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（由适用提供）：项目摘要/摘要该盘状肺上皮执行气体交换的关键生物学功能，并作为防止有害空气载剂进入体内的障碍。为了维持这些功能，肺具有应对损伤和再生损失或受损细胞的广泛能力。当前模型确认上皮修复可以归因于表达成熟谱系标记的细胞。相比之下，我们最近定义了稀有谱系阴性上皮茎/祖细胞（LNEP）细胞的再生作用，存在于正常不同的肺中。 LNEPS的原位移植揭示了直接分化为2型气体细胞和远端气道细胞的惊人能力。然而，在严重影响之后，LNEPS激活了ΔNP63和细胞角蛋白5（KRT5）重塑程序，因此细胞扩散并朝着严重损伤的异质区域迁移。该途径在很大程度上导致异常上皮屏障，而不是II型细胞分化。发育不良的肺泡上皮囊肿会导致I部分持续过多的缺口信号传导，并想起纤维化人肺中的“蜂窝”囊肿。有趣的是，总LNEP种群的移植既表现出细支气管和肺泡分化，而表达较低水平KRT5的细胞则倾向于类似气道的囊性膨胀。此外，单细胞转录组的原理成分分析表明细胞的多个亚群。这些观察结果表明，LNEP种群中的异质性是偏见偏向于特定命运的谱系亚群的表现。该提案旨在以以下特定目的解决这种异质性的生物学性：1）测试鼠LNEP是否由无偏见和启动的茎/祖细胞群体组成。 2）确定LNEP的人类同等学历，并探索它们在人类肺部疾病中的作用。 3）定义不同的信号提示，以调节无偏和启动LNEP亚群的气道和肺泡再生反应。这些目的将利用单细胞RNA-seq，谱系跟踪，器官培养和原位细胞移植来询问具有高度易探性的细胞异质性和再生动力学。这些研究将奠定开发肺上皮损伤反应的定量和预测模型的基础。这样的模型将为未来的努力操纵再生机制，以实现更好的疾病结局。