Heterogeneity and bias of lineage negative progenitors in lung epithelial repair

肺上皮修复中谱系阴性祖细胞的异质性和偏差

• 批准号: 9261590
• 负责人: Andrew Vaughan
• 金额: $ 15.95万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2017-04-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9261590
• 关键词: Address; Affect; Alveolar; Anatomy; Area; Biological; Biological Assay; Biological Markers; Biological Process; Cell Differentiation process; Cell Transplantation; Cell model; Cells; Chronic lung disease; Coculture Techniques; Consensus; Critical Illness; Cues; Cyst; Cytokeratin; Data; Development; Disease Outcome; Distal; Employee Strikes; Epithelial; Epithelial Cells; Epithelial cyst; Epithelium; Foundations; Future; Gases; Heterogeneity; Homeostasis; Human; Immunodeficient Mouse; In Vitro; Individual; Influenza; Injury; Interstitial Lung Diseases; Knowledge; Location; Lung; Lung diseases; Maintenance; Mentors; Mesenchymal; Methodology; Modeling; Molecular; Mus; Natural regeneration; Organ; Organoids; Pathway interactions; Patients; Pharmacology; Phase; Phenotype; Population; Proliferating; Pulmonary Fibrosis; Regenerative response; Reporter; Respiratory physiology; Role; Signal Pathway; Signal Transduction; Sorting - Cell Movement; Stem cells; System; Testing; Transplantation; Type II Epithelial Receptor Cell; base; cell injury; cell type; genetic signature; in vivo; injured; insight; lung injury; lung regeneration; notch protein; novel; novel therapeutics; pneumocyte; predictive modeling; prevent; progenitor; programs; public health relevance; regenerative; repaired; response; response to injury; single cell analysis; stem; tissue regeneration; transcriptome; transcriptome sequencing; transcriptomics

 DESCRIPTION (provided by applicant): Project Summary/Abstract The epithelium of the distal lung performs the critical biological function of gas exchange and serves as a barrier to prevent access of deleterious airborne agents into the body. In order to maintain these functions the lung has an extensive ability to respond to injury and regenerate lost or damaged cells. Current models posit that epithelial repair can be attributed to cells expressing mature lineage markers. By contrast, we have recently defined the regenerative role of rare lineage-negative epithelial stem/progenitor (LNEP) cells present within normal distal lung. Orthotopic transplantation of LNEPs reveals a striking capacity for direct differentiation into type 2 pneumocytes and distal airway cells. However, after severe influenza injury, LNEPs activate a ΔNp63 and cytokeratin 5 (Krt5) remodeling program whereupon cells proliferate and migrate toward heavily injured alveolar areas. This pathway largely results in an abnormal epithelial barrier rather than type II cell differentiation. The dysplastic alveolar epithelial cysts result i part from ongoing excessive Notch signaling and are reminiscent of "honeycombing" cysts in fibrotic human lungs. Interestingly, transplantation of the total LNEP population demonstrates both bronchiolar and alveolar differentiation, whereas cells expressing low levels of Krt5 are heavily biased toward airway-like cystic expansion. Furthermore, principle component analysis of single cell transcriptomes indicates multiple subpopulations of cells. These observations suggest that heterogeneity within the LNEP population is a manifestation of lineage-primed subpopulations predisposed towards particular fates. This proposal seeks to address the biological significance of this heterogeneity with the following specific aims: 1) Test whether murine LNEPs consist of both unbiased and primed stem/progenitor cell populations. 2) Identify the human equivalent(s) of LNEPs and explore their role in human lung disease. 3) Define distinct signaling cues that modulate airway and alveolar regenerative responses of unbiased and primed LNEP subpopulations. These aims will utilize single cell RNA-Seq, lineage tracing, organoid culture, and orthotopic cell transplantation to interrogate cellular heterogeneity and regenerative dynamics with a high degree of tractability. These studies will lay the foundation for development of a quantitative and predictive model of lung epithelial injury responses. Such a model will inform future efforts to manipulate regenerative mechanisms in order to achieve better disease outcomes.

 描述（由申请人提供）：项目总结/摘要远端肺的上皮执行气体交换的关键生物学功能，并作为屏障防止有害的空气传播因子进入体内。为了维持这些功能，肺具有广泛的能力来响应损伤并再生丢失或受损的细胞。目前的模型认为，上皮修复可以归因于表达成熟谱系标志物的细胞。相比之下，我们最近已经确定了罕见的谱系阴性上皮干/祖细胞（LNEP）细胞的再生作用存在于正常远端肺。LNEPs的原位移植揭示了直接分化为2型肺细胞和远端气道细胞的惊人能力。然而，在严重的流感损伤后，LNEP激活Δ Np 63和细胞角蛋白5（Krt 5）重塑程序，于是细胞增殖并向严重损伤的肺泡区域迁移。该途径主要导致异常上皮屏障而不是II型细胞分化。发育不良的肺泡上皮囊肿部分地由持续的过度Notch信号传导引起，并且使人联想到纤维化的人肺中的“蜂窝状”囊肿。有趣的是，总LNEP群体的移植证明了细支气管和肺泡分化，而表达低水平Krt 5的细胞严重偏向于气道样囊性扩张。此外，单细胞转录组的主成分分析表明细胞的多个亚群。这些观察结果表明，异质性内的LNEP人口是一种表现的血统引发的亚群倾向于特定的命运。该提议旨在解决这种异质性的生物学意义，具有以下具体目的：1）测试鼠LNEP是否由无偏倚的和引发的干/祖细胞群体组成。2)确定LNEP的人体等效物并探索其在人类肺部疾病中的作用。3)定义不同的信号线索，调节气道和肺泡再生反应的公正和启动LNEP亚群。这些目标将利用单细胞RNA-Seq，谱系追踪，类器官培养和原位细胞移植来询问细胞异质性和高度易处理的再生动力学。这些研究将为建立肺上皮损伤反应的定量预测模型奠定基础。这样的模型将为未来操纵再生机制以实现更好的疾病结果的努力提供信息。