Abstract：
Tauroursodeoxycholic acid (TUDCA) can activate farnesoid X receptor (FXR) to involve in the formation of gallstones. Here, this study aimed to probe the potential mechanism of TUDCA-FXR network in the formation of bile duct stone. The levels of TUDCA, FXR and NCK1 were decreased, while the level of miR-107 was increased in the serum of bile duct stone patients. FXR expression was positively correlated with TUDCA or NCK1 expression in patients, moreover, TUDCA pretreatment in biliary epithelial cells increased the levels of FXR and NCK1, and rescued the decrease of NCK1 caused by FXR knockdown in cells. Then functional analysis showed FXR knockdown caused apoptosis and endoplasmic reticulum stress (ERS) as well as suppressed proliferation in biliary epithelial cells in vitro, which were attenuated by TUDCA pretreatment or NCK1 overexpression Mechanistically, NCK1 was a target of miR-107, which was up-regulated by FXR silencing, and FXR knockdown-induced decrease of NCK1 was rescued by miR-107 inhibition. Additionally, miR-107 expression was negatively correlated with TUDCA expression in bile duct stone patients, and TUDCA pretreatment in biliary epithelial cells decreased miR-107 expression by FXR. Functionally, the pretreatment of TUDCA or FXR agonist suppressed miR-107-evoked apoptosis and ERS in biliary epithelial cells. In conclusion, TUDCA up-regulates FXR expression to activate NCK1 through absorbing miR-107, thus suppressing the apoptosis and ERS in biliary epithelial cells, these results provided a theoretical basis for elucidating the mechanism of bile duct stone formation.
摘要：
牛磺熊去氧胆酸（TUDCA）可以激活法尼醇X受体（FXR）参与胆结石的形成。这里,本研究旨在探讨TUDCA-FXR网络在胆管结石形成中的潜在机制。TUDCA的水平，FXR和NCK1下降，而miR-107在胆管结石患者血清中的水平升高。FXR表达与TUDCA或NCK1表达呈正相关。此外,TUDCA预处置使胆管上皮细胞中FXR和NCK1的程度增高，挽救了细胞中FXR敲低惹起的NCK1的降低。功能分析显示FXR敲低可引起体外胆管上皮细胞凋亡和内质网应激(ERS),抑制其增殖,通过TUDCA预处理或NCK1过表达机制减弱，NCK1是miR-107的靶标，通过FXR沉默上调，和FXR敲低诱导的NCK1的减少被miR-107抑制挽救。此外,miR-107在胆管结石患者中的表达与TUDCA表达呈负相关。和TUDCA预处理在胆道上皮细胞中通过FXR降低miR-107表达。功能上,TUDCA或FXR激动剂预处理可抑制miR-107诱发的胆管上皮细胞凋亡和ERS.总之,TUDCA通过吸收miR-107上调FXR表达激活NCK1,从而抑制胆管上皮细胞凋亡和ERS,这些结果为阐明胆管结石的形成机制提供了理论依据。
