IBD致上皮内瘤变中REG4+C1QC-巨噬细胞调控OLFM4+SOX9+异型干细胞化生及不典型增生机制研究

炎症性肠病（IBD）致上皮内瘤变（IBD+IN）是肠炎相关性结肠癌（CAC）发生的关键阶段。过去对于IBD+IN的认识仅停留在组织学层面，未完全阐明细胞组群及分子水平调控变化。申请人前期对正常（NC）、IBD、IBD+IN人肠组织进行单细胞测序检测对比，发现OLFM4+SOX9+异型干细胞（ASC）和REG4+巨噬细胞（Mø）进行性增加。生物信息学分析及体外类器官验证，发现ASC具有类似干细胞的分裂增殖功能，而REG4+Mø能调节肠干细胞的生长，提示ASC可能是炎-癌转化过程的起始细胞，REG4+Mø是该过程重要的调节细胞。本项目通过构建IBD+IN小鼠模型，利用LysMCreREG4-/flox小鼠，抑制REG4+Mø转化，研究其对肠ASC分化，增殖，对称/不对称分裂调控。质谱分析比较REG4+Mø和ASC化生前后两组差异表达蛋白，探索两者相互调控机制，为CAC防治新靶点研究提供思路。

Inflammatory bowel disease (IBD)-induced intraepithelial neoplasia (IBD+IN) is a key stage in the occurrence of enteritis-related colon cancer (CAC). In the past, the understanding of IBD+IN only remained at the histological level, and did not fully clarify the changes in cell group and molecular level regulation. The applicant performed single-cell sequencing tests on normal (NC), IBD, and IBD+IN human intestinal tissues in the early stage, and found that OLFM4+SOX9+ atypical stem cells (ASC) and REG4+ macrophages (Mø) increased progressively. Bioinformatics analysis and in vitro organoid verification found that ASC has a function of division and proliferation similar to stem cells, and REG4+Mø can regulate the growth of intestinal stem cells, suggesting that ASC may be the starting cell of the inflammation-cancer transformation process, and REG4+Mø is the Process important regulatory cells. This project uses LysMCreREG4-/flox mice to inhibit the transformation of REG4+Mø by constructing an IBD+IN mouse model to study its regulation of intestinal ASC differentiation, proliferation, and symmetric/asymmetric division. Mass spectrometry analysis compares the differentially expressed proteins of REG4+Mø and ASC before and after metaplasia, explores the mutual regulation mechanism of the two, and provides ideas for the study of new targets for the prevention and treatment of CAC.