GCN5L1通过ROS-ERK-Foxo1-CEBPα轴调控肺表面活性物质生成的分子机制研究

肺表面活性物质的缺乏引起肺泡不张，导致新生儿呼吸窘迫综合征(NRDS)。申请人先前的工作鉴定出GCN5L1可以调控斑马鱼鱼鳔内表面活性物质的生成。利用CRISPR/Cas9技术在小鼠MLE-12细胞中敲除GCN5L1，发现细胞对外分泌的肺表面活性物蛋白和脂质明显的下降；通过RNA-seq鉴定出GCN5L1敲除后转录因子CEBPα及部分板层小体组份基因的表达发生显著下调；在GCN5L1敲除的细胞中过表达CEBPα可以恢复细胞表型；进一步的结果显示ROS-ERK-Foxo1轴发生明显改变，而Foxo1又是CEBPα表达的重要调控因子，提示GCN5L1很可能是通过ROS-ERK-Foxo1-CEBPα轴参与了肺表面活性物质的生成调控。本项研究中，我们拟通过抑制和过表达等方法对GCN5L1发挥功能的分子机制进行深入的研究，为进一步阐明肺表面活性物质生成的调控网络及NRDS的发病机制提供新的线索。

Shortage of pulmonary surfactant causes atelectasis, resulting in neonatal respiratory distress syndrome (NRDS).We previously found that GCN5L1 could regulate formation of the surfactant system in zebrafish swimbladder. Knocking out of GCN5L1 in mouse MLE-12 cell through CRISPR/Cas9, we found out significant reduction of secretion of both surfactant proteins and lipid; We also identified that the expression of transcription factor CEBPα and partial component genes of lamellar body were greatly decreased by RNA-Seq; Overexpression of CEBPα in GCN5L1 knocked out cells could restore the cell phenotype; Further results show significant change of the ROS-ERK-Foxo1 axis; Foxo1 is an important regulator for CEBPαexpression, implying that GCN5L1 might take part in the regulation of pulmonary surfactant formation through the ROS-ERK-Foxo1-Cebpα axis. In the present study, we intend to further explore the molecular mechanism through which GCN5L1 functions by gene suppression and overexpression. Our study will further clarify the regulatory network of surfactant formation and provide new clues for the pathogenesis of NRDS.