Investigating the role of mesenchymal R-Spondin2 during human lung development

项目摘要 哺乳动物呼吸系统的发育受复杂的相互信号事件的调节， 位于气道上皮细胞和周围的间充质细胞之间。尽管肺部 间充质是细胞类型的家园，在发育过程中提供关键信号， 肺间充质中特定细胞类型的功能定义不清，特别是在人类 发展为了探究发育中的人肺中间充质细胞的异质性，我们的实验室 在妊娠8-22周的多个人肺样品上进行单细胞RNA测序。 使用细胞聚类的方法，我们确定了一个间充质细胞群体高度富集的表达 WNT激动剂R-Spondin 2（RSPO 2）。引人注目的是，这种基因的突变会导致严重的肺发育不全， 人类我的共荧光原位杂交（FISH）和免疫荧光（IF）数据从人肺 组织切片显示RSPO 2在增殖的远端上皮祖细胞附近表达， RSPO 2受体LGR 5几乎只在上皮祖细胞中表达。这些数据 提示RSPO 2+间充质细胞可能在调节上皮祖细胞过程中起关键作用， 人肺发育该提案的目标是：1）询问间充质细胞异质性， 功能的背景下，上皮祖细胞的调节，在发展中的人肺和2）解释了一个 RSPO 2+间充质细胞在人肺发育过程中的功能作用。

PROJECT ABSTRACT Mammalian respiratory system development is regulated by complex reciprocal signaling events that take place between the epithelial cells lining the airways and the surrounding mesenchymal cells. Despite the lung mesenchyme being home to cell types that provide crucial signals during development, the identity and function of specific cell types in the lung mesenchyme are poorly defined, especially in the context of human development. To interrogate mesenchymal cell heterogeneity in the developing human lung, our lab has conducted single cell RNA sequencing on multiple human lung samples spanning 8-22 weeks of gestation. Using cell-clustering approaches, we identified a mesenchymal cell population highly enriched for expression of the WNT agonist R-Spondin2 (RSPO2). Strikingly, mutations in this gene cause severe lung aplasia in humans. My co-fluorescent in situ hybridization (FISH) and immunofluorescence (IF) data from human lung tissue sections show that RSPO2 is expressed adjacent to proliferating distal epithelial progenitor cells and that the RSPO2 receptor, LGR5, is expressed almost exclusively in the epithelial progenitor cells. These data suggest that RSPO2+ mesenchymal cells may have a critical role in regulating epithelial progenitor cells during human lung development. The goals of this proposal are to: 1) interrogate mesenchymal cell heterogeneity and function in the context of epithelial progenitor cell regulation in the developing human lung and 2) explain a functional role for RSPO2+ mesenchymal cells during human lung development.