Prdm3/16 Regulate Chromatin Accessibility to Determine Alveolar Maturation

项目摘要 PRDMs调节染色质可及性以确定肺泡成熟。肺表面活性剂是一种 由AT 2（肺泡2型细胞）产生的脂质和蛋白质的复杂混合物，其分泌到肺泡 在呼吸周期中，减少表面张力和防止肺泡塌陷的空间。缺乏肺 表面活性剂是早产儿新生儿呼吸窘迫综合征（RDS）的发病机制之一， 导致成人急性肺损伤（ARDS）的发病机制。胎儿的肺会发生巨大的变化 在结构、细胞分化和基因表达方面， 出生后肺功能所需的蛋白质生产。虽然我们的实验室和其他人已经确定了基因， 转录调节因子和基因调控网络控制表面活性剂稳态，如何染色质 调节可接近性以使AT 1和AT 2细胞成熟和功能所必需的基因转录成为可能 仍然相对无法解释。缺乏有关控制染色质的分子机制的数据 出生前和出生期间激活关键转录因子及其靶点所需的可及性 牙槽修复本申请基于我们最近对PRDM 3的主要作用的鉴定， PRDM 16在调节肺泡成熟、重塑和肺发育所需的基因表达方面的作用 出生后的生存。PRDM 3/16是锌指、富含脯氨酸结构域的转录因子， 修饰调节整个基因组的染色质可及性的活性。我们已经证明，删除 胎儿呼吸道上皮细胞中的Prdm 3/16在出生时引起呼吸衰竭，显著损害表面活性剂 蛋白质生产我们将使用ATAC-Seq、Cut and Run和RNA-Seq来鉴定受 PRDM 3/16来推断PRDM蛋白在出生前与AT 2特异性基因相互作用的机制。在这 应用程序，我们将测试的假设，PRDM 3和PRDM 16在转录复合物相互作用 调节组蛋白的募集和控制AT 2细胞分化的染色质可及性， 在妊娠晚期和成年小鼠病毒诱导的肺损伤后再生期间的功能。我们 将鉴定和测试介导PRDM 3/16的结合伴侣和转录复合物的功能 活动PRDM 3/16在AT 2细胞、肺泡巨噬细胞和肺巨噬细胞中的基因调控网络、生理和生化作用 将在体内和体外鉴定结构和功能。拟议的研究代表了概念上的进步 关于肺泡上皮细胞分化和功能的分子控制，并将提供一个框架 用于开发未来的策略，以修改控制AT 2/AT 1细胞功能的表观遗传景观， 健康和疾病。 版本：9-3-21

PROJECT SUMMARY PRDMs regulate chromatin accessibility to determine alveolar maturation. Pulmonary surfactant is a complex mixture of lipids and proteins produced by AT2 (Alveolar Type 2 Cells) which is secreted into alveolar spaces to reduce surface tension and prevent alveolar collapse during the ventilatory cycle. Lack of pulmonary surfactant underlies the pathogenesis of neonatal respiratory distress syndrome (RDS) in preterm infants and contributes to the pathogenesis of acute lung injury (ARDS) in adults. The fetal lung undergoes dramatic changes in architecture, cell differentiation and gene expression in preparation for birth, increasing surfactant lipid and protein production required for postnatal lung function. While our laboratory and others have identified genes, transcriptional regulators, and gene regulatory networks controlling surfactant homeostasis, how chromatin accessibility is modulated to enable gene transcription necessary for AT1 and AT2 cell maturation and function remains relatively unexplained. Lacking are data regarding the molecular mechanisms controlling chromatin accessibility required for the activation of critical transcription factors and their targets before birth and during alveolar repair. The present application is based on our recent identification of the primary roles of PRDM3 and PRDM16 in regulation of genes critical for alveolar maturation, remodeling, and gene expression required for postnatal survival. PRDM3/16 are zinc finger, proline-rich domain-containing transcription factors with histone modifying activity regulating chromatin accessibility throughout the genome. We have shown that deletion of Prdm3/16 in fetal respiratory epithelial cells caused respiratory failure at birth, dramatically impairing surfactant protein production. We will use ATAC-Seq, Cut and Run, and RNA-Seq to identify gene loci regulated by PRDM3/16 to infer mechanisms by which PRDM proteins interact with AT2 specific genes before birth. In this application, we will test the hypothesis that PRDM3 and PRDM16 interact in transcriptional complexes regulating recruitment of histones and chromatin accessibility controlling AT2 cell differentiation and function in late gestation and during regeneration following viral-induced lung injury in adult mice. We will identify and test the functions of binding partners and transcriptional complexes mediating PRDM3/16 activity. The gene regulatory networks, physiologic and biochemical roles of PRDM3/16 on AT2 cells, alveolar structure and function will be identified in vivo and in vitro. The proposed studies represent conceptual advances regarding the molecular control of alveolar epithelial cell differentiation and function and will provide a framework for the development of future strategies to modify epigenetic landscapes controlling AT2/AT1 cell function in health and disease. Rev: 9-3-21