miR-192-Rictor/mTORC2-自噬信号通路调控肠上皮细胞屏障功能和炎症体活性的分子机制研究

Autophagy plays a protective role in maintaining intestinal homeostasis by regulating the integrity of intestinal epithelial and the rationality of inflammation. Previous reports indicated that miR-192 accumulated in intestinal epithelial cells (IECs) and participated in the homeostasis of intestinal. We found that miR-192 could directly target Rictor, the core molecule of mTORC2 which is the up-stream signal regulator of autophagy. Moreover, miR-192 exerted its protective functions on intestinal homeostasis by regulating of cytoskeletal proteins associated with tight junctions and by attenuating of inflammasome activity through its regulation of autophagy. This function of miR-192 was, at least partially, dependant on its inhibition effect on Rictor. In this project, we would like to reveal more detailed mechanisms of miR-192-Rictor / mTORC2-autophagy signaling pathway in maintenance of intestinal homeostasis and implement the delivery of miR-192 into the IECs of DSS induced colitis mouse model by using our previously developed miRNA-loaded liposome nanoparticle. Our project will support miR-192 as an intervening target for IBD.

肠上皮屏障完整性和适度炎症反应是维持肠道稳态的关键。自噬作为肠道稳态的保护因素参与了上述两者的调控。miR-192在肠上皮细胞中富集且参与肠道功能稳态的调控。前期我们发现miR-192可以直接靶向Rictor，后者为自噬上游信号通路mTORC2中的核心分子。进一步的预实验结果提示，肠上皮来源细胞中miR-192可以调控与紧密连接相关的细胞骨架蛋白，并同时抑制炎症体的活性；这一双重作用可能是通过miR-192介导的自噬实现的。功能模拟实验表明，miR-192对肠道稳态的双向调节作用至少部分是通过靶向Rictor完成。本课题研究旨在上述工作的基础上，重点阐述miR-192-Rictor/mTORC2-自噬信号通路在肠道稳态协同调控中的作用机制；并应用我们已建立的miRNA脂质纳米载药载体实现对小鼠结肠炎模型的干预，以期为miR-192成为IBD干预的分子靶点提供实验依据和开发应用前景。

肠上皮屏障完整性和适度炎症反应是维持肠道稳态的关键。自噬作为肠道稳态的保护因素参与了上述两者的调控。miR-192-5p在肠上皮细胞中富积且参与肠道功能稳态的调控。申请人发现在炎症肠上皮细胞模型中miR-192-5p可以直接靶向Rictor，后者为自噬上游信号通路mTORC2中的核心分子，双荧光素酶报告基因实验也证实了这一点；进一步的实验结果提示，肠上皮来源细胞中miR-192-5p可以调控与紧密连接相关的细胞骨架蛋白ZO-3，并同时抑制炎症体的活性；通过使用自噬抑制剂，证实这一双重作用是通过miR-192-5p介导的自噬来实现的；并且功能模拟实验表明，miR-192对肠道稳态的双向调节作用至少部分是通过靶向Rictor完成的；最后，申请人用动物实验结合自噬诱导剂证实了本课题的核心论点，即miR-192-5p-Rictor/mTORC2-自噬信号通路在肠道稳态协同调控中具有重要作用。该研究可为miR-192-5p成为IBD干预的分子靶点提供实验依据和开发应用前景。