Chemical Fingerprinting

该提案的目标是确定DNA DSBR是否正在杀死神经元。DNA修复与 在患者中通过全基因组关联研究（GWAS）直接发现与亨廷顿病（HD）发病有关。CAG 在DNA氧化损伤的修复过程中发生扩增，并对DNA修复有良好的作用 在小鼠模型中建立。然而，在过去的融资周期中，我们发现mhtt抑制了 在HdhQ（150/150）动物的脑中，以细胞类型和区域特异性方式在脑细胞中进行DNA修复。这 对CAG扩增作用不大，但同时导致DNA双链的积累 未检测到的中断（DSB）。DSB是最具毒性的损伤，如果不修复， 死亡这就提出了未修复和以前未得到承认的争端解决机构是否负有责任的问题 来杀死神经元。我们已经开发出一种新的方法来定义脑细胞中的DNA修复改变，称为 修复指纹在目标1中，我们将使用“修复指纹”来确定DNA双链是否断裂 在星形胶质细胞和神经元中形成或修复的方式不同，以及涉及哪些途径。修复 指纹识别是一种综合的三臂方法，用于识别DNA修复和提取的景观， 通路和机制负责脑细胞中的DSBR。在目标2中，我们将确定 DNA双链断裂是HdhQ（150/150）小鼠体内神经元死亡的主要驱动因素。

The goal of the proposal is to determine whether DNA DSBR are killing neurons. DNA repair bas been linked directly to Huntington Disease (HD) onset by genome-wide association studies (GWAS) in patients. CAG expansion occurs in the process of repairing oxidative DNA damage, and its role for DNA repair was well established in mouse models. During the past funding cycle, however, we have discovered that mhtt suppresses DNA repair in brain cells in a cell-type and region-specific manner in the brains of HdhQ(150/150) animals. This had modest effect on CAG expansion, but at the same time, resulted in the accumulation of DNA double strand breaks (DSBs) that had gone undetected. DSBs are the most toxic of lesions, and if not repaired lead to cell death. This raised the issue as to whether the unrepaired and previously unrecognized DSBs were responsible for killing neurons. We have developed a new approach to defining DNA repair alterations in brain cells, called repair fingerprinting. In Aim 1, we will use “repair fingerprinting” to determine whether DNA double strand breaks are formed or repaired differently in astrocytes and neurons, and what pathways are involved. Repair fingerprinting is an integrated three-arm approach to identify the landscape of DNA repair and extract which pathways and machinery are responsible for the DSBR in brain cells. In Aim 2, we will determine whether cryptic DNA double strand breaks are the primary driver of neuronal death in HdhQ(150/150) mice in vivo.