新生儿呼吸窘迫综合征（NRDS）是儿科重症监护病房中病死率极高的危重症之一，寻找新型治疗技术是当前该危重症研究领域的重要挑战之一。编码肺泡表面活性蛋白SPC的SFTPC基因(IVS4DS,G-A,+1)单碱基突变是该类疾病最为常见的先天性病因。但到目前为止，还未有基于该基因点突变的疾病动物模型，无法进行深入的机制研究和发展新的治疗策略；因此,本项目前期用CRISPR-CAS9系统完成了Sftpc点突变小鼠品系的建立，后续将建立自发诱导的急性肺损伤小鼠模型。在此基础上，使用腺相关病毒AAV分拆包装N端和C端xCas9(3.7)–ABE单碱基编辑系统，合并反式剪接策略以克服AAV的包装容量限制，共转染基因突变鼠的肺部组织，以期修复基因组该位点突变，建立治疗模型，评估单碱基编辑系统治疗该疾病的可行性，为临床试验提供前期实验支持，并为其它基因突变导致的NRDS治疗打下基础。

Neonatal Respiratory Distress Syndrome（NRDS）is one of the most severe disease in the pediatric intensive care unit. Development of new and effective treatments is one of the important challenges in the current. The single-base mutation (IVS4DS, G-A, +1) in the SFTPC gene encoding the alveolar surfactant protein SPC is the most common congenital genetic cause of this disease. But so far, there is no animal model based on point mutation of this gene, it is impossible for mechanism research and developing new treatment strategies. Therefore, in this project we use the CRISPR-CAS9 genome editing system to construct a Sftpc mutation mouse model to mimic Acute Lung Injury and then try to establish the gene therapy model by a base editing tool xCas9(3.7)–ABE. However, due to the limit of the packaging capacity of adeno-associated virus AAV, N-terminal half and the C-terminal half of ABE cassette are respectively packaged into AAV, which are assembly of the full-length ABE7.10 protein after co-transfecting the lung tissues through trans-splicing. Based on this strategy, we can correct the genome point mutation so as to establish a mouse treatment model. Furthermore, the recover efficiency and off-target effect will be measured by second-generation sequencing, which can be used to evaluate the feasibility of single-base editing system to treat the disease, providing the data for future clinical trials, and also lay the foundation for the treatment of NRDS caused by other genetic mutations.