Prdm3/16 Regulate Chromatin Accessibility to Determine Alveolar Maturation

项目总结 PRDM调节染色质的可及性，以确定肺泡的成熟。肺表面活性物质是一种 由肺泡2型细胞分泌到肺泡内的脂类和蛋白质的复杂混合物 空间，以降低表面张力和防止肺泡塌陷在换气周期。肺功能不全 表面活性物质在早产儿新生儿呼吸窘迫综合征(RDS)发病机制中的作用 在成人急性肺损伤(ARDS)的发病机制中起重要作用。胎儿的肺经历了戏剧性的变化 在建筑、细胞分化和基因表达方面为分娩做准备，增加表面活性物质脂质和 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实验室已经确定了基因， 转录调控和基因调控网络控制表面活性物质的动态平衡，染色质如何 可及性被调节以使AT1和AT2细胞成熟和功能所需的基因转录 相对来说还没有得到解释。缺乏关于控制染色质的分子机制的数据 关键转录因子及其靶标在出生前和出生期间激活所需的可及性 牙槽修补术。本申请是基于我们最近确定的PRDM3和PRDM3的主要作用 PRDM16在调节肺泡成熟、重塑和所需基因表达方面的关键基因 出生后的存活率。PRDM3/16是带有组蛋白的锌指、富含脯氨酸结构域的转录因子 调节整个基因组中染色质可及性的修饰活性。我们已经表明，删除 胎儿呼吸道上皮细胞中的Prdm3/16导致出生时呼吸衰竭，极大地损害表面活性物质 蛋白质生产。我们将使用ATAC-Seq、Cut and Run和RNA-Seq来识别受 PRDM3/16，以推断PRDM蛋白在出生前与AT2特定基因相互作用的机制。在这 应用，我们将检验PRDM3和PRDM16在转录复合体中相互作用的假设 调节组蛋白和染色质的募集控制AT2细胞的分化和 在成年小鼠病毒诱导的肺损伤后的妊娠晚期和再生过程中的作用。我们 将确定和测试介导PRDM3/16的结合伙伴和转录复合体的功能 活动。PRDM3/16对AT2细胞的基因调控网络及其生理生化作用 结构和功能将在体内和体外进行鉴定。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调控，将提供一个框架 为了开发未来的策略来修改控制AT2/AT1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