Mechanical signaling through the nuclear membrane in lung alveolar health

通过核膜的机械信号传导影响肺泡健康

基本信息

批准号：
10677169
负责人：
EDWARD E MORRISEY
金额：
$ 79.08万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-06-01 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10677169
关键词：
3-Dimensional Actins Acute Lung Injury Address Adult Agreement Alveolar Alveolus Architecture Biomechanics Blood capillaries Breathing Cell Fate Control Cell Lineage Cell Nucleus Cells Chemicals Chromatin Collaborations Complex Cytoplasm Cytoskeleton Data Disease Endothelial Cells Endothelium Epigenetic Process Epithelial Cells Extracellular Matrix Gases Genes Genetic Genetic Transcription Genome Health Homeostasis In Vitro Injury Laboratories Ligation Longevity Lung Manuscripts Mechanics Mesenchymal Modeling Movement Mus Natural regeneration Nuclear Nuclear Envelope Pathway interactions Periodicity Play Positioning Attribute Principal Investigator Publishing Pulmonary Surfactants Pulmonary alveolar structure Recording of previous events Research Personnel Respiration Respiratory System Role Stretching Technology alveolar epithelium biophysical techniques cell type experience flexibility genetic approach genome-wide in vivo lung development lung regeneration mechanical signal mechanotransduction novel prevent progenitor response response to injury single-cell RNA sequencing

项目摘要

PROJECT SUMMARY The mammalian respiratory system undergoes cyclical mechanical strain as part of its normal function. Lungs have evolved to be flexible to adapt to this strain, which involves rhythmic inflation and deflation of the alveoli for efficient gas exchange. Multiple cell lineages comprise the alveolar niche including alveolar type 1 (AT1) and alveolar type 2 (AT2) epithelial cells as well as various unique mesenchymal and endothelial cell types. AT1 cells are required for efficient gas exchange across the endothelial capillary plexus while AT2 cells generate pulmonary surfactant and act as facultative progenitors that differentiate into AT1 cells. While most studies on mechanotransduction have focused on the response of mesenchymal lineages, the ability of epithelial cells, in particular those within the lung alveoli, to respond to and maintain their identity and function in the face of this continuous and rhythmic biomechanical strain has not been well defined. Using multiple genetic and biophysical approaches, we present new preliminary data demonstrating that loss of cytoskeletal-extracellular matrix interactions via genetic, mechanical and chemical perturbations in AT1cells, leads to their rapid reprogramming into AT2 cells in vivo. Single cell RNA-seq (scRNA-seq) analysis shows that these reprogrammed AT2 cells are very similar to normal AT2 cells. Loss of AT1 cell fate is accompanied by coordinate changes in lamina- associated chromatin domain (LAD) organization, causing sequestration or release of AT1 or AT2 specific loci located in LAD sat the nuclear periphery. This phenomenon inversely correlates to the changes in alveolar epithelial cell fate. Importantly, we have developed a novel model of unilateral mechanical unloading of the cyclical strain from breathing movements in the lungs and show that this causes a profound reprogramming of AT1 into AT2 cells. In agreement with these new Preliminary Data, our laboratories recently demonstrated that Yap/Taz are found in the nucleus of AT1, but not AT2cells, and are essential for maintaining AT1 cell fate throughout the lifespan of mice. Loss of Yap/Taz results in a rapid reprogramming of AT1 cells into AT2 cells in the absence of injury. Since Yap/Taz can function as cytoplasmic mechanotransducers in cells and translocate to the nucleus upon actin-regulated cell stretch and strain, our combined preliminary and published data suggest that mechanotransduction plays a specific role in AT1cells to maintain alveolar function in the homeostatic lung. Thus, our published and preliminary data raise a provocative hypothesis that the lung has evolved specific epigenetic and transcriptional mechanisms to maintain cellular fate in the face of mechanical strain from normal respiration and these pathways are altered in the response to injury and disease. This proposal brings together two complementary laboratories with extensive experience in the study of lung development, epigenetic control of cell fate, and the inherent implications for regeneration and disease and we aim to address key unanswered questions in cell fate regulation in lung development and regeneration.

项目概要作为其正常功能的一部分，哺乳动物的呼吸系统会经历周期性的机械应变。肺已经进化到能够灵活地适应这种压力，这涉及肺泡的有节奏的膨胀和收缩有效的气体交换。多种细胞谱系组成肺泡生态位，包括 1 型肺泡 (AT1) 和肺泡 2 型 (AT2) 上皮细胞以及各种独特的间充质和内皮细胞类型。 AT1细胞 AT2 细胞生成时，需要通过内皮毛细血管丛进行有效的气体交换肺表面活性物质并充当分化为 AT1 细胞的兼性祖细胞。虽然大多数研究关于机械转导重点关注间充质谱系的反应、上皮细胞的能力、特别是肺泡内的肺泡，面对这种情况做出反应并维持其身份和功能连续和有节奏的生物力学应变尚未得到很好的定义。利用多种遗传和生物物理方法，我们提出了新的初步数据，证明细胞骨架细胞外基质的损失通过 AT1 细胞中的遗传、机械和化学扰动相互作用，导致其快速重编程进入体内AT2细胞。单细胞 RNA-seq (scRNA-seq) 分析表明这些重编程的 AT2 细胞与正常 AT2 细胞非常相似。 AT1细胞命运的丧失伴随着层板的坐标变化相关染色质结构域 (LAD) 组织，导致 AT1 或 AT2 特定位点的隔离或释放位于LAD 位于核外围。这种现象与肺泡的变化呈负相关。上皮细胞的命运。重要的是，我们开发了一种单边机械卸载的新模型肺部呼吸运动产生的周期性应变，并表明这会导致肺部的深刻重新编程 AT1细胞转化为AT2细胞。与这些新的初步数据一致，我们的实验室最近证明： Yap/Taz 存在于 AT1 细胞的细胞核中，但不存在于 AT2 细胞的细胞核中，对于维持 AT1 细胞的命运至关重要贯穿小鼠的整个生命周期。 Yap/Taz 缺失导致 AT1 细胞快速重编程为 AT2 细胞没有受伤。由于 Yap/Taz 可以在细胞中充当细胞质机械转导器并易位肌动蛋白调节的细胞拉伸和应变时对细胞核的影响，我们综合的初步数据和已发表的数据表明机械转导在 AT1 细胞中发挥着特定作用，以维持肺部稳态的肺泡功能。因此，我们发表的初步数据提出了一个具有争议性的假设，即肺已经进化出了特定的表观遗传和转录机制在面对正常机械应变时维持细胞命运呼吸和这些途径在对损伤和疾病的反应中发生改变。该提案汇聚了两个互补的实验室，在肺发育、表观遗传控制研究方面拥有丰富的经验细胞命运以及对再生和疾病的内在影响，我们的目标是解决关键的未解答的问题肺发育和再生中细胞命运调控的问题。