Identification, Isolation, and Reprogramming Alveolar Epithelial Progenitor Cells

描述（由申请人提供）：肺泡上皮细胞与许多重要的人类疾病密切相关，包括肺气肿、急性肺损伤和肺纤维化。在每一种情况下，产生新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现有技术的范围。虽然在鉴定和操作心脏和血液祖细胞方面已经取得了很大进展，但是与研究肺相关的几个重大挑战已经减缓了肺中祖细胞生物学的进展，包括其复杂的解剖结构、缓慢的内在周转率以及缺乏评估推定祖细胞发育潜力的移植测定。为了超越目前对肺发育和修复的研究的局限性，该应用程序将集中在远端气道和肺泡上皮的生物学上，汇集了三个具有不同专业知识但在上皮祖细胞生物学方面有重叠兴趣的研究小组。第一组由Ross Metzger领导，他最近发表了对胚胎小鼠肺形成期间气道分支模式的详细描述。这项工作提供了一个框架内，定位和定义的肺泡祖细胞在肺发育过程中出现的时间，并提出了重要的近端和远端上皮分化的新问题。由Zena Werb领导的第二个小组为肺发育问题带来了研究乳房发育和重塑的广泛记录，特别关注间充质对上皮祖细胞（重新）编程的影响以及可视化该过程的测定方法的开发。由PI及其同事领导的第三组正在创建谱系追踪试剂，以促进肺泡上皮祖细胞的识别和分离，允许祖细胞测定的明确解释，并提供一种探索环境线索（特别是细胞外基质）的能力的方法，以指导成人II型细胞向多种表型的编程。该项目的主要目标是开发分离和表征胚胎肺泡祖细胞的方法，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以验证和筛选祖细胞接合血管成分和形成肺泡上皮细胞的能力，组织.

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.