Deciphering the roles of COMPASS-related methyltransferases in intellectual and developmental disability

项目摘要 大约有1,000个基因与智力和发育障碍（IDD）有关，但目标是 缺乏治疗选择。尽管存在这种遗传异质性，但许多相关基因具有相似的功能， 这表明它们在共享机制上趋同。迫切需要确定潜在的趋同 机制，以开发治疗与IDD相关的基因的每个亚类。该提案的重点是 六个相关的染色质调节因子，以确定这些基因中引起IDD的突变是否会影响类似的 分子途径。这六种SET甲基转移酶（SETD 1A、SETD 1B、KMT 2A、KMT 2B、KMT 2C和KMT 2D）是由三种不同的SET甲基转移酶组成的。 KMT 2D）各自形成甲基化H3 K4的单独的COMPASS复合物。每个基因的单倍不足 会导致一种以智力障碍为特征的神经发育综合征。我的核心假设是 这些与COMPASS相关的甲基转移酶的突变会导致智力和发育障碍 通过H3 K4甲基化模式的改变导致的一组共享基因的失调。替代 假设IDD由非重叠基因组的广泛基因表达失调引起。的 我提出的目标将检验这两种假设，我将产生的数据将提供对机制的新见解 无论结果如何，都要驾驶IDD。 我将在人类诱导多能干细胞（iPSC）中使用一个强大的基于CRISPR干扰的平台， 敲除并研究这六个COMPASS相关基因。在目标1中，我将阐明失调的分子 通过转录组和表观基因组的COMPASS甲基转移酶的单倍不足途径 侧写这些数据将使我能够验证这样一个假设，即这些基因的缺失会导致类似的 基因集，并确定这些相似性是否可以解释共享的基因组结合位点。在目标2中， 我将在功能上表征COMPASS甲基转移酶的形态学和神经生理学效应 在人iPSC衍生的神经元上的单倍不足。这些实验将揭示共同的或不同的 在细胞和网络水平的签名，并将提供深入了解的病理生理学知识 残疾。这一建议意义重大，因为它将建立一个框架，阐明趋同机制 在未来的研究中，可以将其扩展到更广泛的基因组。我的奖学金提案还概述了 严格的培训计划集中在五个具体领域，以支持我的长期职业目标，成为一个 独立研究者：（1）确定有趣的研究问题并设计严格的实验;（2） 在口头报告、撰写论文和撰写研究基金方面进行有效的科学交流;（3）新颖的研究 技术，包括CRISPR方法，干细胞培养，钙成像和染色质分析;（4） 指导学生和与同事合作;（5）为独立职业做准备。通过 在Huda Zoghbi博士和Zhandong Liu博士的直接监督下，我将沉浸在一个非常合作的环境中。 和支持性的培训环境。

Project Summary Roughly 1,000 genes have been associated with intellectual and developmental disability (IDD), but targeted treatment options are lacking. Despite this genetic heterogeneity, many implicated genes have similar functions, suggesting they converge on shared mechanisms. There is a critical need to identify potential convergent mechanisms to develop therapeutics for each subclass of genes associated with IDD. This proposal focuses on six related chromatin regulators to determine whether IDD-causing mutations in these genes affect similar molecular pathways. These six SET methyltransferases (SETD1A, SETD1B, KMT2A, KMT2B, KMT2C, and KMT2D) each form a separate COMPASS complex that methylates H3K4. Haploinsufficiency of each gene causes a separate neurodevelopmental syndrome with intellectual disability as a feature. My central hypothesis is that mutations in these COMPASS-related methyltransferases cause intellectual and developmental disability through dysregulating a shared set of genes due to changes in H3K4 methylation patterns. The alternative hypothesis is that IDD results from broad gene expression dysregulation of non-overlapping gene sets. The proposed aims will test both hypotheses and the data I will generate will provide new insight into mechanisms driving IDD irrespective of the outcome. I will use a robust CRISPR interference-based platform in human induced pluripotent stem cells (iPSCs) to knockdown and study these six COMPASS-related genes. In Aim 1, I will elucidate dysregulated molecular pathways due to haploinsufficiency of COMPASS methyltransferases via transcriptomic and epigenomic profiling. These data will allow me to test the hypothesis that loss of these genes leads to dysregulation of similar gene sets and determine whether these similarities can be explained by shared genomic binding sites. In Aim 2, I will functionally characterize morphological and neurophysiological effects of COMPASS methyltransferase haploinsufficiency on human iPSC-derived neurons. These experiments will reveal either common or divergent signatures at the cellular and network levels and will provide insight into the pathophysiology of intellectual disability. This proposal is significant because it will establish a framework to elucidate convergent mechanisms in IDD that could be scaled to a broader set of genes in future studies. My fellowship proposal also outlines a rigorous training plan focused on five specific areas to support my long-term career goal of becoming an independent investigator: (1) identifying interesting research questions and designing rigorous experiments; (2) effective scientific communication in oral presentations, manuscript writing, and grant writing; (3) novel research techniques, including CRISPR methods, stem cell culture, calcium imaging, and chromatin profiling; (4) mentoring students and collaborating with colleagues; and (5) preparation for an independent career. Through direct supervision from Dr. Huda Zoghbi and Dr. Zhandong Liu, I will be immersed in an extremely collaborative and supportive training environment at Baylor College of Medicine.