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 哺乳动物呼吸系统作为其正常功能的一部分经历周期性机械应变。肺 已经进化成灵活的，以适应这种压力，这涉及到有节奏的充气和放气的肺泡， 高效的气体交换。多种细胞谱系构成肺泡生态位，包括肺泡1型（AT 1）和 肺泡2型（AT 2）上皮细胞以及各种独特的间充质和内皮细胞类型。AT 1细胞 当AT 2细胞产生时，需要通过内皮毛细血管丛进行有效的气体交换 肺表面活性剂，并作为兼性祖细胞分化成AT 1细胞。虽然大多数关于 机械转导集中在间充质谱系的反应，上皮细胞的能力， 特别是那些在肺泡内，以响应和保持他们的身份和功能，在面对这一点， 连续的和有节奏的生物力学应变还没有很好地定义。利用多种基因和生物物理 方法，我们提出了新的初步数据表明，细胞外基质的损失， 通过遗传，机械和化学扰动在AT 1细胞中的相互作用，导致其快速重编程 转化为AT 2细胞。单细胞RNA-seq（scRNA-seq）分析显示，这些重编程的AT 2细胞是 与正常的AT 2细胞非常相似。AT 1细胞命运的丧失伴随着纤层的协调变化。 相关染色质结构域（LAD）组织，导致AT 1或AT 2特异性位点的隔离或释放 位于前降支核周。这种现象与肺泡上皮细胞的变化呈负相关， 上皮细胞命运重要的是，我们已经开发了一种新的模型，单边机械卸载的 肺中呼吸运动的周期性应变，并表明这会导致肺细胞的深刻重新编程。 AT 1转化为AT 2细胞。与这些新的初步数据一致，我们的实验室最近证明， 雅普/Taz存在于AT 1细胞的细胞核中，但不存在于AT 2细胞的细胞核中，并且对于维持AT 1细胞的命运是必需的 在老鼠的一生中。雅普/Taz的缺失导致AT 1细胞快速重编程为AT 2细胞， 没有受伤。由于雅普/Taz可以作为细胞内的细胞质机械转换器， 在肌动蛋白调节的细胞拉伸和应变后，我们的初步和已发表的数据表明， 机械传导在AT 1细胞中起着特殊的作用，以维持稳态肺中的肺泡功能。 因此，我们发表的和初步的数据提出了一个挑衅性的假设，即肺已经进化出特异性的 表观遗传和转录机制，以维持细胞的命运，在面对机械应变从正常 这些途径在对损伤和疾病的反应中发生改变。该提案汇集了 两个互补的实验室，在肺发育研究、表观遗传控制 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悬而未决的问题， 肺发育和再生中的细胞命运调节问题。