Brain serotonin neuron gene regulatory networks and chromatin architecture

大脑血清素神经元基因调控网络和染色质结构

• 批准号: 10295748
• 负责人: EVAN S DENERIS
• 金额: $ 44.01万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10295748
• 关键词: ADRA1B gene; ATAC-seq; Address; Anxiety; Architecture; Binding Sites; Biological Assay; Brain; Cell Nucleus; Chromatin; Defect; Dependence; Development; Disease; Environmental Risk Factor; G-Protein-Coupled Receptors; GCHFR gene; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Investigation; Knock-out; Knowledge; Label; Life; Maps; Mental Depression; Molecular; Mus; Neurodevelopmental Disorder; Neurons; Neurotransmitters; Pattern; Plant Roots; Property; Protocols documentation; Regulation; Regulator Genes; Research; Schizophrenia; Series; Serotonin; Stress; Synapses; Testing; Tn5 transposase; Up-Regulation; anxiety-related disorders; autism spectrum disorder; brain health; chromatin remodeling; critical period; environmental stressor; fetal; gene regulatory network; gene synthesis; interest; neural circuit; neuron development; neuropsychiatric disorder; novel; postnatal; postnatal period; preservation; spatiotemporal; transcription factor; transcriptome; transcriptome sequencing; young adult

Precise spatiotemporal control of gene expression is crucial throughout life for maturation of postmitotic neuronal function and preservation of brain health. Although continuously expressed neuronal transcription factors termed terminal selectors, such as Pet1 and Lxm1b, are key regulators of gene expression across fetal and postnatal stages of life the underlying molecular mechanisms through which they control stage specific neuronal gene expression are poorly understood. Here, we aim to fill this gap by comprehensively investigating terminal selector function in postmitotic serotonin (5-HT) neurons. Pet1 and Lmx1b’s control of serotonergic gene expression is of broad interest as 5-HT has wide-ranging modulatory effects on central neural circuitry and altered serotonergic gene expression has been implicated in several developmental neuropsychiatric disorders including depression, stress-related anxiety, autism, OCD, and schizophrenia. The studies proposed here are motivated, in part, by our discovery of changing dependencies of continuously expressed 5-HT neuron terminal effector genes on Pet1 as 5-HT neurons mature. We unexpectedly found that Pet1’s terminal selector control of 5-HT synthesis genes is largely switched off in the early postnatal period and instead Pet1 switches to controlling the upregulation of neurotransmitter GPCR genes, Htr1a, Adra1b, that are needed for afferent synaptic modulation of 5-HT neuron excitability. These recent observations have led us to suggest a new principle that we have termed “terminal selector target switching”. We suggest that as postmitotic neurons progress through life, continuous terminal selector regulated transcription is not static, as is the prevailing assumption. Instead, we hypothesize that terminal selector regulated transcription is highly dynamic in which regulatory factor interactions with target genes are remodeled as postmitotic neurons mature. We hypothesize the remodeling of regulatory interactions is rooted in the temporal remodeling of postmitotic neuronal chromatin architecture. In Aim 1, we will investigate Lmx1b’s control of early postnatal 5-HT gene expression to determine whether postmitotic target switching is a general property of 5-HT terminal selectors. In Aim 2, we will use our newly developed 5HT-ATAC-seq protocol to uncover the temporal dynamics of 5-HT open chromatin as 5-HT neurons develop and mature from fetal to early postnatal stages of life. Specifically, we will address these questions: Do open chromatin states undergo maturational changes in parallel with the maturation of 5-HT neuron transcriptomes? Do switches in target dependence result from gene specific changes in open chromatin? Aim 3 will investigate a plausible potential mechanism through which developing 5-HT gene expression patterns are controlled: Terminal selectors, Pet1 and Lmx1b, directly act to control the maturation of 5-HT neuronal open chromatin states. Understanding how terminal selectors control postmitotic neuronal gene expression may illuminate potential neurodevelopmental disease mechanisms that cause aberrant neuronal gene expression and defects in neuronal maturation.

在整个生命过程中，对基因表达的精确时空控制对于有丝分裂后的成熟至关重要 神经功能与大脑健康的保存。尽管连续表达的神经元转录 被称为末端选择器的因子，如Pet1和Lxm1b，是整个胎儿基因表达的关键调节因素 以及出生后生命阶段的潜在分子机制，它们通过这些机制控制特定阶段 对神经元基因的表达知之甚少。在这里，我们旨在通过全面调查来填补这一空白 有丝分裂后5-羟色胺(5-HT)神经元的终末选择器功能。Pet1和Lmx1b对5-羟色胺能的调控 基因表达受到广泛关注，因为5-羟色胺对中枢神经回路具有广泛的调制作用 5-羟色胺能基因表达的改变与几种发育性神经精神疾病有关 精神障碍包括抑郁症、应激性焦虑、自闭症、强迫症和精神分裂症。这项研究建议 我们发现连续表达的5-羟色胺的依赖关系不断变化，这在一定程度上促使了我们的研究 随着5-羟色胺神经元的成熟，Pet1上的神经末梢效应基因。我们意外地发现，Pet1‘S航站楼 5-羟色胺合成基因的选择器控制在出生后早期大部分被关闭，而不是Pet1 切换到控制神经递质GPCR基因Htr1a，Adra1b的上调，这些基因是 5-羟色胺神经元兴奋性的传入突触调节。这些最近的观察使我们提出了一个 我们称之为“终端选择器目标切换”的新原理。我们认为作为有丝分裂后神经元 在生命的进步中，连续末端选择器调控的转录不是静止的，就像流行的那样 假设。相反，我们假设末端选择器调控的转录是高度动态的，其中 随着有丝分裂后神经元的成熟，调节因子与靶基因的相互作用被重塑。我们假设 调控相互作用的重塑植根于有丝分裂后神经元染色质的时间重塑 建筑。在目标1中，我们将研究Lmx1b对出生后早期5-HT基因表达的调控，以 确定有丝分裂后靶点切换是否是5-羟色胺终末选择器的一般特性。在目标2中，我们 将使用我们最新开发的5HT-ATAC-SEQ协议来揭示5-HT开放的时间动力学 染色质作为5-羟色胺神经元，从胎儿到出生后的早期发育和成熟。具体来说，我们将 回答这些问题：开放染色质状态的成熟变化是否与 5-羟色胺神经元转录本的成熟？靶向依赖中的切换是否由基因特异性导致 开放染色质的变化？目标3将研究一种合理的潜在机制，通过这种机制 5-羟色胺基因的表达模式是受控制的：末端选择子Pet1和Lmx1b直接作用于控制 5-羟色胺神经元开放染色质状态的成熟。了解末端选择器如何控制有丝分裂后 神经元基因表达可能阐明导致神经发育疾病的潜在机制 神经元成熟过程中神经元基因的异常表达和缺陷。