Type I IFN signaling during lung development in Down Syndrome-Multiome sequencing of human fetal and pediatric trisomy 21 lungs

摘要/摘要 21三体(T21)是人类最常见的染色体异常，每700名活产儿中就有1名受到影响， 导致唐氏综合症(DS)。虽然DS可以影响许多器官系统，但肺病和心脏病是 导致发病率和死亡率的主要原因。在患有DS的个体中报告了几种先天性肺畸形。 包括气道分支缺陷，分支数量减少25%，上呼吸道减少 肌肉紧张伴吞咽困难和/或支气管软化症。这些并发症会一直持续到成年，就像 而不是恶化，因此很可能是由于发育不足。 而儿童和成人DS患者的肺结构和功能异常 如上所述，定义这些异常的个体发育的数据有限。我们假设发展中的 差异可以在产前在T21肺开始，现在已经证明肺异常出现在 根据实验确定，大约70%的T21病例在怀孕16周时就开始了 在父母拨款中提出的。我们的单细胞RNAseq数据和免疫荧光染色证明 肺表面活性物质代谢途径上调与分化近端气道细胞数增加 标记(SCGB1A1和FOXJ1)。总而言之，这些发现有力地支持了其中一个假设 在父母资助中提出的，其中我们假设T21肺的早熟发育/分化为 与他们的年龄和性别相匹配的对照组。这些观察结果是符合的，即DS通常 被描述为早衰症。已经证明，这种加速衰老可能与 由于表观遗传调控失调而引起的全基因组扰动；然而，还没有研究调查 发育中的T21肺的表观遗传景观。因此，我们假设细胞和分子的异常 T21肺在子宫中启动，导致与表观遗传调节改变相关的早熟发育。 单细胞表观遗传学方法学的最新进展使我们能够同时检验这一假说 在相同的组织中，我们正在为父项目收集和分析。我们将使用多组测序 (单核RNAseq/ATACseq)以确定在晚期启动的细胞和分子异常 T21肺中胎儿发育的假腺体/小管早期。是一种表观遗传修饰 保存在子细胞中，我们还将确定单个细胞的基因调控网络的变化 出生前和出生后T21肺与非T21肺的水平，以进一步确定肺的个体发育 DS中观察到的异常。 这些研究有望提高我们对关键分子和细胞的理解。 差异，以及控制T21发育肺缺陷的机制。它的创新方面 工作可能在刺激额外活动方面产生巨大的整体影响，从而导致理解方面的进展 肺异常的DS和促进翻译潜力的治疗。

Summary/Abstract Trisomy 21 (T21) is the most common human chromosomal anomaly, affecting 1 in 700 live births, resulting in Down Syndrome (DS). Although DS can affect many organ systems, lung and heart disease are the leading causes of morbidity and mortality. Several congenital lung anomalies are reported in individuals with DS including airway branching defects, with a 25% decrease in the number of branches and reduced upper airway muscle tone with dysphagia and/or bronchomalacia. These complications remain constant into adulthood, as opposed to becoming exacerbated, and are hence likely due to developmental insufficiency. While abnormal pulmonary structure and function in pediatric and adult individuals with DS has been described, there is limited data defining the ontogeny of these abnormalities. We postulated that developmental differences could initiate prenatally in T21 lungs and have now demonstrated pulmonary anomalies arise in approximately 70% of T21 cases starting as early as 16 weeks gestation, as determined from experiments proposed in the parent grant. Our single cell RNAseq data and immunofluorescent stainings have demonstrated upregulation of the surfactant metabolism pathway and increased cell number of differentiated proximal airway markers (SCGB1A1 and FOXJ1) respectively. Altogether these findings strongly support one of the hypotheses proposed in the parent grant, where we postulate precocious development/differentiation in the T21 lungs as compared to their age and sex matched controls. These observations are fitting being that DS is generally described as a progeroid syndrome. It has been demonstrated that this accelerated aging may be associated to genome wide perturbation due to dysregulated epigenetic regulation; however, no studies have investigated the epigenetic landscape of the developing T21 lung. Thus, we hypothesize cellular and molecular abnormalities in T21 lungs initiate in utero, resulting in precocious development associated with altered epigenetic regulation. Recent advances in single cell epigenetic profiling methodology allow us to simultaneously test this hypothesis in the same tissues we are collecting and analyzing for the parent project. We will use multiome sequencing (single nuclear RNAseq/ATACseq) to determine the cellular and molecular abnormalities initiated during the late pseudoglandular/early canalicular stages of fetal development in T21 lungs. Being that epigenetic modifications are preserved in daughter cells, we will also determine alterations in gene regulatory networks at the single cell level between prenatal and postnatal T21 lungs vs non-T21 lungs, to further define the ontogeny of pulmonary anomalies observed in DS. These studies have the promise to improve our understanding of the key molecular and cellular differences, and the mechanisms controlling defects in T21 developing lungs. The innovative aspects of this work are likely to have great overall impact in stimulating additional activity leading to progress on understanding lung anomalies in DS and facilitate the translational potential for therapies.