A systematic study of the environmental etiology of autism spectrum disorder using high-throughput behavioral screening

使用高通量行为筛查系统研究自闭症谱系障碍的环境病因

• 批准号: 10806339
• 负责人: Yijie Geng
• 金额: $ 24.9万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10806339
• 关键词: Affect; Behavior; Behavioral; Binding; Biochemical; Biological; Brain; Chemicals; DNA; DNA Methylation; DNA Modification Methylases; DNA methyltransferase inhibition; DSM-V; Defect; Development; Developmental Gene; Embryo; Embryonic Development; Environmental Risk Factor; Epigenetic Process; Etiology; Exposure to; Gene Expression Regulation; Genetic; Genomics; Goals; Grant; Heterozygote; Human; Investigation; Libraries; Link; Literature; Methods; Mus; Mutation; Names; National Institute of Environmental Health Sciences; PHD Finger; Pathway interactions; Phenocopy; Phenotype; Play; Protein Isoforms; Regulation; Ring Finger Domain; Risk; Rodent Model; Role; Social Behavior; Social Development; Social Responsibility; Stress; Symptoms; System; TOP2A gene; Techniques; Testing; Tissues; Topoisomerase II; Topoisomerase II inhibition; Topoisomerase-II Inhibitor; Ubiquitin; Zebrafish; autism spectrum disorder; conditional knockout; gain of function; genetic risk factor; high throughput screening; loss of function; mouse model; negative affect; new therapeutic target; overexpression; postmitotic; prenatal exposure; prevent; repetitive behavior; screening; small molecule libraries; social; social communication impairment; social deficits

PROJECT SUMMARY/ABSTRACT Identifying the causes of autism spectrum disorder has proven to be a significant challenge. Both genetic and environmental risk factors contribute to the development of autism. However, despite being estimated to account for 41% of autism risk, we know very little about the environmental risk factors of autism. Moreover, current systems that we are using to study how environmental factors influence autism risk, such as rodent models, are slow and laborious, and therefore not suitable for conducting large-scale systematic investigations. My long-term goal is to study the effect of environmental factors on the development of autism. Because social deficit is one of the 2 core symptoms of autism, I developed a high-throughput screening method to systematically search for chemicals that inhibit the development of social behavior in zebrafish. Using this system, I screened 1120 compounds, and identified a group of compounds - topoisomerase II (Top2) inhibitors - that effectively inhibited the normal development of social behavior in zebrafish. Prenatal exposure to the Top2 inhibitor ICRF-193 in mouse also induced behavioral defects related to the two core symptoms of autism. The main objective of this grant is to characterize the role of Top2 in the development of social behavior. Top2 is involved in gene regulation during brain development. Its two isoforms Top2a and Top2b are expressed in dividing and postmitotic tissues, respectively, during development, and modulate the expression of distinct sets of developmental genes. Top2 also regulates DNA methylation by binding to Uhrf1, a key adapter for Dnmt1. My preliminary results demonstrated that: 1) Top2a rather than Top2b is likely to be the biological target responsible for the social deficit phenotype; 2) chemical inhibition of Dnmts phenocopied Top2 inhibition and induced a similar social deficit phenotype in zebrafish; and 3) transient overexpression of Dnmt1 in zebrafish embryos rescued the social deficit phenotype induced by Top2 inhibitors. In addition, previous literatures have linked human mutations in TOP2A, TOP2B, and DNMT1 to increased autism risk. I thus propose the central hypothesis that Top2 plays a critical role in the development of social behavior through regulation of Dnmt1 and DNA methylation, and disruption of this pathway leads to deficits in sociality and other autism-related behaviors. To test this hypothesis, I propose to: 1) determine which Top2 isoform (Top2a or Top2b) is responsible for the social deficit phenotype induced by Top2 inhibition; 2) investigate the role of Dnmt1 and global DNA methylation in the development of social deficit following Top2 inhibition; and 3) To systematically discover environmental factors that affect the development of social behavior by screening the Tox21 library. Together, my proposed studies will have a broad impact on the field and may ultimately reveal novel therapeutic targets to prevent or treat autism.

项目摘要/摘要 确定自闭症谱系障碍的原因已被证明是一个重大挑战。遗传和 环境风险因素有助于自闭症的发展。但是，尽管估计 占自闭症风险的41％，我们对自闭症的环境风险因素知之甚少。而且， 我们用来研究环境因素如何影响自闭症风险的当前系统，例如啮齿 模型缓慢而费力，因此不适合进行大规模的系统研究。 我的长期目标是研究环境因素对自闭症发展的影响。因为社交 赤字是自闭症的两种核心症状之一，我开发了一种高通量筛查方法 系统地寻找抑制斑马鱼社会行为发展的化学物质。使用此 系统，我筛选了1120种化合物，并确定了一组化合物 - 拓扑异构酶II（TOP2）抑制剂 - 有效地抑制了斑马鱼中社会行为的正常发展。产前暴露于 小鼠中的TOP2抑制剂ICRF-193还引起了与自闭症的两个核心症状有关的行为缺陷。 这笔赠款的主要目的是表征Top2在社会行为发展中的作用。 top2 在大脑发育过程中参与了基因调节。它的两个同工型TOP2A和TOP2B在 分别在发育过程中分别分裂和蒙辛后组织，并调节不同集合的表达 发育基因。 TOP2还通过与UHRF1结合（DNMT1的关键适配器）来调节DNA甲基化。 我的初步结果表明：1）TOP2A而不是TOP2B可能是生物学靶标 负责社会赤字表型； 2）DNMT的化学抑制作用top2抑制作用和 在斑马鱼中引起了类似的社会赤字表型； 3）斑马鱼中DNMT1的短暂过表达 胚胎营救了TOP2抑制剂引起的社会缺陷表型。此外，以前的文献有 将人类突变与TOP2A，TOP2B和DNMT1中的人相关联，以增加自闭症风险。 因此，我提出了一个中心假设，即Top2在社会行为的发展中起着至关重要的作用 通过调节DNMT1和DNA甲基化以及这种途径的破坏会导致社会性缺陷 和其他与自闭症相关的行为。要检验该假设，我建议：1）确定哪种TOP2同工型 （TOP2A或TOP2B）负责TOP2抑制引起的社会缺陷表型； 2）调查 在TOP2抑制后，DNMT1和全球DNA甲基化在社会不足发展中的作用； 3） 系统地发现通过筛查影响社会行为发展的环境因素 TOX21库。我提出的研究在一起将对该领域产生广泛的影响，并最终可能 揭示新的治疗靶标，以预防或治疗自闭症。