潜在主转录因子Cebpa调节II型肺泡细胞的发育、稳态及再生的分子机制研究

II型肺泡细胞（AT2）在肺泡稳态维持和再生修复中发挥关键作用，可作为种子细胞治疗特定肺部疾病，但是决定其身份和功能的主转录因子（Master transcription factor）报道却较少。我们通过分析5套人类及小鼠肺单细胞RNA测序数据，并结合文献检索，发现12个潜在的AT2主转录因子；Cebpa是人鼠保守且综合评分较高的基因，同时文献报道其基因敲除小鼠表现出肺泡异常。本项目拟利用带荧光报告系统的AT2特异性Cebpa基因敲除小鼠，体内研究其在AT2发育、生理稳态和损伤再生中的作用；利用人类胚胎干细胞分化的肺泡类器官，研究其在人AT2自我更新、分化和生成肺表面活性物的作用及机制；最后，通过控制Cebpa信号通路的活性，提高肺泡类器官中AT2的质量和数量，改善治疗肺纤维化的效果。本项目可为最终鉴定AT2的核心主转录因子打下基础，也可为提升肺损伤细胞治疗有效性提供新思路。

Alveolar type II cells (AT2) play a key role in alveolar homeostasis and regeneration and thus can be used as therapeutic cells to treat specific lung diseases. However, only few master transcription factors that define the identity and function of AT2 has been reported. By analyzing 5 sets of human and mouse lung single cell RNA sequencing data and combining with literature search, we discovered 12 potential AT2 master transcription factors; Cebpa is a candidate gene conserved in humans and mice with a high master transcription factor score, and Cebpa knockout mice show abnormal alveoli. Thus, in this project, we plan to use AT2-specific Cebpa gene knockout mice with a fluorescent reporter system to study its role in AT2 development, homeostasis, and regeneration. Using alveolar organoids differentiated from human embryonic stem cells, we intend to study its role and mechanism involved in self-renewal, differentiation, and biosynthesis of surfactants in human AT2. Finally, by controlling the activity of the Cebpa signaling pathway, we plan to improve the quality and quantity of human AT2 in alveolar organoids and treat a mouse model with alveolar injury. This project can facilitate the identification of the core master transcription factor of AT2, and can also provide new ideas for improving the efficacy of cell therapy for lung injury.