SAA3基因促进中性粒细胞形成胞外诱捕网致胆道闭锁的机制研究

我们的前期研究显示在胆道闭锁（BA)小鼠上清除中性粒细胞（PMN）可抑制胆管闭锁，但PMN的功能及作用机制尚未阐明。进一步体外研究发现PMN可引起胆道上皮细胞凋亡，提示PMN可通过损伤胆道上皮细胞引起胆道闭锁。BA中PMN通过什么方式损伤胆道上皮细胞？胞外诱捕网（NETs）是PMN发挥作用的重要方式，预实验显示给予NETs抑制剂可抑制小鼠胆道闭锁的形成，且RNA测序结果显示PMN中SAA3表达显著上调。文献报道SAA3可通过TLR4信号通路促进ROS的生成，而ROS是NETs生成的最重要组分。因此，我们假设BA中SAA3基因通过促进NETs的形成损伤胆道上皮细胞。为此，本项目拟1）在体内外干扰SAA3的表达，观察其对胆道上皮细胞的影响；2）对临床BA患者的SAA3同源性基因进行检测；3）在BA小鼠上尝试已上市NETs抑制药物。本项目有助于阐明BA的发病机制，并为BA的治疗提供新靶点。

Our previous studies have shown that the removal of neutrophils (PMN) on biliary atresia (BA) mice can inhibit biliary atresia, but the function and mechanism of PMN in BA have not been clarified. Further in-vitro studies showed that PMN could induce apoptosis of biliary epithelial cells (BEC), suggesting that PMN could induce biliary atresia by promoting BEC apoptosis. How does PMN damage biliary epithelial cells in BA? Extracellular trap nets (NETs) play an important role in PMN. Preliminary experiments show that NETs inhibitors can inhibit the formation of biliary atresia in mice, and RNA sequencing results showed that SAA3 expression was significantly up-regulated in PMN cells. It has been reported that up-regulation of SAA3 can promote the production of ROS through the TLR4 signaling pathway, and ROS is the most important component of NETs production. Therefore, we hypothesis that the high expression of SAA3 gene on BA promotes the formation of NETs and leads to damage of biliary epithelial cells. To demonstrate this hypothesis, we intends to 1) interfere the expression of SAA3 in-vivo and in-vitro and observe its effects on biliary epithelial cells; 2) detect and verify SAA3 Homology Genes in BA patients; 3) Try to use the NETs inhibitors that are already on the market on BA mice. This project will help to further elucidate the pathogenesis of BA and provide a new target for the treatment of BA.