The shielding role of the nuclear periphery against the genetic and non-genetic consequences of DNA damage (ChromoSENSOR)

哺乳动物细胞核的一个关键特征是核空间内基因组的非随机排列，这与细胞如何科普DNA损伤有关。将异染色质拴系到核纤层以形成纤层相关结构域（LAD），保护重复DNA免受非法重组，并增强核抵抗可导致DNA损伤的机械力的能力。除了危害基因组的完整性外，DNA损伤还具有非遗传性后果。它影响核纤层的完整性，导致表观基因组的变化，并改变DNA与核周边结合的倾向。所有这些变化都需要恢复，以维持细胞的健康。非随机基因组组织，特别是LAD，保护细胞免受DNA损伤的遗传和非遗传后果的机制是未知的。我们将使用创新的蛋白质靶向策略诱导LAD特异性DNA断裂，以解开LAD如何控制DNA修复途径的选择，以抑制重复序列之间的重组，以及是否损害LAD完整性与癌症基因组的结构变异相关。我们将确定DNA修复后表观基因组是否恢复，以及LAD位置是否固有地改变，影响细胞身份。最后，使用精确的机械操作的细胞核，我们将研究如何核周边保护基因组从机械应力诱导的DNA损伤。该提案将揭示保持LAD基因组和表观基因组完整性的机制，并将对我们理解DNA损伤后细胞适应性如何产生重大影响。我们还将深入了解染色质力学和DNA损伤之间的复杂关系，并揭示核外围为保护基因组完整性而发生的变化。这些知识对于确定我们如何设计染色质状态以将其用于癌症治疗至关重要。

A key feature of the mammalian nucleus is the non-random arrangement of the genome within the nuclear space, which is linked to how cells cope with DNA damage. Tethering heterochromatin to the nuclear lamina to form the Lamina Associated domains (LADs), protects repetitive DNA from illegitimate recombination and enhances the ability of the nucleus to resist mechanical forces, which can lead to DNA damage. In addition to jeopardizing genomic integrity, DNA damage has non genetic consequences. It affects the integrity of the nuclear lamina, leads to changes in the epigenome and alters the propensity of DNA to associate with the nuclear periphery. All these changes, need to be restored to maintain cell fitness. The mechanisms by which non-random genome organization, and particularly LADs, protect cells against the genetic and non-genetic consequences of DNA damage are unknown.We will use innovative protein-targeting strategies to induce LAD-specific DNA breaks, to unravel how LADs control DNA repair pathway choice to supress recombination between repeats and whether compromising LAD integrity correlates with structural variations in cancer genomes. We will determine whether the epigenome is restored after DNA repair and whether LAD-position is inherently altered, impacting cell identity. Finally, using precise mechanical manipulation of the nucleus, we will investigate how the nuclear periphery protects the genome from mechanical stress-induced DNA damage. This proposal will uncover the mechanisms that preserve LAD genome and epigenome integrity and will have a significant impact on our understanding of how cell fitness after DNA damage is enforced. We will also gain insight into the complex relationship between chromatin mechanics and DNA damage and reveal the changes that the nuclear periphery undergoes to protect genome integrity. This knowledge will be essential to determine how we can engineer chromatin state to exploit it for cancer treatment.