Coding and Noncoding RNA Contributions to 22q11.2 Deletion Syndrome

项目摘要/摘要 22q11.2缺失综合征(22q11.2del)是已知的最常见的人类微缺失综合征， 影响到约1/4000人。大多数患者在一份染色体上有3Mb的缺失 22q11.2，导致107多个基因单倍性缺失，46个蛋白质编码，其余 非编码RNA和假基因。有这种缺失的孩子出生时可能会有一系列先天性 通常包括三种发育相关的异常：胸腺发育不全， 先天性心脏病(CHD)和甲状旁腺功能减退症。大约60%-70%的患者有 一种免疫缺陷，由发育不良的胸腺输出的T细胞减少引起，临床上常为 被称为患有迪乔治综合征。导致缺陷的潜在机制 胸腺组织的形成/模式仍然知之甚少。我们的结果是在 这笔赠款的前一个周期表明，神经脊来源的间充质细胞存在缺陷， 它们形成胸腺被膜和血管，并调节胸腺的扩张。在我们的第一次 目的：咽部器官发育异常可导致骨质疏松症 胸腺发育不全将被确定。具体地说，神经脊来源的间充质的作用 将研究调节胸腺发育和扩张的细胞。胚胎胸腺 来自小鼠模型的22q11.2del将用于重组胎儿胸腺器官培养，以确定 间充质细胞在胸腺扩张过程中的作用。RNA测序方法， 包括单细胞RNA测序将用于确定间充质转录本是什么 参与了这一过程。这些实验将与人类的特征相补充 来自22q11.2del患者和正常对照的胸腺。在人类中，22q11.2del和 在小鼠模型中，出生后存在miRNA失调现象。在目标2中，我们将探索 这些miRNA变化的后果使用了对人类和 不同的鼠标型号。这将揭示miRNAs的失调是否会影响免疫 与胸腺有关的功能。这两个目标的结果将使我们能够更好地发展 在导致胸腺发育不良的各种临床环境中恢复胸腺功能的策略 组织。

Project Summary/Abstract 22q11.2 deletion syndrome (22q11.2del) is the most com~mon human microdeletion syndrome known, affecting some 1/4000 individuals. Most patients have a 3 Mb deletion on one copy of chromosome 22q11.2, resulting in a haploinsufficiency of over 107 genes, 46 protein coding and the remainder noncoding RNAs and pseudogenes. Children born with this deletion can have a range of congenital anomalies that often include three that are developmentally linked; hypoplasia of the thymus, congenital heart defects (CHD), and hypoparathyroidism. Approximately 60-70% of the patients have an immunodeficiency due to reduced T cell output from a hypoplastic thymus and are often clinically referred to as having DiGeorge syndrome. The underlying mechanisms causing the defective formation/patterning of the thymic tissue remains poorly understood. Our results, obtained during the previous cycle of this grant, suggest a defect among the neural crest derived mesenchymal cells, which form the thymic capsule and vasculature and regulate the expansion of the thymus. In our first aim, the developmental abnormalities of the pharyngeal apparatus leading to the formation of a hypoplastic thymus will be determined. Specifically, the role of the neural crest-derived mesenchymal cells in regulating the development and expansion of the thymus will be studied. Embryonic thymii from mouse models of 22q11.2del will be used in reaggregate fetal thymic organ cultures to define the role of mesenchymal cells in the process of thymus expansion. RNA sequencing approaches, including single cell RNA sequencing will be used to determine what mesenchymal transcripts are involved in this process. These experiments will be complemented with a characterization of human thymii from 22q11.2del patients and normal controls. In humans with 22q11.2del along with the mouse models, there is a post-natal miRNA dysregulation noted. In aim 2, we will explore the consequence of these miRNA changes using a combination of longitudinal studies in humans and diverse mouse models. This will reveal whether the dysregulation of miRNAs impacts immune functions pertaining to the thymus. Results from the two aims will enable us to develop better strategies for restoring thymus functions in various clinical settings resulting in the hypoplasia of this tissue.