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.

项目摘要/摘要 近20年来，下呼吸道感染是全球第四大死亡原因，在 2019年随着新冠肺炎大流行的爆发，呼吸道感染迅速上升为导致 到目前为止，许多国家的死亡导致全球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损伤中恢复过来。然而，就像在许多情况下一样 在新冠肺炎案例中，干细胞并不总是能承担起损伤的负担。肺泡II型(AT2)细胞 肺的兼性干细胞，分泌表面活性物质并帮助气体交换。在损伤过程中，AT2细胞 通过增殖和分化为肺泡来修复损伤 I型(AT1)细胞，然后在上皮恢复时恢复到静止状态。AT2细胞背后的机制 可逆激活尚不清楚。为了更好地理解这一机制，我们模拟了小鼠的呼吸损伤。 通过一种被称为仙台病毒的小鼠副流感病毒。AT2细胞的谱系追踪与增殖 研究发现，AT2细胞不仅被激活以进行原位创伤修复，而且在 远离损坏的区域，具体到呼吸道和血管的边缘，以及 代表新生生长的组织。对感染小鼠的AT2细胞进行ATAC测序 AT2细胞增殖高峰，恢复后处于恢复期。AT2细胞获得 AP-1基序在损伤修复过程中的可及性，随后在恢复时失去AP-1基序的可及性。 这一建议的假设是AP-1转录调节AT2细胞的激活以诱导 肺损伤反应中的原位修复和从头修复。我们将首先确定时空 AT2细胞在感染过程中的活化通过对AT2细胞增殖和分化的谱系追踪 用光片显微镜检测，生成3D图像，用于破译是否建议原位和De 新星的激活区域确实是截然不同的。我们还将扰乱已知的呼吸道干细胞种群 有助于原位伤口修复，以研究AT2细胞在呼吸道时激活的区域特异性变化 援助中断(Aim1)。第二，我们将研究AT2细胞激活的调节机制 用块状ATAC和单细胞观察表观遗传随时间变化的动力学 多组测序。我们还将研究AP-1通过AT2细胞特异性条件性敲除 FosB检测其对AT2细胞激活和修复(AIM2)的影响。这项研究将有助于描述 原位和从头激活AT2细胞的新概念以及未发现的表观遗传学和 肺再生的转录调控。