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.

项目总结/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。然而，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。此外，委员会认为， 目前我们用来研究环境因素如何影响自闭症风险的系统，比如啮齿动物， 模型，是缓慢和费力的，因此不适合进行大规模的系统调查。 我的长期目标是研究环境因素对自闭症发展的影响。因为社会 缺陷是自闭症的2个核心症状之一，我开发了一种高通量筛选方法， 系统地寻找抑制斑马鱼社会行为发展的化学物质。使用此 系统筛选了1120个化合物，鉴定了一组化合物-拓扑异构酶II（Top2）抑制剂 - 有效地抑制了斑马鱼社会行为的正常发展。产前暴露于 Top2抑制剂ICRF-193在小鼠中也诱导了与自闭症的两个核心症状相关的行为缺陷。 这项资助的主要目的是描述Top2在社会行为发展中的作用。Top2 参与大脑发育过程中的基因调控。它的两种同种型Top 2a和Top 2b在大肠杆菌中表达。 分裂和有丝分裂后的组织，分别在发展过程中，并调节表达的不同集 的发育基因。Top2还通过与Dnmt 1的关键衔接子Uhrf 1结合来调节DNA甲基化。 初步结果表明：1）Top 2a而不是Top 2b可能是生物学靶标 负责社会缺陷表型; 2）Dnmts表型模仿Top2抑制的化学抑制和 在斑马鱼中诱导类似的社会缺陷表型;和3）在斑马鱼中瞬时过表达Dnmt 1 胚胎挽救了Top2抑制剂诱导的社会缺陷表型。此外，以前的文献 将人类TOP 2A、TOP 2B和DNMT 1突变与自闭症风险增加联系起来。 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关键作用 通过调节Dnmt 1和DNA甲基化，破坏这一途径导致社会性缺陷， 和其他自闭症相关的行为为了验证这一假设，我建议：1）确定Top2亚型 （Top 2a或Top 2b）负责由Top2抑制诱导的社会缺陷表型; 2）研究 Dnmt 1和整体DNA甲基化在Top2抑制后社交缺陷发展中的作用;和3） 通过筛选，系统地发现影响社会行为发展的环境因素 Tox 21文库。总之，我提出的研究将对该领域产生广泛的影响，并可能最终 揭示了预防或治疗自闭症的新的治疗靶点。