Functional Role for H3 Serotonylation During Critical Periods of Postnatal Brain Development and Plasticity

项目总结/摘要 多巴胺能（5 HTergic）系统涉及广泛的神经发育和神经精神疾病。 现象，包括情绪和压力反应的调节。虽然5 HT行动已被假定为 仅通过5 HT受体及其突触效应介导，最近的研究表明， 中缝背核多巴胺能神经元和前脑靶神经元中存在5-HT核池。我们 一个实验室已经证实，5-羟色胺与组蛋白H3-形成共价键，产生H3谷氨酰胺5-羟色胺 （H3 Q5 ser）-称为H3乙酰化的过程。我们进一步表明，H3乙酰化起关键作用， 在建立正常的胚胎和成人大脑转录可塑性模式中的调节作用。然而，在这方面， 在出生后早期脑发育过程中H3乙酰化的功能作用，时间点包括 神经可塑性的关键时期，在很大程度上尚未探索，环境刺激的影响 （异常或其他）在早期生活中对这种修饰的影响仍然未知。假设H3 在出生后的大脑中，乙酰化轨迹以区域特异性的方式变化，以控制关键的 神经发育基因表达和早期生活压力的各个方面破坏了这些模式， 易受压力相关行为异常的影响。在Ian迷宫和Eric Nestler博士的指导下 在西奈山的伊坎医学院，我将用三个不同的目标来解决这个假设， 各种方法。在目标1中，我将从功能上评估出生后H3乙酰化动力学， 发展，研究早期生活压力如何破坏这些模式，并阐明这种因果关系， 使用表观基因组和表观基因组的策略整合对基因表达调控的新型组蛋白修饰 转录组学方法（即，RNA测序和CUT&RUN）。在目标2中，我将描述 出生后的去甲肾上腺素相关基因表达直接导致脑回路的改变， 使用先进的基因编辑技术增加了与压力相关的行为异常的脆弱性， 行为分析在目标3中，我将描述出生后大脑中H3乙酰化的全脑模式 发展和响应早期一样的压力，使用全脑清除和成像技术（即， iDISCO+）。总的来说，这个项目将提供新的见解的方式，h3乙酰化控制大脑 发展和机制，破坏这一翻译后标记引起异常的 病理生理状态。

Project Summary/Abstract The serotonergic (5HTergic) system is implicated in a wide range of neurodevelopmental and neuropsychiatric phenomena, including the regulation of mood and stress reactivity. While 5HT actions have been assumed to be mediated exclusively through 5HT receptors and their synaptic effects, recent studies have demonstrated the presence of nuclear pools of 5HT in dorsal raphe serotonergic neurons and forebrain target neurons. Our laboratory has established that 5HT forms covalent bonds with histone H3—resulting in H3 glutamine 5 serotonin (H3Q5ser)–a process known as H3 serotonylation. We have further shown that H3 serotonylation plays key regulatory roles in establishing normal embryonic and adult patterns of brain transcriptional plasticity. However, functional roles for H3 serotonylation during early post-natal brain development, time points encompassing critical periods of neural plasticity, have largely been unexplored, and the impact of environmental stimuli (aberrant or otherwise) on this modification during early life remains unknown. I hypothesize that H3 serotonylation trajectories vary – in a region-specific manner – across the post-natal brain to control critical aspects of neurodevelopmental gene expression and early life stress disrupts these patterns directly influencing vulnerability to stress-related behavioral abnormalities. Under the mentorship of Drs. Ian Maze and Eric Nestler at the Icahn School of Medicine at Mount Sinai, I will address this hypothesis with three distinct aims using a variety of approaches. In Aim 1, I will functionally assess H3 serotonylation dynamics during post-natal development, examine how early life stress disrupts these patterns, and elucidate the causal relationship of this novel histone modification on gene expression regulation using strategic integration of epigenomic and transcriptomic approaches (ie. RNA sequencing and CUT&RUN). In Aim 2, I will characterize how disruptions in post-natal serotonylation-associated gene expression directly result in alterations in brain circuitry leading to increased vulnerability to stress-related behavioral abnormalities using advanced gene-editing techniques and behavioral analyses. In Aim 3, I will characterize brain-wide patterns of H3 serotonylation across post-natal brain development and in response to early like stress using whole brain clearing and imaging techniques (ie. iDISCO+). Overall, this project will provide novel insight into the ways that h3 serotonylation controls brain development and the mechanisms by which disruptions to this posttranslational mark cause aberrant pathophysiological states.