Identification, Isolation, and Reprogramming Alveolar Epithelial Progenitor Cells

描述（由申请人提供）：肺泡上皮在许多重要的人类疾病中起重要作用，包括肺气肿、急性肺损伤和肺纤维化。在这些疾病中，产生新的肺泡上皮的能力将具有巨大的潜在治疗价值，但这样的项目仍然超出了当前技术的范围。尽管在鉴定和操纵心脏和血液祖细胞方面已经取得了很大进展，但肺部祖细胞生物学的进展一直受到与肺研究相关的几个重大挑战的影响，包括其复杂的解剖结构、缓慢的内在周转率，以及缺乏移植试验来评估假定的祖细胞的发育潜力。为了突破当前肺发育和修复研究的局限性，本申请将重点关注远端气道和肺泡上皮的生物学，将三个研究小组聚集在一起，他们在上皮祖细胞生物学方面具有不同的专业知识，但兴趣重叠。第一个小组由Ross Metzger领导，他最近发表了关于胚胎小鼠肺形成过程中气道分支模式的详细描述。这项工作为定位和确定肺发育过程中肺泡祖细胞出现的时间提供了一个框架，并提出了关于近端和远端上皮分化的重要新问题。第二组，由Zena Werb领导，带来了广泛的记录，研究乳房发育和重塑肺发育的问题，特别关注间质对上皮祖细胞（再）编程的影响，并开发了可视化这一过程的检测方法。第三组，由PI及其同事领导，正在创建谱系追踪试剂，以促进肺泡上皮祖细胞的鉴定和分离，允许祖细胞测定的明确解释，并提供一种方法来探索环境线索的能力，特别是细胞外基质，以指导成年II型细胞向多种表型的编程。该项目的主要目标是开发胚胎肺泡细胞祖细胞的分离和表征方法，比较这些细胞与成人II型细胞的基因表达和发育潜力，阐明具有祖细胞潜力的成人II型细胞重编程的线索，并建立体内移植试验来验证和筛选祖细胞参与血管元件并形成肺泡组织的能力。

DESCRIPTION (provided by applicant): The pulmonary alveolar epithelium is prominently involved in a number of important human diseases, including emphysema, acute lung injury, and pulmonary fibrosis. In each of these conditions the capacity to generate new alveolar epithelium would be of great potential therapeutic value, but such a project remains beyond the reach of current technology. Although much progress has been made in identifying and manipulating cardiac and blood progenitor cells, progress on progenitor cell biology in the lung has been slowed by several significant challenges associated with studying the lung, including its complex anatomical structure, slow intrinsic rate of turnover, and the absence of a transplantation assay to assess the developmental potential of putative progenitor cells. In order to move beyond the limitations of current research into lung development and repair, this application will focus on the biology of the distal airway and alveolar epithelium, bringing together three investigative groups with different expertise but overlapping interests in epithelial progenitor cell biology. The first group is led by Ross Metzger, who generated the recently published detailed description of the pattern of airway branching during embryonic mouse lung formation. This work provides a framework within which to locate and define the time of appearance of alveolar progenitor cells during lung development, and raises important new questions about proximal and distal epithelial differentiation. The second group, led by Zena Werb, brings an extensive record of studying breast development and remodeling to the issues of lung development, with particular focus on the influence of the mesenchyme on epithelial progenitor cell (re)programming and the development of assays to visualize this process. The third group, led by the PI and colleagues, is creating lineage tracing reagents to facilitate the identification and isolation of alveolar epithelial progenitors, allow for the unambiguous interpretation of progenitor cell assays, and provide a means to explore the capacity of environmental cues, especially the extracellular matrix, to direct programming of adult type II cells toward multiple phenotypes. The major objectives of the project are to develop methods for the isolation and characterization of embryonic alveolar cell progenitors, compare the gene expression and developmental potential of these cells with adult type II cells, elucidate cues that reprogram adult type II cells with progenitor potential, and establish an in vivo transplantation assay to validate and screen for the capacity of progenitors to engage vascular elements and form alveolar tissue.