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）： 项目摘要/摘要 远端肺的上皮执行气体交换的关键生物功能，并充当防止有害空气传播物质进入体内的屏障，以维持肺所具有的这些功能。对损伤做出反应并再生丢失或受损细胞的广泛能力认为，上皮修复可归因于表达成熟谱系标记的细胞。相比之下，我们最近定义了罕见谱系阴性的再生作用。正常远端肺中存在的上皮干/祖细胞 (LNEP) 的原位移植显示出直接分化为 2 型肺细胞和远端气道细胞的惊人能力。然而，在严重流感损伤后，LNEP 会激活 ΔNp63 和细胞角蛋白 5 (Krt5)。 ）重塑程序，细胞增殖并迁移到严重受损的肺泡区域，该途径很大程度上导致异常的上皮屏障。发育不良的肺泡上皮囊肿部分是由持续过度的Notch信号传导引起的，并且让人想起纤维化人肺中的“蜂窝状”囊肿，提示整个LNEP群体的移植显示出细支气管和肺泡细胞的分化，而表达低水平的 Krt5 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存在多个亚群。 LNEP 群体内的异质性是谱系引发的亚群倾向于特定命运的表现，该提案旨在通过以下具体目标解决这种异质性的生物学意义：1）测试小鼠 LNEP 是否由无偏和引发的干/祖细胞组成。 2) 识别 LNEP 的人类等效物并探索它们在人类肺部疾病中的作用 3) 定义调节气道和肺部疾病的独特信号线索。这些目标将利用单细胞 RNA 测序、谱系追踪、类器官培养和原位细胞移植来探究细胞异质性和高度可处理的再生动力学。开发肺上皮损伤反应的定量和预测模型，这种模型将为未来操纵再生机制的努力提供信息，以实现更好的疾病结果。