AP-1 as a transcriptional regulator of AT2 cell reversible activation during lung injury response

AP-1 作为肺损伤反应期间 AT2 细胞可逆激活的转录调节因子

• 批准号: 10535199
• 负责人: ANNE LYNCH
• 金额: $ 4.68万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-20 至 2025-09-19
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10535199
• 关键词: 3-Dimensional; ATAC-seq; Acute Lung Injury; Address; Alveolar; Alveolar Cell Type I; Area; Benchmarking; COVID-19; COVID-19 pandemic; Cause of Death; Cell Death; Cell Differentiation process; Cell Proliferation; Cells; ChIP-seq; Chemical Injury; Chromatin; Complement; Complement Activation; Country; Data; Detection; Distal; Epigenetic Process; Epithelial; FOSB gene; Gases; Genetic Transcription; Genomic approach; Goals; Growth; Heterogeneity; In Situ; Infection; Inhalation; Injury; Intervention; Kinetics; Label; Light; Lobe; Lower Respiratory Tract Infection; Lung; Lung Adenocarcinoma; Lung diseases; Malignant neoplasm of lung; Maps; Mediating; Microscopy; Modeling; Molecular; Mus; Natural regeneration; Nature; Nuclear; Persons; Phase; Pneumonectomy; Poison; Proliferating; Recovery; Respiratory Tract Infections; Risk; Role; Running; STEM field; Sendai virus; Testing; Three-Dimensional Image; Time; Tissues; Toxin; Transcription Factor AP-1; Transcriptional Regulation; Viral; Virus Diseases; XCL1 gene; alveolar epithelium; alveolar type II cell; combat; conditional knockout; epigenetic regulation; epigenomics; epithelial injury; genetic approach; imaging approach; injured airway; injury and repair; injury burden; lung injury; lung lobe; lung regeneration; member; mouse model; novel; parainfluenza virus; pathogen; repaired; response to injury; single cell analysis; spatiotemporal; stem cell biology; stem cell function; stem cell population; stem cells; surfactant; tissue regeneration; tissue repair; training opportunity; wound healing

PROJECT SUMMARY/ABSTRACT Lower respiratory infections were the fourth leading cause of death worldwide for nearly twenty years, and in 2019 with the onset of the COVID-19 pandemic, respiratory infections quickly rose to the leading cause of death in many countries killing over 5 million people worldwide thus far. Our lungs are equipped with stem cells to help us recover from lung related injury caused by inhaling toxins and pathogens. However, like in many COVID-19 cases, the stem cells cannot always handle the injury burden. Alveolar type II (AT2) cells are facultative stem cells of the lung that secrete surfactant and aid with gas exchange. During injury, AT2 cells withdraw from homeostatic quiescence to repair damage through proliferation and differentiation into alveolar type I (AT1) cells, then revert to quiescence when the epithelium is restored. The mechanism behind AT2 cell reversible activation is unclear. To better understand this mechanism, we modeled respiratory injury in mice through a murine parainfluenza virus known as Sendai virus. Lineage tracing of AT2 cells and proliferation revealed that AT2 cells not only activate to perform in situ wound repair, but also cluster and proliferate at regions away from damage, specific to the edges of airways and vessels, as well as the most distal border of the tissue, representing de novo growth. ATAC-sequencing was performed on AT2 cells from infected mice at the peak of AT2 cell proliferation and in the recovery phase after returning to quiescence. AT2 cells gained accessibility of AP-1 motifs during injury repair and subsequently lost accessibility for AP-1 motifs at recovery. The hypothesis of this proposal is that AP-1 transcriptionally regulates AT2 cell activation to induce both in situ and de novo repair during lung injury response. We will first identify the spatiotemporal activation of AT2 cells during infection through lineage tracing AT2 cell proliferation and differentiation for detection with light sheet microscopy to generate 3D images for deciphering if the proposed in situ and de novo regions of activation are truly distinct. We will also perturb an airway stem cell population known to contribute to in situ wound repair to study region specific changes in AT2 cell activation when airway assistance is disrupted (Aim1). Second, we will investigate the regulatory mechanism in AT2 cell activation by looking at the kinetics of epigenetic change over time through injury response with bulk ATAC and single-cell mutiome-sequencing. We will also examine the role of AP-1 through AT2 cell specific conditional knockout of FOSB to examine its impact on AT2 cell activation and repair (Aim2). This study will help characterize the novel concept of in situ and de novo AT2 cell activation as well as the undiscovered epigenetic and transcriptional regulation of lung regeneration.

项目总结/摘要 近二十年来，下呼吸道感染是全球第四大死亡原因， 2019年，随着COVID-19大流行的爆发，呼吸道感染迅速上升为导致 许多国家的死亡，迄今为止，全世界有500多万人死亡。我们的肺里有干细胞 帮助我们从吸入毒素和病原体引起的肺部损伤中恢复过来。然而，就像许多 在COVID-19病例中，干细胞不能总是处理损伤负担。肺泡II型（AT 2）细胞是 分泌表面活性剂并帮助气体交换的肺的兼性干细胞。在损伤过程中，AT 2细胞 从稳态静止中退出，通过增殖和分化成肺泡细胞来修复损伤 I型（AT 1）细胞，然后当上皮恢复时恢复静止。AT 2细胞的机制 可逆活化尚不清楚。为了更好地理解这一机制，我们模拟了小鼠呼吸道损伤 一种叫做仙台病毒的鼠副流感病毒AT 2细胞的谱系追踪和增殖 揭示AT 2细胞不仅激活进行原位伤口修复，而且在伤口愈合时聚集和增殖。 远离损伤的区域，特定于气道和血管的边缘，以及 组织，代表从头生长。ATAC-测序在来自感染小鼠的AT 2细胞上进行， AT 2细胞增殖高峰期和恢复静止期。AT 2细胞获得 在损伤修复过程中AP-1基序的可接近性，随后在恢复时失去AP-1基序的可接近性。 该提议的假设是AP-1转录调节AT 2细胞活化以诱导细胞凋亡。 在肺损伤反应期间原位和从头修复。我们将首先确定时空 通过谱系追踪AT 2细胞增殖和分化， 用光片显微镜进行检测，以生成3D图像，用于破译是否建议在原位和deb 激活的新区域是完全不同的。我们还将干扰已知的气道干细胞群， 有助于原位伤口修复，以研究气道损伤时AT 2细胞活化的区域特异性变化， 援助中断（目标1）。其次，我们将通过以下方法研究AT 2细胞活化的调控机制： 通过大量ATAC和单细胞损伤反应观察表观遗传变化随时间的动力学 多基因组测序我们还将研究AP-1通过AT 2细胞特异性条件性敲除的作用。 FOSB检查其对AT 2细胞活化和修复的影响（Aim 2）。这项研究将有助于描述 原位和从头AT 2细胞活化的新概念以及未发现的表观遗传和 肺再生的转录调控。