Promoting Resilience to Early Life Stress through Epigenetic Editing

项目摘要/摘要 早期生活压力(ELS)是情绪和焦虑症发展的最强预测因子之一。 ELS可包括创伤(忽视，和/或身体、性和/或情感虐待)或其他消极的童年 经历。然而，ELS后抑郁风险的增加并不是很清楚。以前的工作在 在ELS和成体后，一种跨越寿命的应激小鼠模型显示出独特的基因表达模式 伏隔核(NAC)中的应激，这是与应激反应有关的奖赏通路的关键区域。这个 染色质的三维结构是决定基因如何调控和 表达，更开放和可接近的染色质允许基因表达，更封闭 染色质抑制表达。我们假设ELS改变了染色质的可及性 NAC中的应激反应神经细胞使染色质采用相对开放的 构象，使转录对未来的刺激更具反应性。在目标1中，我将确定染色质如何 在ELS激活的神经元中，使用双转基因小鼠标记和 捕获激活和非激活的神经元，然后执行ATAC测序和计算分析 以确定整个基因组中染色质的可及性。我将研究ELS如何改变染色质 幼年和成年小鼠的激活和非激活细胞的结构。在目标2中，我将测试 染色质状态对成年应激源转录和行为易感性的功能影响。 首先，我将应用基于CRISPR-dCas9的表观基因组编辑工具关闭目标基因组中的染色质 已经在初步数据中确定了增强子区，以防止体外激活的超敏反应。然后，我 将使用这一工具在体内测试关闭异常打开的染色质可以逆转 ELS，并促进转录和行为弹性。总之，这项研究将产生基本的 对关键发育时期的压力如何增加对未来分子压力的敏感性的见解 这个项目有助于我们理解表观遗传驱动机制 ELS后情绪障碍的风险增加。

PROJECT SUMMARY / ABSTRACT Early life stress (ELS) is one of the strongest predictors for development of mood and anxiety disorders. ELS can include trauma (neglect, and/or physical, sexual, and/or emotional abuse) or other negative childhood experiences. However, the increased risk for depression following ELS is not well understood. Previous work in a mouse model of stress across the lifespan has shown unique gene expression patterns after ELS and adult stress in the nucleus accumbens (NAc), a key region of the reward pathway implicated in stress response. The three-dimensional structure of chromatin is a key factor in determining how genes are regulated and expressed, with more open and accessible chromatin being permissive for gene expression and more closed chromatin repressing expression. We hypothesize that ELS changes chromatin accessibility within stress-responsive neuronal cells in the NAc such that the chromatin adopts a comparatively open conformation, making transcription more reactive to future stimuli. In Aim 1, I will determine how chromatin architecture is altered specifically within ELS-activated neurons using a double-transgenic mouse to label and capture both activated and non-activated neurons, then perform ATAC-sequencing and computational analyses to determine chromatin accessibility across the entire genome. I will examine how ELS alters chromatin structure in activated and non-activated cells in juvenile and adult mice of both sexes. In Aim 2, I will test the functional impact of chromatin state on transcriptional and behavioral susceptibility to adulthood stressors. First, I will apply CRISPR-dCas9-based epigenome editing tools to close chromatin at target genomic enhancer regions already identified in preliminary data to prevent hypersensitivity to activation in vitro. Then, I will use this tool in vivo to test the hypothesis that closing aberrantly open chromatin can reverse the impact of ELS and promote transcriptional and behavioral resilience. Together, this research will generate fundamental insights into how stress during key periods of development increases sensitivity to future stress at a molecular level in the brain.This project contributes to our understanding of the epigenetic mechanisms driving heightened risk of mood disorders following ELS.