Role of DNA methylation in regulating striatal molecular rhythm alterations in depression

项目总结/摘要 重度抑郁症（MDD）是导致残疾的主要全球原因。MDD的一个显著特征是昼夜节律 节律紊乱最近的研究表明，人类大脑中的基因表达（GE）节律使用了一种新的方法。 死后（PM）脑组织的“死亡时间”分析，其中GE数据在24小时内组织 根据个人的死亡时间使用这种方法，先前表明MDD受试者具有 扰乱了包括纹状体在内的多个大脑区域的GE节律。纹状体是由 背侧纹状体和腹侧纹状体，两者都与应激、快感缺乏和抑郁有关。在 在初步研究中，候选人描述了GE节律和人类背侧的相位关系， 和腹侧纹状体纹状体中GE节律模式的驱动机制以及 在MDD中观察到的情况仍有待研究。本K 01提案采用多组学方法来研究 DNA甲基化（DNAm）作为一种潜在的表观遗传机制，GE节律在抑郁症中改变。 鉴于（1）纹状体中的DNAm与抑郁症密切相关，并直接受到压力的影响，以及（2） DNA m节律与人类皮层中的GE节律相关并时间锁定，中心假设是， 抑郁症中纹状体GE节律的破坏是由慢性应激诱导的DNAm节律的改变驱动的。 这一假设将通过以下目的进行检验：（1）确定人PM中DNAm的节律性变化 MDD受试者的背侧和腹侧纹状体;（2）采用多组学数据整合方法， DNAm的节律性变化如何影响人类PM背侧和腹侧纹状体的全转录组节律 在MDD受试者中;和（3）确定转录组范围的节律和快感缺乏样行为的调节 在慢性应激的小鼠模型中，背侧和腹侧纹状体中的DNA m。这些研究对 了解MDD中昼夜节律中断的潜在机制，并可能导致发现新的 未来治疗的治疗目标。完成拟议的研究，并支持他的职业目标， 建立一个独立的实验室，研究驱动昼夜节律破坏的表观遗传机制 在抑郁症中，候选人将需要以下方面的指导培训：（1）发展概念和技术专长 使用啮齿动物模型和人类PM脑组织研究抑郁症的神经生物学;（2）开发 表观遗传学领域的概念和技术专长;（3）学习先进的生物统计学， 生物信息学技能，整合转录组学和表观基因组学数据的昼夜节律分析。实现这些 培训目标，候选人已经组建了一个导师团队，在神经生物学方面具有广泛的专业知识， 抑郁症表观遗传学和生物统计学匹兹堡大学精神病学系提供了一个 资金充足的环境，提供卓越的职业发展机会，成为成功的企业家 独立调查员在完成本提案后，候选人将处于独特的地位， 自己的研究项目，研究驱动抑郁症昼夜节律中断的表观遗传机制。

PROJECT SUMMARY/ABSTRACT Major depressive disorder (MDD) is a leading global cause of disability. A prominent feature of MDD is circadian rhythm disturbances. Recent studies have shown gene expression (GE) rhythms in the human brain using a “time of death” analysis of postmortem (PM) brain tissue, where GE data is organized across a 24-hour clock based on individual time of death. Using this approach, it was previously shown that MDD subjects have disrupted GE rhythms across a number of brain regions, including the striatum. The striatum is composed of the dorsal striatum and ventral striatum and both have been implicated in stress, anhedonia, and depression. In preliminary studies, the candidate characterized GE rhythms and phase relationships across the human dorsal and ventral striatum. The mechanisms driving these rhythmic patterns of GE in the striatum and the alterations observed in MDD remain to be investigated. This K01 proposal utilizes a multi-omics approach to investigate DNA methylation (DNAm) as a potential epigenetic mechanism by which GE rhythms are altered in depression. Given that (1) DNAm in the striatum is strongly implicated in depression and directly influenced by stress and (2) DNAm rhythms are correlated and time-locked to GE rhythms in the human cortex, the central hypothesis is that striatal GE rhythm disruptions in depression are driven by chronic-stress induced alterations in DNAm rhythms. This hypothesis will be tested by the following aims: (1) Determine rhythmic changes in DNAm in the human PM dorsal and ventral striatum in MDD subjects; (2) Employ a multi-omics data integration approach to determine how rhythmic changes in DNAm affect transcriptome-wide rhythms in the human PM dorsal and ventral striatum in MDD subjects; and (3) Determine the regulation of transcriptome-wide rhythms and anhedonia-like behavior by DNAm in the dorsal and ventral striatum in a mouse model of chronic stress. These studies are central to understanding the mechanisms underlying circadian disruptions in MDD and may result in the discovery of novel therapeutic targets for future treatments. To complete the proposed studies and support his career goal of establishing an independent laboratory to study the epigenetic mechanisms driving circadian rhythm disruptions in depression, the candidate will require mentored training in: (1) developing conceptual and technical expertise in the use of rodent models and human PM brain tissue to study the neurobiology of depression; (2) developing conceptual and technical expertise in the field of epigenetics; and (3) learning advanced biostatistics and bioinformatics skills to integrate circadian analyses of transcriptomics and epigenomics data. To achieve these training goals, the candidate has assembled a mentorship team with extensive expertise in the neurobiology of depression, epigenetics, and biostatistics. The Department of Psychiatry at the University of Pittsburgh offers a well-funded environment with exceptional career development opportunities to become a successful independent investigator. At completion of this proposal, the candidate will be uniquely positioned to lead his own research program studying the epigenetic mechanisms driving circadian rhythm disruptions in depression.