Integrins in the Developing Lung

发育中的肺中的整合素

• 批准号: 10674710
• 负责人: Erin J Plosa
• 金额: $ 64.33万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10674710
• 关键词: 3-Dimensional; Adhesions; Basement membrane; Binding; Cell Differentiation process; Cell physiology; Cells; Cessation of life; Cilia; Collagen; Critical Pathways; Data; Defect; Development; Developmental Biology; ECM receptor; Epithelial Cells; Epithelium; Exhibits; Extracellular Matrix; Extracellular Matrix Proteins; Fetal Lung; Functional disorder; Gene Expression; Genes; Genetic; Hemidesmosomes; Histologic; Human; Impairment; In Vitro; Integrin Binding; Integrin alpha3beta1; Integrin alpha6beta4; Integrins; Intermediate Filaments; Keratin; Laminin; Ligands; Link; LoxP-flanked allele; Lung; Lung diseases; Minor; Morphogenesis; Mus; Mutation; Neonatal; Organ; Organogenesis; Pathway Analysis; Pathway interactions; Perinatal mortality demographics; Phenotype; Phosphorylation; Play; Primary Cell Cultures; Proliferating; Pulmonary Emphysema; Regulation; Reporting; Role; SHH gene; Signal Pathway; Signal Transduction; Structure; Testing; Tissues; Tracheal Epithelium; Transmission Electron Microscopy; airway epithelium; airway obstruction; bone morphogenetic protein receptors; cell behavior; cilium biogenesis; human disease; kinetosome; lung development; lung health; migration; novel; novel strategies; pulmonary hypoplasia; receptor; receptor expression; reconstitution; single-cell RNA sequencing; support network; transcription factor

PROJECT SUMMARY Human and murine lung development requires the coordinated efforts of the lung epithelium with the surrounding extracellular matrix (ECM), but the ECM-directed mechanisms that govern epithelial cell behavior in the lung remain undefined. In epithelial tissues, integrins serve as receptors for the basement membrane components collagen and laminins (LMs), with LMs being the most important ECM protein for lung organogenesis. Lung epithelial cells bind to LMs through integrins α3β1, α6β1, and α6β4. Recent studies reported that mutations in these integrins cause pulmonary hypoplasia or neonatal emphysema complicated by abnormal airways, suggesting they play a major role in human developmental lung diseases. To investigate the role of LM-binding integrins, we generated lung epithelial specific integrin deletions. Deletion of both the β1 and α6 subunits resulted in marked branching defects and early death. Deletion of α3 caused only minor airway branching disruption. β4 deficient mice exhibited normal branching but, surprisingly, were also perinatal lethal. The β4 histological examination was notable for proteinaceous material filling the airways and lack of cilia, similar to α6 deficient mice, suggesting their demise resulted from airway dysfunction. Pathway analysis of α6 deficient lung sequencing data revealed disruptions in BMP signaling, a critical pathway for airway branching. BMP receptor expression was increased in α6-null epithelial cells, but BMP target gene expression remained markedly reduced, implicating α6-containing integrins in regulation of the BMP pathway in the fetal lung. Consistent with loss of cilia in β4 deficient mice, β4-null epithelial cells exhibited reduced expression of transcription factors linked to MCC terminal differentiation. As a critical component of hemidesmosomes, α6β4 controls tight adhesion to the basement membrane and connects with the intracellular keratin intermediate filaments. Keratin also forms a support network apically for cilia, suggesting that α6β4 regulates keratin organization critical for terminal differentiation of MCCs in the lung. Taken together, these findings indicate that: 1) α6β1 is the principal integrin required for airway branching likely through BMP signaling and 2) α6β4 regulates terminal differentiation of MCCs. Based on preliminary data, we propose the hypothesis that α6-containing integrins are critical integrins for fetal lung development through regulation of BMP signaling during airway branching and terminal differentiation of multi-ciliated epithelial cells. AIM 1: Determine the mechanisms whereby α6-containing integrins regulate lung branching morphogenesis. AIM 2: Define the mechanisms whereby α6-containing integrins regulate BMP signaling during fetal lung development. AIM 3: Identify the role of α6β4 integrin in airway epithelial cell differentiation.

项目摘要 人类和鼠肺发育需要肺上皮与 围绕细胞外基质（ECM），但是控制上皮细胞行为的ECM指导机制 在上皮组织中，整联蛋白充当基底膜的受体 成分胶原蛋白和层粘连蛋白（LMS），LMS是肺最重要的ECM蛋白 器官发生。肺上皮细胞通过整联蛋白α3β1，α6β1和α6β4与LMS结合。最近的研究 据报道，这些整合素的突变引起肺动脉瘤或新生儿肺气肿的复杂性 异常气道，表明它们在人类发育性肺部疾病中起着重要作用。 为了研究LM结合素的作用，我们产生了肺上皮特异性整合素缺失。 β1和α6亚基的缺失导致了明显的分支缺陷和早期死亡。 α3的缺失 仅造成较小的气道分支破坏。 β4缺乏小鼠暴露了正常分支，但令人惊讶的是 他们也是围产期致死的。 β4组织学检查是填充蛋白质材料的知名度 气道和缺乏纤毛，类似于α6缺乏小鼠，这表明它们的灭亡是气道功能障碍引起的。 α6缺陷肺测序数据的途径分析揭示了BMP信号的中断，这是关键的 气道分支的途径。在α6-NULL上皮细胞中，BMP受体表达增加，但BMP 靶基因表达显着降低，暗示含α6的整联蛋白在调节 胎儿肺中的BMP途径。与β4缺陷小鼠中纤毛的损失一致，暴露于β4-null上皮细胞 与MCC末端分化有关的转录因子的表达降低。作为关键组成部分 hemidesmosomes，α6β4控制着对地下膜的紧密粘附，并与 角蛋白还顶端为纤毛构成了一个支持网络，这表明 α6β4调节角蛋白组织对于肺中MCC终末分化至关重要。在一起， 这些发现表明：1）α6β1是可能通过BMP分支所需的主要整合素 信号传导和2）α6β4调节MCC的末端分化。根据初步数据，我们提出了 假设含α6的整联蛋白是通过 在气道分支期间的BMP信号传导和多丝的终末分化的调节 上皮细胞。 AIM 1：确定含α6的整联蛋白调节肺分支的机制 形态发生。 AIM 2：定义含α6整联蛋白在胎儿期间调节BMP信号的机制 肺发育。 AIM 3：确定α6β4整合素在气道上皮细胞分化中的作用。