肠粘膜屏障功能障碍是溃疡性结肠炎(UC)发生、发展的重要因素。紧密连接（TJ）构成了肠屏障功能的核心元件，在肠粘膜屏障功能（IBF）的维护中起着关键作用。既往研究多关注不同病理条件下TJ蛋白表达变化对IBF功能的影响,但TJ蛋白的正确膜定位对IBF的影响，具体机制仍不清楚。新近的研究发现A2BR通过调控GTPase Rab1B的异戊烯化水平，进而可能参与TJ正确的膜定位过程。因此我们推测：UC不仅影响了TJ蛋白表达变化，还通过A2BR介导调控GTPase Rab1B的异戊烯化水平，从而影响IBF。本研究拟采用体内外UC模型，利用RNAi、WB、CHIP、激光共聚焦、及尤斯灌流系统等，研究A2BR通路调节GTPase Rab1B的异戊烯化水平，进而影响肠屏障TJ蛋白膜定位，为溃疡性结肠炎IBF的损伤及损伤防治提供新的研究策略及靶点。

Intestinal barrier dysfunction plays an important role in the development and progression of ulcerative colitis. Tight junction(TJ) Constitutes the core components of intestinal barrier function, and having a significant role in the maintance of intestinal barrier function(IBF). Most of previous studies about IBF impairment focus on the expression of TJ proteins,but the impact of correct membrane localization of tight junction on IBF remains unclear. Recently, studies have demonstrated that the role of A2BR in regulation of GTPase Rap1B prenylation, which may participate in the membrane localization of tight junction. Is the IBF defects of ulcerative colitis not only due to the decreased expression of TJ proteins, but also due to altered TJ protein membrane localization related to GTPase Rap1B prenylation modulatied by A2BR pathway? Therefore, this study will investigate the role of GTPase Rap1B prenylation modulatied by A2BR pathway which altered TJ protein membrane localization in the loss of IBF of ulcerative colitis both in vivo and in vitro models, utilizing RNA interference,Western Blot, CHIP,laser confocal microscopy technique,Ussing Chamber and so on. Thus, this study will inaugurate a new way for the research of IBF injury mechinism of ulcerative colitis and its prevention.