5’-tiRNA-Lys在肠道上皮细胞自噬中的作用及机制研究

肠道上皮细胞(IEC)结构和功能的完整是肠道稳态的基础。前期研究发现血管生成素能够切割tRNA形成tRNA半分子(tiRNA)来维持IEC在不良环境下的存活，但不清楚tiRNA的具体作用机制。进一步实验显示，5’-tiRNA-Lys在炎症性肠病患者IEC中高表达，并能促进细胞自噬的发生；5’-tiRNA-Lys可以与miRNA成熟调控因子EWSR1结合，并改变自噬相关基因的表达水平。为全面揭示5’-tiRNA-Lys在自噬中的作用及调控机制，本项目计划在肠道类器官培养模型中明确5’-tiRNA-Lys对IEC自噬发生的调控作用，综合运用生物化学和分子细胞生物学等方法阐明5’-tiRNA-Lys与EWSR1相互作用在选择性调控靶miRNA成熟及影响下游自噬相关蛋白水平的机制，并在小鼠肠道疾病模型中验证该作用通路。本项目将有助于全面了解tiRNA的新功能新机制，并为肠道疾病的防治提供新方案。

The structure-function integrity of the intestinal epithelial cell (IEC) is the basis of intestinal homeostasis. We have previously identified angiogenin as a novel IEC regulatory factor that can maintain the survival of IEC in adverse environment through cleaving tRNA to form tRNA halves (tiRNA), but the exact mechanism of action of tiRNA is unknown. Further experiments showed that tiRNA (especially 5’-tiRNA-Lys) was highly expressed in patient’s IECs with inflammatory bowel disease, and induced autophagy; 5’-tiRNA-Lys could interact with EWSR1, a miRNA maturation regulator, and alter the expression levels of autophagy-related genes. In order to fully reveal the role of 5’-tiRNA-Lys in autophagy and its underlying regulatory mechanism, this project plans to clarify the regulatory function of 5’-tiRNA-Lys in IEC autophagy based on intestinal organoid culture system, and then to elucidate how 5’-tiRNA-Lys selectively regulates target miRNA maturation and changes the levels of downstream autophagy-related proteins through interaction with EWSR1. We believe that this research will not only contributes to a comprehensive understanding of tiRNA's new functions and mechanisms, but also provides new ideas and measures for the prevention and treatment of intestinal diseases.