MOLECULAR MECHANISMS UNDERLYING INTELLECTUAL DISABILITY CAUSED BY MUTATIONS IN THE CHROMATIN MODIFIER KDM5C

项目摘要/摘要-研究项目 编码转录调节因子赖氨酸去甲基酶5C(KDM5C)的基因突变在 智障患者(ID)。而KDM5C功能突变的丧失与 ID是清楚的，KDM5C如何发挥功能来调节关键的神经元过程，因此， IDD机制的突变仍不清楚。这项建议的目标是了解 KDM5C调控的基因表达程序与内异症和附加症发生的关系 在患者身上观察到的并存特征。我们将通过汇集多个学科来实现这一目标 在互补的分析工具和模型系统方面具有专业知识的研究团队，以检验两个假设。 目的1验证使用KDM5C诱导的ID的人IPSC体外细胞模型将 结果确定了临床相关基因表达的变化和神经元功能缺陷。一 我们将使用的主要模型系统是IPSC衍生的脑有机化合物，它概括了结构和分子 胎儿大脑发育的方方面面，是用来确定胎儿大脑发育的根本原因的重要研究工具(S) 神经发育障碍。事实上，使用体外有机系统的分子和细胞研究使我们能够 在人体细胞环境中进行研究，而这在体内是不可能的。IPSCs和有机化合物将 来自两个来源：(1)来自新招募队列的KDM5C诱导的ID患者的细胞 (2)CRISPR-Cas9介导型 基因编辑以产生KDM5C零等位基因和已发表的缺失组蛋白的ID等位基因(KDM5CA388P) 使用通常开发的对照产生的现有IPSC品系的去甲基酶活性。我们将使用这个 结合形态、功能和多种OMICS方法的系统，以定义患者- KDM5C的相关突变。目的2检验以下假设：翻译效率的调节在 KDM5C的苍蝇同源基因的神经元在哺乳动物系统中是保守的，这一功能是重要的 用于认知。在这里，我们利用苍蝇和老鼠动物模型系统作为发现工具和 测试关于KDM5C突变对认知影响的可能贡献者的假设。因为其他人 遗传形式的ID改变了翻译，纠正这种缺陷在小鼠模型中显示出了希望 其他ID障碍，我们将测试改变的翻译是否类似地在小鼠模型中发挥关键作用 KDM5C诱导的ID。 这项工作意义重大，因为我们将确定人类KDM5C突变之间的病因学联系 和ID。拟议的研究在使用补充模型系统和 最先进的基因组学技术，如单细胞转录组学(scRNA-seq)。它在概念上也是 创新地提出了翻译在KDM5C诱导的ID中的作用。

PROJECT SUMMARY/ABSTRACT – RESEARCH PROJECT Mutations in the gene encoding the transcriptional regulator lysine demethylase 5C (KDM5C) are found in patients with intellectual disability (ID). While the direct link between loss of function mutations in KDM5C and ID is clear, how KDM5C functions to mediate critical neuronal processes, and therefore the consequence of mutations for mechanisms of IDD, remains unknown. The goal of this proposal is to understand the relationship between KDM5C-regulated gene expression programs and the occurrence of ID and additional comorbid features that are observed in patients. We will achieve this by bringing together a multi-disciplinary research team with expertise in complementary analytical tools and model systems to test two hypotheses. Aim 1 tests the hypothesis that the use of human iPSC-derived in vitro cell models of KDM5C-induced ID will result in the identification of clinically relevant gene expression changes and neuronal functional deficits. One key model system we will use is iPSC-derived cerebral organoids, which recapitulate structural and molecular aspects of fetal brain development and are a critical research tool used to define the underlying cause(s) of neurodevelopmental disorders. Indeed, molecular and cellular studies using in vitro organoid systems allow us to carry out studies in a human cell context that would simply not be possible in vivo. iPSCs and organoids will be generated from two sources: (1) Cells from patients with KDM5C-induced ID from a newly recruited cohort of individuals from which we are generating a genotype-phenotype database; (2) CRISPR-Cas9-mediated gene editing to generate a KDM5C null allele and a published ID allele (KDM5CA388P) that lacks histone demethylase activity using existing iPSC lines generated from typically developing controls. We will use this system to combine morphological, functional and multi-OMICS approaches to define the impact of patient- associated mutations in KDM5C. Aim 2 tests the hypothesis that the regulation of translation efficiency in neurons by the fly homolog of KDM5C is conserved in mammalian systems and that this function is important for cognition. Here we take advantage of fly and mouse animal model systems, both as discovery tools and to test hypotheses regarding possible contributors to the cognitive effects of mutations in KDM5C. Because other inherited forms of ID have altered translation and correcting this deficit has shown promise in mouse models of other ID disorders, we will test whether altered translation similarly plays a key role in a mouse model of KDM5C-induced ID. This work is significant because we will define the etiological links between mutations in human KDM5C and ID. The proposed studies are technologically innovative in the use of complementary model systems and state-of-the-art genomics techniques such as single cell transcriptomics (scRNA-seq). It is also conceptually innovative in proposing a role for translation in KDM5C-induced ID.