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

• 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
• 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

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.

项目摘要 哺乳动物呼吸系统是其正常功能的一部分，经历周期性的机械应变。肺 已经演变为灵活以适应这种菌株，这涉及节奏通胀和肺泡的放气。 有效的气体交换。多个细胞谱系包括肺泡小裂，包括1型牙槽（AT1）和 牙槽2（AT2）上皮细胞以及各种独特的间质细胞和内皮细胞类型。 AT1细胞 在跨内皮毛细血管上有效的气体交换需要，而AT2细胞产生 肺表面活性剂并充当分化为AT1细胞的兼职祖细胞。而大多数研究 机械转导的重点是间充质谱系的响应，上皮细胞的能力，在 尤其是肺肺泡内的人，面对这 连续和节奏的生物力学应变尚未得到很好的定义。使用多个遗传和生物物理 方法，我们提供了新的初步数据，表明细胞骨架 - 骨骼矩阵的丧失 通过AT1细胞中遗传，机械和化学扰动的相互作用，导致其快速重新编程 在体内进入AT2细胞。单细胞RNA-SEQ（SCRNA-SEQ）分析表明，这些重编程的AT2细胞是 与正常AT2细胞非常相似。 AT1细胞命运的损失伴随着椎板的坐标变化 相关的染色质结构域（LAD）组织，导致AT1或AT2特定基因座的隔离或释放 位于LAD坐在核外围。这种现象与牙槽的变化成反比 上皮细胞命运。重要的是，我们开发了一种新型的单方面机械卸载模型 来自肺部呼吸运动的周期性应变，表明这导致了深刻的重新编程 AT1进入AT2细胞。与这些新的初步数据一致，我们的实验室最近证明 在AT1的核中发现YAP/TAZ，但没有AT2细胞，对于维持AT1细胞命运至关重要 在整个小鼠的寿命中。 YAP/TAZ的丢失导致AT1细胞快速重编程为AT2细胞中的AT2细胞 没有伤害。由于yap/taz可以用作细胞中的细胞质机械转换器并运输 在肌动蛋白调节的细胞拉伸和应变时，我们的组合初步和已发表的数据表明 该机械转导的作用在AT1细胞中起着特定的作用，以维持稳态肺中的肺泡功能。 因此，我们已发表的初步数据提出了一个挑衅的假设，即肺已经发展为特定 表观遗传和转录机制，以正常的机械应变状态维持细胞命运 呼吸和这些途径在对损伤和疾病的反应中发生了改变。该提议汇集了 两个互补的实验室，在肺发育研究，表观遗传控制方面具有丰富经验 细胞命运以及对再生和疾病的固有含义，我们旨在解决未解决的关键 细胞命运调节肺发育和再生中的问题。