变和这些DNA结构的积累已被证明是加速衰老综合征，如Cockayne综合征的根本原因。针对DNA及其结构特征来进一步低估我们在基础衰老生物学中的作用，并探索对罕见的加速衰老疾病进行治疗干预的可能性，是一个需要研究的未知机会。在这里，我将利用一系列化学生物学工具来研究DNA G-四链结构在衰老生物学中的基本作用，并通过开发小分子来靶向和破坏这些结构，探索对罕见的加速衰老综合征进行治疗干预的可能性。具体地说，我将把我在DNA G-四链打靶和全基因组作图方面的经验与伦敦帝国理工学院化学系与维拉尔博士合作开发的G-四链选择性活细胞成像方法结合起来。我打算回答这些具体的问题：1)在加速衰老疾病中，全基因组G-四链体流行的全球变化是什么？DNA包装是如何受到它们的形成的影响的？2)靶向和破坏通过老化积累的G-四链体能否通过恢复正确的DNA包装来逆转衰老表型？3)活细胞中关于DNA转录和复制的动力学是什么，导致G-四链体在整个衰老过程中形成？解决这些问题将有助于我们进一步理解DNA二级结构形成和导致衰老的基因错误调控之间的因果关系。这将为开发新的治疗剂铺平道路，最终将增加健康寿命并治疗罕见的加速衰老综合征。

The underlying cause of aging remains one of the central mysteries of biology. Recent studies in several different biological models suggest that not only can the rate of aging be modified by environmental and genetic factors, but also that the aging clock can be reversed, restoring characteristics of youthfulness to aged cells and tissues.DNA packaging and organisation in the cell nucleus has been shown to be significantly altered thorough ageing and some accelerating ageing disorders. Treatment with small molecule ligands can interfere with nuclear organisation and revert premature ageing sings in patient-derived cells. DNA non-canonical structures, in particular DNA G-quadruplex structures, have also shown to play a role in DNA packaging in some accelerating ageing syndromes. Indeed, mutation of specific G-quadruplex unwinding proteins and accumulation of these DNA structures have been shown to be the underlying cause of accelerating ageing syndromes, such as Cockayne syndromes. Targeting DNA and its structural feature to both further our understating in fundamental ageing biology and explore potential for therapeutic intervention of rare accelerating ageing disorders, is an unexplored opportunity that needs to be investigated.Here, I will exploit a range of chemical biology tools to both investigate the fundamental role of DNA G-quadruplex structures in ageing biology, and explore the potential for therapeutic intervention of rare accelerating ageing syndromes by developing small molecules to target and disrupt these structures. Specifically, I will combine my experience with DNA G-quadruplex targeting and genome-wide mapping with a G-quadruplex selective live-cell imaging methodology that has been developed at the chemistry department of Imperial College London in collaboration with Dr. Vilar. I intend to address these specific questions:1) What are the global changes in G-quadruplex prevalence genome-wide in accelerating ageing disorders and how is DNA packaging affected by their formation? 2) Can targeting and disrupting the G-quadruplexes that accumulate via ageing be used to revert the ageing phenotypes by restoring correct DNA packaging?3) What are the dynamics in living cells, with respect to transcription and replication of DNA, that cause G-quadruplex formation thorough ageing?Addressing these questions will further our understanding of the cause and effect relationship between DNA secondary structure formation and gene mis-regulation that cause ageing. This will pave the way towards the development of novel therapeutic agents which will ultimately increase health-span and treat rare accelerating ageing syndromes.