Cerebellar hypoplasia and chromosome elimination in mouse models of Down syndrome

唐氏综合症小鼠模型中的小脑发育不全和染色体消除

基本信息

批准号：
10017057
负责人：
Anna Joyce Moyer
金额：
$ 4.55万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-17 至 2022-07-16
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10017057
关键词：
Address Affect Agonist Aneuploid Cells Artificial Chromosomes Attenuated Biological Assay Birth Brain CRISPR/Cas technology Candidate Disease Gene Cell Density Cell Line Cells Cerebellar Cortex Cerebellum Chromosome 21 Chromosomes Code Cognitive Cognitive deficits Congenital cerebellar hypoplasia Data Defect Development Developmental Process Dose Down Syndrome Drug Targeting Embryo Gene Expression Genes Goals Grant Guide RNA Hippocampus (Brain)Human Human Chromosomes Impairment In Vitro Individual Intellectual functioning disability Intervention Investigation Lead Learning Life Luciferases Measures Mediating Memory Methods Mitogens Morphology Mus Neural Crest Phenotype Proliferating Proteins Research Role SHH gene Series Sonic Hedgehog Pathway Sonication Syndrome Techniques Testing Transcript Trisomy United States Zebrafish arm base cDNA Library cell type chromosome loss classical conditioning dosage granule cell improved insight mouse Ts65Dn mouse model osteoblast differentiation overexpression response screening smoothened signaling pathway stem cells targeted treatment therapy design tool transcriptome sequencing

项目摘要

Project Summary/Abstract Cerebellar hypoplasia may contribute to syndrome-specific cognitive and adaptive deficits in Down syndrome, which affects more than a quarter million individuals in the United States. The Ts65Dn mouse model of Down syndrome reflects several important cerebellar phenotypes observed in individuals with Down syndrome, including reduced total volume and reduced granule cell density. During development of the cerebellar cortex, granule cell precursors proliferate in response to the mitogen Sonic hedgehog. Granule cell precursors isolated from Ts65Dn mice proliferate less than control cells when treated with Sonic hedgehog, and a single dose of the Sonic hedgehog agonist, SAG, on the first day after birth rescues cerebellar morphology and some learning deficits in Ts65Dn mice. However, it is unknown which trisomic genes contribute to inhibition of Sonic hedgehog-dependent proliferation. Understanding how trisomy causes cerebellar hypoplasia and other developmental phenotypes is critical to establishing tractable drug targets for ameliorating Down syndrome- associated cognitive deficits. Therefore, we hypothesize that the overexpression of specific trisomic genes negatively regulates the endogenous Sonic hedgehog pathway during cerebellar development. We will address this hypothesis by overexpressing human chromosome 21 genes in a series of in vitro screens to identify candidates that inhibit Sonic hedgehog signaling. Candidates that are identified in these screens and are expressed in the developing cerebellum will be overexpressed in primary granule cell precursors. We will also optimize a technique for CRISPR/Cas9-mediated chromosome elimination in aneuploid cell lines derived from a mouse model of Down syndrome. Inducible chromosome elimination in a mouse model of Down syndrome would provide a method for detecting the developmental origins of phenotypes caused by trisomy. Together, successful completion of this project will yield new insights into how overexpression of human chromosome 21 genes dampen response to Sonic hedgehog during cerebellar development and will produce a powerful tool for identifying how dosage imbalance acts to produce phenotypes in Down syndrome.

项目摘要/摘要小脑发育不全可能导致唐氏综合症的综合征特异性认知和适应性缺陷，在美国影响超过25万个人。 TS65DN鼠标模型综合征反映了在唐氏综合症个体中观察到的几个重要小脑表型，包括总体积减小和颗粒细胞密度降低。在小脑皮层的开发过程中，颗粒细胞前体响应有丝分裂的声音刺猬增殖。颗粒细胞前体分离从TS65DN小鼠用声音刺猬处理时，小鼠比对照细胞少于对照细胞，单剂量 Sonic刺猬激动剂，SAG，出生后的第一天，拯救了小脑形态，有些 TS65DN小鼠的学习缺陷。但是，尚不清楚哪种三体基因有助于抑制声音刺猬依赖性增殖。了解三体性如何导致小脑发育不全和其他发育表型对于建立可疗法的药物靶标至关重要，以改善唐氏综合症 - 相关的认知缺陷。因此，我们假设特异性三体基因的过表达在小脑发育过程中，负面调节内源声音刺猬途径。我们将通过在一系列体外筛选中过度表达人类染色体21基因来解决这一假设确定抑制声音刺猬信号传导的候选人。在这些屏幕中确定的候选人在发育中的小脑中表达，将在原代颗粒细胞前体中过表达。我们将还可以优化一种在衍生的非整倍体细胞系中CRISPR/CAS9介导的染色体消除的技术来自唐氏综合症的小鼠模型。小鼠模型中的诱导染色体消除综合征将提供一种检测三体术引起的表型发育起源的方法。共同完成该项目将产生有关人类过度表达的新见解在小脑发育过程中，染色体21基因抑制对声波刺猬的反应，并会产生识别剂量不平衡如何在唐氏综合症中产生表型的强大工具。