piRNA-823结合SFPQ促进肠成纤维细胞转分化修复肠黏膜屏障损伤的作用机制研究

肠成纤维细胞转分化对维持肠上皮完整性至关重要。piRNA是新发现的一类非编码小分子RNA，预实验发现piRNA-823可促进肠成纤维细胞转分化，但机制尚不清楚。我们前期发现piRNA-823与转录抑制因子SFPQ存在相互作用。鉴于SFPQ能通过抑制CD40转录抑制成纤维细胞转分化，我们推测piRNA-823通过结合并抑制SFPQ功能，激活CD40转录活性，促进肠成纤维细胞转分化及维持肠上皮屏障功能。本项目将①分析肠成纤维细胞转分化后piRNA-823、SFPQ表达变化；②在体内外过表达/干扰肠成纤维细胞piRNA-823，明确piRNA-823对肠成纤维细胞转分化及肠黏膜屏障的作用；③在细胞水平共表达/共干扰piRNA-823、SFPQ，明确piRNA-823通过SFPQ调控肠成纤维细胞转分化。重点探索piRNA-823与SFPQ相互作用的分子机制；为修复肠黏膜屏障损伤提供新的治疗靶点。

It is critically important for fibroblasts in small intestinal to transdifferentiate into myofibroblasts to repair the damaged intestinal epithelium. piRNA is a newly identified small non-coding RNA. Our previous study found that piRNA-823 promoted the transdifferentiation from intestinal fibroblasts to myofibroblasts. However, the molecular mechanism is not clear. We found that piRNA-823 combined with SFPQ which inhibited the transcription of CD40 to suppress the transdifferentiation of fibroblasts. We hypothesized that the combination of piRNA-823 and SFPQ inhibits the function of SFPQ and actives the transcription of CD40 to promot the transdifferentiation of intestinal fibroblasts and repairs intestinal epithelial barrier damage. The present study will first evaluate the expressions of piRNA-823 and SFPQ after the transdifferentiation of intestinal fibroblasts. We will transfect the intestinal fibroblasts with piRNA-823 mimics and antagomir to create the models of piRNA-823 overexpression/downregulation in intestinal fibroblasts to clarify the effect of piRNA-823 on fibroblasts transdifferentiation and intestinal mucosal barrier. Subsequently, we will create the models of co-overexpression/co-downregulation of piRNA-823 and SFPQ to clarify our hypothesis that piRNA-823 regulates intestinal fibroblasts transdifferentiation via SFPQ. Our final protocol is to explore the molecular mechanism of the interaction between piRNA-823 and SFPQ. This study will provide a new insight into the mechanism of intestinal mucosal repair and find a new therapeutic target for intestinal mucosal injury.