DNA methylation as a mechanism for reduced dendritic spine density in schizophrenia

7.项目摘要/摘要。 精神分裂症(SZ)是一种毁灭性的精神疾病，治疗选择有限。大脑皮质的破坏 环路是SZ病理和病理生理学的重要特征。树突棘密度(DSD)降低 皮质第三层是尸检研究中观察到的最稳定的皮质环路异常之一。 SZ，影响包括颞上回(STG)在内的多个脑区。降低DSD被认为是 SZ存在多种症状，包括损害社会认知的听觉处理缺陷和 然而，幻听导致DSD降低的机制却知之甚少。脱氧核糖核酸 甲基化(DNaM)，即在胞嘧啶核苷酸上加一个甲基，是基因转录的调节因子。 假设(1)dNaM在SZ受试者的大脑中改变，以及(2)dNaM在其他环境中改变 以DSD异常为特征的dNaM是SZ DSD降低的有力候选机制。尽管 证据表明dNaM在调节DSD中的作用，dNaM与降低的DSD的关系 在深圳之前还没有被探索过。我们提出了一些研究来检验这样的假设，即在深圳降低DSD 结果，部分是由于dNaM的改变引起的多个基因的转录改变。 首先，我们将在一个大型的SZ-NPC队列中有选择地评估STG第三层中全基因组、位点特异性的dNaM。 DSD已经对其进行了描述。然后，我们将深入研究dNaM-DSD的关联，以及 DNaM-在STG第三层PYR神经元中，可能介导这些相关性的基因转录关系。 最后，我们将使用CRISPR/CAS9系统来检验dNaM和DSD之间的因果关系 候选基因dNaM以基因组区域特定的方式，并在神经元培养中测量DSD。至 对这一研究项目的赞扬，我开发了一种创新的、全面的、多学科的培训 计划促进我向独立调查员的转变。 在完成拟议的研究和培训计划后，我将成为精神病学表观遗传学的专家， 一般说来，特别是在应用尖端方法研究深圳树突棘病理方面。 很少有研究人员有必要的背景和培训来连接多个层面的调查- 临床观察/行为、回路、神经元、转录本表达、表观遗传修饰和遗传 密码-对理解表观遗传学做出创新和临床相关贡献所必需的 精神障碍的机制。正是凭借这种独特的背景和训练的结合，我将 建立我的独立的、由NIH资助的实验室，并在我的K23获奖期的第三年提交R01资金。

7. Project Summary/Abstract. Schizophrenia (SZ) is a devastating psychiatric disorder with limited treatment options. Disruptions in cortical circuitry are a key feature of SZ pathology and pathophysiology. Reduced dendritic spine density (DSD) in cortical layer 3 is among the most consistently observed cortical circuit abnormalities in postmortem studies of SZ, affecting multiple brain regions including the superior temporal gyrus (STG). Reduced DSD is thought to underlie multiple symptom domains in SZ including auditory processing deficits that impair social cognition and auditory hallucinations, however, the mechanisms that contribute to reduced DSD are poorly understood. DNA methylation (DNAm), the addition of a methyl group to a cytosine nucleotide, is a regulator of gene transcription. Given that (1) DNAm is altered in the brains of SZ subjects and (2) DNAm is altered in other contexts characterized by DSD abnormalities, DNAm is a strong candidate mechanism for reduced DSD in SZ. Despite evidence suggesting a role for DNAm in regulation of DSD, the relationship between DNAm and reduced DSD in SZ has not previously been explored. We propose studies to test the hypothesis that reduced DSD in SZ results, in part, from the altered transcription of multiple genes caused by alterations in DNAm. First, we will assess genome-wide, site-specific DNAm selectively in layer 3 of STG in a large SZ-NPC cohort for which DSD has already been characterized. Then, we will hone in on the DNAm-DSD correlations, and the DNAm-gene transcription relationships that may mediate those correlations, in STG layer 3 PYR neurons. Finally, we will test the causal relationship between DNAm and DSD by using the CRISPR/Cas9 system to alter candidate gene DNAm in a genome-region-specific manner and measure DSD in neuron cultures. To compliment this research project, I have developed an innovative, comprehensive, and multidisciplinary training plan to facilitate my transition to independent investigator. Upon completion of the proposed research and training plans, I will be an expert in psychiatric epigenetics, generally, and in applying cutting-edge approaches to the study of dendritic spine pathology in SZ, specifically. Few researchers have the necessary background and training to connect the multiple levels of investigation— clinical observation/behavior, circuits, neurons, transcript expression, epigenetic modifications, and genetic code—necessary to make innovative and clinically-relevant contributions to understanding the epigenetic mechanisms of psychiatric disorders. It is with this unique combination of background and training, that I will establish my independent, NIH-funded lab and submit for R01 funding in year 3 of my K23 award period.